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Renaudin M, Laforest-Lapointe I, Bellenger JP. Unraveling global and diazotrophic bacteriomes of boreal forest floor feather mosses and their environmental drivers at the ecosystem and at the plant scale in North America. Sci Total Environ 2022; 837:155761. [PMID: 35533858 DOI: 10.1016/j.scitotenv.2022.155761] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 04/29/2022] [Accepted: 05/03/2022] [Indexed: 06/14/2023]
Abstract
Feather mosses are abundant cryptogams of the boreal forest floor and shelter a broad diversity of bacteria who have important ecological functions (e.g., decomposition, nutrient cycling). In particular, nitrogen (N2-) fixation performed by feather moss-associated diazotrophs constitutes an important entry of nitrogen in the boreal forest ecosystem. However, the composition of the feather moss bacteriome and its environmental drivers are still unclear. Using cDNA amplicon sequencing of the 16S rRNA and nifH genes and cyanobacterial biomass quantification, we explored the active global and diazotrophic bacterial communities of two dominant feather moss species (i) at the ecosystem scale, along a 500-km climatic and nutrient deposition gradient in the North American boreal forest, and (ii) at the plant scale, along the moss shoot senescence gradient. We found that cyanobacteria were major actors of the feather moss bacteriome, accounting for 33% of global bacterial communities and 65% of diazotrophic communities, and that several cyanobacterial and methanotrophic genera were contributing to N2-fixation. Moreover, we showed that bacteria were occupying ecological niches along the moss shoot, with phototrophs being dominant in the apical part and methanotrophs being dominant in the basal part. Finally, climate (temperature, precipitation), environmental variables (moss species, month, tree density) and nutrients (nitrogen, phosphorus, molybdenum, vanadium, iron) strongly shaped global and diazotrophic bacteriomes. In summary, this work presents evidence that the feather moss bacteriome plays crucial roles in supporting moss growth, health, and decomposition, as well as in the boreal forest carbon and nitrogen cycles. This study also highlights the substantial effects of climate and nutrients on the feather moss bacteriome, suggesting the importance of understanding the impacts of global change on moss-associated bacterial growth and activity.
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Affiliation(s)
- Marie Renaudin
- Centre Sève, Département de Chimie, Université de Sherbrooke, J1K 2R1 Sherbrooke, QC, Canada.
| | | | - Jean-Philippe Bellenger
- Centre Sève, Département de Chimie, Université de Sherbrooke, J1K 2R1 Sherbrooke, QC, Canada.
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52
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Chen C, Huang JH, Meusburger K, Li K, Fu X, Rinklebe J, Alewell C, Feng X. The interplay between atmospheric deposition and soil dynamics of mercury in Swiss and Chinese boreal forests: A comparison study. Environ Pollut 2022; 307:119483. [PMID: 35595001 DOI: 10.1016/j.envpol.2022.119483] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 05/12/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
Taking advantage of the different histories of Hg deposition in Davos Seehornwald in E-Switzerland and Changbai Mountain in NE-China, the influence of atmospheric deposition on Hg soil dynamics in forest soil profiles was investigated. Today, Hg fluxes in bulk precipitation were similar, and soil profiles were generally sinks for atmospherically deposited Hg at both sites. Noticeably, a net release of 2.07 μg Hg m-2 yr-1 from the Bs horizon (Podzol) in Seehornwald was highlighted, where Hg concentration (up to 73.9 μg kg-1) and soil storage (100 mg m-3) peaked. Sequential extraction revealed that organic matter and crystalline Fe and Al hydr (oxide)-associated Hg decreased in the E horizon but increased in the Bs horizon as compared to the Ah horizon, demonstrating the coupling of Hg dynamics with the podzolisation process and accumulation of legacy Hg deposited last century in the Bs horizon. The mor humus in Seehornwald allowed Hg enrichment in the forest floor (182-269 μg kg-1). In Changbai Mountain, the Hg concentrations in the Cambisol surface layer with mull humus were markedly lower (<148 μg kg-1), but with much higher Hg soil storage (54-120 mg m-3) than in the Seehornwald forest floor (18-27 mg m-3). Thus, the vertical distribution pattern of Hg was influenced by humus form and soil type. The concentrations of Hg in soil porewater in Seehornwald (3.4-101 ng L-1) and in runoff of Changbai Mountain (1.26-5.62 ng L-1) were all low. Moreover, the pools of readily extractable Hg in the soils at both sites were all <2% of total Hg. Therefore, the potential of Hg release from the forest soil profile to the adjacent aquatic environment is currently low at both sites.
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Affiliation(s)
- Chaoyue Chen
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jen-How Huang
- Environmental Geosciences, University of Basel, 4056, Basel, Switzerland
| | - Katrin Meusburger
- Swiss Federal Institute for Forest, Snow and Landscape Research, 8903, Birmensdorf, Switzerland
| | - Kai Li
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xuewu Fu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China; Center for Excellence in Quaternary Science and Global Change, Chinese Academy of Sciences, Xian, 710061, China
| | - Jörg Rinklebe
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water and Waste Management, Laboratory of Soil and Groundwater Management, Pauluskirchstraße 7, 42285, Wuppertal, Germany; International Research Centre of Nanotechnology for Himalayan Sustainability (IRCNHS), Shoolini University, Solan, 173212, Himachal Pradesh, India
| | - Christine Alewell
- Environmental Geosciences, University of Basel, 4056, Basel, Switzerland
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China; Center for Excellence in Quaternary Science and Global Change, Chinese Academy of Sciences, Xian, 710061, China.
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53
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Liu P, Barr AG, Zha T, Black TA, Jassal RS, Nesic Z, Helgason WD, Jia X, Tian Y. Re-assessment of the climatic controls on the carbon and water fluxes of a boreal aspen forest over 1996-2016: Changing sensitivity to long-term climatic conditions. Glob Chang Biol 2022; 28:4605-4619. [PMID: 35474386 DOI: 10.1111/gcb.16218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 03/19/2022] [Indexed: 06/14/2023]
Abstract
Recent evidence suggests that the relationships between climate and boreal tree growth are generally non-stationary; however, it remains uncertain whether the relationships between climate and carbon (C) fluxes of boreal forests are stationary or have changed over recent decades. In this study, we used continuous eddy-covariance and microclimate data over 21 years (1996-2016) from a 100-year-old trembling aspen stand in central Saskatchewan, Canada to assess the relationships between climate and ecosystem C and water fluxes. Over the study period, the most striking climatic event was a severe, 3-year drought (2001-2003). Gross ecosystem production (GEP) showed larger interannual variability than ecosystem respiration (Re ) over 1996-2016, but Re was the dominant component contributing to the interannual variation in net ecosystem production (NEP) during post-drought years. The interannual variations in evapotranspiration (ET) and C fluxes were primarily driven by temperature and secondarily by water availability. Two-factor linear models combining precipitation and temperature performed well in explaining the interannual variation in C and water fluxes (R2 > .5). The temperature sensitivities of all three C fluxes (NEP, GEP and Re ) declined over the study period (p < .05), and, as a result, the phenological controls on annual NEP weakened. The decreasing temperature sensitivity of the C fluxes may reflect changes in forest structure, related to the over-maturity of the aspen stand at 100 years of age, and exacerbated by high tree mortality following the severe 2001-2003 drought. These results may provide an early warning signal of driver shift or even an abrupt status shift of aspen forest dynamics. They may also imply a universal weakening in the relationship between temperature and GEP as forests become over-mature, associated with the structural and compositional changes that accompany forest ageing.
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Affiliation(s)
- Peng Liu
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Alan G Barr
- Global Institute for Water Security, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Tianshan Zha
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - T Andrew Black
- Biometeorology and Soil Physics Group, University of British Columbia, Vancouver, British Columbia, Canada
| | - Rachhpal S Jassal
- Biometeorology and Soil Physics Group, University of British Columbia, Vancouver, British Columbia, Canada
| | - Zoran Nesic
- Biometeorology and Soil Physics Group, University of British Columbia, Vancouver, British Columbia, Canada
| | - Warren D Helgason
- Chemical and Biological Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Xin Jia
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Yun Tian
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing, China
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54
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Callahan G, Fillier T, Pham TH, Zhu X, Thomas R. The effects of clearcut harvesting on moss chloroplast lipidome and adaptation to light stress during boreal forest regeneration. J Environ Manage 2022; 315:115126. [PMID: 35526393 DOI: 10.1016/j.jenvman.2022.115126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 04/06/2022] [Accepted: 04/18/2022] [Indexed: 06/14/2023]
Abstract
Moss plays an important role in boreal forest ecosystems as an understory bryophyte species. Clearcut harvesting is a common boreal forest regeneration method that can expose understory vegetation to abiotic stressors impeding their recovery following post-harvest conditions. Very little is known concerning how moss remodel their chloroplast lipidome to enhance photosynthetic performance for successful acclimation to light and water stress during boreal forest regeneration following clearcut harvesting. The chloroplast lipidome and photosynthetic performance of Sphagnum sp. and three feathermoss species (Pleurozium schreberi, Hylocomium splendens, and Ptilium crista-castrensis) from a boreal black spruce (Picea mariana) forest were assessed using liquid chromatography-mass spectrometry (LC-MS), photospectrometry, and light response curves. We observed an overall increase in monogalactosyldiacylglycerol (MGDG) and sulfoquinovosyldiacylglycerol (SQDG) and decrease in digalactosyldiacylglycerol (DGDG) and phosphatidylglycerol (PG). In addition, unsaturation of the chloroplast lipidome occurred concomitant with photoprotection by carotenoid pigments to enhance the efficiency and photosynthetic capacity in moss exposed to light and water stress following clearcut harvesting. This appears to be a successful acclimation strategy used by moss to circumvent light stress during boreal forest regeneration following clearcut harvesting. These findings could be of significance in the development of boreal forest management strategies following resource harvesting.
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Affiliation(s)
- Grace Callahan
- Environmental Science, Boreal Ecosystem Research Facility, Memorial University of Newfoundland, Grenfell Campus, 20 University Drive, Corner Brook, NL, A2H 5G4, Canada.
| | - Tiffany Fillier
- Environmental Science, Boreal Ecosystem Research Facility, Memorial University of Newfoundland, Grenfell Campus, 20 University Drive, Corner Brook, NL, A2H 5G4, Canada
| | - Thu Huong Pham
- Environmental Science, Boreal Ecosystem Research Facility, Memorial University of Newfoundland, Grenfell Campus, 20 University Drive, Corner Brook, NL, A2H 5G4, Canada
| | - Xinbiao Zhu
- Natural Resources Canada, Canadian Forest Service - Atlantic Forestry Centre, 26 University Drive, Corner Brook, NL, A2H 6J3, Canada
| | - Raymond Thomas
- Environmental Science, Boreal Ecosystem Research Facility, Memorial University of Newfoundland, Grenfell Campus, 20 University Drive, Corner Brook, NL, A2H 5G4, Canada.
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55
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Burrell AL, Sun Q, Baxter R, Kukavskaya EA, Zhila S, Shestakova T, Rogers BM, Kaduk J, Barrett K. Climate change, fire return intervals and the growing risk of permanent forest loss in boreal Eurasia. Sci Total Environ 2022; 831:154885. [PMID: 35358519 DOI: 10.1016/j.scitotenv.2022.154885] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 03/23/2022] [Accepted: 03/24/2022] [Indexed: 06/14/2023]
Abstract
Climate change has driven an increase in the frequency and severity of fires in Eurasian boreal forests. A growing number of field studies have linked the change in fire regime to post-fire recruitment failure and permanent forest loss. In this study we used four burned area and two forest loss datasets to calculate the landscape-scale fire return interval (FRI) and associated risk of permanent forest loss. We then used machine learning to predict how the FRI will change under a high emissions scenario (SSP3-7.0) by the end of the century. We found that there are currently 133,000 km2 forest at high, or extreme, risk of fire-induced forest loss, with a further 3 M km2 at risk by the end of the century. This has the potential to degrade or destroy some of the largest remaining intact forests in the world, negatively impact the health and economic wellbeing of people living in the region, as well as accelerate global climate change.
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Affiliation(s)
- Arden L Burrell
- Woodwell Climate Research Center, Falmouth, MA, United States of America; Centre for Landscape and Climate Research, School of Geography, Geology and Environment, University of Leicester, University Road, LE1 7RH, United Kingdom.
| | - Qiaoqi Sun
- Department of Biosciences, University of Durham, Upper Mountjoy, South Road, Durham DH1 3LE, United Kingdom; College of Wildlife and Protected Area, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China
| | - Robert Baxter
- Department of Biosciences, University of Durham, Upper Mountjoy, South Road, Durham DH1 3LE, United Kingdom
| | - Elena A Kukavskaya
- V.N. Sukachev Institute of Forest of the Siberian Branch of the Russian Academy of Sciences - separate subdivision of the FRC KSC SB RAS, 660036 Krasnoyarsk, Akademgorodok 50/28, Russian Federation
| | - Sergey Zhila
- V.N. Sukachev Institute of Forest of the Siberian Branch of the Russian Academy of Sciences - separate subdivision of the FRC KSC SB RAS, 660036 Krasnoyarsk, Akademgorodok 50/28, Russian Federation
| | - Tatiana Shestakova
- Woodwell Climate Research Center, Falmouth, MA, United States of America
| | - Brendan M Rogers
- Woodwell Climate Research Center, Falmouth, MA, United States of America
| | - Jörg Kaduk
- Centre for Landscape and Climate Research, School of Geography, Geology and Environment, University of Leicester, University Road, LE1 7RH, United Kingdom
| | - Kirsten Barrett
- Centre for Landscape and Climate Research, School of Geography, Geology and Environment, University of Leicester, University Road, LE1 7RH, United Kingdom
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56
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Shahbaz M, Bengtson P, Mertes JR, Kulessa B, Kljun N. Spatial heterogeneity of soil carbon exchanges and their drivers in a boreal forest. Sci Total Environ 2022; 831:154876. [PMID: 35358518 DOI: 10.1016/j.scitotenv.2022.154876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 03/02/2022] [Accepted: 03/24/2022] [Indexed: 06/14/2023]
Abstract
Boreal forests have a large impact on the global greenhouse gas balance and their soils constitute an important carbon (C) reservoir. Mature boreal forests are typically a net CO2 sink, but there are also examples of boreal forests that are persistent CO2 sources. The reasons remain often unknown, presumably due to a lack of understanding of how biotic and abiotic drivers interact to determine the microbial respiration of soil organic matter (SOM). This study aimed at identifying the main drivers of microbial SOM respiration and CO2 and CH4 soil chamber-fluxes within dry and wet sampling areas at the mature boreal forest of Norunda, Sweden, a persistent net CO2 source. The spatial heterogeneity of the drivers was assessed with a geostatistical approach combined with stepwise multiple regression. We found that heterotrophic soil respiration increased with SOM content and nitrogen (N) availability, while the SOM reactivity, i.e., SOM specific respiration, was determined by soil moisture and N availability. The latter suggests that microbial activity was N rather than C limited and that microbial N mining might be driving old-SOM decomposition, which was observed through a positive correlation between soil respiration and its δ13C values. SOM specific heterotrophic respiration was lower in wet than in dry areas, while no such dependencies were found for chamber-based soil CO2 fluxes, implying that oxygen depletion resulted in lower SOM reactivity. The chamber-based soil CH4 flux differed significantly between the wet and dry areas. In the wet area, we observed net CH4 emission that was positively related to soil moisture and NH4+-N content. Taken together, our findings suggest that N availability has a strong regulatory effect on soil CO2 and CH4 emissions at Norunda, and that microbial decomposition of old-SOM to release bioavailable N might be partly responsible for the net CO2 emission at the site.
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Affiliation(s)
- Muhammad Shahbaz
- Centre for Environmental and Climate Science, Lund University, 223 62 Lund, Sweden.
| | - Per Bengtson
- Department of Biology, Microbial Ecology Group, Lund University, 223 62 Lund, Sweden
| | - Jordan R Mertes
- Centre for Environmental and Climate Science, Lund University, 223 62 Lund, Sweden
| | - Bernd Kulessa
- Department of Geography, Swansea University, Singleton Park, Swansea SA2 8PP, United Kingdom
| | - Natascha Kljun
- Centre for Environmental and Climate Science, Lund University, 223 62 Lund, Sweden
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57
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Manninen S, Zverev V, Kozlov MV. Foliar stable isotope ratios of carbon and nitrogen in boreal forest plants exposed to long-term pollution from the nickel-copper smelter at Monchegorsk, Russia. Environ Sci Pollut Res Int 2022; 29:48880-48892. [PMID: 35199271 PMCID: PMC9252950 DOI: 10.1007/s11356-022-19261-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 02/13/2022] [Indexed: 06/14/2023]
Abstract
Long-term exposure to primary air pollutants, such as sulphur dioxide (SO2) and nitrogen oxides (NOx), alters the structure and functions of forest ecosystems. Many biochemical and biogeochemical processes discriminate against the heavier isotopes in a mixture; thus, the values of δ13C and δ15N (i.e. the ratio of stable isotopes 13C to 12C and that of 15 N to 14 N, respectively) may give insights into changes in ecosystem processes and identify the immediate drivers of these changes. We studied sources of variation in the δ13C and δ15N values in the foliage of eight boreal forest C3 plants at 10 sites located at the distance of 1-40 km from the Monchegorsk nickel-copper smelter in Russia. From 1939‒2019, this smelter emitted over 14,000,000 metric tons (t) of SO2, 250,000 t of metals, primarily nickel and copper, and 140,000 t of NOx. The δ13C value in evergreen plants and the δ15N value in all plants increased near the smelter independently of the plant mycorrhizal type. We attribute the pollution-related increase in the foliar δ13C values of evergreen species mainly to direct effects of SO2 on stomatal conductance, in combination with pollution-related water stress, which jointly override the potential opposite effect of increasing ambient CO2 concentration on δ13C values. Stomatal uptake of NOx and root uptake of 15N-enriched organic N compounds and NH4+ may explain the increased foliar δ15N values and elevated foliar N concentrations, especially in the evergreen trees (Pinus sylvestris), close to Monchegorsk, where the soil inorganic N supply is reduced due to the impact of long-term SO2 and heavy metal emissions on plant biomass. We conclude that, despite the uncertainties in interpreting δ13C and δ15N responses to pollution, the Monchegorsk smelter has imposed and still imposes a great impact on C and N cycling in the surrounding N-limited subarctic forest ecosystems.
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Affiliation(s)
- Sirkku Manninen
- Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65 , 00014, Helsinki, Finland
| | - Vitali Zverev
- Department of Biology, University of Turku, 20014, Turku, Finland
| | - Mikhail V Kozlov
- Department of Biology, University of Turku, 20014, Turku, Finland.
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Roivainen P, Muurinen SM, Sorvari J, Juutilainen J, Naarala J, Salomaa S. Transfer of elements into boreal forest ants at a former uranium mining site. Environ Pollut 2022; 304:119231. [PMID: 35358630 DOI: 10.1016/j.envpol.2022.119231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 03/25/2022] [Accepted: 03/26/2022] [Indexed: 06/14/2023]
Abstract
Ants can influence ecological processes, such as the transfer of elements or radionuclides, in several ways. For example, they redistribute materials while foraging and maintaining their nests and have an important role in terrestrial food webs. Quantitative data of the transfer of elements into ants is needed, e.g., for developing improved radioecological models. In this study, samples of red wood ants (genus Formica), nest material, litter and soil were collected from a former uranium mining site in Eastern Finland. Concentrations of 33 elements were analyzed by Inductively Coupled Plasma-Mass Spectroscopy/Optical Emission Spectroscopy. Estimated element concentrations in spruce needles were used as a proxy for studying the transfer of elements into ants via aphids because spruces host the most important aphid farms in boreal forests. Empirically determined organism/medium concentration ratios (CRs) are commonly used in radioecological models. Ant/soil CRs were calculated and the validity of the fundamental assumption behind the of use of CRs (linear transfer) was evaluated. Elements that accumulated in ants in comparison to other compartments were cadmium, potassium, phosphorus, sulfur, and zinc. Ant uranium concentrations were low in comparison to soil, litter, or nest material but slightly elevated in comparison to spruce needles. Ant element concentrations were quite constant regardless of the soil concentrations. Non-linear transfer models could therefore describe the soil-to-ant transfer better than conventional CRs.
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Affiliation(s)
- Päivi Roivainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland; Radiation and Nuclear Safety Authority (STUK), P.O. Box 14, 00811 Helsinki, Finland.
| | - Saara-Maria Muurinen
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland; Radiation and Nuclear Safety Authority (STUK), P.O. Box 14, 00811 Helsinki, Finland
| | - Jouni Sorvari
- Department of Biology, University of Turku, 20014 Turku, Finland
| | - Jukka Juutilainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland
| | - Jonne Naarala
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland
| | - Sisko Salomaa
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland; Radiation and Nuclear Safety Authority (STUK), P.O. Box 14, 00811 Helsinki, Finland
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59
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Mundra S, Kauserud H, Økland T, Nordbakken J, Ransedokken Y, Kjønaas OJ. Shift in tree species changes the belowground biota of boreal forests. New Phytol 2022; 234:2073-2087. [PMID: 35307841 PMCID: PMC9325058 DOI: 10.1111/nph.18109] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 03/14/2022] [Indexed: 06/14/2023]
Abstract
The replacement of native birch with Norway spruce has been initiated in Norway to increase long-term carbon storage in forests. However, there is limited knowledge on the impacts that aboveground changes will have on the belowground microbiota. We examined which effects a tree species shift from birch to spruce stands has on belowground microbial communities, soil fungal biomass and relationships with vegetation biomass and soil organic carbon (SOC). Replacement of birch with spruce negatively influenced soil bacterial and fungal richness and strongly altered microbial community composition in the forest floor layer, most strikingly for fungi. Tree species-mediated variation in soil properties was a major factor explaining variation in bacterial communities. For fungi, both soil chemistry and understorey vegetation were important community structuring factors, particularly for ectomycorrhizal fungi. The relative abundance of ectomycorrhizal fungi and the ectomycorrhizal : saprotrophic fungal ratio were higher in spruce compared to birch stands, particularly in the deeper mineral soil layers, and vice versa for saprotrophs. The positive relationship between ergosterol (fungal biomass) and SOC stock in the forest floor layer suggests higher carbon sequestration potential in spruce forest soil, alternatively, that the larger carbon stock leads to an increase in soil fungal biomass.
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Affiliation(s)
- Sunil Mundra
- Section for Genetics and Evolutionary Biology (EvoGene)Department of BiosciencesUniversity of OsloPO Box 1066 BlindernOsloNO‐0316Norway
- Department of BiologyCollege of ScienceUnited Arab Emirates UniversityPO Box 15551Al‐Ain, Abu‐DhabiUnited Arab Emirates
| | - Håvard Kauserud
- Section for Genetics and Evolutionary Biology (EvoGene)Department of BiosciencesUniversity of OsloPO Box 1066 BlindernOsloNO‐0316Norway
| | - Tonje Økland
- Norwegian Institute of Bioeconomy ResearchPO Box 115ÅsNO‐1431Norway
| | | | - Yngvild Ransedokken
- Faculty of Environmental Sciences and Natural Resource ManagementNorwegian University of Life SciencesPO Box 5003ÅsNO‐1432Norway
| | - O. Janne Kjønaas
- Norwegian Institute of Bioeconomy ResearchPO Box 115ÅsNO‐1431Norway
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60
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Fisher JT, Ladle A. Syntopic species interact with large boreal mammals' response to anthropogenic landscape change. Sci Total Environ 2022; 822:153432. [PMID: 35090931 DOI: 10.1016/j.scitotenv.2022.153432] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/07/2022] [Accepted: 01/22/2022] [Indexed: 06/14/2023]
Abstract
Landscape change alters species' distributions, and understanding these changes is a key ecological and conservation goal. Species-habitat relationships are often modelled in the absence of syntopic species, but niche theory and emerging empirical research suggests heterospecifics should entrain (and statistically explain) variability in distribution, perhaps synergistically by interacting with landscape features. We examined the effects of syntopic species in boreal mammals' relationship to landscape change, using three years of camera-trap data in the western Nearctic boreal forest. Using an information-theoretic framework, we weighed evidence for additive and interactive variables measuring heterospecifics' co-occurrence in species distribution models built on natural and anthropogenic landscape features. We competed multiple hypotheses about the roles of natural features, anthropogenic features, predators, competitors, and species-habitat interaction terms in explaining relative abundance of carnivores, herbivores, and omnivores/scavengers. For most species, models including heterospecifics explained occurrence frequency better than landscape features alone. Dominant predator (wolf) occurrence was best explained by prey, while prey species were explained by apparent competitors and subdominant predators. Evidence for interactions between landscape features and heterospecifics was strong for coyotes and wolves but variable for other species. Boreal mammals' spatial distribution is a function of heterospecific co-occurrence as well as landscape features, with synergistic effects observed for most species. Understanding species' responses to anthropogenic landscape change thus requires a multi-taxa approach that incorporates interspecific relationships, enabling better inference into underlying processes from observed patterns.
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Affiliation(s)
- Jason T Fisher
- School of Environmental Studies, University of Victoria, PO Box 1700 STN CSC, Victoria, British Columbia V8W 2Y2, Canada.
| | - Andrew Ladle
- School of Environmental Studies, University of Victoria, PO Box 1700 STN CSC, Victoria, British Columbia V8W 2Y2, Canada
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Edwards M, Lisgo K, Leroux S, Krawchuk M, Cumming S, Schmiegelow F. Conservation planning integrating natural disturbances: Estimating minimum reserve sizes for an insect disturbance in the boreal forest of eastern Canada. PLoS One 2022; 17:e0268236. [PMID: 35533149 PMCID: PMC9084528 DOI: 10.1371/journal.pone.0268236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 04/25/2022] [Indexed: 11/19/2022] Open
Abstract
Large natural disturbances such as insect outbreaks and fire are important processes for biodiversity in forest landscapes. However, few methods exist for incorporating natural disturbances into conservation planning. Intact forest landscapes, such as in the North American boreal forest, can produce large natural disturbance footprints. They also have the potential to support large reserves but size estimates based on natural disturbance are needed to guide reserve design. Historical fire data have been used to estimate minimum dynamic reserves, reserve size estimates based on maintaining natural disturbance dynamics and ensuring resilience to large natural disturbance events. While this has been a significant step towards incorporating natural disturbance into reserve design, managers currently lack guidance on how to apply these concepts in areas where fire is not the dominant natural disturbance. We generalize the minimum dynamic reserve framework to accommodate insect outbreaks and demonstrate the framework in a case study for eastern spruce budworm (Choristoneura fumiferana) in the Canadian boreal forest. Our methods use geospatial analysis to identify minimum dynamic reserves based on a set of spatially explicit initial conditions, and simulation models to test for the maintenance of a set of dynamic conditions over time. We found considerable variability in minimum dynamic reserve size depending on the size of historic budworm disturbance events and the spatial patterns of disturbance-prone vegetation types. The minimum dynamic reserve framework provides an approach for incorporating wide-ranging natural disturbances into biodiversity conservation plans for both pro-active planning in intact landscapes, and reactive planning in more developed regions.
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Affiliation(s)
- Marc Edwards
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
- * E-mail:
| | - Kim Lisgo
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
| | - Shawn Leroux
- Department of Biology, Memorial University of Newfoundland, St John’s, NL, Canada
| | - Meg Krawchuk
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, United States of America
| | - Steve Cumming
- Département des sciences du bois et de la forêt, Université Laval, QC, Canada
| | - Fiona Schmiegelow
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
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Esseen P, Ekström M, Grafström A, Jonsson BG, Palmqvist K, Westerlund B, Ståhl G. Multiple drivers of large-scale lichen decline in boreal forest canopies. Glob Chang Biol 2022; 28:3293-3309. [PMID: 35156274 PMCID: PMC9310866 DOI: 10.1111/gcb.16128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/14/2022] [Indexed: 06/14/2023]
Abstract
Thin, hair-like lichens (Alectoria, Bryoria, Usnea) form conspicuous epiphyte communities across the boreal biome. These poikilohydric organisms provide important ecosystem functions and are useful indicators of global change. We analyse how environmental drivers influence changes in occurrence and length of these lichens on Norway spruce (Picea abies) over 10 years in managed forests in Sweden using data from >6000 trees. Alectoria and Usnea showed strong declines in southern-central regions, whereas Bryoria declined in northern regions. Overall, relative loss rates across the country ranged from 1.7% per year in Alectoria to 0.5% in Bryoria. These losses contrasted with increased length of Bryoria and Usnea in some regions. Occurrence trajectories (extinction, colonization, presence, absence) on remeasured trees correlated best with temperature, rain, nitrogen deposition, and stand age in multinomial logistic regression models. Our analysis strongly suggests that industrial forestry, in combination with nitrogen, is the main driver of lichen declines. Logging of forests with long continuity of tree cover, short rotation cycles, substrate limitation and low light in dense forests are harmful for lichens. Nitrogen deposition has decreased but is apparently still sufficiently high to prevent recovery. Warming correlated with occurrence trajectories of Alectoria and Bryoria, likely by altering hydration regimes and increasing respiration during autumn/winter. The large-scale lichen decline on an important host has cascading effects on biodiversity and function of boreal forest canopies. Forest management must apply a broad spectrum of methods, including uneven-aged continuous cover forestry and retention of large patches, to secure the ecosystem functions of these important canopy components under future climates. Our findings highlight interactions among drivers of lichen decline (forestry, nitrogen, climate), functional traits (dispersal, lichen colour, sensitivity to nitrogen, water storage), and population processes (extinction/colonization).
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Affiliation(s)
- Per‐Anders Esseen
- Department of Ecology and Environmental ScienceUmeå UniversityUmeåSweden
| | - Magnus Ekström
- Department of Statistics, USBEUmeå UniversityUmeåSweden
- Department of Forest Resource ManagementSwedish University of Agricultural SciencesUmeåSweden
| | - Anton Grafström
- Department of Forest Resource ManagementSwedish University of Agricultural SciencesUmeåSweden
| | - Bengt Gunnar Jonsson
- Department of Natural SciencesMid Sweden UniversitySundsvallSweden
- Department of Fish, Wildlife and Environmental SciencesSwedish University of Agricultural SciencesUmeåSweden
| | - Kristin Palmqvist
- Department of Ecology and Environmental ScienceUmeå UniversityUmeåSweden
| | - Bertil Westerlund
- Department of Forest Resource ManagementSwedish University of Agricultural SciencesUmeåSweden
| | - Göran Ståhl
- Department of Forest Resource ManagementSwedish University of Agricultural SciencesUmeåSweden
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63
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Östlund L, Laestander S, Aurell G, Hörnberg G. The war on deciduous forest: Large-scale herbicide treatment in the Swedish boreal forest 1948 to 1984. Ambio 2022; 51:1352-1366. [PMID: 34784006 PMCID: PMC8931146 DOI: 10.1007/s13280-021-01660-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 10/02/2021] [Accepted: 10/20/2021] [Indexed: 06/13/2023]
Abstract
At the mid-twentieth century the pace of the transformation of the Swedish forest increased. New methods; large-scale clearcutting, mechanization of logging and planting of seedlings were developed. Chemicals were used to control insects and unwanted tree species. The aims of this study were to elucidate the timing, chain of events and the spatial extent of the large-scale spraying of phenoxy acids in Swedish forests and the drivers for this practice. More than 700 000 hectares of productive forest land was sprayed and the main driving force was a strong will to transform the forest into high-yield coniferous forest plantations. We conclude that; (1) the use of herbicides in forestry in Sweden was done on a very large scale in the period 1948-1984, (2) the ecosystem legacy of herbicide spraying must be investigated and (3) a homogenous cadre of like-minded professionals working across commercial companies, state agencies and universities is dangerous.
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Affiliation(s)
- Lars Östlund
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
| | - Sandra Laestander
- Sveaskog AB, Arvidsjaur, Sweden
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Gerd Aurell
- Umeå Academy of Fine Arts, Umeå University, Umeå, Sweden
| | - Greger Hörnberg
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
- County Board Jämtland, Östersund, Sweden
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64
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Berner LT, Goetz SJ. Satellite observations document trends consistent with a boreal forest biome shift. Glob Chang Biol 2022; 28:3275-3292. [PMID: 35199413 PMCID: PMC9303657 DOI: 10.1111/gcb.16121] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/13/2022] [Indexed: 05/03/2023]
Abstract
The boreal forest biome is a major component of Earth's biosphere and climate system that is projected to shift northward due to continued climate change over the coming century. Indicators of a biome shift will likely first be evident along the climatic margins of the boreal forest and include changes in vegetation productivity, mortality, and recruitment, as well as overall vegetation greenness. However, the extent to which a biome shift is already underway remains unclear because of the local nature of most field studies, sparsity of systematic ground-based ecological monitoring, and reliance on coarse resolution satellite observations. Here, we evaluated early indicators of a boreal forest biome shift using four decades of moderate resolution (30 m) satellite observations and biogeoclimatic spatial datasets. Specifically, we quantified interannual trends in annual maximum vegetation greenness using an ensemble of vegetation indices derived from Landsat observations at 100,000 sample sites in areas without signs of recent disturbance. We found vegetation greenness increased (greened) at 38 [29, 42] % and 22 [15, 26] % of sample sites from 1985 to 2019 and 2000 to 2019, whereas vegetation greenness decreased (browned) at 13 [9, 15] % and 15 [13, 19] % of sample sites during these respective periods [95% Monte Carlo confidence intervals]. Greening was thus 3.0 [2.6, 3.5] and 1.5 [0.8, 2.0] times more common than browning and primarily occurred in cold sparsely treed areas with high soil nitrogen and moderate summer warming. Conversely, browning primarily occurred in the climatically warmest margins of both the boreal forest biome and major forest types (e.g., evergreen conifer forests), especially in densely treed areas where summers became warmer and drier. These macroecological trends reflect underlying shifts in vegetation productivity, mortality, and recruitment that are consistent with early stages of a boreal biome shift.
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Affiliation(s)
- Logan T. Berner
- School of Informatics, Computing, and Cyber SystemsNorthern Arizona UniversityFlagstaffArizonaUSA
| | - Scott J. Goetz
- School of Informatics, Computing, and Cyber SystemsNorthern Arizona UniversityFlagstaffArizonaUSA
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65
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Palm EC, Suitor MJ, Joly K, Herriges JD, Kelly AP, Hervieux D, Russell KLM, Bentzen TW, Larter NC, Hebblewhite M. Increasing fire frequency and severity will increase habitat loss for a boreal forest indicator species. Ecol Appl 2022; 32:e2549. [PMID: 35094462 PMCID: PMC9286541 DOI: 10.1002/eap.2549] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 09/14/2021] [Accepted: 10/06/2021] [Indexed: 06/01/2023]
Abstract
Climate change will lead to more frequent and more severe fires in some areas of boreal forests, affecting the distribution and availability of late-successional forest communities. These forest communities help to protect globally significant carbon reserves beneath permafrost layers and provide habitat for many animal species, including forest-dwelling caribou. Many caribou populations are declining, yet the mechanisms by which changing fire regimes could affect caribou declines are poorly understood. We analyzed resource selection of 686 GPS-collared female caribou from three ecotypes and 15 populations in a ~600,000 km2 region of northwest Canada and eastern Alaska. These populations span a wide gradient of fire frequency but experience low levels of human-caused habitat disturbance. We used a mixed-effects modeling framework to characterize caribou resource selection in response to burns at different seasons and spatiotemporal scales, and to test for functional responses in resource selection to burn availability. We also tested mechanisms driving observed selection patterns using burn severity and lichen cover data. Caribou avoided burns more strongly during winter relative to summer and at larger spatiotemporal scales relative to smaller scales. During the winter, caribou consistently avoided burns at both spatiotemporal scales as burn availability increased, indicating little evidence of a functional response. However, they decreased their avoidance of burns during summer as burn availability increased. Burn availability explained more variation in caribou selection for burns than ecotype. Within burns, caribou strongly avoided severely burned areas in winter, and this avoidance lasted nearly 30 years after a fire. Caribou within burns also selected higher cover of terrestrial lichen (an important caribou food source). We found a negative relationship between burn severity and lichen cover, confirming that caribou avoidance of burns was consistent with lower lichen abundance. Consistent winter avoidance of burns and severely burned areas suggests that caribou will experience increasing winter habitat loss as fire frequency and severity increase. Our results highlight the potential for climate-induced alteration of natural disturbance regimes to affect boreal biodiversity through habitat loss. We suggest that management strategies prioritizing protection of core winter range habitat with lower burn probabilities would provide important climate-change refugia for caribou.
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Affiliation(s)
- Eric C. Palm
- Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, W. A. Franke College of Forestry and ConservationUniversity of MontanaMissoulaMontanaUSA
| | - Michael J. Suitor
- Department of EnvironmentYukon GovernmentDawson CityYukon TerritoriesCanada
| | - Kyle Joly
- Yukon‐Charley Rivers National Preserve, National Park ServiceFairbanksAlaskaUSA
| | | | - Allicia P. Kelly
- Department of Environment and Natural ResourcesGovernment of the Northwest TerritoriesFort SmithNorthwest TerritoriesCanada
| | - Dave Hervieux
- Alberta Environment and Parks − Operations DivisionGrande PrairieAlbertaCanada
| | | | | | - Nicholas C. Larter
- Department of Environment and Natural ResourcesGovernment of the Northwest TerritoriesFort SimpsonNorthwest TerritoriesCanada
| | - Mark Hebblewhite
- Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, W. A. Franke College of Forestry and ConservationUniversity of MontanaMissoulaMontanaUSA
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66
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Sonerud GA. Predation of boreal owl nests by pine martens in the boreal forest does not vary as predicted by the alternative prey hypothesis. Oecologia 2022; 198:995-1009. [PMID: 35305156 PMCID: PMC9056444 DOI: 10.1007/s00442-022-05149-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 03/06/2022] [Indexed: 11/25/2022]
Abstract
The alternative prey hypothesis (APH) states that temporally synchronous population fluctuations of microtine rodents and other small herbivores are caused by generalist predators that show functional and numerical responses to the abundance of microtines. This would lead to an increased predation of alternative prey in the low phase of the microtine population fluctuations. One candidate for such a predator is the tree-climbing pine marten (Martes martes), which includes bird eggs in its diet, among them eggs of the cavity-nesting boreal owl (Aegolius funereus). I used long-term data to test whether pine marten predation of boreal owl eggs in nest boxes varied as predicted by the APH. The probability of predation of owl nests situated < 45 km from a site where microtines were trapped in spring during four decades increased with microtine trapping index, which is opposite to the prediction from the APH. As the data set was limited to one nest per box, I extended it spatially and temporally using the clutch size of each boreal owl nest as a proxy for the actual microtine abundance at the site. The probability of nest predation increased with clutch size. However, the effects of microtine index and owl clutch size became non-significant when I controlled for habitat, and in particular cavity age, which had an overriding effect. The increase in predation probability with cavity age suggests that the long-term spatial memory of pine marten is an important factor in the pattern of its nest predation in tree cavities.
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Affiliation(s)
- Geir A Sonerud
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P. O. Box 5003, NO-1432, Ås, Norway.
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67
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Pau M, Gauthier S, Chavardès RD, Girardin MP, Marchand W, Bergeron Y. Site index as a predictor of the effect of climate warming on boreal tree growth. Glob Chang Biol 2022; 28:1903-1918. [PMID: 34873797 DOI: 10.1111/gcb.16030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 10/15/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
The boreal forest represents the terrestrial biome most heavily affected by climate change. However, no consensus exists regarding the impacts of these changes on the growth of tree species therein. Moreover, assessments of young tree responses in metrics transposable to forest management remain scarce. Here, we assessed the impacts of climate change on black spruce (Picea mariana [Miller] BSP) and jack pine (Pinus banksiana Lambert) growth, two dominant tree species in boreal forests of North America. Starting with a retrospective analysis including data from 2591 black spruces and 890 jack pines, we forecasted trends in 30-year height growth at the transitions from closed to open boreal coniferous forests in Québec, Canada. We considered three variables: (1) height growth, rarely used, but better-reflecting site potential than other growth proxies, (2) climate normals corresponding to the growth period of each stem, and (3) site type (as a function of texture, stoniness, and drainage), which can modify the effects of climate on tree growth. We found a positive effect of vapor pressure deficit on the growth of both species, although the effect on black spruce leveled off. For black spruce, temperatures had a positive effect on the height at 30 years, which was attenuated when and where climatic conditions became drier. Conversely, drought had a positive effect on height under cold conditions and a negative effect under warm conditions. Spruce growth was also better on mesic than on rocky and sub-hydric sites. For portions of the study areas with projected future climate within the calibration range, median height-change varied from 10 to 31% for black spruce and from 5 to 31% for jack pine, depending on the period and climate scenario. As projected increases are relatively small, they may not be sufficient to compensate for potential increases in future disturbances like forest fires.
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Affiliation(s)
- Mathilde Pau
- Centre d'étude de la forêt, Université du Québec à Montréal, Montréal, Québec, Canada
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec, Québec, Canada
| | - Sylvie Gauthier
- Centre d'étude de la forêt, Université du Québec à Montréal, Montréal, Québec, Canada
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec, Québec, Canada
| | - Raphaël D Chavardès
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec, Canada
| | - Martin P Girardin
- Centre d'étude de la forêt, Université du Québec à Montréal, Montréal, Québec, Canada
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec, Québec, Canada
| | - William Marchand
- Department of Forest Ecology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Praha, Suchdol, Czech Republic
| | - Yves Bergeron
- Centre d'étude de la forêt, Université du Québec à Montréal, Montréal, Québec, Canada
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec, Canada
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68
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Pusfitasari ED, Ruiz-Jimenez J, Heiskanen I, Jussila M, Hartonen K, Riekkola ML. Aerial drone furnished with miniaturized versatile air sampling systems for selective collection of nitrogen containing compounds in boreal forest. Sci Total Environ 2022; 808:152011. [PMID: 34861308 DOI: 10.1016/j.scitotenv.2021.152011] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/21/2021] [Accepted: 11/23/2021] [Indexed: 06/13/2023]
Abstract
A wide variety of nitrogen-containing compounds are present in the environment, which contributes to air pollution and new particle formation, for example. These eventually affect human health and the climate. With all this consideration, there is a growing interest in the development of efficient and reliable methods to determine these compounds in the atmosphere. In this study, titanium hydrogen phosphate-modified Mobil Composition of Matter No. 41 was used as sorbent material for in-tube extraction (ITEX) sampling system, to selectively collect nitrogen-containing compounds from natural air samples. The effect of sampling accessories, based on adsorbent coatings (with Tenax-GR as an adsorbent material) and polytetrafluoroethylene filters, was studied to improve the selectivity of the sampling system and to remove particles. Aerial drone with miniaturized air sampling system was employed for the reliable collection of nitrogen-containing compounds in both gas phase and aerosol particles. A total of 170 air samples were collected in July 2020 at the SMEAR II station, Finland to evaluate nitrogen-containing compounds diurnal patterns and vertical profiles (0.25, 5, 50, and 150 m). More than twenty nitrogen-containing compounds, such as aliphatic amines, imines, imidazoles, and pyridines, were identified, quantified or semi-quantified. The average concentrations of detected aliphatic amines at the altitude of 50 m were up to 40.4 ng m-3 (dimethylamine) in gas phase and 128 ng m-3 (ethylamine) in aerosol particles. Among nitrogen-containing compounds detected, pyridine gave the highest average concentration of 746 ng m-3 in gas phase and 644 ng m-3 in particle phase.
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Affiliation(s)
- Eka Dian Pusfitasari
- Department of Chemistry and Institute for Atmospheric and Earth System Research, P.O. Box 55, FI-00014, University of Helsinki, Finland
| | - Jose Ruiz-Jimenez
- Department of Chemistry and Institute for Atmospheric and Earth System Research, P.O. Box 55, FI-00014, University of Helsinki, Finland
| | - Ilmari Heiskanen
- Department of Chemistry and Institute for Atmospheric and Earth System Research, P.O. Box 55, FI-00014, University of Helsinki, Finland
| | - Matti Jussila
- Department of Chemistry and Institute for Atmospheric and Earth System Research, P.O. Box 55, FI-00014, University of Helsinki, Finland
| | - Kari Hartonen
- Department of Chemistry and Institute for Atmospheric and Earth System Research, P.O. Box 55, FI-00014, University of Helsinki, Finland
| | - Marja-Liisa Riekkola
- Department of Chemistry and Institute for Atmospheric and Earth System Research, P.O. Box 55, FI-00014, University of Helsinki, Finland.
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69
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Fang Z, Brandt M, Wang L, Fensholt R. A global increase in tree cover extends the growing season length as observed from satellite records. Sci Total Environ 2022; 806:151205. [PMID: 34710418 DOI: 10.1016/j.scitotenv.2021.151205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
Plant phenology provides information on the seasonal dynamics of plants, and changes herein are important for understanding the impact of climate change and human management on the biosphere. Land surface phenology is the study of plant phenology across large spatial scales estimated by satellite observations. However, satellite observations (pixels) are often composed of a mixture of vegetation types, like woody vegetation and herbaceous vegetation, having different phenological characteristics. Therefore, any changes in tree cover presumably impact land surface phenology, as trees usually have a different seasonal cycle compared to herbaceous vegetation. On the other hand, changes in land surface phenology are often interpreted as a result of climate change-induced impacts on the photosynthetic activity of vegetation. Therefore, it is important to better understand the role of changes in vegetation cover (here, the proportion between tree and short vegetation cover) in satellite-derived land surface phenology analysis. We studied the impact of changes in tree cover on satellite observed land surface phenology at a global scale over the past three decades. We found an extension of the growing season length in 36.6% of the areas where tree cover increased, whereas only 20.1% of the areas where tree cover decreased showed an increase in growing season length. Furthermore, the ratio between tree cover and short vegetation cover was found to affect changes in the length of the growing season, with the denser tree cover showing a more pronounced extension of the growing season length (especially in boreal forests). These results highlight the importance of changes in tree cover when analyzing the impact of climate change on vegetation phenology. Our study thereby addresses a critical knowledge gap for an improved understanding of changes in land surface phenology during recent decades in the context of climate and human-induced global land cover change.
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Affiliation(s)
- Zhongxiang Fang
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Martin Brandt
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Lanhui Wang
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark; Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark.
| | - Rasmus Fensholt
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
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70
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Schulte‐Uebbing LF, Ros GH, de Vries W. Experimental evidence shows minor contribution of nitrogen deposition to global forest carbon sequestration. Glob Chang Biol 2022; 28:899-917. [PMID: 34699094 PMCID: PMC9299138 DOI: 10.1111/gcb.15960] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/09/2021] [Indexed: 05/12/2023]
Abstract
Human activities have drastically increased nitrogen (N) deposition onto forests globally. This may have alleviated N limitation and thus stimulated productivity and carbon (C) sequestration in aboveground woody biomass (AGWB), a stable C pool with long turnover times. This 'carbon bonus' of human N use partly offsets the climate impact of human-induced N2 O emissions, but its magnitude and spatial variation are uncertain. Here we used a meta-regression approach to identify sources of heterogeneity in tree biomass C-N response (additional C stored per unit of N) based on data from fertilization experiments in global forests. We identified important drivers of spatial variation in forest biomass C-N response related to climate (potential evapotranspiration), soil fertility (N content) and tree characteristics (stand age), and used these relationships to quantify global spatial variation in N-induced forest biomass C sequestration. Results show that N deposition enhances biomass C sequestration in only one-third of global forests, mainly in the boreal region, while N reduces C sequestration in 5% of forests, mainly in the tropics. In the remaining 59% of global forests, N addition has no impact on biomass C sequestration. Average C-N responses were 11 (4-21) kg C per kg N for boreal forests, 4 (0-8) kg C per kg N for temperate forests and 0 (-4 to 5) kg C per kg N for tropical forests. Our global estimate of the N-induced forest biomass C sink of 41 (-53 to 159) Tg C yr-1 is substantially lower than previous estimates, mainly due to the absence of any response in most tropical forests (accounting for 58% of the global forest area). Overall, the N-induced C sink in AGWB only offsets ~5% of the climate impact of N2 O emissions (in terms of 100-year global warming potential), and contributes ~1% to the gross forest C sink.
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Affiliation(s)
- Lena F. Schulte‐Uebbing
- Environmental Systems Analysis GroupWageningen University & ResearchWageningenthe Netherlands
| | - Gerard H. Ros
- Environmental Systems Analysis GroupWageningen University & ResearchWageningenthe Netherlands
- Nutrient Management InstituteWageningenthe Netherlands
| | - Wim de Vries
- Environmental Systems Analysis GroupWageningen University & ResearchWageningenthe Netherlands
- Wageningen Environmental ResearchWageningen University & ResearchWageningenthe Netherlands
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71
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Su WQ, Tang C, Lin J, Yu M, Dai Z, Luo Y, Li Y, Xu J. Recovery patterns of soil bacterial and fungal communities in Chinese boreal forests along a fire chronosequence. Sci Total Environ 2022; 805:150372. [PMID: 34818758 DOI: 10.1016/j.scitotenv.2021.150372] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/11/2021] [Accepted: 09/12/2021] [Indexed: 05/17/2023]
Abstract
Wildfire has profound and pervasive consequences for forest ecosystems via directly altering soil physicochemical properties and modulating microbial community. In this study, we examined the changes in soil properties and microbial community composition and structure at different periods after highly severe wildfire events (44 plots, 113 samples) in the Chinese Great Khingan Mountains. We also separated charcoal from burnt soils to establish the relationship between microbial community structures in soils and charcoal. We found that wildfire only significantly altered bacterial and fungal β-diversity, but had no effect on microbial α-diversity across a 29-year chronosequence. The network analysis revealed that the complexity and connectivity of bacterial and fungal communities were significantly increased from 17 years after fire, compared with either unburnt soils or soils with recent fires (0-4 years after fire). Differential abundance analysis suggested that bacterial and fungal OTUs were enriched or depleted only during 0-4 years after fire compared with the unburnt soils. In addition, soil pH, dissolved organic C and dissolved organic N were key determinants of soil bacterial and fungal communities during 17-29 years after fire. The fire-derived charcoal provided a new niche for microbial colonization, and microbes colonized in the charcoal had a significantly different community structure from those of burnt soils. Our data suggest that soil bacterial and fungal communities changed significantly during the recovery from fire events in terms of the abundance and co-occurrence networks in the boreal forest ecosystems.
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Affiliation(s)
- Wei-Qin Su
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Caixian Tang
- Department of Animal, Plant and Soil Sciences, La Trobe University, Melbourne Campus, Bundoora, VIC 3086, Australia
| | - Jiahui Lin
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Mengjie Yu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Zhongmin Dai
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Yu Luo
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Yong Li
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China
| | - Jianming Xu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China.
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72
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Cerrejón C, Valeria O, Muñoz J, Fenton NJ. Small but visible: Predicting rare bryophyte distribution and richness patterns using remote sensing-based ensembles of small models. PLoS One 2022; 17:e0260543. [PMID: 34990454 PMCID: PMC8735603 DOI: 10.1371/journal.pone.0260543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 10/26/2021] [Indexed: 11/30/2022] Open
Abstract
In Canadian boreal forests, bryophytes represent an essential component of biodiversity and play a significant role in ecosystem functioning. Despite their ecological importance and sensitivity to disturbances, bryophytes are overlooked in conservation strategies due to knowledge gaps on their distribution, which is known as the Wallacean shortfall. Rare species deserve priority attention in conservation as they are at a high risk of extinction. This study aims to elaborate predictive models of rare bryophyte species in Canadian boreal forests using remote sensing-derived predictors in an Ensemble of Small Models (ESMs) framework. We hypothesize that high ESMs-based prediction accuracy can be achieved for rare bryophyte species despite their low number of occurrences. We also assess if there is a spatial correspondence between rare and overall bryophyte richness patterns. The study area is located in western Quebec and covers 72,292 km2. We selected 52 bryophyte species with <30 occurrences from a presence-only database (214 species, 389 plots in total). ESMs were built from Random Forest and Maxent techniques using remote sensing-derived predictors related to topography and vegetation. Lee's L statistic was used to assess and map the spatial relationship between rare and overall bryophyte richness patterns. ESMs yielded poor to excellent prediction accuracy (AUC > 0.5) for 73% of the modeled species, with AUC values > 0.8 for 19 species, which confirmed our hypothesis. In fact, ESMs provided better predictions for the rarest bryophytes. Likewise, our study revealed a spatial concordance between rare and overall bryophyte richness patterns in different regions of the study area, which have important implications for conservation planning. This study demonstrates the potential of remote sensing for assessing and making predictions on inconspicuous and rare species across the landscape and lays the basis for the eventual inclusion of bryophytes into sustainable development planning.
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Affiliation(s)
- Carlos Cerrejón
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, boul. de l’Université, Rouyn-Noranda, Québec, Canada
| | - Osvaldo Valeria
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, boul. de l’Université, Rouyn-Noranda, Québec, Canada
- Hémera Centro de Observación de la Tierra, Escuela de Ingeniería Forestal, Facultad de Ciencias, Universidad Mayor, Huechuraba, Santiago, Chile
| | - Jesús Muñoz
- Real Jardín Botánico (RJB-CSIC), Madrid, España
| | - Nicole J. Fenton
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, boul. de l’Université, Rouyn-Noranda, Québec, Canada
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73
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Sánchez-Pinillos M, D'Orangeville L, Boulanger Y, Comeau P, Wang J, Taylor AR, Kneeshaw D. Sequential droughts: A silent trigger of boreal forest mortality. Glob Chang Biol 2022; 28:542-556. [PMID: 34606657 DOI: 10.1111/gcb.15913] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 08/30/2021] [Indexed: 06/13/2023]
Abstract
Despite great concern for drought-driven forest mortality, the effects of frequent low-intensity droughts have been largely overlooked in the boreal forest because of their negligible impacts over the short term. In this study, we used data from 6876 permanent plots distributed across most of the Canadian boreal zone to assess the effects of repeated low-intensity droughts on forest mortality. Specifically, we compared the relative impact of sequential years under low-intensity dry conditions with the effects of variables related to the intensity of dry conditions, stand characteristics, and local climate. Then, we searched for thresholds in forest mortality as a function of the number of years between two forest surveys affected by dry conditions of any intensity. Our results showed that, in general, frequent low-intensity dry conditions had stronger effects on forest mortality than the intensity of the driest conditions in the plot. Frequent low-intensity dry conditions acted as an inciting factor of forest mortality exacerbated by stand characteristics and environmental conditions. Overall, the mortality of forests dominated by shade-tolerant conifers was significantly and positively related to frequent low-intensity dry conditions, supporting, in some cases, the existence of thresholds delimiting contrasting responses to drought. In mixtures with broadleaf species, however, sequential dry conditions had a negligible impact. The effects of frequent dry conditions on shade-intolerant forests mainly depended on local climate, inciting or mitigating the mortality of forests located in wet places and dominated by broadleaf species or jack pine, respectively. Our results highlight the importance of assessing not only climate-driven extreme events but also repeated disturbances of low intensity. In the long term, the smooth response of forests to dry conditions might abruptly change leading to disproportional mortality triggered by accumulated stress conditions. Forest and wildlife managers should consider the cumulative effects of climate change on mortality to avoid shortfalls in timber and habitat.
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Affiliation(s)
- Martina Sánchez-Pinillos
- Centre for Forest Research, Université du Québec à Montréal, Montreal, Quebec, Canada
- Faculty of Forestry and Environmental Management, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Loïc D'Orangeville
- Faculty of Forestry and Environmental Management, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Yan Boulanger
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, Quebec, Canada
| | - Phil Comeau
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Jiejie Wang
- Faculty of Forestry and Environmental Management, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Anthony R Taylor
- Faculty of Forestry and Environmental Management, University of New Brunswick, Fredericton, New Brunswick, Canada
- Natural Resources Canada, Canadian Forest Service, Atlantic Forestry Centre, Fredericton, New Brunswick, Canada
| | - Daniel Kneeshaw
- Centre for Forest Research, Université du Québec à Montréal, Montreal, Quebec, Canada
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74
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Högberg MN, Högberg P, Wallander H, Nilsson LO. Carbon-nitrogen relations of ectomycorrhizal mycelium across a natural nitrogen supply gradient in boreal forest. New Phytol 2021; 232:1839-1848. [PMID: 34449884 DOI: 10.1111/nph.17701] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
The supply of carbon (C) from tree photosynthesis to ectomycorrhizal (ECM) fungi is known to decrease with increasing plant nitrogen (N) supply, but how this affects fungal nutrition and growth remains to be clarified. We placed mesh-bags with quartz sand, with or without an organic N (15 N-, 13 C-labeled) source, in the soil along a natural N supply gradient in boreal forest, to measure growth and use of N and C by ECM extramatrical mycelia. Mycelial C : N declined with increasing N supply. Addition of N increased mycelial growth at the low-N end of the gradient. We found an inverse relationship between uptake of added N and C; the use of added N was high when ambient N was low, whereas use of added C was high when C from photosynthesis was low. We propose that growth of ECM fungi is N-limited when soil N is scarce and tree belowground C allocation to ECM fungi is high, but is C-limited when N supply is high and tree belowground C allocation is low. This suggests that ECM fungi have a major role in soil N retention in nutrient-poor, but less so in nutrient-rich boreal forests.
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Affiliation(s)
- Mona N Högberg
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, SE-901 83, Sweden
| | - Peter Högberg
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, SE-901 83, Sweden
| | - Håkan Wallander
- Department of Biology, Lund University, Lund, SE-22362, Sweden
| | - Lars-Ola Nilsson
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Frederiksberg C, DK-1958, Denmark
- Chancellery, Halmstad University, Halmstad, SE-301 18, Sweden
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75
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Kharuk VI, Ponomarev EI, Ivanova GA, Dvinskaya ML, Coogan SCP, Flannigan MD. Wildfires in the Siberian taiga. Ambio 2021; 50:1953-1974. [PMID: 33512668 PMCID: PMC8497666 DOI: 10.1007/s13280-020-01490-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 11/12/2020] [Accepted: 12/16/2020] [Indexed: 05/09/2023]
Abstract
The majority of area burned by wildfire are located in Siberia. Mainly low-intensity surface fires occur in larch forests, whereas in evergreen forests both surface and crown fires are observed. Warming has led to an increase in the frequency and area of wildfires that have reached the Arctic Ocean shore. However, wildfires are the most important factor in taiga dynamics; larch and Scots pine have evolved under conditions of periodic forest fires, thereby gaining a competitive advantage over non-fire adapted species; in the permafrost zone, periodic fires are a prerequisite for the dominance of larch. Wildfires support ecosystem health, biodiversity, and conservation; periodic wildfires decrease the danger of catastrophic wildfires. With an amplified rate of increase in fires, it is necessary to focus fire suppression on areas of high social, natural, and economic value, while allowing a greater number of wildfires to burn in the vast Siberian forest landscapes.
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Affiliation(s)
- Viacheslav I. Kharuk
- Sukachev Institute of Forests, Federal Research Center, Russian Academy of Science, Siberian Branch, Academgorodok 50/28, Krasnoyarsk, Russia 660036
- Siberian Federal University, Svobodny str.79, Krasnoyarsk, Russia 660041
| | - Evgenii I. Ponomarev
- Sukachev Institute of Forests, Federal Research Center, Russian Academy of Science, Siberian Branch, Academgorodok 50/28, Krasnoyarsk, Russia 660036
- Siberian Federal University, Svobodny str.79, Krasnoyarsk, Russia 660041
| | - Galina A. Ivanova
- Sukachev Institute of Forests, Federal Research Center, Russian Academy of Science, Siberian Branch, Academgorodok 50/28, Krasnoyarsk, Russia 660036
| | - Maria L. Dvinskaya
- Sukachev Institute of Forests, Federal Research Center, Russian Academy of Science, Siberian Branch, Academgorodok 50/28, Krasnoyarsk, Russia 660036
| | - Sean C. P. Coogan
- Department of Renewable Resources, University of Alberta, Edmonton, AB T6G 2H1 Canada
| | - Mike D. Flannigan
- Department of Renewable Resources, University of Alberta, Edmonton, AB T6G 2H1 Canada
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76
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Tsyganov AN, Zarov EA, Mazei YA, Kulkov MG, Babeshko KV, Yushkovets SY, Payne RJ, Ratcliffe JL, Fatyunina YA, Zazovskaya EP, Lapshina ED. Key periods of peatland development and environmental changes in the middle taiga zone of Western Siberia during the Holocene. Ambio 2021; 50:1896-1909. [PMID: 33825155 PMCID: PMC8497661 DOI: 10.1007/s13280-021-01545-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 12/16/2020] [Accepted: 02/10/2021] [Indexed: 05/26/2023]
Abstract
The response of peatlands to climate change can be highly variable. Through understanding past changes we can better predict the response of peatlands to future climate change. We use a multi-proxy approach to reconstruct the surface wetness and carbon accumulation of the Mukhrino mire (Western Siberia), describing the development of the mire since peat formation in the early Holocene, around 9360 cal. year BP. The mire started as a rich fen which initiated after paludification of a spruce forest (probably in response to a wetter climate), while the Mukhrino mire progressed to ombrotrophic bog conditions (8760 cal. year BP). This transition coincided with the intensive development of mires in Western Siberia and was associated with active carbon accumulation (31 g m-2 year-1). The ecosystem underwent a change to a tree-covered state around 5860 cal. year BP, likely in response to warming and possible droughts and this accompanied low carbon accumulation (12 g m2 year-1). If the future climate will be warmer and wetter, then regional mires are likely to remain a carbon sink, alternatively, a reversion to the wooded state with reduced carbon sink strength is possible.
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Affiliation(s)
- Andrey N. Tsyganov
- Department of General Ecology and Hydrobiology, Lomonosov Moscow State University, Leninskie Gory 1, building 12, Moscow, Russia 119234
- Laboratory of Soil Zoology and General Entomology, A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninskiy prospekt 33, Moscow, Russia 119071
| | - Evgeny A. Zarov
- Research Education Center of Environmental Dynamics and Climate Change (UNESCO Chair), Yugra State University, Chekhova str. 16, Khanty-Mansiysk, Russia 628007
| | - Yuri A. Mazei
- Department of General Ecology and Hydrobiology, Lomonosov Moscow State University, Leninskie Gory 1, building 12, Moscow, Russia 119234
- Laboratory of Soil Zoology and General Entomology, A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninskiy prospekt 33, Moscow, Russia 119071
- Faculty of Biology, Shenzhen MSU-BIT University, 1 International University Park Road, Dayun New Town, Longgang District, Shenzhen, 517182 China
| | - Mikhail G. Kulkov
- Research Education Center of Environmental Dynamics and Climate Change (UNESCO Chair), Yugra State University, Chekhova str. 16, Khanty-Mansiysk, Russia 628007
- Research and Analytical Centre for the Rational Use of the Subsoil named after V.I.Shpilman, Studencheskaya str. 2, Khanty-Mansiysk, Russia 628007
| | - Kirill V. Babeshko
- Department of General Biology and Biochemistry, Penza State University, Lermontova str. 37, building 15, Penza, Russia 440026
- Department of Zoology and Ecology, Penza State University, Lermontova str. 37, building 15, Penza, Russia 440026
| | - Svetlana Y. Yushkovets
- Department of Zoology and Ecology, Penza State University, Lermontova str. 37, building 15, Penza, Russia 440026
| | | | - Joshua L. Ratcliffe
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Yulia A. Fatyunina
- Department of General Biology and Biochemistry, Penza State University, Lermontova str. 37, building 15, Penza, Russia 440026
| | - Elya P. Zazovskaya
- Laboratory of Radiocarbon Dating and Electron Microscopy, Institute of Geography of the Russian Academy of Science (IG RAS), Staromonetniy Lane 29, Moscow, Russia 119017
| | - Elena D. Lapshina
- Research Education Center of Environmental Dynamics and Climate Change (UNESCO Chair), Yugra State University, Chekhova str. 16, Khanty-Mansiysk, Russia 628007
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77
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Martinsson J, Pédehontaa-Hiaa G, Malmborg V, Madsen D, Rääf C. Experimental wildfire induced mobility of radiocesium in a boreal forest environment. Sci Total Environ 2021; 792:148310. [PMID: 34146801 DOI: 10.1016/j.scitotenv.2021.148310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/08/2021] [Accepted: 06/02/2021] [Indexed: 06/12/2023]
Abstract
Wildfires are expected to increase with warmer climate, which can contribute to the mobility and the resuspension of long-lived and potentially hazardous radionuclides. The release of 137Cs during combustion of dried litter, forest floor organic soil, and peat was investigated in a small-scale experimental set-up. Combustion conditions were varied to simulate different wildfire scenarios, and the fuels were dried organic material collected in a boreal environment of Sweden that was contaminated following the Chernobyl accident in 1986. The combustion-related release of 137Cs to the air was on average 29% of the initial fuel content, while 71% of the initial 137Cs remained in the ashes after the combustion. Peat and forest soil had the highest releases (39% and 37%, respectively), although these numbers should be viewed as potential releases since authentic wildfire combustion of these fuels are usually less effective than observed in these experiments. These results indicates that the 137Cs has migrated downwards in the organic material, which imply potentially significantly more 137Cs emissions in severe wildfires with intense combustion of the organic vertical profile in peatbogs and forests. More 137Cs tended to be released during intense and efficient combustion processes, although no significant differences among combustion intensities were observed. The generated experimental data was used in an emission scenario to investigate the possible range in 137Cs emissions from a wildfire. Our study shows that a severe wildfire in a contaminated area of 10,000 ha could potentially release up to 7 TBq of 137Cs. This is the first laboratory study to investigate 137Cs release upon varying combustion conditions using real fallout contaminated organic material obtained from a boreal environment.
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Affiliation(s)
- Johan Martinsson
- Medical Radiation Physics, Lund University, Lund, Box 118, 221 00, Sweden.
| | | | - Vilhelm Malmborg
- Ergonomics and Aerosol Technology, Lund University, Lund, Box 118, 221 00, Sweden
| | - Dan Madsen
- Division of Fire Safety Engineering, Lund University, Lund, Box 118, 221 00, Sweden
| | - Christopher Rääf
- Medical Radiation Physics, Lund University, Lund, Box 118, 221 00, Sweden
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78
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Henriksson N, Lim H, Marshall J, Franklin O, McMurtrie RE, Lutter R, Magh R, Lundmark T, Näsholm T. Tree water uptake enhances nitrogen acquisition in a fertilized boreal forest - but not under nitrogen-poor conditions. New Phytol 2021; 232:113-122. [PMID: 34166537 DOI: 10.1111/nph.17578] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 06/17/2021] [Indexed: 06/13/2023]
Abstract
Understanding how plant water uptake interacts with acquisition of soil nitrogen (N) and other nutrients is fundamental for predicting plant responses to a changing environment, but it is an area where models disagree. We present a novel isotopic labelling approach which reveals spatial patterns of water and N uptake, and their interaction, by trees. The stable isotopes 15 N and 2 H were applied to a small area of the forest floor in stands with high and low soil N availability. Uptake by surrounding trees was measured. The sensitivity of N acquisition to water uptake was quantified by statistical modelling. Trees in the high-N stand acquired twice as much 15 N as in the low-N stand and around half of their N uptake was dependent on water uptake (2 H enrichment). By contrast, in the low-N stand there was no positive effect of water uptake on N uptake. We conclude that tree N acquisition was only marginally dependent on water flux toward the root surface under low-N conditions whereas under high-N conditions, the water-associated N uptake was substantial. The results suggest a fundamental shift in N acquisition strategy under high-N conditions.
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Affiliation(s)
- Nils Henriksson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, SE-90283, Sweden
| | - Hyungwoo Lim
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, SE-90283, Sweden
| | - John Marshall
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, SE-90283, Sweden
- Global Change Research Institute CAS, Bělidla 986/4a, Brno, 603 00, Czech Republic
| | - Oskar Franklin
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, SE-90283, Sweden
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, A-2361, Austria
| | - Ross E McMurtrie
- School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Reimo Lutter
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, SE-90283, Sweden
- Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Kreutzwaldi 5, Tartu, EE-510 06, Estonia
| | - Ruth Magh
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, SE-90283, Sweden
| | - Tomas Lundmark
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, SE-90283, Sweden
| | - Torgny Näsholm
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, SE-90283, Sweden
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79
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Dulamsuren C, Hauck M. Drought stress mitigation by nitrogen in boreal forests inferred from stable isotopes. Glob Chang Biol 2021; 27:5211-5224. [PMID: 34309985 DOI: 10.1111/gcb.15813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/21/2021] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
Forest growth in most parts of the boreal zone is originally limited by low temperatures and low nitrogen availability. Due to the rapid climate warming at high latitudes, an increasing forest area is switching to drought limitation, especially in continental and southern parts of the boreal forest. Studies addressing this issue were mostly dendrochronological and remote-sensing analyses focusing on climatic effects, but not answering the question whether drought is effective alone or in combination with nitrogen shortage at limiting the forests' productivity and vitality. Here we show in a case study from larch forests of Mongolia with a combination of stable isotope analyses, tree-ring analysis and bioindication of the local variability of livestock densities using epiphytic lichens that, in the studied highly drought-prone forests at the southern fringe of the boreal forest in Inner Asia, the trees' vulnerability to drought is modified by nitrogen fertilization from livestock kept in the vicinity and the edge of the forests. The most likely mechanism behind this drought-nitrogen interaction is the reduction of stomatal conductance, which is known to be induced by low nitrogen levels in plants. Nitrogen fertilization by the livestock could, thus, shorten the times of stomatal closure and thereby increase tree growth, which we measured as radial stem increment. Even though the underlying mechanisms, which were so far examined in angiosperms, should be experimentally tested for conifers, our results indicate that focusing on water alone is not enough to understand the climate change response of drought-limited boreal forests.
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Affiliation(s)
| | - Markus Hauck
- Applied Vegetation Ecology, University of Freiburg, Freiburg, Germany
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80
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Kelly J, Ibáñez TS, Santín C, Doerr SH, Nilsson MC, Holst T, Lindroth A, Kljun N. Boreal forest soil carbon fluxes one year after a wildfire: Effects of burn severity and management. Glob Chang Biol 2021; 27:4181-4195. [PMID: 34028945 DOI: 10.1111/gcb.15721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 04/20/2021] [Indexed: 06/12/2023]
Abstract
The extreme 2018 hot drought that affected central and northern Europe led to the worst wildfire season in Sweden in over a century. The Ljusdal fire complex, the largest area burnt that year (8995 ha), offered a rare opportunity to quantify the combined impacts of wildfire and post-fire management on Scandinavian boreal forests. We present chamber measurements of soil CO2 and CH4 fluxes, soil microclimate and nutrient content from five Pinus sylvestris sites for the first growing season after the fire. We analysed the effects of three factors on forest soils: burn severity, salvage-logging and stand age. None of these caused significant differences in soil CH4 uptake. Soil respiration, however, declined significantly after a high-severity fire (complete tree mortality) but not after a low-severity fire (no tree mortality), despite substantial losses of the organic layer. Tree root respiration is thus key in determining post-fire soil CO2 emissions and may benefit, along with heterotrophic respiration, from the nutrient pulse after a low-severity fire. Salvage-logging after a high-severity fire had no significant effects on soil carbon fluxes, microclimate or nutrient content compared with leaving the dead trees standing, although differences are expected to emerge in the long term. In contrast, the impact of stand age was substantial: a young burnt stand experienced more extreme microclimate, lower soil nutrient supply and significantly lower soil respiration than a mature burnt stand, due to a thinner organic layer and the decade-long effects of a previous clear-cut and soil scarification. Disturbance history and burn severity are, therefore, important factors for predicting changes in the boreal forest carbon sink after wildfires. The presented short-term effects and ongoing monitoring will provide essential information for sustainable management strategies in response to the increasing risk of wildfire.
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Affiliation(s)
- Julia Kelly
- Centre for Environmental and Climate Science, Lund University, Lund, Sweden
| | - Theresa S Ibáñez
- Department of Forest Ecology and Management, Faculty of Forest Sciences, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Cristina Santín
- Department of Biosciences, Swansea University, Swansea, Wales, UK
- Research Unit of Biodiversity, Spanish National Research Council, Mieres, Spain
| | - Stefan H Doerr
- Department of Geography, Swansea University, Swansea, Wales, UK
| | - Marie-Charlotte Nilsson
- Department of Forest Ecology and Management, Faculty of Forest Sciences, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Thomas Holst
- Department of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden
| | - Anders Lindroth
- Department of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden
| | - Natascha Kljun
- Centre for Environmental and Climate Science, Lund University, Lund, Sweden
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81
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Cogos S, Östlund L, Roturier S. Fire Management in The Boreal Forest of Swedish Sápmi: Prescribed Burning and Consideration of Sami Reindeer Herding During 1920-1970. Environ Manage 2021; 68:295-309. [PMID: 34297195 DOI: 10.1007/s00267-021-01503-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
Forest owners and Indigenous Sami reindeer herders use the same land in northern Sweden for commercial forestry and winter grazing, respectively. Fire management has been controlled by foresters since the late-19th century, and Sami herders have had to deal with the effects of both fire suppression and prescribed burning. However, the environmental history of fire management and reindeer herding in Sweden has never been thoroughly investigated. We therefore analyzed written archives in order to understand how reindeer herding was considered in planned burning during the mid-20th century, and how the effects of prescribed burning on reindeer herding were interpreted by foresters. We supplemented the interpretation of written sources by including local Sami reindeer herders' insights about prescribed burning. Written records show that reindeer herding was increasingly integrated into the planning process during the 20th century, yet foresters failed to include important aspects of reindeer herding in their interpretation of the effects of prescribed burning. The Sami consider the effects of burning in terms of fodder availability, opportunities for reindeer to graze the fodder, and any impact on the reindeer's movement patterns and thus herd management. The Sami's historical perspective is essential in order to reconstruct a comprehensive picture of the past, and adapt forestry measures effectively in the future.
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Affiliation(s)
- Sarah Cogos
- Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique Evolution, F-91405, Orsay, France.
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 90183, Umeå, Sweden.
| | - Lars Östlund
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 90183, Umeå, Sweden
| | - Samuel Roturier
- Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique Evolution, F-91405, Orsay, France
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82
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Lavergne SG, Krebs CJ, Kenney AJ, Boutin S, Murray D, Palme R, Boonstra R. The impact of variable predation risk on stress in snowshoe hares over the cycle in North America's boreal forest: adjusting to change. Oecologia 2021; 197:71-88. [PMID: 34435235 DOI: 10.1007/s00442-021-05019-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/16/2021] [Indexed: 11/26/2022]
Abstract
The boreal forest is one of the world's ecosystems most affected by global climate warming. The snowshoe hare, its predators, and their population dynamics dominate the mammalian component of the North American boreal forest. Our past research has shown the 9-11-year hare cycle to be predator driven, both directly as virtually all hares that die are killed by their predators, and indirectly through sublethal risk effects on hare stress physiology, behavior, and reproduction. We replicated this research over the entire cycle by measuring changes in predation risk expected to drive changes in chronic stress. We examined changes in hare condition and stress axis function using a hormonal challenge protocol in the late winter of 7 years-spanning all phases of the cycle from the increase through to the low (2014-2020). We simultaneously monitored changes in hare abundance as well as those of their primary predators, lynx and coyotes. Despite observing the expected changes in hare-predator numbers over the cycle, we did not see the predicted changes in chronic stress metrics in the peak and decline phases. Thus, the comprehensive physiological signature indicative of chronic predator-induced stress seen from our previous work was not present in this current cycle. We postulate that hares may now be increasingly showing behavior-mediated rather than stress-mediated responses to their predators. We present evidence that increases in primary productivity have affected boreal community structure and function. We speculate that climate change has caused this major shift in the indirect effects of predation on hares.
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Affiliation(s)
- Sophia G Lavergne
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | - Charles J Krebs
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Alice J Kenney
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Dennis Murray
- Department of Biology, Trent University, Peterborough, ON, Canada
| | - Rupert Palme
- Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Rudy Boonstra
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada.
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83
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Savard MM, Martineau C, Laganière J, Bégin C, Marion J, Smirnoff A, Stefani F, Bergeron J, Rheault K, Paré D, Séguin A. Nitrogen isotopes in the soil-to-tree continuum - Tree rings express the soil biogeochemistry of boreal forests exposed to moderate airborne emissions. Sci Total Environ 2021; 780:146581. [PMID: 33774298 DOI: 10.1016/j.scitotenv.2021.146581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/15/2021] [Accepted: 03/15/2021] [Indexed: 06/12/2023]
Abstract
Anthropogenic N emissions represent a potential threat for forest ecosystems, and environmental indicators that provide insight into the changing forest N cycle are needed. Tree ring N isotopic ratios (δ15N) appear as a contentious choice for this role as the exact mechanisms behind tree-ring δ15N changes seldom benefit from a scrutiny of the soil-to-tree N continuum. This study integrates the results from the analysis of soil chemistry, soil microbiome genomics, and δ15N values of soil N compounds, roots, ectomycorrhizal (EcM) fungi and recent tree rings of thirteen white spruce trees sampled in five stands, from two regions exposed to moderate anthropogenic N emissions (3.9 to 8.1 kg/ha/y) with distinctive δ15N signals. Our results reveal that airborne anthropogenic N with distinct δ15N signals may directly modify the NO3- δ15N values in surface soils, but not the ones of NH4+, the preferred N form of the studied trees. Hence, the tree-ring δ15N values reflect specific soil N conditions and assimilation modes by trees. Along with a wide tree-ring δ15N range, we report differences in: soil nutrient content and N transformation rates; δ15N values of NH4+, total dissolved N (TDN) and EcM mantle enveloping the root tips; and bacterial and fungal community structures. We combine EcM mantle and root δ15N values with fungal identification to infer that hydrophobic EcM fungi transfer N from the dissolved organic N (DON) pool to roots under acidic conditions, and hydrophilic EcM fungi transfer various N forms to roots, which also assimilate N directly under less acidic conditions. Despite the complexities of soil biogeochemical properties and processes identified in the studied sites, in the end, the tree-ring δ15N averages inversely correlate with soil pH and anthropogenic N inputs, confirming white spruce tree-ring δ15N values as a suitable indicator for environmental research on forest N cycling.
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Affiliation(s)
- Martine M Savard
- Geological Survey of Canada, Natural Resources Canada, 490 rue de la Couronne, Québec, QC G1K 9A9, Canada.
| | - Christine Martineau
- Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., Stn. Sainte-Foy, P.O. Box 10380, Québec, QC G1V 4C7, Canada
| | - Jérôme Laganière
- Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., Stn. Sainte-Foy, P.O. Box 10380, Québec, QC G1V 4C7, Canada
| | - Christian Bégin
- Geological Survey of Canada, Natural Resources Canada, 490 rue de la Couronne, Québec, QC G1K 9A9, Canada
| | - Joëlle Marion
- Geological Survey of Canada, Natural Resources Canada, 490 rue de la Couronne, Québec, QC G1K 9A9, Canada
| | - Anna Smirnoff
- Geological Survey of Canada, Natural Resources Canada, 490 rue de la Couronne, Québec, QC G1K 9A9, Canada
| | - Franck Stefani
- Agriculture and Agri-Food Canada, 960 Avenue Carling, Ottawa, ON K1A 0C6, Canada
| | - Jade Bergeron
- Geological Survey of Canada, Natural Resources Canada, 490 rue de la Couronne, Québec, QC G1K 9A9, Canada
| | - Karelle Rheault
- Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., Stn. Sainte-Foy, P.O. Box 10380, Québec, QC G1V 4C7, Canada
| | - David Paré
- Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., Stn. Sainte-Foy, P.O. Box 10380, Québec, QC G1V 4C7, Canada
| | - Armand Séguin
- Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., Stn. Sainte-Foy, P.O. Box 10380, Québec, QC G1V 4C7, Canada
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84
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Hisano M, Ryo M, Chen X, Chen HYH. Rapid functional shifts across high latitude forests over the last 65 years. Glob Chang Biol 2021; 27:3846-3858. [PMID: 33993581 DOI: 10.1111/gcb.15710] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 05/07/2021] [Indexed: 06/12/2023]
Abstract
Global environmental changes have strongly affected forest demographic rates, particularly amplified tree mortality in high latitude forests (e.g., two to five times greater mortality probability over the half-century). Although forest functional composition is critical for multitrophic biodiversity and ecosystem functioning, it remains unclear how functional composition has changed over time across large high latitude regions, which have been warming twice the rate of the globe as a whole. Using extensive spatial and long-term forest inventory data (17,107 plots monitored 1951-2016) across Canada, we found that after accounting for stand age-dependent functional shifts, functional composition shifted toward fast-growing deciduous broadleaved trees and higher drought tolerance over time. The temporal shift toward deciduous broadleaved trees was consistent across the baseline climate. However, over the study period, drought tolerance increased (or shade tolerance decreased) by 300% in colder boreal regions, while drought tolerance did not shift significantly in warmer temperate climates. A further analysis accounting for temporal changes in atmospheric CO2 , temperature, and water availability indicated that the functional composition of colder regions shifted toward drought tolerance more rapidly with rising CO2 than warmer regions, suggesting the greater vulnerability of boreal forests than temperate forests under ongoing global environmental changes. Future ecosystem management practices should consider spatial differences in functional responses to global environmental change, focusing on high latitude forests experiencing higher rates of warming and compositional changes.
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Affiliation(s)
- Masumi Hisano
- Faculty of Natural Resources Management, Lakehead University, Thunder Bay, ON, Canada
- Department of Ecosystem Studies, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Japan
| | - Masahiro Ryo
- Leibniz Centre for Agricultural Landscape Research (ZALF), Muencheberg, Germany
| | - Xinli Chen
- Faculty of Natural Resources Management, Lakehead University, Thunder Bay, ON, Canada
| | - Han Y H Chen
- Faculty of Natural Resources Management, Lakehead University, Thunder Bay, ON, Canada
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85
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Kang JH, Hwang H, Lee SJ, Choi SD, Kim JS, Hong S, Hur SD, Baek JH. Record of North American boreal forest fires in northwest Greenland snow. Chemosphere 2021; 276:130187. [PMID: 33740646 DOI: 10.1016/j.chemosphere.2021.130187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/24/2021] [Accepted: 03/02/2021] [Indexed: 05/16/2023]
Abstract
We present boreal forest fire proxies in a northwest Greenland snowpit spanning a period of six years, from spring 2003 to summer 2009. Levoglucosan (C6H10O5) is a specific organic molecular marker of biomass burning caused by boreal forest fires. In this study, levoglucosan was determined via liquid chromatography/negative ion electrospray ionization-tandem mass spectrometry, wherein isotope-dilution and multiple reaction monitoring methods are employed. Ammonium (NH4+) and oxalate (C2O42-), traditional biomass burning proxies, were determined using two-channel ion chromatography. In the northwest Greenland snowpit, peaks in levoglucosan, ammonium, and oxalate were observed in snow layers corresponding to the summer-fall seasons of 2004 and 2005. Considered together, these spikes are a marker for large boreal forest fires. The levoglucosan deposited in the Greenland snow was strongly dependent on long-range atmospheric transportation. A 10-day backward air mass trajectory analysis supports that the major contributors were air masses from North America. In addition, satellite-derived carbon monoxide (CO) and ammonia (NH3) concentrations suggest that chemicals from North American boreal forest fires during the summer-fall of 2004 and 2005 were transported to Greenland. However, large boreal fires in Siberia in 2003 and 2008 were not recorded in the snowpit. The sub-annual resolution measurements of levoglucosan and ammonium can distinguish between the contributions of past boreal forest fires and soil emissions from anthropogenic activity to Greenland snow and ice.
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Affiliation(s)
- Jung-Ho Kang
- Division of Glacial Environment Research, Korea Polar Research Institute, Incheon, 21990, Republic of Korea.
| | - Heejin Hwang
- Division of Glacial Environment Research, Korea Polar Research Institute, Incheon, 21990, Republic of Korea
| | - Sang-Jin Lee
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Sung-Deuk Choi
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Jin-Soo Kim
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Sangbum Hong
- Division of Glacial Environment Research, Korea Polar Research Institute, Incheon, 21990, Republic of Korea
| | - Soon Do Hur
- Division of Glacial Environment Research, Korea Polar Research Institute, Incheon, 21990, Republic of Korea
| | - Je-Hyun Baek
- Analysis Service Center, Diatech Korea Co., Ltd., Seoul, 05808, Republic of Korea
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86
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Gutierrez Lopez J, Tor-Ngern P, Oren R, Kozii N, Laudon H, Hasselquist NJ. How tree species, tree size, and topographical location influenced tree transpiration in northern boreal forests during the historic 2018 drought. Glob Chang Biol 2021; 27:3066-3078. [PMID: 33949757 DOI: 10.1111/gcb.15601] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 02/26/2021] [Accepted: 03/02/2021] [Indexed: 06/12/2023]
Abstract
Trees in northern latitude ecosystems are projected to experience increasing drought stress as a result of rising air temperatures and changes in precipitation patterns in northern latitude ecosystems. However, most drought-related studies on high-latitude boreal forests (>50°N) have been conducted in North America, with few studies quantifying the response in European and Eurasian boreal forests. Here, we tested how daily whole-tree transpiration (Q, Liters day-1 ) and Q normalized for mean daytime vapor pressure deficit (QDZ , Liters day-1 kPa-1 ) were affected by the historic 2018 drought in Europe. More specifically, we examined how tree species, size, and topographic position affected drought response in high-latitude mature boreal forest trees. We monitored 30 Pinus sylvestris (pine) and 30 Picea abies (spruce) trees distributed across a topographic gradient in northern Sweden. In general, pine showed a greater QDZ control compared to spruce during periods of severe drought (standardized precipitation-evapotranspiration index: SPEI < -1.5), suggesting that the latter are more sensitive to drought. Overall, QDZ reductions (using non-drought QDZ as reference) were less pronounced in larger trees during severe drought, but there was a species-specific pattern: QDZ reductions were greater in pine trees at high elevations and greater in spruce trees at lower elevations. Despite lower QDZ during severe drought, drought spells were interspersed with small precipitation events and overcast conditions, and QDZ returned to pre-drought conditions relatively quickly. This study highlights unique species-specific responses to drought, which are additionally driven by a codependent interaction among tree size, relative topographic position, and unique regional climate conditions.
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Affiliation(s)
- Jose Gutierrez Lopez
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Pantana Tor-Ngern
- Department of Environmental Science, Chulalongkorn University, Bangkok, Thailand
- Environment, Health and Social Data Analytics Research Group, Chulalongkorn University, Bangkok, Thailand
- Water Science and Technology for Sustainable Environment Research Group, Chulalongkorn University, Bangkok, Thailand
| | - Ram Oren
- Division of Environmental Science & Policy, Nicholas School of the Environment, Duke University, Durham, NC, USA
- Department of Forest Science, University of Helsinki, Helsinki, Finland
| | - Nataliia Kozii
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Hjalmar Laudon
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Niles J Hasselquist
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
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87
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Lednev SA, Semenkov IN, Klink GV, Krechetov PP, Sharapova AV, Koroleva TV. Impact of kerosene pollution on ground vegetation of southern taiga in the Amur Region, Russia. Sci Total Environ 2021; 772:144965. [PMID: 33770897 DOI: 10.1016/j.scitotenv.2021.144965] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/08/2020] [Accepted: 01/02/2021] [Indexed: 06/12/2023]
Abstract
The present study is the field experiment on kerosene pollution impact on southern taiga plant communities. Experimental sites were located in a mixed forest, a deciduous forest, a sedge fen and a wet meadow within the Amur Region of the Russian Far East. Kerosene loads from 1 to 500 g/kg of soil were applied to 50 × 50 cm plots in three replications and their effects on number of species and projective cover of ground vegetation were analysed in 1.5 months and 1 year after exposure. Statistical analyses of data included Student's t-test, Friedman ANOVA and correlation coefficient (r). Phylogenetic analysis was carried out for herbaceous plants on experimental plots. The highest susceptibility to kerosene pollution was found in the mixed forest, where the edificator species (Pteridium aquilinum subsp. pinetorum) was significantly suppressed by the kerosene load of only 1 g/kg of soil. Wetland communities regenerated faster than ground vegetation of forests, especially, in tests with high (>25 g/kg) kerosene loads. The wet meadow community was the most resistant to kerosene pollution, i.e., despite significant decreases in projective cover and number of species after exposure to kerosene loads of 5 and 25 g/kg in the first season, it had the highest regeneration success in the next season. In our study, the kerosene load of 25 g/kg of soil was the threshold level of pollution, above which there were significant structural changes in the studied plant communities. Depending on their abilities to resist kerosene pollution and to regenerate in the next year, dominant species of the studied plant communities were arranged in the following ascending order: Pteridium aquilinum ssp. pinetorum, Convallaria keiskei < Carex cespitosa, Calamagrostis purpurea < Lespedeza bicolor < Vaccinium uliginosum.
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Affiliation(s)
- Sergey A Lednev
- Faculty of Geography, Lomonosov Moscow State University, Leninskie Gory 1, Moscow 119991, Russia.
| | - Ivan N Semenkov
- Faculty of Geography, Lomonosov Moscow State University, Leninskie Gory 1, Moscow 119991, Russia.
| | - Galya V Klink
- Institute for Information Transmission Problems (Kharkevich Institute) of the Russian Academy of Sciences, 127051, Russia
| | - Pavel P Krechetov
- Faculty of Geography, Lomonosov Moscow State University, Leninskie Gory 1, Moscow 119991, Russia
| | - Anna V Sharapova
- Faculty of Geography, Lomonosov Moscow State University, Leninskie Gory 1, Moscow 119991, Russia
| | - Tatyana V Koroleva
- Faculty of Geography, Lomonosov Moscow State University, Leninskie Gory 1, Moscow 119991, Russia
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88
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Pompa-García M, González-Cásares M, Gazol A, Camarero JJ. Run to the hills: Forest growth responsiveness to drought increased at higher elevation during the late 20th century. Sci Total Environ 2021; 772:145286. [PMID: 33578149 DOI: 10.1016/j.scitotenv.2021.145286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/14/2021] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
Climate warming is expected to enhance forest growth in cold-limited biomes while triggering reductions in drought-limited biomes. However, as temperature raises, it is unclear how temperature- and drought-growth couplings shift across elevation gradients in different biomes. We still lack comprehensive analyses on how altitude modulates the influence of temperature and drought on tree growth during the second half of the 20th century when climate warming accelerated. We compared the worldwide responses of tree growth (RWI, ring-width indices) to two of its major climatic constraints, growing-season minimum temperatures and drought (SPEI index), across biomes and elevation gradients during two periods with different warming rates (1960-1980 vs. 1980-2000). We found a decrease in the correlations of minimum temperatures with growth, but a strengthening of drought-growth relationships. However, these patterns varied across biomes because correlations between growth and temperature decreased in temperate forests and woodland shrubland, while correlations between growth and SPEI increased in boreal forests and decreased in temperate forests. Differences in growth responsiveness to climate between the two periods were more marked for mid-latitude forests situated between 1200 and 1600 m. The slopes of the relationships between growth-temperature correlations and elevation decreased in late spring and midsummer. The slopes of the relationships between growth-drought correlations and elevation increased in temperate forests and woodland shrubland suggesting that drought impacts are "climbing" in these biomes. Temperature controls on forest growth are relaxing as the climate warms, while drought is becoming a more significant constraint for tree growth, particularly for mid-elevation forests and in drought-prone woodland and shrubland. The strengthening of drought-growth coupling should be considered in vegetation models to reduce the uncertainty on forest climate mitigation.
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Affiliation(s)
- Marín Pompa-García
- Facultad de Ciencias Forestales, Universidad Juárez del Estado de Durango, Durango, Mexico.
| | | | - Antonio Gazol
- Instituto Pirenaico de Ecología (IPE-CSIC), Zaragoza, Spain.
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89
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Bykova MV, Alekseenko AV, Pashkevich MA, Drebenstedt C. Thermal desorption treatment of petroleum hydrocarbon-contaminated soils of tundra, taiga, and forest steppe landscapes. Environ Geochem Health 2021; 43:2331-2346. [PMID: 33452955 PMCID: PMC8189942 DOI: 10.1007/s10653-020-00802-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 12/19/2020] [Indexed: 05/04/2023]
Abstract
The results of field, analytical, and experimental research at a number of production facilities reflect the properties of oil-contaminated soils in 3 landscapes: the permafrost treeless Arctic ecosystem, boreal forest, and temperate-climate grassland-woodland ecotone. Laboratory studies have revealed the concentrations of petroleum hydrocarbons in soils, ranging from medium levels of 2000-3000 mg/kg to critical figures over 5000 mg/kg, being 2-25 times higher than the permissible content of oil products in soils. The experimentally applied thermal effects for the oil products desorption from the soil allowed finding an optimal regime: the treatment temperature from 25 to 250 °C reduces the concentrations to an acceptable value. The conditions are environmentally sound, given that the complete combustion point of humates is ca. 450 °C. The outcomes suggest the eco-friendly solution for soil remediation, preserving the soil fertility in fragile cold environments and in more resilient temperate climates, where revitalized brownfields are essential for food production.
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Affiliation(s)
- Marina V. Bykova
- Department of Geoecology, Saint Petersburg Mining University, 2, 21st line V.O., Saint Petersburg, Russian Federation 199106
| | - Alexey V. Alekseenko
- Department of Geoecology, Saint Petersburg Mining University, 2, 21st line V.O., Saint Petersburg, Russian Federation 199106
| | - Mariya A. Pashkevich
- Department of Geoecology, Saint Petersburg Mining University, 2, 21st line V.O., Saint Petersburg, Russian Federation 199106
| | - Carsten Drebenstedt
- Technische Universität Bergakademie Freiberg, 1a, Gustav-Zeuner-Str., Freiberg, 09596 Germany
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90
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Liu F, Liu H, Xu C, Shi L, Zhu X, Qi Y, He W. Old-growth forests show low canopy resilience to droughts at the southern edge of the taiga. Glob Chang Biol 2021; 27:2392-2402. [PMID: 33740267 DOI: 10.1111/gcb.15605] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 02/22/2021] [Accepted: 03/04/2021] [Indexed: 06/12/2023]
Abstract
Forest mortality and resilience driven by drought disturbances have attracted tons of attention. However, the acquisition of continuous spatial-temporal data is generally enslaved to the conventional field investigations. In this study, the resilience of semiarid forest was characterized with canopy dynamics from remote sensing observations, combining the variations in canopy greenness and water content. We integrated dense normalized difference vegetation index (NDVI) and normalized difference infrared index (NDII) time series from Landsat datasets, intending to assess the canopy resilience in 24 conifer patches along a climatic aridity gradient at the southern edge of the taiga in northern Mongolia and southern Siberia of Russia. The results exhibited four patterns of coordinated NDVI-NDII variation trends, indicating that the canopy water content of coniferous forests may decrease at first during a drought period, and sustained water loss may, in turn, induce an accompanying reduction in canopy greenness. Meanwhile, the patches with canopy recovery growth after initial declines were considered to have resilience to climate change. We further observed the combined effects of aridity degree and tree age on canopy resilience, and all seven patches with no resilience corresponded to the old-tree group (the oldest trees reached or exceeded the age of 90). The observations indicated that the old-growth forests in semiarid regions were less likely to show canopy resilience, which corresponded to a higher risk of sustained decline.
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Affiliation(s)
- Feng Liu
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Hongyan Liu
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Chongyang Xu
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Liang Shi
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Xinrong Zhu
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Yang Qi
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Wenqi He
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
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91
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Dearborn KD, Baltzer JL. Unexpected greening in a boreal permafrost peatland undergoing forest loss is partially attributable to tree species turnover. Glob Chang Biol 2021; 27:2867-2882. [PMID: 33742732 DOI: 10.1111/gcb.15608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 03/07/2021] [Indexed: 06/12/2023]
Abstract
Time series of vegetation indices derived from satellite imagery are useful in measuring vegetation response to climate warming in remote northern regions. These indices show that productivity is generally declining in the boreal forest, but it is unclear which components of boreal vegetation are driving these trends. We aimed to compare trends in the normalized difference vegetation index (NDVI) to forest growth and demographic data taken from a 10 ha mapped plot located in a spruce-dominated boreal peatland. We used microcores to quantify recent growth trends and tree census data to characterize mortality and recruitment rates of the three dominant tree species. We then compared spatial patterns in growth and demography to patterns in Landsat-derived maximum NDVI trends (1984-2019) in 78 pixels that fell within the plot. We found that NDVI trends were predominantly positive (i.e., "greening") in spite of the ongoing loss of black spruce (the dominant species; 80% of stems) from the plot. The magnitude of these trends correlated positively with black spruce growth trends, but was also governed to a large extent by tree mortality and recruitment. Greening trends were weaker (lower slope) in areas with high larch mortality, and high turnover of spruce and birch, but stronger (higher slope) in areas with high larch recruitment. Larch dominance is currently low (~11% of stems), but it is increasing in abundance as permafrost thaw progresses and will likely have a substantial influence on future NDVI trends. Our results emphasize that NDVI trends in boreal peatlands can be positive even when the forest as a whole is in decline, and that the magnitude of trends can be strongly influenced by the demographics of uncommon species.
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92
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Berglund H, Kuuluvainen T. Representative boreal forest habitats in northern Europe, and a revised model for ecosystem management and biodiversity conservation. Ambio 2021; 50:1003-1017. [PMID: 33454914 PMCID: PMC8035375 DOI: 10.1007/s13280-020-01444-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 08/22/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
The natural range of variation of ecosystems provides reference conditions for sustainable management and biodiversity conservation. We review how the understanding of natural reference conditions of boreal forests in northern Europe has changed from earlier perceptions of even-aged dynamics driven by stand-replacing disturbances towards current understanding highlighting the role of non-stand-replacing disturbances and the resultant complex forest dynamics and structures. We show how earlier views and conceptual models of forest disturbance dynamics, including the influential ASIO model, provide estimates of reference conditions that are outside the natural range of variation. Based on a research synthesis, we present a revised forest reference model incorporating the observed complexity of ecosystem dynamics and the prevalence of old forests. Finally, we outline a management model and demonstrate its use in forest ecosystem management and show how regional conservation area needs can be estimated. We conclude that attaining favourable conservation status in northern Europe's boreal forests requires increasing emphasis on ecosystem management and conservation for old forest characteristics.
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Affiliation(s)
- Håkan Berglund
- Swedish Species Information Center, Swedish University of Agricultural Sciences, Box 7007, 750 07 Uppsala, Sweden
| | - Timo Kuuluvainen
- Department of Forest Sciences, University of Helsinki, Box 27, 00014 Helsinki, Finland
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93
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Marupakula S, Mahmood S, Clemmensen KE, Jacobson S, Högbom L, Finlay RD. Root associated fungi respond more strongly than rhizosphere soil fungi to N fertilization in a boreal forest. Sci Total Environ 2021; 766:142597. [PMID: 33077205 DOI: 10.1016/j.scitotenv.2020.142597] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 09/23/2020] [Accepted: 09/23/2020] [Indexed: 06/11/2023]
Abstract
Nitrogen (N) fertilization is a routine practice in boreal forests but its effects on fungal functional guilds in Pinus sylvestris forests are still incompletely understood. Sampling is often restricted to the upper organic horizons and based on DNA extracted from mixtures of soil and roots without explicitly analysing different spatial niches. Fungal community structure in soil and roots of an 85-y-old Pinus sylvestris forest was investigated using high throughput sequencing. Fertilized plots had been treated with a single dose of N fertilizer, 15 months prior to sampling. Species richness of fungi colonizing roots was reduced in all horizons by N fertilization. In contrast, species richness of soil fungi in the organic horizon was increased by N fertilization, but unaffected in the mineral horizons. Community composition of fungi colonizing roots differed from that of soil fungi, and both communities were significantly influenced by soil horizon and N. The ectomycorrhizal community composition in both roots and soil was significantly affected by N fertilization but no significant effect was found on saprotrophic fungi. The results highlight the importance of analysing the rhizosphere soil and root compartments separately since the fungal communities in these two niches appear to respond differently to environmental perturbations involving the addition of nitrogen.
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Affiliation(s)
- Srisailam Marupakula
- Uppsala BioCenter, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden
| | - Shahid Mahmood
- Uppsala BioCenter, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.
| | - Karina E Clemmensen
- Uppsala BioCenter, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.
| | | | - Lars Högbom
- Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden.
| | - Roger D Finlay
- Uppsala BioCenter, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.
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94
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Li Y, Liu H, Zhu X, Yue Y, Xue J, Shi L. How permafrost degradation threatens boreal forest growth on its southern margin? Sci Total Environ 2021; 762:143154. [PMID: 33131839 DOI: 10.1016/j.scitotenv.2020.143154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
Boreal forests are adapted to cold climates and are thus especially sensitive and vulnerable to climate change. In this study, we chose 10 plots covering different topographies at the southern edge of a boreal forest. The annual ring widths of the 249 Dahurican larch (Larix gmelinii) tree cores from these plots were measured and used to calculate the basal area increment (BAI) and the interannual sensitivity (Sx). We found that forests in 10 plots showed a significant change in Sx consistently around 1980. The growth of slope forest was significantly correlated with increases in temperature and precipitation, while the wetland forests, including bogs and peatland plateaus, responded negatively to temperature. In terms of precipitation, there was no effect in the peatland plateaus, but a negative effect occurred in bogs. Our results imply that the depth of the frost table could lead to different soil waterlogging from surplus water from thawing permafrost, resulting in different responses of tree growth to climate change.
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Affiliation(s)
- Yunyun Li
- College of Urban and Environmental Science, MOE Laboratory for Earth Surface Processes, Peking University, Beijing 100871, China
| | - Hongyan Liu
- College of Urban and Environmental Science, MOE Laboratory for Earth Surface Processes, Peking University, Beijing 100871, China.
| | - Xinrong Zhu
- College of Urban and Environmental Science, MOE Laboratory for Earth Surface Processes, Peking University, Beijing 100871, China
| | - Yongyu Yue
- College of Urban and Environmental Science, MOE Laboratory for Earth Surface Processes, Peking University, Beijing 100871, China
| | - Jiaxin Xue
- College of Urban and Environmental Science, MOE Laboratory for Earth Surface Processes, Peking University, Beijing 100871, China
| | - Liang Shi
- College of Urban and Environmental Science, MOE Laboratory for Earth Surface Processes, Peking University, Beijing 100871, China
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95
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Wittische J, Heckbert S, James PMA, Burton AC, Fisher JT. Community-level modelling of boreal forest mammal distribution in an oil sands landscape. Sci Total Environ 2021; 755:142500. [PMID: 33049527 DOI: 10.1016/j.scitotenv.2020.142500] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 09/07/2020] [Accepted: 09/15/2020] [Indexed: 05/05/2023]
Abstract
Anthropogenic landscape disturbances are known to alter, destroy, and fragment habitat, which typically leads to biodiversity loss. The effects of landscape disturbance generally vary among species and depend on the nature of the disturbances, which may interact and result in synergistic effects. Western Canada's oil sands region experiences disturbances from forestry and energy sector activities as well as municipal and transportation infrastructure. The effects of those disturbances on single species have been studied and have been implicated in declines of the boreal woodland caribou (Rangifer tarandus caribou). Yet, the specific responses of the mammal community, and of functional groups such as prey and predators, to those interacting disturbances are still poorly known. We investigated the responses of black bear, grey wolf, coyote, fisher, lynx, red fox, American red squirrel, white-tailed deer, moose, caribou, and snowshoe hare to both natural habitat and disturbance associated with anthropogenic features within Alberta's northeast boreal forest. We used a novel community-level modelling framework on three years of camera-trap data collected in an oil sands landscape. This framework allowed us to identify the natural and anthropogenic features which explained the most variation in occurrence frequency among functional groups, as well as compare responses to linear and non-linear anthropogenic disturbance. Occurrence frequency by predators was better explained by anthropogenic features than by natural habitat. Both linear and non-linear anthropogenic features helped explain occurrence frequency by prey and predators, although the effects differed in magnitude and spatial scale. To better conserve boreal biodiversity, management actions should extend beyond a focus on caribou and wolves and aim to restore habitat across a diversity of anthropogenic disturbances and monitor the dynamics of the entire mammal community.
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Affiliation(s)
- Julian Wittische
- Département de Sciences Biologiques, Université de Montréal, Montréal, QC H3C 3J7, Canada.
| | - Scott Heckbert
- Department of Geography, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada; Alberta Energy Regulator, Calgary, AB T2P 0R4, Canada
| | - Patrick M A James
- Département de Sciences Biologiques, Université de Montréal, Montréal, QC H3C 3J7, Canada; Graduate Department of Forestry, John H. Daniels Faculty of Architecture, Landscape, and Design, University of Toronto, 33 Willcocks St., Toronto M5S 2J5, ON, Canada
| | - A Cole Burton
- Department of Forest Resources Management, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Biodiversity Research Centre, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Jason T Fisher
- School of Environmental Studies, University of Victoria, Victoria, BC V8W 2Y2, Canada
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96
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Hall D, Olsson J, Zhao W, Kroon J, Wennström U, Wang XR. Divergent patterns between phenotypic and genetic variation in Scots pine. Plant Commun 2021; 2:100139. [PMID: 33511348 PMCID: PMC7816077 DOI: 10.1016/j.xplc.2020.100139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 12/12/2020] [Accepted: 12/25/2020] [Indexed: 05/06/2023]
Abstract
In boreal forests, autumn frost tolerance in seedlings is a critical fitness component because it determines survival rates during regeneration. To understand the forces that drive local adaptation in this trait, we conducted freezing tests in a common garden setting for 54 Pinus sylvestris (Scots pine) populations (>5000 seedlings) collected across Scandinavia into western Russia, and genotyped 24 of these populations (>900 seedlings) at >10 000 SNPs. Variation in cold hardiness among populations, as measured by QST , was above 80% and followed a distinct cline along latitude and longitude, demonstrating significant adaptation to climate at origin. In contrast, the genetic differentiation was very weak (mean FST 0.37%). Despite even allele frequency distribution in the vast majority of SNPs among all populations, a few rare alleles appeared at very high or at fixation in marginal populations restricted to northwestern Fennoscandia. Genotype-environment associations showed that climate variables explained 2.9% of the genetic differentiation, while genotype-phenotype associations revealed a high marker-estimated heritability of frost hardiness of 0.56, but identified no major loci. Very extensive gene flow, strong local adaptation, and signals of complex demographic history across markers are interesting topics of forthcoming studies on this species to better clarify signatures of selection and demography.
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Affiliation(s)
- David Hall
- Department of Ecology and Environmental Science, Umeå Plant Science Center, Umeå University, Umeå, Sweden
| | - Jenny Olsson
- Department of Ecology and Environmental Science, Umeå Plant Science Center, Umeå University, Umeå, Sweden
| | - Wei Zhao
- Department of Ecology and Environmental Science, Umeå Plant Science Center, Umeå University, Umeå, Sweden
- Advanced Innovation Center for Tree Breeding by Molecular Design, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Johan Kroon
- The Forestry Research Institute of Sweden (Skogforsk), Uppsala Sweden
| | | | - Xiao-Ru Wang
- Department of Ecology and Environmental Science, Umeå Plant Science Center, Umeå University, Umeå, Sweden
- Advanced Innovation Center for Tree Breeding by Molecular Design, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- Corresponding author
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97
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Bermudez R, Stefanski A, Montgomery RA, Reich PB. Short- and long-term responses of photosynthetic capacity to temperature in four boreal tree species in a free-air warming and rainfall manipulation experiment. Tree Physiol 2021; 41:89-102. [PMID: 32864704 DOI: 10.1093/treephys/tpaa115] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/25/2020] [Indexed: 06/11/2023]
Abstract
High latitude forests cope with considerable variation in moisture and temperature at multiple temporal scales. To assess how their photosynthetic physiology responds to short- and long-term temperature variation, we measured photosynthetic capacity for four tree species growing in an open-air experiment in the boreal-temperate ecotone `Boreal Forest Warming at an Ecotone in Danger' (B4WarmED). The experiment factorially manipulated temperature above- and below-ground (ambient, +3.2 °C) and summer rainfall (ambient, 40% removal). We measured A/Ci curves at 18, 25 and 32 °C for individuals of two boreal (Pinus banksiana Lamb., Betula papyrifera Marsh.) and two temperate species (Pinus strobus L., Acer rubrum L.) experiencing the long-term warming and/or reduced-rainfall conditions induced by our experimental treatments. We calculated the apparent photosynthetic capacity descriptors VCmax,Ci and Jmax,Ci and their ratio for each measurement temperate. We hypothesized that (i) VCmax,Ci and Jmax,Ci would be down-regulated in plants experiencing longer term (e.g., weeks to months) warming and reduced rainfall (i.e., have lower values at a given measurement temperature), as is sometimes found in the literature, and that (ii) plants growing at warmer temperatures or from warmer ranges would show greater sensitivity (steeper slope) to short-term (minutes to hours) temperature variation. Neither hypothesis was supported as a general trend across the four species, as there was not a significant main effect (across species) of either warming or rainfall reduction on VCmax,Ci and Jmax,Ci. All species markedly increased VCmax,Ci and Jmax,Ci (and decreased their ratio) with short-term increases in temperature (i.e., contrasting values at 18, 25 and 32 °C), and those responses were independent of long-term treatments and did not differ among species. The Jmax,Ci:VCmax,Ci ratio was, however, significantly lower across species in warmed and reduced rainfall treatments. Collectively, these results suggest that boreal trees possess considerable short-term plasticity that may allow homeostasis of VCmax,Ci and Jmax,Ci to a longer term temperature treatment. Our results also caution against extrapolating results obtained under controlled and markedly contrasting temperature treatments to responses of photosynthetic parameters to more modest temperature changes expected in the near-term with climate warming in field conditions.
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Affiliation(s)
- Raimundo Bermudez
- Department of Forest Resources, University of Minnesota, St Paul, MN 55108, USA
| | - Artur Stefanski
- Department of Forest Resources, University of Minnesota, St Paul, MN 55108, USA
| | | | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St Paul, MN 55108, USA
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, Locked Bag 1797, Penrith, NSW 2753, Australia
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98
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Rice KE, Montgomery RA, Stefanski A, Rich RL, Reich PB. Species-specific flowering phenology responses to experimental warming and drought alter herbaceous plant species overlap in a temperate-boreal forest community. Ann Bot 2021; 127:203-211. [PMID: 32853366 PMCID: PMC7789104 DOI: 10.1093/aob/mcaa156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND AND AIMS Warmer temperatures and altered precipitation patterns are expected to continue to occur as the climate changes. How these changes will impact the flowering phenology of herbaceous perennials in northern forests is poorly understood but could have consequences for forest functioning and species interactions. Here, we examine the flowering phenology responses of five herbaceous perennials to experimental warming and reduced summer rainfall over 3 years. METHODS This study is part of the B4WarmED experiment located at two sites in northern Minnesota, USA. Three levels of warming (ambient, +1.6 °C and +3.1 °C) were crossed with two rainfall manipulations (ambient and 27 % reduced growing season rainfall). KEY RESULTS We observed species-specific responses to the experimental treatments. Warming alone advanced flowering for four species. Most notably, the two autumn blooming species showed the strongest advance of flowering to warming. Reduced rainfall alone advanced flowering for one autumn blooming species and delayed flowering for the other, with no significant impact on the three early blooming species. Only one species, Solidago spp., showed an interactive response to warming and rainfall manipulation by advancing in +1.6 °C warming (regardless of rainfall manipulation) but not advancing in the warmest, driest treatment. Species-specific responses led to changes in temporal overlap between species. Most notably, the two autumn blooming species diverged significantly in their flowering timing. In ambient conditions, these two species flowered within the same week. In the warmest, driest treatment, flowering occurred over a month apart. CONCLUSIONS Herbaceous species may differ in how they respond to future climate conditions. Changes to phenology may lead to fewer resources for insects or a mismatch between plants and pollinators.
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Affiliation(s)
- Karen E Rice
- University of Minnesota, Department of Forest Resources, St. Paul, MN USA
- University of Florida Extension Education, Fort Lauderdale, FL, USA
| | | | - Artur Stefanski
- University of Minnesota, Department of Forest Resources, St. Paul, MN USA
| | - Roy L Rich
- University of Minnesota, Department of Forest Resources, St. Paul, MN USA
- Smithsonian Environmental Research Center, Edgewater, MD, USA
| | - Peter B Reich
- University of Minnesota, Department of Forest Resources, St. Paul, MN USA
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
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99
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Anderson CG, Bond-Lamberty B, Stegen JC. Active layer depth and soil properties impact specific leaf area variation and ecosystem productivity in a boreal forest. PLoS One 2021; 15:e0232506. [PMID: 33382711 PMCID: PMC7775069 DOI: 10.1371/journal.pone.0232506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 11/09/2020] [Indexed: 11/25/2022] Open
Abstract
Specific leaf area (SLA, leaf area per unit dry mass) is a key canopy structural characteristic, a measure of photosynthetic capacity, and an important input into many terrestrial process models. Although many studies have examined SLA variation, relatively few data exist from high latitude, climate-sensitive permafrost regions. We measured SLA and soil and topographic properties across a boreal forest permafrost transition, in which dominant tree species changed as permafrost deepened from 54 to >150 cm over 75 m hillslope transects in Caribou-Poker Creeks Research Watershed, Alaska. We characterized both linear and threshold relationships between topographic and edaphic variables and SLA and developed a conceptual model of these relationships. We found that the depth of the soil active layer above permafrost was significantly and positively correlated with SLA for both coniferous and deciduous boreal tree species. Intraspecific SLA variation was associated with a fivefold increase in net primary production, suggesting that changes in active layer depth due to permafrost thaw could strongly influence ecosystem productivity. While this is an exploratory study to begin understanding SLA variation in a non-contiguous permafrost system, our results indicate the need for more extensive evaluation across larger spatial domains. These empirical relationships and associated uncertainty can be incorporated into ecosystem models that use dynamic traits, improving our ability to predict ecosystem-level carbon cycling responses to ongoing climate change.
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Affiliation(s)
- Carolyn G. Anderson
- Pacific Northwest National Laboratory, Richland, Washington, United States of America
- * E-mail:
| | - Ben Bond-Lamberty
- Pacific Northwest National Laboratory, Joint Global Change Research Institute, College Park, Maryland, United States of America
| | - James C. Stegen
- Pacific Northwest National Laboratory, Richland, Washington, United States of America
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100
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Kohl L, Myers-Pigg A, Edwards KA, Billings SA, Warren J, Podrebarac FA, Ziegler SE. Microbial inputs at the litter layer translate climate into altered organic matter properties. Glob Chang Biol 2021; 27:435-453. [PMID: 33112459 DOI: 10.1111/gcb.15420] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 08/31/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
Plant litter chemistry is altered during decomposition but it remains unknown if these alterations, and thus the composition of residual litter, will change in response to climate. Selective microbial mineralization of litter components and the accumulation of microbial necromass can drive litter compositional change, but the extent to which these mechanisms respond to climate remains poorly understood. We addressed this knowledge gap by studying needle litter decomposition along a boreal forest climate transect. Specifically, we investigated how the composition and/or metabolism of the decomposer community varies with climate, and if that variation is associated with distinct modifications of litter chemistry during decomposition. We analyzed the composition of microbial phospholipid fatty acids (PLFAs) in the litter layer and measured natural abundance δ13 CPLFA values as an integrated measure of microbial metabolisms. Changes in litter chemistry and δ13 C values were measured in litterbag experiments conducted at each transect site. A warmer climate was associated with higher litter nitrogen concentrations as well as altered microbial community structure (lower fungi:bacteria ratios) and microbial metabolism (higher δ13 CPLFA ). Litter in warmer transect regions accumulated less aliphatic-C (lipids, waxes) and retained more O-alkyl-C (carbohydrates), consistent with enhanced 13 C-enrichment in residual litter, than in colder regions. These results suggest that chemical changes during litter decomposition will change with climate, driven primarily by indirect climate effects (e.g., greater nitrogen availability and decreased fungi:bacteria ratios) rather than direct temperature effects. A positive correlation between microbial biomass δ13 C values and 13 C-enrichment during decomposition suggests that change in litter chemistry is driven more by distinct microbial necromass inputs than differences in the selective removal of litter components. Our study highlights the role that microbial inputs during early litter decomposition can play in shaping surface litter contribution to soil organic matter as it responds to climate warming effects such as greater nitrogen availability.
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Affiliation(s)
- Lukas Kohl
- Department of Earth Sciences, Memorial University, St. John's, NL, Canada
- Department of Agricultural Sciences, Helsinki University, Helsinki, Finland
- Institute for Atmospheric and Earth System Research/Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, Helsinki, Finland
| | - Allison Myers-Pigg
- Department of Earth Sciences, Memorial University, St. John's, NL, Canada
| | - Kate A Edwards
- Natural Resources Canada, Canadian Forest Service, Atlantic Forestry Centre, Corner Brook, NL, Canada
| | - Sharon A Billings
- Department of Ecology and Evolutionary Biology, Kansas Biological Survey, University of Kansas, Lawrence, KS, USA
| | - Jamie Warren
- Department of Earth Sciences, Memorial University, St. John's, NL, Canada
| | | | - Susan E Ziegler
- Department of Earth Sciences, Memorial University, St. John's, NL, Canada
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