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Jiménez-Alfaro B, Aunina L, Carbognani M, Dítě D, Fernández-Pascual E, Garbolino E, Hájek O, Hájková P, Ivchenko TG, Jandt U, Jansen F, Kolari THM, Pawlikowski P, Pérez-Haase A, Peterka T, Petraglia A, Plesková Z, Tahvanainen T, Tomaselli M, Hájek M. Habitat-based biodiversity responses to macroclimate and edaphic factors in European fen ecosystems. GLOBAL CHANGE BIOLOGY 2023; 29:6756-6771. [PMID: 37818677 DOI: 10.1111/gcb.16965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 07/30/2023] [Accepted: 09/12/2023] [Indexed: 10/12/2023]
Abstract
Understanding large-scale drivers of biodiversity in palustrine wetlands is challenging due to the combined effects of macroclimate and local edaphic conditions. In boreal and temperate fen ecosystems, the influence of macroclimate on biodiversity is modulated by hydrological settings across habitats, making it difficult to assess their vulnerability to climate change. Here, we investigate the influence of macroclimate and edaphic factors on three Essential Biodiversity Variables across eight ecologically defined habitats that align with ecosystem classifications and red lists. We used 27,555 vegetation plot samples from European fens to assess the influence of macroclimate and groundwater pH predictors on the geographic distribution of each habitat type. Additionally, we modeled the relative influence of macroclimate, water pH, and water table depth on community species richness and composition, focusing on 309 plant specialists. Our models reveal strong effects of mean annual temperature, diurnal thermal range, and summer temperature on biodiversity variables, with contrasting differences among habitats. While macroclimatic factors primarily shape geographic distributions and species richness, edaphic factors emerge as the primary drivers of composition for vascular plants and bryophytes. Annual precipitation exhibits non-linear effects on fen biodiversity, with varying impact across habitats with different hydrological characteristics, suggesting a minimum requirement of 600 mm of annual precipitation for the occurrence of fen ecosystems. Our results anticipate potential impacts of climate warming on European fens, with predictable changes among habitat types and geographic regions. Moreover, we provide evidence that the drivers of biodiversity in boreal and temperate fens are closely tied to the ecological characteristics of each habitat type and the dispersal abilities of bryophytes and vascular plants. Given that the influence of macroclimate and edaphic factors on fen ecosystems is habitat specific, climate change research and conservation actions should consider ecological differentiation within functional IUCN ecosystems at continental and regional scales.
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Affiliation(s)
- Borja Jiménez-Alfaro
- Biodiversity Research Institute, IMIB (Univ.Oviedo-CSIC-Princ.Asturias), Mieres, Spain
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Liene Aunina
- Institute of Biology of University of Latvia, Riga, Latvia
| | - Michele Carbognani
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Daniel Dítě
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Bratislava, Slovakia
| | | | - Emmanuel Garbolino
- Climpact Data Science, Nova Sophia-Regus Nova, Sophia Antipolis Cedex, France
| | - Ondřej Hájek
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Petra Hájková
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic
- Department of Paleoecology, Institute of Botany, The Czech Academy of Sciences, Brno, Czech Republic
| | - Tatiana G Ivchenko
- Laboratory of General Geobotany, Komarov Botanical Institute, Russian Academy of Sciences, St. Petersburg, Russia
- Group of Ecology of Living Organisms, Tobolsk Complex Scientific Station, Ural Branch of the Russian Academy of Sciences, Tobolsk, Russia
| | - Ute Jandt
- Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | - Florian Jansen
- Faculty of Agricultural- and Environmental Sciences, University of Rostock, Rostock, Germany
| | - Tiina H M Kolari
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Paweł Pawlikowski
- Department of Ecology and Environmental Conservation, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Aaron Pérez-Haase
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain
| | - Tomáš Peterka
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Alessandro Petraglia
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Zuzana Plesková
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Teemu Tahvanainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Marcello Tomaselli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Michal Hájek
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic
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New and Noteworthy Taxa of the Genus Dactylorhiza Necker ex Nevski (Orchidaceae Juss.) in Kazakhstan Flora and Its Response to Global Warming. DIVERSITY 2023. [DOI: 10.3390/d15030369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
A critical study of the herbarium material representing the orchid genus Dactylorhiza Necker ex Nevski in Kazakhstan was conducted in 2019–2020. The information on the species composition was clarified. Dactylorhiza fuchsii subsp. hebridensis (Wilmott) Soó and D. × kerneri (Soó) Soó were identified for the first time in the country. New taxa were noted for individual botanical and geographical areas. All taxa were presented in the list and annotated with studied herbarium materials from the Kazakhstan area. Based on the collected and available locations for the studied taxa, distribution modeling was carried out for the four taxa (D. incarnata, D. majalis subsp. baltica, D. salina, and D. umbrosa). Bioclimatic data for the present and future (2041–2060) based on four possible scenarios were used. The occurrence of Dactylorhiza representatives in Kazakhstan is threatened by global climate warming. It is likely that some of them may not occur in the country in the future (D. incarnata and D. majalis subsp. baltica), losing up to 99.87% of their modern range or their range may be significantly reduced (D. salina and D. umbrosa), losing up to 80.83% of their present distribution. It is worth considering global changes in planning conservation activities and identifying areas that may play a significant role in the functioning of the national flora in the future.
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Bhuiyan R, Mäkiranta P, Straková P, Fritze H, Minkkinen K, Penttilä T, Rajala T, Tuittila ES, Laiho R. Fine-root biomass production and its contribution to organic matter accumulation in sedge fens under changing climate. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:159683. [PMID: 36336060 DOI: 10.1016/j.scitotenv.2022.159683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 10/20/2022] [Accepted: 10/20/2022] [Indexed: 06/16/2023]
Abstract
Climate change may affect the carbon sink function of peatlands through warming and drying. Fine-root biomass production (FRBP) of sedge fens, a widespread peatland habitat, is important in this context, since most of the biomass is below ground in these ecosystems. We examined the response of fine-root biomass production, depth distribution (10 cm intervals down to 60 cm), chemical characteristics, and decomposition along with other main litter types (sedge leaves, Sphagnum moss shoots) to an average May-to-October warming of 1.7 °C above ambient daily mean temperature and drying of 2-8 cm below ambient soil water-table level (WL) in two sedge fens situated in Northern and Southern Boreal zones. Warming was induced with open top chambers and drying with shallow ditching. Finally, we simulated short-term organic matter (OM) accumulation using net primary production and mass loss data. Total FRBP, and FRBP in deeper layers, was clearly higher in southern than northern fen. Drying significantly increased, and warming marginally increased, total FRBP, while warming significantly increased, and drying marginally increased, the proportional share of FRBP in deeper layers. Drying, especially, modified root chemistry as the relative proportions of fats, wax, lipids, lignin and other aromatics increased while the proportion of polysaccharides decreased. Warming did not affect the decomposition of any litter types, while drying reduced the decomposition of sedge leaf litter. Although drying increased OM accumulation from root litter at both fens, total OM accumulation decreased at the southern fen, while the northern fen with overall lower values showed no such pattern. Our results suggest that in warmer and/or modestly drier conditions, sedge fen FRBP will increase and/or be allocated to deeper soil layers. These changes along with the altered litter inputs may sustain the soil carbon sink function through OM accumulation, unless the WL falls below a tipping point.
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Affiliation(s)
- Rabbil Bhuiyan
- Natural Resources Institute Finland (Luke), Box 2 (Latokartanonkaari 9), FI-00791 Helsinki, Finland; Department of Forest Sciences, University of Helsinki, Box 27 (Latokartanonkaari 7), FI-00014 Helsinki University, Finland.
| | - Päivi Mäkiranta
- Natural Resources Institute Finland (Luke), Box 2 (Latokartanonkaari 9), FI-00791 Helsinki, Finland.
| | - Petra Straková
- Natural Resources Institute Finland (Luke), Box 2 (Latokartanonkaari 9), FI-00791 Helsinki, Finland; Department of Forest Sciences, University of Helsinki, Box 27 (Latokartanonkaari 7), FI-00014 Helsinki University, Finland.
| | - Hannu Fritze
- Natural Resources Institute Finland (Luke), Box 2 (Latokartanonkaari 9), FI-00791 Helsinki, Finland.
| | - Kari Minkkinen
- Department of Forest Sciences, University of Helsinki, Box 27 (Latokartanonkaari 7), FI-00014 Helsinki University, Finland.
| | - Timo Penttilä
- Natural Resources Institute Finland (Luke), Box 2 (Latokartanonkaari 9), FI-00791 Helsinki, Finland.
| | - Tuomas Rajala
- Natural Resources Institute Finland (Luke), Box 2 (Latokartanonkaari 9), FI-00791 Helsinki, Finland.
| | - Eeva-Stiina Tuittila
- Peatland and Soil Ecology Group, School of Forest Sciences, University of Eastern Finland, Box 111 (Yliopistokatu 7), FI-80101 Joensuu, Finland.
| | - Raija Laiho
- Natural Resources Institute Finland (Luke), Box 2 (Latokartanonkaari 9), FI-00791 Helsinki, Finland.
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Antala M, Juszczak R, van der Tol C, Rastogi A. Impact of climate change-induced alterations in peatland vegetation phenology and composition on carbon balance. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 827:154294. [PMID: 35247401 DOI: 10.1016/j.scitotenv.2022.154294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/03/2022] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
Global climate is changing faster than humankind has ever experienced. Model-based predictions of future climate are becoming more complex and precise, but they still lack crucial information about the reaction of some important ecosystems, such as peatlands. Peatlands belong to one of the largest carbon stores on the Earth. They are mostly distributed in high latitudes, where the temperature rises faster than in the other parts of the planet. Warmer climate and changes in precipitation patterns cause changes in the composition and phenology of peatland vegetation. Peat mosses are becoming less abundant, vascular plants cover is increasing, and the vegetation season and phenophases of vascular plants start sooner. The alterations in vegetation cause changes in the carbon assimilation and release of greenhouse gases. Therefore, this article reviews the impact of climate change-induced alterations in peatland vegetation phenology and composition on future climate and the uncertainties that need to be addressed for more accurate climate prediction.
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Affiliation(s)
- Michal Antala
- Laboratory of Bioclimatology, Department of Ecology and Environmental Protection, Faculty of Environmental Engineering and Mechanical Engineering, Poznan University of Life Sciences, Piątkowska 94, 60-649 Poznań, Poland
| | - Radoslaw Juszczak
- Laboratory of Bioclimatology, Department of Ecology and Environmental Protection, Faculty of Environmental Engineering and Mechanical Engineering, Poznan University of Life Sciences, Piątkowska 94, 60-649 Poznań, Poland
| | - Christiaan van der Tol
- Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, 7500 AE Enschede, the Netherlands
| | - Anshu Rastogi
- Laboratory of Bioclimatology, Department of Ecology and Environmental Protection, Faculty of Environmental Engineering and Mechanical Engineering, Poznan University of Life Sciences, Piątkowska 94, 60-649 Poznań, Poland; Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, 7500 AE Enschede, the Netherlands.
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Kokkonen N, Laine AM, Männistö E, Mehtätalo L, Korrensalo A, Tuittila ES. Two Mechanisms Drive Changes in Boreal Peatland Photosynthesis Following Long-Term Water Level Drawdown: Species Turnover and Altered Photosynthetic Capacity. Ecosystems 2022. [DOI: 10.1007/s10021-021-00736-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractClimate change and the related increases in evapotranspiration threaten to make northern peatlands drier. The carbon sink function in peatlands is based on the delicate balance between the photosynthesis and decomposition. However, little is known about how existing and invading plant species will photosynthesize under drier conditions. The aim of this study is to quantify the long-term consequences of climate change-induced drying for peatland photosynthesis in the level of individual species and vegetation community. We measured the species-level photosynthesis of vascular plants and mosses characteristic for the three peatland types (rich fen, poor fen, bog) within a 16-year water level drawdown (WLD) experiment. Measurements were made in the laboratory from mesocosms collected from the field within the same day. We applied nonlinear mixed-effects models to test the impact of WLD on hyperbolic photosynthetic light response curve parameters. The model was then used to upscale photosynthesis to site-level. WLD impacted site-level photosynthesis through two mechanisms: species turnover and changes in species-level photosynthesis rate. The rich fen was the most sensitive and underwent major changes through both mechanisms; the vascular plant community shifted to woody plant dominance with higher rate of photosynthesis than the pre-treatment vegetation, and the rate of species-level photosynthesis increased significantly. The bog had a stable plant community with little change in photosynthesis, while the poor fen was an intermediate of the three peatland types. Our results suggest that vascular plants are the main drivers of site-level productivity changes, while mosses are more resistant to change. The change seems proportional to the availability of mineral nutrients, with higher nutrient status supporting vascular plant expansion.
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Sun B, Jiang M, Han G, Zhang L, Zhou J, Bian C, Du Y, Yan L, Xia J. Experimental warming reduces ecosystem resistance and resilience to severe flooding in a wetland. SCIENCE ADVANCES 2022; 8:eabl9526. [PMID: 35080980 PMCID: PMC8791607 DOI: 10.1126/sciadv.abl9526] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Climate warming and extreme hydrological events are threatening the sustainability of wetlands across the globe. However, whether climate warming will amplify or diminish the impact of extreme flooding on wetland ecosystems is unknown. Here, we show that climate warming significantly reduced wetland resistance and resilience to a severe flooding event via a 6-year warming experiment. We first found that warming rapidly altered plant community structure by increasing the dominance of low-canopy species. Then, we showed that warming reduced the resistance and resilience of vegetation productivity to a 72-cm flooding event. Last, we detected slower postflooding carbon processes, such as gross ecosystem productivity, soil respiration, and soil methane emission, under the warming treatment. Our results demonstrate how severe flooding can destabilize wetland vegetation structure and ecosystem function under climate warming. These findings indicate an enhanced footprint of extreme hydrological events in wetland ecosystems in a warmer climate.
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Affiliation(s)
- Baoyu Sun
- State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200000, China
- Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264000, China
| | - Ming Jiang
- State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200000, China
| | - Guangxuan Han
- Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264000, China
- University of Chinese Academy of Sciences, Beijing 100000, China
| | - Liwen Zhang
- Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264000, China
- University of Chinese Academy of Sciences, Beijing 100000, China
| | - Jian Zhou
- State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200000, China
- Research Center for Global Change and Complex Ecosystems, East China Normal University, Shanghai 200000, China
| | - Chenyu Bian
- State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200000, China
- Research Center for Global Change and Complex Ecosystems, East China Normal University, Shanghai 200000, China
| | - Ying Du
- State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200000, China
- Research Center for Global Change and Complex Ecosystems, East China Normal University, Shanghai 200000, China
| | - Liming Yan
- State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200000, China
- Research Center for Global Change and Complex Ecosystems, East China Normal University, Shanghai 200000, China
| | - Jianyang Xia
- State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200000, China
- Research Center for Global Change and Complex Ecosystems, East China Normal University, Shanghai 200000, China
- Corresponding author.
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Lindborg R, Ermold M, Kuglerová L, Jansson R, Larson KW, Milbau A, Cousins SAO. How does a wetland plant respond to increasing temperature along a latitudinal gradient? Ecol Evol 2021; 11:16228-16238. [PMID: 34824823 PMCID: PMC8601882 DOI: 10.1002/ece3.8303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 10/01/2021] [Accepted: 10/13/2021] [Indexed: 11/16/2022] Open
Abstract
Global warming affects plant fitness through changes in functional traits and thereby ecosystem function. Wetlands are declining worldwide, and hence, ecosystem functions linked to wetlands are threatened. We use Caltha palustris "a common wetland plant" to study whether warming affects growth and reproduction differently depending on origin of source population, potentially affecting phenotypic response to local climate. We conducted a 2-year in situ temperature manipulation experiment using clone pairs of C. palustris in four regions, along a 1300-km latitudinal gradient of Sweden. Open-top chambers were used to passively increase temperature, paired with controls. Growth and reproductive traits were measured from 320 plants (four regions × five sites × two treatments × eight plants) over two consecutive seasons to assess the effect of warming over time. We found that warming increased plant height, leaf area, number of leaves, and roots. High-latitude populations responded more strongly to warming than low-latitude populations, especially by increasing leaf area. Warming increased number of flowers in general, but only in the second year, while number of fruits increased in low-latitude populations the first year. Prolonged warming leads to an increase in both number of leaves and flowers over time. While reproduction shows varying and regional responses to warming, impacts on plant growth, especially in high-latitude populations, have more profound effects. Such effects could lead to changes in plant community composition with increased abundance of fast-growing plants with larger leaves and more clones, affecting plant competition and ecological functions such as decomposition and nutrient retention. Effects of warming were highly context dependent; thus, we encourage further use of warming experiments to predict changes in growth, reproduction, and community composition across wetland types and climate gradients targeting different plant forms.
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Affiliation(s)
- Regina Lindborg
- Landscape, Environment and GeomaticsDepartment of Physical GeographyStockholm UniversityStockholmSweden
- Bolin Centre for Climate ResearchStockholm UniversityStockholmSweden
| | - Matti Ermold
- Landscape, Environment and GeomaticsDepartment of Physical GeographyStockholm UniversityStockholmSweden
| | - Lenka Kuglerová
- Department of Forest Ecology and ManagementSwedish University of Agricultural SciencesUmeåSweden
| | - Roland Jansson
- Department of Ecology and Environmental ScienceUmeå UniversityUmeåSweden
| | - Keith W. Larson
- Climate Impacts Research CentreDepartment of Ecology and Environmental ScienceUmeå UniversityUmeåSweden
| | - Ann Milbau
- Province of AntwerpDepartment of Sustainable Environment and Nature PolicyAntwerpBelgium
| | - Sara A. O. Cousins
- Landscape, Environment and GeomaticsDepartment of Physical GeographyStockholm UniversityStockholmSweden
- Bolin Centre for Climate ResearchStockholm UniversityStockholmSweden
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Integrating Decomposers, Methane-Cycling Microbes and Ecosystem Carbon Fluxes Along a Peatland Successional Gradient in a Land Uplift Region. Ecosystems 2021. [DOI: 10.1007/s10021-021-00713-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AbstractPeatlands are carbon dioxide (CO2) sinks that, in parallel, release methane (CH4). The peatland carbon (C) balance depends on the interplay of decomposer and CH4-cycling microbes, vegetation, and environmental conditions. These interactions are susceptible to the changes that occur along a successional gradient from vascular plant-dominated systems to Sphagnum moss-dominated systems. Changes similar to this succession are predicted to occur from climate change. Here, we investigated how microbial and plant communities are interlinked with each other and with ecosystem C cycling along a successional gradient on a boreal land uplift coast. The gradient ranged from shoreline to meadows and fens, and further to bogs. Potential microbial activity (aerobic CO2 production; CH4 production and oxidation) and biomass were greatest in the early successional meadows, although their communities of aerobic decomposers (fungi, actinobacteria), methanogens, and methanotrophs did not differ from the older fens. Instead, the functional microbial communities shifted at the fen–bog transition concurrent with a sudden decrease in C fluxes. The successional patterns of decomposer versus CH4-cycling communities diverged at the bog stage, indicating strong but distinct microbial responses to Sphagnum dominance and acidity. We highlight young meadows as dynamic sites with the greatest microbial potential for C release. These hot spots of C turnover with dense sedge cover may represent a sensitive bottleneck in succession, which is necessary for eventual long-term peat accumulation. The distinctive microbes in bogs could serve as indicators of the C sink function in restoration measures that aim to stabilize the C in the peat.
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Salimi S, Berggren M, Scholz M. Response of the peatland carbon dioxide sink function to future climate change scenarios and water level management. GLOBAL CHANGE BIOLOGY 2021; 27:5154-5168. [PMID: 34157201 DOI: 10.1111/gcb.15753] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 06/09/2021] [Indexed: 06/13/2023]
Abstract
Stress factors such as climate change and drought may switch the role of temperate peatlands from carbon dioxide (CO2 ) sinks to sources, leading to positive feedback to global climate change. Water level management has been regarded as an important climate change mitigation strategy as it can sustain the natural net CO2 sink function of a peatland. Little is known about how resilient peatlands are in the face of future climate change scenarios, as well as how effectively water level management can sustain the CO2 sink function to mitigate global warming. The authors assess the effect of climate change on CO2 exchange of south Swedish temperate peatlands, which were either unmanaged or subject to water level regulation. Climate chamber simulations were conducted using experimental peatland mesocosms exposed to current and future representative concentration pathway (RCP) climate scenarios (RCP 2.6, 4.5 and 8.5). The results showed that all managed and unmanaged systems under future climate scenarios could serve as CO2 sinks throughout the experimental period. However, the 2018 extreme drought caused the unmanaged mesocosms under the RCP 4.5 and RCP 8.5 switch from a net CO2 sink to a source during summer. Surprisingly, the unmanaged mesocosms under RCP 2.6 benefited from the warmer climate, and served as the best sink among the other unmanaged systems. Water level management had the greatest effect on the CO2 sink function under RCP 8.5 and RCP 4.5, which improved their CO2 sink capability up to six and two times, respectively. Under the current climate scenario, water level management had a negative effect on the CO2 sink function, and it had almost no effect under RCP 2.6. Therefore, the researchers conclude that water level management is necessary for RCP 8.5, beneficial for RCP 4.5 and unimportant for RCP 2.6 and the current climate.
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Affiliation(s)
- Shokoufeh Salimi
- Division of Water Resources Engineering, Faculty of Engineering, Lund University, Lund, Sweden
| | - Martin Berggren
- Department of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden
| | - Miklas Scholz
- Division of Water Resources Engineering, Faculty of Engineering, Lund University, Lund, Sweden
- Department of Civil Engineering Science, School of Civil Engineering and the Built Environment, University of Johannesburg, Johannesburg, South Africa
- Department of Town Planning, Engineering Networks and Systems, South Ural State University (National Research University), Chelyabinsk, The Russian Federation
- Institute of Environmental Engineering, Wroclaw University of Environmental and Life Sciences, Wrocław, Poland
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10
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Bera BK, Tzuk O, Bennett JJR, Meron E. Linking spatial self-organization to community assembly and biodiversity. eLife 2021; 10:e73819. [PMID: 34570698 PMCID: PMC8497052 DOI: 10.7554/elife.73819] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 09/19/2021] [Indexed: 11/29/2022] Open
Abstract
Temporal shifts to drier climates impose environmental stresses on plant communities that may result in community reassembly and threatened ecosystem services, but also may trigger self-organization in spatial patterns of biota and resources, which act to relax these stresses. The complex relationships between these counteracting processes - community reassembly and spatial self-organization - have hardly been studied. Using a spatio-temporal model of dryland plant communities and a trait-based approach, we study the response of such communities to increasing water-deficit stress. We first show that spatial patterning acts to reverse shifts from fast-growing species to stress-tolerant species, as well as to reverse functional-diversity loss. We then show that spatial self-organization buffers the impact of further stress on community structure. Finally, we identify multistability ranges of uniform and patterned community states and use them to propose forms of non-uniform ecosystem management that integrate the need for provisioning ecosystem services with the need to preserve community structure.
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Affiliation(s)
- Bidesh K Bera
- Department of Solar Energy and Environmental Physics, BIDR, Ben-Gurion University of the NegevSede Boqer CampusIsrael
| | - Omer Tzuk
- Physics Department, Ben-Gurion University of the NegevBeer ShevaIsrael
| | - Jamie JR Bennett
- Department of Solar Energy and Environmental Physics, BIDR, Ben-Gurion University of the NegevSede Boqer CampusIsrael
| | - Ehud Meron
- Department of Solar Energy and Environmental Physics, BIDR, Ben-Gurion University of the NegevSede Boqer CampusIsrael
- Physics Department, Ben-Gurion University of the NegevBeer ShevaIsrael
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11
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Salimi S, Almuktar SAAAN, Scholz M. Impact of climate change on wetland ecosystems: A critical review of experimental wetlands. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 286:112160. [PMID: 33611067 DOI: 10.1016/j.jenvman.2021.112160] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 01/20/2021] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
Climate change is identified as a major threat to wetlands. Altered hydrology and rising temperature can change the biogeochemistry and function of a wetland to the degree that some important services might be turned into disservices. This means that they will, for example, no longer provide a water purification service and adversely they may start to decompose and release nutrients to the surface water. Moreover, a higher rate of decomposition than primary production (photosynthesis) may lead to a shift of their function from being a sink of carbon to a source. This review paper assesses the potential response of natural wetlands (peatlands) and constructed wetlands to climate change in terms of gas emission and nutrients release. In addition, the impact of key climatic factors such as temperature and water availability on wetlands has been reviewed. The authors identified the methodological gaps and weaknesses in the literature and then introduced a new framework for conducting a comprehensive mesocosm experiment to address the existing gaps in literature to support future climate change research on wetland ecosystems. In the future, higher temperatures resulting in drought might shift the role of both constructed wetland and peatland from a sink to a source of carbon. However, higher temperatures accompanied by more precipitation can promote photosynthesis to a degree that might exceed the respiration and maintain the carbon sink role of the wetland. There might be a critical water level at which the wetland can preserve most of its services. In order to find that level, a study of the key factors of climate change and their interactions using an appropriate experimental method is necessary. Some contradictory results of past experiments can be associated with different methodologies, designs, time periods, climates, and natural variability. Hence a long-term simulation of climate change for wetlands according to the proposed framework is recommended. This framework provides relatively more accurate and realistic simulations, valid comparative results, comprehensive understanding and supports coordination between researchers. This can help to find a sustainable management strategy for wetlands to be resilient to climate change.
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Affiliation(s)
- Shokoufeh Salimi
- Division of Water Resources Engineering, Faculty of Engineering, Lund University, P.O. Box 118, 221 00, Lund, Sweden.
| | - Suhad A A A N Almuktar
- Division of Water Resources Engineering, Faculty of Engineering, Lund University, P.O. Box 118, 221 00, Lund, Sweden; Department of Architectural Engineering, Faculty of Engineering, The University of Basrah, Al Basrah, Iraq.
| | - Miklas Scholz
- Division of Water Resources Engineering, Faculty of Engineering, Lund University, P.O. Box 118, 221 00, Lund, Sweden; Department of Civil Engineering Science, School of Civil Engineering and the Built Environment, University of Johannesburg, Kingsway Campus, PO Box 524, Aukland Park 2006, Johannesburg, South Africa; Department of Town Planning, Engineering Networks and Systems, South Ural State University (National Research University), 76, Lenin prospekt, Chelyabinsk, 454080, Russian Federation.
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12
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Warren JM, Jensen AM, Ward EJ, Guha A, Childs J, Wullschleger SD, Hanson PJ. Divergent species-specific impacts of whole ecosystem warming and elevated CO 2 on vegetation water relations in an ombrotrophic peatland. GLOBAL CHANGE BIOLOGY 2021; 27:1820-1835. [PMID: 33528056 DOI: 10.1111/gcb.15543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 01/08/2021] [Accepted: 01/11/2021] [Indexed: 06/12/2023]
Abstract
Boreal peatland forests have relatively low species diversity and thus impacts of climate change on one or more dominant species could shift ecosystem function. Despite abundant soil water availability, shallowly rooted vascular plants within peatlands may not be able to meet foliar demand for water under drought or heat events that increase vapor pressure deficits while reducing near surface water availability, although concurrent increases in atmospheric CO2 could buffer resultant hydraulic stress. We assessed plant water relations of co-occurring shrub (primarily Rhododendron groenlandicum and Chamaedaphne calyculata) and tree (Picea mariana and Larix laricina) species prior to, and in response to whole ecosystem warming (0 to +9°C) and elevated CO2 using 12.8-m diameter open-top enclosures installed within an ombrotrophic bog. Water relations (water potential [Ψ], turgor loss point, foliar and root hydraulic conductivity) were assessed prior to treatment initiation, then Ψ and peak sap flow (trees only) assessed after 1 or 2 years of treatments. Under the higher temperature treatments, L. laricina Ψ exceeded its turgor loss point, increased its peak sap flow, and was not able to recover Ψ overnight. In contrast, P. mariana operated below its turgor loss point and maintained constant Ψ and sap flow across warming treatments. Similarly, C. calyculata Ψ stress increased with temperature while R. groenlandicum Ψ remained at pretreatment levels. The more anisohydric behavior of L. laricina and C. calyculata may provide greater net C uptake with warming, while the more conservative P. mariana and R. groenlandicum maintained greater hydraulic safety. These latter species also responded to elevated CO2 by reduced Ψ stress, which may also help limit hydraulic failure during periods of extreme drought or heat in the future. Along with Sphagnum moss, the species-specific responses of peatland vascular communities to drier or hotter conditions will shape boreal peatland composition and function in the future.
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Affiliation(s)
- Jeffrey M Warren
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Anna M Jensen
- Department of Forestry and Wood Technology, Linnaeus University, Växjö, Sweden
| | - Eric J Ward
- U.S. Geological Survey, Wetland and Aquatic Research Center, Lafayette, LA, USA
| | - Anirban Guha
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Joanne Childs
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Stan D Wullschleger
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Paul J Hanson
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, USA
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13
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Purre A, Ilomets M, Truus L, Pajula R, Sepp K. The effect of different treatments of moss layer transfer technique on plant functional types' biomass in revegetated milled peatlands. Restor Ecol 2020. [DOI: 10.1111/rec.13246] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anna‐Helena Purre
- School of Natural Science and Health Tallinn University Narva Road 29 Tallinn 10120 Estonia
| | - Mati Ilomets
- Institute of Ecology Tallinn University Uus‐Sadama 5 Tallinn 10120 Estonia
| | - Laimdota Truus
- Institute of Ecology Tallinn University Uus‐Sadama 5 Tallinn 10120 Estonia
| | - Raimo Pajula
- Institute of Ecology Tallinn University Uus‐Sadama 5 Tallinn 10120 Estonia
| | - Kairi Sepp
- School of Natural Science and Health Tallinn University Narva Road 29 Tallinn 10120 Estonia
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14
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Malhotra A, Brice DJ, Childs J, Graham JD, Hobbie EA, Vander Stel H, Feron SC, Hanson PJ, Iversen CM. Peatland warming strongly increases fine-root growth. Proc Natl Acad Sci U S A 2020; 117:17627-17634. [PMID: 32661144 PMCID: PMC7395547 DOI: 10.1073/pnas.2003361117] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Belowground climate change responses remain a key unknown in the Earth system. Plant fine-root response is especially important to understand because fine roots respond quickly to environmental change, are responsible for nutrient and water uptake, and influence carbon cycling. However, fine-root responses to climate change are poorly constrained, especially in northern peatlands, which contain up to two-thirds of the world's soil carbon. We present fine-root responses to warming between +2 °C and 9 °C above ambient conditions in a whole-ecosystem peatland experiment. Warming strongly increased fine-root growth by over an order of magnitude in the warmest treatment, with stronger responses in shrubs than in trees or graminoids. In the first year of treatment, the control (+0 °C) shrub fine-root growth of 0.9 km m-2 y-1 increased linearly by 1.2 km m-2 y-1 (130%) for every degree increase in soil temperature. An extended belowground growing season accounted for 20% of this dramatic increase. In the second growing season of treatment, the shrub warming response rate increased to 2.54 km m-2 °C-1 Soil moisture was negatively correlated with fine-root growth, highlighting that drying of these typically water-saturated ecosystems can fuel a surprising burst in shrub belowground productivity, one possible mechanism explaining the "shrubification" of northern peatlands in response to global change. This previously unrecognized mechanism sheds light on how peatland fine-root response to warming and drying could be strong and rapid, with consequences for the belowground growing season duration, microtopography, vegetation composition, and ultimately, carbon function of these globally relevant carbon sinks.
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Affiliation(s)
- Avni Malhotra
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830;
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | - Deanne J Brice
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | - Joanne Childs
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | - Jake D Graham
- Department of Geosciences, Boise State University, Boise, ID 83725
| | - Erik A Hobbie
- Earth Systems Research Center, University of New Hampshire, Durham, NH 03824
| | - Holly Vander Stel
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Kellogg Biological Station, Michigan State University, Hickory Corners, MI 49060
| | - Sarah C Feron
- Department of Physics, Universidad de Santiago de Chile, Santiago, 9170022, Chile
- School of Earth, Energy and Environmental Sciences, Department of Earth System Science, Stanford University, Stanford, CA 94305
| | - Paul J Hanson
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | - Colleen M Iversen
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830
- Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37830
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15
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Haynes KM, Kane ES, Potvin L, Lilleskov EA, Kolka RK, Mitchell CPJ. Impacts of experimental alteration of water table regime and vascular plant community composition on peat mercury profiles and methylmercury production. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 682:611-622. [PMID: 31129544 DOI: 10.1016/j.scitotenv.2019.05.072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/22/2019] [Accepted: 05/06/2019] [Indexed: 06/09/2023]
Abstract
Climate change is expected to alter the hydrology and vascular plant communities in peatland ecosystems. These changes may have as yet unexplored impacts on peat mercury (Hg) concentrations and net methylmercury (MeHg) production. In this study, peat was collected from PEATcosm, an outdoor, controlled mesocosm experiment where peatland water table regimes and vascular plant functional groups were manipulated over several years to simulate potential climate change effects. Potential Hg(II) methylation and MeHg demethylation rate constants were assessed using enriched stable isotope incubations at the end of the study in 2015, and ambient peat total Hg (THg) and MeHg concentration depth profiles were tracked annually from 2011 to 2014. Peat THg and MeHg concentrations and the proportion of THg methylated (%MeHg) increased significantly within the zone of water table fluctuation when water tables were lowered, but potential Hg(II) methylation rate constants were similar regardless of water table treatment. When sedges dominate over ericaceous shrubs, MeHg concentrations and %MeHg became significantly elevated within the sedge rooting zone. Increased desorption of Hg(II) and MeHg from the solid phase peat into pore water occurred with a lowered water table and predominant sedge cover, likely due to greater aerobic peat decomposition. Deeper, more variable water tables and a transition to sedge-dominated communities coincided with increased MeHg accumulation within the zone of water table fluctuation. Sustained high water tables promoted the net downward migration of Hg(II) and MeHg. The simultaneous decrease in Hg(II) and MeHg concentrations in the near-surface peat and accumulation deeper in the peat profile, combined with the trends in Hg(II) and MeHg partitioning to mobile pore waters, suggest that changes to peatland hydrology and vascular plant functional groups redistribute peat Hg(II) and MeHg via vertical hydrochemical transport mechanisms.
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Affiliation(s)
- Kristine M Haynes
- University of Toronto Scarborough, Department of Physical and Environmental Sciences, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada; University of Toronto, Department of Geography, 100 St. George Street, Toronto, Ontario M5S 3G3, Canada.
| | - Evan S Kane
- Michigan Technological University, School of Forest Resources and Environmental Science, Houghton, MI 49931, USA; USDA Forest Service Northern Research Station, Houghton, MI 49931, USA
| | - Lynette Potvin
- USDA Forest Service Northern Research Station, Houghton, MI 49931, USA
| | - Erik A Lilleskov
- USDA Forest Service Northern Research Station, Houghton, MI 49931, USA
| | - Randall K Kolka
- USDA Forest Service Northern Research Station, Grand Rapids, MN 55744, USA
| | - Carl P J Mitchell
- University of Toronto Scarborough, Department of Physical and Environmental Sciences, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada; University of Toronto, Department of Geography, 100 St. George Street, Toronto, Ontario M5S 3G3, Canada
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Owen RK, Webb EB, Goyne KW, Svoma BM, Gautam S. Framework for using downscaled climate model projections in ecological experiments to quantify plant and soil responses. Ecosphere 2019. [DOI: 10.1002/ecs2.2857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- Rachel K. Owen
- School of Natural Resources University of Missouri Columbia Missouri 65211 USA
| | - Elisabeth B. Webb
- School of Natural Resources University of Missouri Columbia Missouri 65211 USA
- U.S. Geological Survey Missouri Cooperative Fish and Wildlife Research Unit Columbia Missouri 65211 USA
| | - Keith W. Goyne
- School of Natural Resources University of Missouri Columbia Missouri 65211 USA
| | - Bohumil M. Svoma
- School of Natural Resources University of Missouri Columbia Missouri 65211 USA
- Salt River Project, Surface Water Resources Tempe Arizona 85072 USA
| | - Sagar Gautam
- Department of Biomedical, Biological and Chemical Engineering University of Missouri Columbia Missouri 65211 USA
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17
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Characterizing Boreal Peatland Plant Composition and Species Diversity with Hyperspectral Remote Sensing. REMOTE SENSING 2019. [DOI: 10.3390/rs11141685] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Peatlands, which account for approximately 15% of land surface across the arctic and boreal regions of the globe, are experiencing a range of ecological impacts as a result of climate change. Factors that include altered hydrology resulting from drought and permafrost thaw, rising temperatures, and elevated levels of atmospheric carbon dioxide have been shown to cause plant community compositional changes. Shifts in plant composition affect the productivity, species diversity, and carbon cycling of peatlands. We used hyperspectral remote sensing to characterize the response of boreal peatland plant composition and species diversity to warming, hydrologic change, and elevated CO2. Hyperspectral remote sensing techniques offer the ability to complete landscape-scale analyses of ecological responses to climate disturbance when paired with plot-level measurements that link ecosystem biophysical properties with spectral reflectance signatures. Working within two large ecosystem manipulation experiments, we examined climate controls on composition and diversity in two types of common boreal peatlands: a nutrient rich fen located at the Alaska Peatland Experiment (APEX) in central Alaska, and an ombrotrophic bog located in northern Minnesota at the Spruce and Peatland Responses Under Changing Environments (SPRUCE) experiment. We found a strong effect of plant functional cover on spectral reflectance characteristics. We also found a positive relationship between species diversity and spectral variation at the APEX field site, which is consistent with other recently published findings. Based on the results of our field study, we performed a supervised land cover classification analysis on an aerial hyperspectral dataset to map peatland plant functional types (PFTs) across an area encompassing a range of different plant communities. Our results underscore recent advances in the application of remote sensing measurements to ecological research, particularly in far northern ecosystems.
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18
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Laine AM, Mäkiranta P, Laiho R, Mehtätalo L, Penttilä T, Korrensalo A, Minkkinen K, Fritze H, Tuittila ES. Warming impacts on boreal fen CO 2 exchange under wet and dry conditions. GLOBAL CHANGE BIOLOGY 2019; 25:1995-2008. [PMID: 30854735 DOI: 10.1111/gcb.14617] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/11/2019] [Accepted: 02/21/2019] [Indexed: 05/14/2023]
Abstract
Northern peatlands form a major soil carbon (C) stock. With climate change, peatland C mineralization is expected to increase, which in turn would accelerate climate change. A particularity of peatlands is the importance of soil aeration, which regulates peatland functioning and likely modulates the responses to warming climate. Our aim is to assess the impacts of warming on a southern boreal and a sub-arctic sedge fen carbon dioxide (CO2 ) exchange under two plausible water table regimes: wet and moderately dry. We focused this study on minerotrophic treeless sedge fens, as they are common peatland types at boreal and (sub)arctic areas, which are expected to face the highest rates of climate warming. In addition, fens are expected to respond to environmental changes faster than the nutrient poor bogs. Our study confirmed that CO2 exchange is more strongly affected by drying than warming. Experimental water level draw-down (WLD) significantly increased gross photosynthesis and ecosystem respiration. Warming alone had insignificant impacts on the CO2 exchange components, but when combined with WLD it further increased ecosystem respiration. In the southern fen, CO2 uptake decreased due to WLD, which was amplified by warming, while at northern fen it remained stable. As a conclusion, our results suggest that a very small difference in the WLD may be decisive, whether the C sink of a fen decreases, or whether the system is able to adapt within its regime and maintain its functions. Moreover, the water table has a role in determining how much the increased temperature impacts the CO2 exchange.
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Affiliation(s)
- Anna M Laine
- School of Forest Sciences, University of Eastern Finland, Joensuu, Finland
| | | | - Raija Laiho
- Natural Resources Institute Finland, Helsinki, Finland
| | - Lauri Mehtätalo
- School of Computing, University of Eastern Finland, Joensuu, Finland
| | - Timo Penttilä
- Natural Resources Institute Finland, Helsinki, Finland
| | - Aino Korrensalo
- School of Forest Sciences, University of Eastern Finland, Joensuu, Finland
| | - Kari Minkkinen
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Hannu Fritze
- Natural Resources Institute Finland, Helsinki, Finland
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19
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Graham EB, Yang F, Bell S, Hofmockel KS. High Genetic Potential for Proteolytic Decomposition in Northern Peatland Ecosystems. Appl Environ Microbiol 2019; 85:e02851-18. [PMID: 30850433 PMCID: PMC6498154 DOI: 10.1128/aem.02851-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 02/13/2019] [Indexed: 11/28/2022] Open
Abstract
Nitrogen (N) is a scarce nutrient commonly limiting primary productivity. Microbial decomposition of complex carbon (C) into small organic molecules (e.g., free amino acids) has been suggested to supplement biologically fixed N in northern peatlands. We evaluated the microbial (fungal, bacterial, and archaeal) genetic potential for organic N depolymerization in peatlands at Marcell Experimental Forest (MEF) in northern Minnesota. We used guided gene assembly to examine the abundance and diversity of protease genes and further compared them to those of N fixation (nifH) genes in shotgun metagenomic data collected across depths and in two distinct peatland environments (bogs and fens). Microbial protease genes greatly outnumbered nifH genes, with the most abundant genes (archaeal M1 and bacterial trypsin [S01]) each containing more sequences than all sequences attributed to nifH Bacterial protease gene assemblies were diverse and abundant across depth profiles, indicating a role for bacteria in releasing free amino acids from peptides through depolymerization of older organic material and contrasting with the paradigm of fungal dominance in depolymerization in forest soils. Although protease gene assemblies for fungi were much less abundant overall than those for bacteria, fungi were prevalent in surface samples and therefore may be vital in degrading large soil polymers from fresh plant inputs during the early stage of depolymerization. In total, we demonstrate that depolymerization enzymes from a diverse suite of microorganisms, including understudied bacterial and archaeal lineages, are prevalent within northern peatlands and likely to influence C and N cycling.IMPORTANCE Nitrogen (N) is a common limitation on primary productivity, and its source remains unresolved in northern peatlands that are vulnerable to environmental change. Decomposition of complex organic matter into free amino acids has been proposed as an important N source, but the genetic potential of microorganisms mediating this process has not been examined. Such information can inform possible responses of northern peatlands to environmental change. We show high genetic potential for microbial production of free amino acids across a range of microbial guilds in northern peatlands. In particular, the abundance and diversity of bacterial genes encoding proteolytic activity suggest a predominant role for bacteria in regulating productivity and contrasts with a paradigm of fungal dominance of organic N decomposition. Our results expand our current understanding of coupled carbon and nitrogen cycles in northern peatlands and indicate that understudied bacterial and archaeal lineages may be central in this ecosystem's response to environmental change.
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Affiliation(s)
- Emily B Graham
- Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Fan Yang
- Department of Agricultural & Biosystems Engineering, Iowa State University, Ames, Iowa, USA
| | - Sheryl Bell
- Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Kirsten S Hofmockel
- Pacific Northwest National Laboratory, Richland, Washington, USA
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa, USA
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Villa JA, Mejía GM, Velásquez D, Botero A, Acosta SA, Marulanda JM, Osorno AM, Bohrer G. Carbon sequestration and methane emissions along a microtopographic gradient in a tropical Andean peatland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 654:651-661. [PMID: 30447603 DOI: 10.1016/j.scitotenv.2018.11.109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/07/2018] [Accepted: 11/08/2018] [Indexed: 06/09/2023]
Abstract
Tropical alpine peatlands are among the least studied wetlands types on earth. Their important ecosystem services at local and regional scope are currently threatened by climate and land use changes. Recent studies in these ecosystems suggest their importance to the provision of climate regulation services, prompting a better understanding of the underlying functions and their variability at ecosystem scales. The objective of this study is to determine the variability of methane (CH4) fluxes and carbon (C) sequestration within a tropical alpine peatland in three locations along a microtopographic gradient and its associated plant diversity. These locations accounted for: 1) hummocks, found mostly near the edge of the peat with a water table below the soil surface, 2) lawns, in the transition zone, with a water-table near the soil surface, and 3) hollows, permanently flooded with a water table above the soil surface, composed of small patches of open water intermingled with unconsolidated hummocks that surface the water level. Results indicate that CH4 flux is lowest in the lawns, while C sequestration is highest. Conversely, the hummock and hollow have higher CH4 flux and lower C sequestration. In addition, plant diversity in the lawns is higher than in the hummock and hollow location. Dryer conditions brought by current climate change in the northern Andes are expected to lower the water tables in the peatland. This change is expected to drive a change in CH4 flux and C sequestration at the lawns, currently dominating the peatland, towards values more similar to those measured in the hummocks. This decrease may also represent a change towards the lower plant diversity that characterized the hummock. Such changes will reduce the ratio of C sequestration:CH4 flux signifying the reduction of resilience and increment of vulnerability of the climate-regulating service to further perturbations.
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Affiliation(s)
- Jorge A Villa
- Grupo de Investigación Aplicada al Medio Ambiente GAMA, Corporación Universitaria Lasallista, Carrera 51 no. 118 sur-57, Caldas, Antioquia 055440, Colombia; Department of Civil, Environmental & Geodetic Engineering, The Ohio State University, 470 Hitchcock Hall, 2070 Neil Avenue, Columbus, OH 43210, USA.
| | - Gloria M Mejía
- Grupo de Investigación Aplicada al Medio Ambiente GAMA, Corporación Universitaria Lasallista, Carrera 51 no. 118 sur-57, Caldas, Antioquia 055440, Colombia
| | - Daniela Velásquez
- Grupo de Investigación Aplicada al Medio Ambiente GAMA, Corporación Universitaria Lasallista, Carrera 51 no. 118 sur-57, Caldas, Antioquia 055440, Colombia
| | - Andrés Botero
- Grupo de Investigación Aplicada al Medio Ambiente GAMA, Corporación Universitaria Lasallista, Carrera 51 no. 118 sur-57, Caldas, Antioquia 055440, Colombia
| | - Sharon A Acosta
- Grupo de Investigación Aplicada al Medio Ambiente GAMA, Corporación Universitaria Lasallista, Carrera 51 no. 118 sur-57, Caldas, Antioquia 055440, Colombia
| | - Juliana M Marulanda
- Grupo de Investigación Aplicada al Medio Ambiente GAMA, Corporación Universitaria Lasallista, Carrera 51 no. 118 sur-57, Caldas, Antioquia 055440, Colombia
| | - Ana M Osorno
- Grupo de Investigación Aplicada al Medio Ambiente GAMA, Corporación Universitaria Lasallista, Carrera 51 no. 118 sur-57, Caldas, Antioquia 055440, Colombia
| | - Gil Bohrer
- Department of Civil, Environmental & Geodetic Engineering, The Ohio State University, 470 Hitchcock Hall, 2070 Neil Avenue, Columbus, OH 43210, USA
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Abstract
Seismic lines are narrow linear (~3–8 m wide) forest clearings that are used for petroleum exploration in Alberta’s boreal forest. Many seismic lines have experienced poor tree regeneration since initial disturbance, with most failures occurring in treed peatlands that are used by the threatened woodland caribou (Rangifer tarandus caribou). Extensive networks of seismic lines, which often reach densities of 40 km/km2, are thought to have contributed to declines in caribou. The reforestation of seismic lines is therefore a focus of conservation. Methods to reforest seismic lines are expensive (averaging $12,500 per km) with uncertainty of which seismic lines need which treatments, if any, resulting in inefficiencies in restoration actions. Here, we monitored the effectiveness of treatments on seismic lines as compared to untreated seismic lines and adjacent undisturbed reference stands for treed peatlands in northeast Alberta, Canada. Mechanical site preparation (mounding and ripping) increased tree density when compared to untreated lines, despite averaging 3.8-years since treatment (vs. 22 years since disturbance for untreated). Specifically, treated lines had, on average, 12,290 regenerating tree stems/ha, which is 1.6-times more than untreated lines (7680 stems/ha) and 1.5-times more than the adjacent undisturbed forest (8240 stems/ha). Using only mechanical site preparation, treated seismic lines consistently have more regenerating trees across all four ecosites, although the higher amounts of stems that were observed on treated poor fens are not significant when compared to untreated or adjacent undisturbed reference stands.
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McPartland MY, Kane ES, Falkowski MJ, Kolka R, Turetsky MR, Palik B, Montgomery RA. The response of boreal peatland community composition and NDVI to hydrologic change, warming, and elevated carbon dioxide. GLOBAL CHANGE BIOLOGY 2019; 25:93-107. [PMID: 30295397 DOI: 10.1111/gcb.14465] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 09/07/2018] [Indexed: 06/08/2023]
Abstract
Widespread changes in arctic and boreal Normalized Difference Vegetation Index (NDVI) values captured by satellite platforms indicate that northern ecosystems are experiencing rapid ecological change in response to climate warming. Increasing temperatures and altered hydrology are driving shifts in ecosystem biophysical properties that, observed by satellites, manifest as long-term changes in regional NDVI. In an effort to examine the underlying ecological drivers of these changes, we used field-scale remote sensing of NDVI to track peatland vegetation in experiments that manipulated hydrology, temperature, and carbon dioxide (CO2 ) levels. In addition to NDVI, we measured percent cover by species and leaf area index (LAI). We monitored two peatland types broadly representative of the boreal region. One site was a rich fen located near Fairbanks, Alaska, at the Alaska Peatland Experiment (APEX), and the second site was a nutrient-poor bog located in Northern Minnesota within the Spruce and Peatland Responses Under Changing Environments (SPRUCE) experiment. We found that NDVI decreased with long-term reductions in soil moisture at the APEX site, coincident with a decrease in photosynthetic leaf area and the relative abundance of sedges. We observed increasing NDVI with elevated temperature at the SPRUCE site, associated with an increase in the relative abundance of shrubs and a decrease in forb cover. Warming treatments at the SPRUCE site also led to increases in the LAI of the shrub layer. We found no strong effects of elevated CO2 on community composition. Our findings support recent studies suggesting that changes in NDVI observed from satellite platforms may be the result of changes in community composition and ecosystem structure in response to climate warming.
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Affiliation(s)
- Mara Y McPartland
- Department of Geography, Environment and Society, University of Minnesota, Minneapolis, Minnesota
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota
| | - Evan S Kane
- School of Forest Resources and Environmental Sciences, Michigan Technological University, Houghton, Michigan
- Northern Research Station, USDA Forest Service, Houghton, Michigan
| | - Michael J Falkowski
- Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, Colorado
| | - Randy Kolka
- Northern Research Station, USDA Forest Service, Grand Rapids, Minnesota
| | - Merritt R Turetsky
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Brian Palik
- Northern Research Station, USDA Forest Service, Grand Rapids, Minnesota
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23
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Gavazov K, Albrecht R, Buttler A, Dorrepaal E, Garnett MH, Gogo S, Hagedorn F, Mills RTE, Robroek BJM, Bragazza L. Vascular plant-mediated controls on atmospheric carbon assimilation and peat carbon decomposition under climate change. GLOBAL CHANGE BIOLOGY 2018; 24:3911-3921. [PMID: 29569798 DOI: 10.1111/gcb.14140] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 03/06/2018] [Indexed: 06/08/2023]
Abstract
Climate change can alter peatland plant community composition by promoting the growth of vascular plants. How such vegetation change affects peatland carbon dynamics remains, however, unclear. In order to assess the effect of vegetation change on carbon uptake and release, we performed a vascular plant-removal experiment in two Sphagnum-dominated peatlands that represent contrasting stages of natural vegetation succession along a climatic gradient. Periodic measurements of net ecosystem CO2 exchange revealed that vascular plants play a crucial role in assuring the potential for net carbon uptake, particularly with a warmer climate. The presence of vascular plants, however, also increased ecosystem respiration, and by using the seasonal variation of respired CO2 radiocarbon (bomb-14 C) signature we demonstrate an enhanced heterotrophic decomposition of peat carbon due to rhizosphere priming. The observed rhizosphere priming of peat carbon decomposition was matched by more advanced humification of dissolved organic matter, which remained apparent beyond the plant growing season. Our results underline the relevance of rhizosphere priming in peatlands, especially when assessing the future carbon sink function of peatlands undergoing a shift in vegetation community composition in association with climate change.
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Affiliation(s)
- Konstantin Gavazov
- Swiss Federal Institute for Forest, Snow and Landscape Research, WSL Site Lausanne, Lausanne, Switzerland
- Laboratory of Ecological Systems ECOS, School of Architecture, Civil and Environmental Engineering ENAC, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland
- Department of Ecology and Environmental Science, Climate Impacts Research Centre, Umeå University, Abisko, Sweden
| | - Remy Albrecht
- Swiss Federal Institute for Forest, Snow and Landscape Research, WSL Site Lausanne, Lausanne, Switzerland
- Laboratory of Ecological Systems ECOS, School of Architecture, Civil and Environmental Engineering ENAC, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland
| | - Alexandre Buttler
- Swiss Federal Institute for Forest, Snow and Landscape Research, WSL Site Lausanne, Lausanne, Switzerland
- Laboratory of Ecological Systems ECOS, School of Architecture, Civil and Environmental Engineering ENAC, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland
- Laboratoire de Chrono-Environnement, UMR CNRS 6249, UFR des Sciences et Techniques, Université de Franche-Comté, Besançon, France
| | - Ellen Dorrepaal
- Department of Ecology and Environmental Science, Climate Impacts Research Centre, Umeå University, Abisko, Sweden
| | - Mark H Garnett
- NERC Radiocarbon Facility (East Kilbride), East Kilbride, UK
| | - Sebastien Gogo
- ISTO, UMR 7327, Université d'Orléans, Orléans, France
- ISTO, UMR 7327, CNRS, Orléans, France
- ISTO, UMR 7327, BRGM, Orléans, France
| | - Frank Hagedorn
- Swiss Federal Institute for Forest, Snow and Landscape Research, WSL Site Birmensdorf, Birmensdorf, Switzerland
| | - Robert T E Mills
- Swiss Federal Institute for Forest, Snow and Landscape Research, WSL Site Lausanne, Lausanne, Switzerland
- Laboratory of Ecological Systems ECOS, School of Architecture, Civil and Environmental Engineering ENAC, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Bjorn J M Robroek
- Swiss Federal Institute for Forest, Snow and Landscape Research, WSL Site Lausanne, Lausanne, Switzerland
- Laboratory of Ecological Systems ECOS, School of Architecture, Civil and Environmental Engineering ENAC, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland
- Biological Sciences, University of Southampton, Southampton, UK
| | - Luca Bragazza
- Swiss Federal Institute for Forest, Snow and Landscape Research, WSL Site Lausanne, Lausanne, Switzerland
- Laboratory of Ecological Systems ECOS, School of Architecture, Civil and Environmental Engineering ENAC, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland
- Department of Life Science and Biotechnologies, University of Ferrara, Ferrara, Italy
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24
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Järveoja J, Nilsson MB, Gažovič M, Crill PM, Peichl M. Partitioning of the net CO 2 exchange using an automated chamber system reveals plant phenology as key control of production and respiration fluxes in a boreal peatland. GLOBAL CHANGE BIOLOGY 2018; 24:3436-3451. [PMID: 29710420 DOI: 10.1111/gcb.14292] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 03/12/2018] [Accepted: 04/10/2018] [Indexed: 05/23/2023]
Abstract
The net ecosystem CO2 exchange (NEE) drives the carbon (C) sink-source strength of northern peatlands. Since NEE represents a balance between various production and respiration fluxes, accurate predictions of its response to global changes require an in depth understanding of these underlying processes. Currently, however, detailed information of the temporal dynamics as well as the separate biotic and abiotic controls of the NEE component fluxes is lacking in peatland ecosystems. In this study, we address this knowledge gap by using an automated chamber system established across natural and trenching/vegetation removal plots to partition NEE into its production (i.e., gross and net primary production; GPP and NPP) and respiration (i.e., ecosystem, heterotrophic and autotrophic respiration; ER, Rh and Ra) fluxes in a boreal peatland in northern Sweden. Our results showed that daily NEE patterns were driven by GPP while variations in ER were governed by Ra rather than Rh. Moreover, we observed pronounced seasonal shifts in the Ra/Rh and above/belowground NPP ratios throughout the main phenological phases. Generalized linear model analysis revealed that the greenness index derived from digital images (as a proxy for plant phenology) was the strongest control of NEE, GPP and NPP while explaining considerable fractions also in the variations of ER and Ra. In addition, our data exposed greater temperature sensitivity of NPP compared to Rh resulting in enhanced C sequestration with increasing temperature. Overall, our study suggests that the temporal patterns in NEE and its component fluxes are tightly coupled to vegetation dynamics in boreal peatlands and thus challenges previous studies that commonly identify abiotic factors as key drivers. These findings further emphasize the need for integrating detailed information on plant phenology into process-based models to improve predictions of global change impacts on the peatland C cycle.
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Affiliation(s)
- Järvi Järveoja
- Department of Forest Ecology & Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Mats B Nilsson
- Department of Forest Ecology & Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Michal Gažovič
- Department of Forest Ecology & Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Patrick M Crill
- Department of Geological Sciences, Stockholm University, Stockholm, Sweden
- Bolin Center for Climate Research, Stockholm, Sweden
| | - Matthias Peichl
- Department of Forest Ecology & Management, Swedish University of Agricultural Sciences, Umeå, Sweden
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25
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Peichl M, Gažovič M, Vermeij I, de Goede E, Sonnentag O, Limpens J, Nilsson MB. Peatland vegetation composition and phenology drive the seasonal trajectory of maximum gross primary production. Sci Rep 2018; 8:8012. [PMID: 29789673 PMCID: PMC5964230 DOI: 10.1038/s41598-018-26147-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 05/02/2018] [Indexed: 11/09/2022] Open
Abstract
Gross primary production (GPP) is a key driver of the peatland carbon cycle. Although many studies have explored the apparent GPP under natural light conditions, knowledge of the maximum GPP at light-saturation (GPPmax) and its spatio-temporal variation is limited. This information, however, is crucial since GPPmax essentially constrains the upper boundary for apparent GPP. Using chamber measurements combined with an external light source across experimental plots where vegetation composition was altered through long-term (20-year) nitrogen addition and artificial warming, we could quantify GPPmax in-situ and disentangle its biotic and abiotic controls in a boreal peatland. We found large spatial and temporal variations in the magnitudes of GPPmax which were related to vegetation species composition and phenology rather than abiotic factors. Specifically, we identified vegetation phenology as the main driver of the seasonal GPPmax trajectory. Abiotic anomalies (i.e. in air temperature and water table level), however, caused species-specific divergence between the trajectories of GPPmax and plant development. Our study demonstrates that photosynthetically active biomass constrains the potential peatland photosynthesis while abiotic factors act as secondary modifiers. This further calls for a better representation of species-specific vegetation phenology in process-based peatland models to improve predictions of global change impacts on the peatland carbon cycle.
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Affiliation(s)
- Matthias Peichl
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 90183, Umeå, Sweden.
| | - Michal Gažovič
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 90183, Umeå, Sweden
| | - Ilse Vermeij
- Plant Ecology and Nature Conservation Group, Wageningen University, 6708 PB, Wageningen, The Netherlands
| | - Eefje de Goede
- Department of Aquatic Ecology, Radboud University Nijmegen, 6525 AJ, Nijmegen, The Netherlands.,Institute of Environmental Sciences, Leiden University, 2333CC, Leiden, The Netherlands
| | - Oliver Sonnentag
- Département de géographie, Université de Montréal, Montréal, QC H2V 2B8, Canada
| | - Juul Limpens
- Plant Ecology and Nature Conservation Group, Wageningen University, 6708 PB, Wageningen, The Netherlands
| | - Mats B Nilsson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 90183, Umeå, Sweden
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26
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Kylander ME, Martínez-Cortizas A, Bindler R, Kaal J, Sjöström JK, Hansson SV, Silva-Sánchez N, Greenwood SL, Gallagher K, Rydberg J, Mörth CM, Rauch S. Mineral dust as a driver of carbon accumulation in northern latitudes. Sci Rep 2018; 8:6876. [PMID: 29720603 PMCID: PMC5932003 DOI: 10.1038/s41598-018-25162-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 04/16/2018] [Indexed: 11/13/2022] Open
Abstract
Peatlands in northern latitudes sequester one third of the world’s soil organic carbon. Mineral dusts can affect the primary productivity of terrestrial systems through nutrient transport but this process has not yet been documented in these peat-rich regions. Here we analysed organic and inorganic fractions of an 8900-year-old sequence from Store Mosse (the “Great Bog”) in southern Sweden. Between 5420 and 4550 cal yr BP, we observe a seven-fold increase in net peat-accumulation rates corresponding to a maximum carbon-burial rate of 150 g C m−2 yr−1 – more than six times the global average. This high peat accumulation event occurs in parallel with a distinct change in the character of the dust deposited on the bog, which moves from being dominated by clay minerals to less weathered, phosphate and feldspar minerals. We hypothesize that this shift boosted nutrient input to the bog and stimulated ecosystem productivity. This study shows that diffuse sources and dust dynamics in northern temperate latitudes, often overlooked by the dust community in favour of arid and semi-arid regions, can be important drivers of peatland carbon accumulation and by extension, global climate, warranting further consideration in predictions of future climate variability.
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Affiliation(s)
- Malin E Kylander
- Department of Geological Sciences, Stockholm University, SE-10691, Stockholm, Sweden. .,The Bolin Centre for Climate Research, Stockholm University, SE-10691, Stockholm, Sweden.
| | - A Martínez-Cortizas
- Departamento de Edafoloxía e Química Agrícola, Facultade de Bioloxía, Universidade de Santiago de Compostela, Campus Sur, E-15706, Santiago de Compostela, Spain
| | - Richard Bindler
- Department of Ecology and Environmental Sciences, Umeå University, SE-901 87, Umeå, Sweden
| | - Joeri Kaal
- Departamento de Edafoloxía e Química Agrícola, Facultade de Bioloxía, Universidade de Santiago de Compostela, Campus Sur, E-15706, Santiago de Compostela, Spain
| | - Jenny K Sjöström
- Department of Geological Sciences, Stockholm University, SE-10691, Stockholm, Sweden.,The Bolin Centre for Climate Research, Stockholm University, SE-10691, Stockholm, Sweden
| | - Sophia V Hansson
- Department of Bioscience - Arctic Research Centre, Aarhus University, Frederiksborgvej 399, DK-4000, Roskilde, Denmark
| | - Noemí Silva-Sánchez
- Departamento de Edafoloxía e Química Agrícola, Facultade de Bioloxía, Universidade de Santiago de Compostela, Campus Sur, E-15706, Santiago de Compostela, Spain
| | - Sarah L Greenwood
- Department of Geological Sciences, Stockholm University, SE-10691, Stockholm, Sweden.,The Bolin Centre for Climate Research, Stockholm University, SE-10691, Stockholm, Sweden
| | | | - Johan Rydberg
- Department of Ecology and Environmental Sciences, Umeå University, SE-901 87, Umeå, Sweden
| | - Carl-Magnus Mörth
- Department of Geological Sciences, Stockholm University, SE-10691, Stockholm, Sweden.,The Bolin Centre for Climate Research, Stockholm University, SE-10691, Stockholm, Sweden
| | - Sebastien Rauch
- Water Environment Technology, Chalmers University of Technology, 41296, Göteborg, Sweden
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27
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Mäkiranta P, Laiho R, Mehtätalo L, Straková P, Sormunen J, Minkkinen K, Penttilä T, Fritze H, Tuittila ES. Responses of phenology and biomass production of boreal fens to climate warming under different water-table level regimes. GLOBAL CHANGE BIOLOGY 2018; 24:944-956. [PMID: 28994163 DOI: 10.1111/gcb.13934] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 09/21/2017] [Accepted: 09/27/2017] [Indexed: 05/03/2023]
Abstract
Climate change affects peatlands directly through increased air temperatures and indirectly through changes in water-table level (WL). The interactions of these two still remain poorly known. We determined experimentally the separate and interactive effects of temperature and WL regime on factors of relevance for the inputs to the carbon cycle: plant community composition, phenology, biomass production, and shoot:root allocation in two wet boreal sedge-dominated fens, "southern" at 62°N and "northern" at 68°Ν. Warming (1.5°C higher average daily air temperature) was induced with open-top chambers and WL drawdown (WLD; 3-7 cm on average) by shallow ditches. Total biomass production varied from 250 to 520 g/m2 , with belowground production comprising 25%-63%. Warming was associated with minor effects on phenology and negligible effects on community composition, biomass production, and allocation. WLD clearly affected the contribution of different plant functional types (PFTs) in the community and the biomass they produced: shrubs benefited while forbs and mosses suffered. These responses did not depend on the warming treatment. Following WLD, aboveground biomass production decreased mainly due to reduced growth of mosses in the southern fen. Aboveground vascular plant biomass production remained unchanged but the contribution of different PFTs changed. The observed changes were also reflected in plant phenology, with different PFTs showing different responses. Belowground production increased following WLD in the northern fen only, but an increase in the contributions of shrubs and forbs was observed in both sites, while sedge contribution decreased. Moderate warming alone seems not able to drive significant changes in plant productivity or community composition in these wet ecosystems. However, if warming is accompanied by even modest WL drawdown, changes should be expected in the relative contribution of PFTs, which could lead to profound changes in the function of fens. Consequently, hydrological scenarios are of utmost importance when estimating their future function.
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Affiliation(s)
- Päivi Mäkiranta
- Natural Resources Institute Finland (Luke), Helsinki, Finland
| | - Raija Laiho
- Natural Resources Institute Finland (Luke), Helsinki, Finland
| | - Lauri Mehtätalo
- School of Computing, University of Eastern Finland, Joensuu, Finland
| | - Petra Straková
- Natural Resources Institute Finland (Luke), Helsinki, Finland
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Janne Sormunen
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Kari Minkkinen
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Timo Penttilä
- Natural Resources Institute Finland (Luke), Helsinki, Finland
| | - Hannu Fritze
- Natural Resources Institute Finland (Luke), Helsinki, Finland
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28
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Purre AH, Ilomets M. Relationships between bryophyte production and substrate properties in restored milled peatlands. Restor Ecol 2017. [DOI: 10.1111/rec.12656] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anna-Helena Purre
- School of Natural Sciences and Health; Tallinn University, Narva Road 29; 10120 Tallinn Estonia
| | - Mati Ilomets
- Institute of Ecology; Tallinn University, Uus-Sadama 5; 10120 Tallinn Estonia
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29
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Robroek BJM, Jassey VEJ, Beltman B, Hefting MM. Diverse fen plant communities enhance carbon-related multifunctionality, but do not mitigate negative effects of drought. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170449. [PMID: 29134063 PMCID: PMC5666246 DOI: 10.1098/rsos.170449] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 09/27/2017] [Indexed: 05/13/2023]
Abstract
Global change, like droughts, can destabilize the carbon sink function of peatlands, either directly or indirectly through changes in plant community composition. While the effects of drought and plant community composition on individual carbon (C) related processes are well understood, their effect on multiple C-related processes simultaneously-multifunctionality-is poorly known. We studied the effect of drought on four C-related processes (net and gross CO2 exchange, methane fluxes, and dissolved organic carbon content) in a plant removal experiment. Plant functional type (PFT) removal (graminoids, herbs, Polytrichum spp., incl. combinations) negatively affected multifunctionality; most markedly when all PFTs were removed. Our results corroborate a negative drought effect on C-related multifunctionality. Drought reduced multifunctionality, and this reduction was again largest when all PFTs were removed. Our data further indicate that much of these negative drought effects were carried over and maintained from the initial removal treatment. These results suggest that while a high diversity in plant functional types is associated to high C-related multifunctionality, plant community assembly does not drive the ability of peatlands to withstand the negative impacts of drought on multifunctionality. Hence, to safeguard the carbon cycling function in intact peatlands, the effects of climate change on the functional composition of the peatland plant community needs to be minimized.
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Affiliation(s)
- Bjorn J. M. Robroek
- Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
- Author for correspondence: Bjorn J. M. Robroek e-mail:
| | - Vincent E. J. Jassey
- INP, UPS, CNRS, Laboratoire d'Ecologie Fonctionnelle et Environnement (Ecolab), Université de Toulouse, 31062 Toulouse Cedex, France
| | - Boudewijn Beltman
- Ecology and Biodiversity, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Mariet M. Hefting
- Ecology and Biodiversity, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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30
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31
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Olefeldt D, Euskirchen ES, Harden J, Kane E, McGuire AD, Waldrop MP, Turetsky MR. A decade of boreal rich fen greenhouse gas fluxes in response to natural and experimental water table variability. GLOBAL CHANGE BIOLOGY 2017; 23:2428-2440. [PMID: 28055128 DOI: 10.1111/gcb.13612] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 11/06/2016] [Accepted: 12/07/2016] [Indexed: 06/06/2023]
Abstract
Rich fens are common boreal ecosystems with distinct hydrology, biogeochemistry and ecology that influence their carbon (C) balance. We present growing season soil chamber methane emission (FCH4 ), ecosystem respiration (ER), net ecosystem exchange (NEE) and gross primary production (GPP) fluxes from a 9-years water table manipulation experiment in an Alaskan rich fen. The study included major flood and drought years, where wetting and drying treatments further modified the severity of droughts. Results support previous findings from peatlands that drought causes reduced magnitude of growing season FCH4 , GPP and NEE, thus reducing or reversing their C sink function. Experimentally exacerbated droughts further reduced the capacity for the fen to act as a C sink by causing shifts in vegetation and thus reducing magnitude of maximum growing season GPP in subsequent flood years by ~15% compared to control plots. Conversely, water table position had only a weak influence on ER, but dominant contribution to ER switched from autotrophic respiration in wet years to heterotrophic in dry years. Droughts did not cause inter-annual lag effects on ER in this rich fen, as has been observed in several nutrient-poor peatlands. While ER was dependent on soil temperatures at 2 cm depth, FCH4 was linked to soil temperatures at 25 cm. Inter-annual variability of deep soil temperatures was in turn dependent on wetness rather than air temperature, and higher FCH4 in flooded years was thus equally due to increased methane production at depth and decreased methane oxidation near the surface. Short-term fluctuations in wetness caused significant lag effects on FCH4 , but droughts caused no inter-annual lag effects on FCH4 . Our results show that frequency and severity of droughts and floods can have characteristic effects on the exchange of greenhouse gases, and emphasize the need to project future hydrological regimes in rich fens.
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Affiliation(s)
- David Olefeldt
- Department of Integrative Biology, University of Guelph, Science Complex, Guelph, ON, N1G 2W1, Canada
- Department of Renewable Resources, University of Alberta, Edmonton, AB T6G 2H1, Canada
| | - Eugénie S Euskirchen
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA
| | | | - Evan Kane
- School of Forest Resources and Environmental Sciences, and USDA Forest Service, Michigan Tech University, Northern Research Station, Houghton, MI, 49931, USA
| | - A David McGuire
- U.S. Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA
| | | | - Merritt R Turetsky
- Department of Integrative Biology, University of Guelph, Science Complex, Guelph, ON, N1G 2W1, Canada
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32
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Hedwall PO, Brunet J, Rydin H. Peatland plant communities under global change: negative feedback loops counteract shifts in species composition. Ecology 2017; 98:150-161. [DOI: 10.1002/ecy.1627] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 08/19/2016] [Accepted: 10/11/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Per-Ola Hedwall
- Southern Swedish Forest Research Centre; Swedish University of Agricultural Sciences; Sundsvägen 3 SE-230 53 Alnarp Sweden
| | - Jörg Brunet
- Southern Swedish Forest Research Centre; Swedish University of Agricultural Sciences; Sundsvägen 3 SE-230 53 Alnarp Sweden
| | - Håkan Rydin
- Department of Ecology and Genetics; Uppsala University; Norbyvägen 18c SE-752 36 Uppsala Sweden
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33
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Chimner RA, Pypker TG, Hribljan JA, Moore PA, Waddington JM. Multi-decadal Changes in Water Table Levels Alter Peatland Carbon Cycling. Ecosystems 2016. [DOI: 10.1007/s10021-016-0092-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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34
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Tang B, Yin C, Wang Y, Sun Y, Liu Q. Positive effects of night warming on physiology of coniferous trees in late growing season: Leaf and root. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2016. [DOI: 10.1016/j.actao.2016.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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35
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Lou Y, Pan Y, Gao C, Jiang M, Lu X, Xu YJ. Response of Plant Height, Species Richness and Aboveground Biomass to Flooding Gradient along Vegetation Zones in Floodplain Wetlands, Northeast China. PLoS One 2016; 11:e0153972. [PMID: 27097325 PMCID: PMC4838329 DOI: 10.1371/journal.pone.0153972] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 04/06/2016] [Indexed: 11/25/2022] Open
Abstract
Flooding regime changes resulting from natural and human activity have been projected to affect wetland plant community structures and functions. It is therefore important to conduct investigations across a range of flooding gradients to assess the impact of flooding depth on wetland vegetation. We conducted this study to identify the pattern of plant height, species richness and aboveground biomass variation along the flooding gradient in floodplain wetlands located in Northeast China. We found that the response of dominant species height to the flooding gradient depends on specific species, i.e., a quadratic response for Carex lasiocarpa, a negative correlation for Calamagrostis angustifolia, and no response for Carex appendiculata. Species richness showed an intermediate effect along the vegetation zone from marsh to wet meadow while aboveground biomass increased. When the communities were analysed separately, only the water table depth had significant impact on species richness for two Carex communities and no variable for C. angustifolia community, while height of dominant species influenced aboveground biomass. When the three above-mentioned communities were grouped together, variations in species richness were mainly determined by community type, water table depth and community mean height, while variations in aboveground biomass were driven by community type and the height of dominant species. These findings indicate that if habitat drying of these herbaceous wetlands in this region continues, then two Carex marshes would be replaced gradually by C. angustifolia wet meadow in the near future. This will lead to a reduction in biodiversity and an increase in productivity and carbon budget. Meanwhile, functional traits must be considered, and should be a focus of attention in future studies on the species diversity and ecosystem function in this region.
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Affiliation(s)
- Yanjing Lou
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, P. R. China
- * E-mail:
| | - Yanwen Pan
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, P. R. China
| | - Chuanyu Gao
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, P. R. China
| | - Ming Jiang
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, P. R. China
| | - Xianguo Lu
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, P. R. China
| | - Y. Jun Xu
- School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, United States of America
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Leppälä M, Kukko-Oja K, Laine J, Tuittila ES. Seasonal dynamics of CO2 exchange during primary succession of boreal mires as controlled by phenology of plants. ECOSCIENCE 2015. [DOI: 10.2980/15-4-3142] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Bailey LD, van de Pol M. Tackling extremes: challenges for ecological and evolutionary research on extreme climatic events. J Anim Ecol 2015; 85:85-96. [PMID: 26433114 DOI: 10.1111/1365-2656.12451] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 09/04/2015] [Indexed: 11/30/2022]
Abstract
Extreme climatic events (ECEs) are predicted to become more frequent as the climate changes. A rapidly increasing number of studies - though few on animals - suggest that the biological consequences of ECEs can be severe. However, ecological research on the impacts of ECEs has been limited by a lack of cohesiveness and structure. ECEs are often poorly defined and have often been confusingly equated with climatic variability, making comparison between studies difficult. In addition, a focus on short-term studies has provided us with little information on the long-term implications of ECEs, and the descriptive and anecdotal nature of many studies has meant it is still unclear what the key research questions are. Synthesizing the current state of work is essential to identify ways to make progress. We conduct a synthesis of the literature and discuss conceptual and practical challenges faced by research on ECEs. We consider three steps to advance research. First, we discuss the importance of choosing an ECE definition and identify the pros and cons of 'climatological' and 'biological' definitions of ECEs. Secondly, we advocate research beyond short-term descriptive studies to address questions concerning the long-term implications of ECEs, focussing on selective pressures and phenotypically plastic responses and how they might differ from responses to a changing climatic mean. Finally, we encourage a greater focus on multi-event studies that help us understand the implications of changing patterns of ECEs, through the combined use of modelling, experimental and observational field studies. This study aims to open a discussion on the definitions, questions and methods currently used to study ECEs, which will lead to a more cohesive approach to future ECE research.
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Affiliation(s)
- Liam D Bailey
- Division of Evolution, Ecology & Genetics, Research School of Biology, Australian National University, Canberra, 0200, ACT, Australia
| | - Martijn van de Pol
- Division of Evolution, Ecology & Genetics, Research School of Biology, Australian National University, Canberra, 0200, ACT, Australia.,Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands
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Hyyryläinen A, Rautio P, Turunen M, Huttunen S. Seasonal and inter-annual variation in the chlorophyll content of three co-existing Sphagnum species exceeds the effect of solar UV reduction in a subarctic peatland. SPRINGERPLUS 2015; 4:478. [PMID: 26361579 PMCID: PMC4559556 DOI: 10.1186/s40064-015-1253-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 08/17/2015] [Indexed: 11/25/2022]
Abstract
We measured chlorophyll (chl) concentration and chl a/b ratio in Sphagnum balticum, S. jensenii, and S. lindbergii, sampled after 7 and 8 years of ultraviolet-B (UVB) and temperature manipulation in an open field experiment in Finnish Lapland (68°N). We used plastic filters with different transmittance of UVB radiation to manipulate the environmental conditions. The plants were exposed to (1) attenuated UVB and increased temperature, (2) ambient UVB and increased temperature and (3) ambient conditions. Chlorophyll was extracted from the capitula of the mosses and the content and a/b ratio were measured spectrophotometrically. Seasonal variation of chlorophyll concentration in the mosses was species specific. Temperature increase to 0.5-1 °C and/or attenuation of solar UVB radiation to ca. one fifth of the ambient (on average 12 vs. 59 uW/cm(2)) had little effect on the chlorophyll concentration or its seasonal variation. In the dominant S. lindbergii, UVB attenuation under increased temperature led to a transient decrease in chlorophyll concentration. Altogether, species-specific patterns of seasonal chlorophyll variation in the studied Sphagna were more pronounced than temperature and UVB treatment effects.
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Affiliation(s)
- Anna Hyyryläinen
- />Department of Biology, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland
| | - Pasi Rautio
- />The Natural Resources Institute Finland, P.O. Box 16, 96300 Rovaniemi, Finland
| | - Minna Turunen
- />Arctic Centre, University of Lapland, P.O. Box 122, 96101 Rovaniemi, Finland
| | - Satu Huttunen
- />Department of Biology, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland
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Weston DJ, Timm CM, Walker AP, Gu L, Muchero W, Schmutz J, Shaw AJ, Tuskan GA, Warren JM, Wullschleger SD. Sphagnum physiology in the context of changing climate: emergent influences of genomics, modelling and host-microbiome interactions on understanding ecosystem function. PLANT, CELL & ENVIRONMENT 2015; 38:1737-1751. [PMID: 25266403 DOI: 10.1111/pce.12458] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Revised: 09/16/2014] [Accepted: 09/18/2014] [Indexed: 06/03/2023]
Abstract
Peatlands harbour more than one-third of terrestrial carbon leading to the argument that the bryophytes, as major components of peatland ecosystems, store more organic carbon in soils than any other collective plant taxa. Plants of the genus Sphagnum are important components of peatland ecosystems and are potentially vulnerable to changing climatic conditions. However, the response of Sphagnum to rising temperatures, elevated CO2 and shifts in local hydrology have yet to be fully characterized. In this review, we examine Sphagnum biology and ecology and explore the role of this group of keystone species and its associated microbiome in carbon and nitrogen cycling using literature review and model simulations. Several issues are highlighted including the consequences of a variable environment on plant-microbiome interactions, uncertainty associated with CO2 diffusion resistances and the relationship between fixed N and that partitioned to the photosynthetic apparatus. We note that the Sphagnum fallax genome is currently being sequenced and outline potential applications of population-level genomics and corresponding plant photosynthesis and microbial metabolic modelling techniques. We highlight Sphagnum as a model organism to explore ecosystem response to a changing climate and to define the role that Sphagnum can play at the intersection of physiology, genetics and functional genomics.
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Affiliation(s)
- David J Weston
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Collin M Timm
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Anthony P Walker
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Lianhong Gu
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Wellington Muchero
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jeremy Schmutz
- Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA
- HudsonAlpha Institute of Biotechnology, Huntsville, AL, 35806, USA
| | - A Jonathan Shaw
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - Gerald A Tuskan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jeffrey M Warren
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Stan D Wullschleger
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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40
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Hedwall PO, Skoglund J, Linder S. Interactions with successional stage and nutrient status determines the life-form-specific effects of increased soil temperature on boreal forest floor vegetation. Ecol Evol 2015; 5:948-60. [PMID: 25750720 PMCID: PMC4338976 DOI: 10.1002/ece3.1412] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 01/06/2015] [Indexed: 11/10/2022] Open
Abstract
The boreal forest is one of the largest terrestrial biomes and plays a key role for the global carbon balance and climate. The forest floor vegetation has a strong influence on the carbon and nitrogen cycles of the forests and is sensitive to changes in temperature conditions and nutrient availability. Additionally, the effects of climate warming on forest floor vegetation have been suggested to be moderated by the tree layer. Data on the effects of soil warming on forest floor vegetation from the boreal forest are, however, very scarce. We studied the effects on the forest floor vegetation in a long-term (18 years) soil warming and fertilization experiment in a Norway spruce stand in northern Sweden. During the first 9 years, warming favored early successional species such as grasses and forbs at the expense of dwarf shrubs and bryophytes in unfertilized stands, while the effects were smaller after fertilization. Hence, warming led to significant changes in species composition and an increase in species richness in the open canopy nutrient limited forest. After another 9 years of warming and increasing tree canopy closure, most of the initial effects had ceased, indicating an interaction between forest succession and warming. The only remaining effect of warming was on the abundance of bryophytes, which contrary to the initial phase was strongly favored by warming. We propose that the suggested moderating effects of the tree layer are specific to plant life-form and conclude that the successional phase of the forest may have a considerable impact on the effects of climate change on forest floor vegetation and its feedback effects on the carbon and nitrogen cycles, and thus on the climate.
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Affiliation(s)
- Per-Ola Hedwall
- Swedish University of Agricultural Sciences, SLU, Southern Swedish Forest Research Centre PO Box 49, SE-230 53, Alnarp, Sweden
| | | | - Sune Linder
- Swedish University of Agricultural Sciences, SLU, Southern Swedish Forest Research Centre PO Box 49, SE-230 53, Alnarp, Sweden
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41
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Dieleman CM, Branfireun BA, McLaughlin JW, Lindo Z. Climate change drives a shift in peatland ecosystem plant community: implications for ecosystem function and stability. GLOBAL CHANGE BIOLOGY 2015; 21:388-95. [PMID: 24957384 DOI: 10.1111/gcb.12643] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 05/13/2014] [Indexed: 05/03/2023]
Abstract
The composition of a peatland plant community has considerable effect on a range of ecosystem functions. Peatland plant community structure is predicted to change under future climate change, making the quantification of the direction and magnitude of this change a research priority. We subjected intact, replicated vegetated poor fen peat monoliths to elevated temperatures, increased atmospheric carbon dioxide (CO2 ), and two water table levels in a factorial design to determine the individual and synergistic effects of climate change factors on the poor fen plant community composition. We identify three indicators of a regime shift occurring in our experimental poor fen system under climate change: nonlinear decline of Sphagnum at temperatures 8 °C above ambient conditions, concomitant increases in Carex spp. at temperatures 4 °C above ambient conditions suggesting a weakening of Sphagnum feedbacks on peat accumulation, and increased variance of the plant community composition and pore water pH through time. A temperature increase of +4 °C appeared to be a threshold for increased vascular plant abundance; however the magnitude of change was species dependent. Elevated temperature combined with elevated CO2 had a synergistic effect on large graminoid species abundance, with a 15 times increase as compared to control conditions. Community analyses suggested that the balance between dominant plant species was tipped from Sphagnum to a graminoid-dominated system by the combination of climate change factors. Our findings indicate that changes in peatland plant community composition are likely under future climate change conditions, with a demonstrated shift toward a dominance of graminoid species in poor fens.
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Affiliation(s)
- Catherine M Dieleman
- Department of Biology, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
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42
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Reynolds LL, Johnson BR, Pfeifer-Meister L, Bridgham SD. Soil respiration response to climate change in Pacific Northwest prairies is mediated by a regional Mediterranean climate gradient. GLOBAL CHANGE BIOLOGY 2015; 21:487-500. [PMID: 25205511 DOI: 10.1111/gcb.12732] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 08/04/2014] [Accepted: 08/25/2014] [Indexed: 06/03/2023]
Abstract
Soil respiration is expected to increase with rising global temperatures but the degree of response may depend on soil moisture and other local factors. Experimental climate change studies from single sites cannot discern whether an observed response is site-dependent or generalizable. To deconvolve site-specific vs. regional climatic controls, we examined soil respiration for 18 months along a 520 km climate gradient in three Pacific Northwest, USA prairies that represents increasingly severe Mediterranean conditions from north to south. At each site we implemented a fully factorial combination of 2.5-3 °C warming and 20% added precipitation intensity. The response of soil respiration to warming was driven primarily by the latitudinal climate gradient and not site-specific factors. Warming increased respiration at all sites during months when soil moisture was not limiting. However, these gains were offset by reductions in respiration during seasonal transitions and summer drought due to lengthened periods of soil moisture limitation. The degree of this offset varied along the north-south climate gradient such that in 2011 warming increased cumulative annual soil respiration 28.6% in the northern site, 13.5% in the central site, and not at all in the southern site. Precipitation also stimulated soil respiration more frequently in the south, consistent with an increased duration of moisture limitation. The best predictors of soil respiration in nonlinear models were the Normalized Difference Vegetation Index (NDVI), antecedent soil moisture, and temperature but these models provided biased results at high and low soil respiration. NDVI was an effective integrator of climate and site differences in plant productivity in terms of their combined effects on soil respiration. Our results suggest that soil moisture limitation can offset the effect of warming on soil respiration, and that greater growing-season moisture limitation would constrain cumulative annual responses to warming.
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Affiliation(s)
- Lorien L Reynolds
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, 97403, USA
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43
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Lou XD, Zhai SQ, Kang B, Hu YL, Hu LL. Rapid response of hydrological loss of DOC to water table drawdown and warming in Zoige peatland: results from a mesocosm experiment. PLoS One 2014; 9:e109861. [PMID: 25369065 PMCID: PMC4219674 DOI: 10.1371/journal.pone.0109861] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 09/03/2014] [Indexed: 11/19/2022] Open
Abstract
A large portion of the global carbon pool is stored in peatlands, which are sensitive to a changing environment conditions. The hydrological loss of dissolved organic carbon (DOC) is believed to play a key role in determining the carbon balance in peatlands. Zoige peatland, the largest peat store in China, is experiencing climatic warming and drying as well as experiencing severe artificial drainage. Using a fully crossed factorial design, we experimentally manipulated temperature and controlled the water tables in large mesocosms containing intact peat monoliths. Specifically, we determined the impact of warming and water table position on the hydrological loss of DOC, the exported amounts, concentrations and qualities of DOC, and the discharge volume in Zoige peatland. Our results revealed that of the water table position had a greater impact on DOC export than the warming treatment, which showed no interactive effects with the water table treatment. Both DOC concentration and discharge volume were significantly increased when water table drawdown, while only the DOC concentration was significantly promoted by warming treatment. Annual DOC export was increased by 69% and 102% when the water table, controlled at 0 cm, was experimentally lowered by -10 cm and -20 cm. Increases in colored and aromatic constituents of DOC (measured by Abs(254 nm), SUVA(254 nm), Abs(400 nm), and SUVA(400 nm)) were observed under the lower water tables and at the higher peat temperature. Our results provide an indication of the potential impacts of climatic change and anthropogenic drainage on the carbon cycle and/or water storage in a peatland and simultaneously imply the likelihood of potential damage to downstream ecosystems. Furthermore, our results highlight the need for local protection and sustainable development, as well as suggest that more research is required to better understand the impacts of climatic change and artificial disturbances on peatland degradation.
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Affiliation(s)
- Xue-Dong Lou
- Chinese Research Academy of Environmental Sciences, Beijing, China
- College of Life Sciences, Northwest Agriculture & Forestry University, Yangling, Shaanxi, China
| | - Sheng-Qiang Zhai
- Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Bing Kang
- College of Life Sciences, Northwest Agriculture & Forestry University, Yangling, Shaanxi, China
| | - Ya-Lin Hu
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Li-Le Hu
- Chinese Research Academy of Environmental Sciences, Beijing, China
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Xu MH, Peng F, You QG, Guo J, Tian XF, Liu M, Xue X. Initial Effects of Experimental Warming on Temperature, Moisture, and Vegetation Characteristics in an Alpine Meadow on the Qinghai-Tibetan Plateau. POLISH JOURNAL OF ECOLOGY 2014. [DOI: 10.3161/104.062.0310] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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45
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Response of two dominant boreal freshwater wetland plants to manipulated warming and altered precipitation. PLoS One 2014; 9:e104454. [PMID: 25105764 PMCID: PMC4126707 DOI: 10.1371/journal.pone.0104454] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 07/11/2014] [Indexed: 11/30/2022] Open
Abstract
This study characterized the morphological and photosynthetic responses of two wetland plant species when they were subject to 2–6°C fluctuations in growth temperature and ±50% of precipitation, in order to predict the evolution of natural wetlands in Sanjiang Plain of North-eastern China. We investigated the morphological and photosynthetic responses of two dominant and competitive boreal freshwater wetland plants in Northeastern China to manipulation of warming (ambient, +2.0°C, +4.0°C, +6.0°C) and altered precipitation (−50%, ambient, +50%) simultaneously by incubating the plants from seedling to senescence within climate-controlled environmental chambers. Post-harvest, secondary growth of C. angustifolia was observed to explore intergenerational effects. The results indicated that C. angustifolia demonstrated a greater acclimated capacity than G. spiculosa to respond to climate change due to higher resistance to temperature and precipitation manipulations. The accumulated effect on aboveground biomass of post-harvest secondary growth of C. angustifolia was significant. These results explain the expansion of C. angustifolia during last 40 years and indicate the further expansion in natural boreal wetlands under a warmer and wetter future. Stability of the natural surface water table is critical for the conservation and restoration of G. spiculosa populations reacting to encroachment stress from C. angustifolia expansion.
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46
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Cheng H, Ren W, Ding L, Liu Z, Fang C. Responses of a rice–wheat rotation agroecosystem to experimental warming. Ecol Res 2013. [DOI: 10.1007/s11284-013-1078-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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47
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Peñuelas J, Sardans J, Estiarte M, Ogaya R, Carnicer J, Coll M, Barbeta A, Rivas-Ubach A, Llusià J, Garbulsky M, Filella I, Jump AS. Evidence of current impact of climate change on life: a walk from genes to the biosphere. GLOBAL CHANGE BIOLOGY 2013; 19:2303-38. [PMID: 23505157 DOI: 10.1111/gcb.12143] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 12/31/2012] [Accepted: 01/14/2013] [Indexed: 05/19/2023]
Abstract
We review the evidence of how organisms and populations are currently responding to climate change through phenotypic plasticity, genotypic evolution, changes in distribution and, in some cases, local extinction. Organisms alter their gene expression and metabolism to increase the concentrations of several antistress compounds and to change their physiology, phenology, growth and reproduction in response to climate change. Rapid adaptation and microevolution occur at the population level. Together with these phenotypic and genotypic adaptations, the movement of organisms and the turnover of populations can lead to migration toward habitats with better conditions unless hindered by barriers. Both migration and local extinction of populations have occurred. However, many unknowns for all these processes remain. The roles of phenotypic plasticity and genotypic evolution and their possible trade-offs and links with population structure warrant further research. The application of omic techniques to ecological studies will greatly favor this research. It remains poorly understood how climate change will result in asymmetrical responses of species and how it will interact with other increasing global impacts, such as N eutrophication, changes in environmental N : P ratios and species invasion, among many others. The biogeochemical and biophysical feedbacks on climate of all these changes in vegetation are also poorly understood. We here review the evidence of responses to climate change and discuss the perspectives for increasing our knowledge of the interactions between climate change and life.
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Affiliation(s)
- Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CEAB-CSIC-UAB, Cerdanyola del Vallès, Catalonia, Spain.
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48
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Modeling CO2 and CH4 flux changes in pristine peatlands of Finland under changing climate conditions. Ecol Modell 2013. [DOI: 10.1016/j.ecolmodel.2013.04.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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49
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Heijmans MMPD, van der Knaap YAM, Holmgren M, Limpens J. Persistent versus transient tree encroachment of temperate peat bogs: effects of climate warming and drought events. GLOBAL CHANGE BIOLOGY 2013; 19:2240-2250. [PMID: 23526779 DOI: 10.1111/gcb.12202] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 12/13/2012] [Accepted: 02/19/2013] [Indexed: 06/02/2023]
Abstract
Peatlands store approximately 30% of global soil carbon, most in moss-dominated bogs. Future climatic changes, such as changes in precipitation patterns and warming, are expected to affect peat bog vegetation composition and thereby its long-term carbon sequestration capacity. Theoretical work suggests that an episode of rapid environmental change is more likely to trigger transitions to alternative ecosystem states than a gradual, but equally large, change in conditions. We used a dynamic vegetation model to explore the impacts of drought events and increased temperature on vegetation composition of temperate peat bogs. We analyzed the consequences of six patterns of summer drought events combined with five temperature scenarios to test whether an open peat bog dominated by moss (Sphagnum) could shift to a tree-dominated state. Unexpectedly, neither a gradual decrease in the amount of summer precipitation nor the occurrence of a number of extremely dry summers in a row could shift the moss-dominated peat bog permanently into a tree-dominated peat bog. The increase in tree biomass during drought events was unable to trigger positive feedbacks that keep the ecosystem in a tree-dominated state after a return to previous 'normal' rainfall conditions. In contrast, temperature increases from 1 °C onward already shifted peat bogs into tree-dominated ecosystems. In our simulations, drought events facilitated tree establishment, but temperature determined how much tree biomass could develop. Our results suggest that under current climatic conditions, peat bog vegetation is rather resilient to drought events, but very sensitive to temperature increases, indicating that future warming is likely to trigger persistent vegetation shifts.
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Affiliation(s)
- Monique M P D Heijmans
- Nature Conservation and Plant Ecology Group, Wageningen University, Wageningen, The Netherlands.
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50
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Gornish ES, Tylianakis JM. Community shifts under climate change: mechanisms at multiple scales. AMERICAN JOURNAL OF BOTANY 2013; 100:1422-1434. [PMID: 23825134 DOI: 10.3732/ajb.1300046] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
PREMISE OF THE STUDY Processes that drive ecological dynamics differ across spatial scales. Therefore, the pathways through which plant communities and plant-insect relationships respond to changing environmental conditions are also expected to be scale-dependent. Furthermore, the processes that affect individual species or interactions at single sites may differ from those affecting communities across multiple sites. METHODS We reviewed and synthesized peer-reviewed literature to identify patterns in biotic or abiotic pathways underpinning changes in the composition and diversity of plant communities under three components of climate change (increasing temperature, CO2, and changes in precipitation) and how these differ across spatial scales. We also explored how these changes to plants affect plant-insect interactions. KEY RESULTS The relative frequency of biotic vs. abiotic pathways of climate effects at larger spatial scales often differ from those at smaller scales. Local-scale studies show variable responses to climate drivers, often driven by biotic factors. However, larger scale studies identify changes to species composition and/or reduced diversity as a result of abiotic factors. Differing pathways of climate effects can result from different responses of multiple species, habitat effects, and differing effects of invasions at local vs. regional to global scales. Plant community changes can affect higher trophic levels as a result of spatial or phenological mismatch, foliar quality changes, and plant abundance changes, though studies on plant-insect interactions at larger scales are rare. CONCLUSIONS Climate-induced changes to plant communities will have considerable effects on community-scale trophic exchanges, which may differ from the responses of individual species or pairwise interactions.
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Affiliation(s)
- Elise S Gornish
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306-4295, USA.
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