201
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Kiedrowicz A, Rector BG, Zawierucha K, Szydło W, Skoracka A. Phytophagous mites (Acari: Eriophyoidea) recorded from Svalbard, including the description of a new species. Polar Biol 2016. [DOI: 10.1007/s00300-015-1858-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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202
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Jiang LL, Wang SP, Meng FD, Duan JC, Niu HS, Xu GP, Zhu XX, Zhang ZH, Luo CY, Cui SJ, Li YM, Li XE, Wang Q, Zhou Y, Bao XY, Li YN, Dorji T, Piao SL, Ciais P, Peñuelas J, Du MY, Zhao XQ, Zhao L, Zhang FW, Wang GJ. Relatively stable response of fruiting stage to warming and cooling relative to other phenological events. Ecology 2016; 97:1961-1969. [DOI: 10.1002/ecy.1450] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 02/23/2016] [Accepted: 03/04/2016] [Indexed: 11/11/2022]
Affiliation(s)
- L. L. Jiang
- Key Laboratory of Alpine Ecology and Biodiversity; Institute of Tibetan Plateau Research; Chinese Academy of Sciences; Beijing 100101 China
- Naqu Integrated Observation and Research Station of Ecology and Environment; Tibet University and Institute of Tibetan Plateau Research of the Chinese Academy of Sciences; Lasa 850012 China
| | - S. P. Wang
- Key Laboratory of Alpine Ecology and Biodiversity; Institute of Tibetan Plateau Research; Chinese Academy of Sciences; Beijing 100101 China
- Naqu Integrated Observation and Research Station of Ecology and Environment; Tibet University and Institute of Tibetan Plateau Research of the Chinese Academy of Sciences; Lasa 850012 China
- CAS Center for Excellence in Tibetan Plateau Earth Science; Chinese Academy of Sciences; Beijing 100101 China
| | - F. D. Meng
- Key Laboratory of Alpine Ecology and Biodiversity; Institute of Tibetan Plateau Research; Chinese Academy of Sciences; Beijing 100101 China
- University of Chinese Academy of Sciences; Beijing 100049 China
| | - J. C. Duan
- Binhai Research Institute in Tianjin; Tianjin 300457 China
| | - H. S. Niu
- University of Chinese Academy of Sciences; Beijing 100049 China
| | - G. P. Xu
- Guangxi Institute of Botany; Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences; Guangxi 541006 China
| | - X. X. Zhu
- Naqu Integrated Observation and Research Station of Ecology and Environment; Tibet University and Institute of Tibetan Plateau Research of the Chinese Academy of Sciences; Lasa 850012 China
- Key Laboratory of Adaptation and Evolution of Plateau Biota; Northwest Institute of Plateau Biology; Chinese Academy of Sciences; Xining 810008 China
| | - Z. H. Zhang
- Key Laboratory of Adaptation and Evolution of Plateau Biota; Northwest Institute of Plateau Biology; Chinese Academy of Sciences; Xining 810008 China
| | - C. Y. Luo
- Key Laboratory of Adaptation and Evolution of Plateau Biota; Northwest Institute of Plateau Biology; Chinese Academy of Sciences; Xining 810008 China
| | - S. J. Cui
- Key Laboratory of Alpine Ecology and Biodiversity; Institute of Tibetan Plateau Research; Chinese Academy of Sciences; Beijing 100101 China
- Naqu Integrated Observation and Research Station of Ecology and Environment; Tibet University and Institute of Tibetan Plateau Research of the Chinese Academy of Sciences; Lasa 850012 China
| | - Y. M. Li
- Key Laboratory of Alpine Ecology and Biodiversity; Institute of Tibetan Plateau Research; Chinese Academy of Sciences; Beijing 100101 China
| | - X. E. Li
- Key Laboratory of Alpine Ecology and Biodiversity; Institute of Tibetan Plateau Research; Chinese Academy of Sciences; Beijing 100101 China
| | - Q. Wang
- Key Laboratory of Alpine Ecology and Biodiversity; Institute of Tibetan Plateau Research; Chinese Academy of Sciences; Beijing 100101 China
- University of Chinese Academy of Sciences; Beijing 100049 China
| | - Y. Zhou
- Key Laboratory of Alpine Ecology and Biodiversity; Institute of Tibetan Plateau Research; Chinese Academy of Sciences; Beijing 100101 China
- University of Chinese Academy of Sciences; Beijing 100049 China
| | - X. Y. Bao
- University of Chinese Academy of Sciences; Beijing 100049 China
| | - Y. N. Li
- Key Laboratory of Adaptation and Evolution of Plateau Biota; Northwest Institute of Plateau Biology; Chinese Academy of Sciences; Xining 810008 China
| | - T. Dorji
- Key Laboratory of Alpine Ecology and Biodiversity; Institute of Tibetan Plateau Research; Chinese Academy of Sciences; Beijing 100101 China
- Naqu Integrated Observation and Research Station of Ecology and Environment; Tibet University and Institute of Tibetan Plateau Research of the Chinese Academy of Sciences; Lasa 850012 China
| | - S. L. Piao
- Key Laboratory of Alpine Ecology and Biodiversity; Institute of Tibetan Plateau Research; Chinese Academy of Sciences; Beijing 100101 China
| | - P. Ciais
- Laboratoire des Sciences du Climat et de l'Environnement; CEA CNRS UVSQ; 91191 Gif-sur-Yvette France
| | - J. Peñuelas
- CREAF; Cerdanyola del Valles Barcelona 08193 Catalonia, Spain
- CSIC; Global Ecology Unit CREAF-CEAB-CSIC-UAB; Cerdanyola del Vallès Barcelona 08193 Catalonia Spain
| | - M. Y. Du
- National Institute for Agro-Environment Sciences; Tsukuba 305-8604 Japan
| | - X. Q. Zhao
- Key Laboratory of Adaptation and Evolution of Plateau Biota; Northwest Institute of Plateau Biology; Chinese Academy of Sciences; Xining 810008 China
| | - L. Zhao
- Key Laboratory of Adaptation and Evolution of Plateau Biota; Northwest Institute of Plateau Biology; Chinese Academy of Sciences; Xining 810008 China
| | - F. W. Zhang
- Key Laboratory of Adaptation and Evolution of Plateau Biota; Northwest Institute of Plateau Biology; Chinese Academy of Sciences; Xining 810008 China
| | - G. J. Wang
- Oregon State University Agriculture and Natural Resource Program at Eastern Oregon University; La Grande Oregon 97850 USA
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203
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Sagata K, Gibb H. The Effect of Temperature Increases on an Ant-Hemiptera-Plant Interaction. PLoS One 2016; 11:e0155131. [PMID: 27434232 PMCID: PMC4951116 DOI: 10.1371/journal.pone.0155131] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 04/25/2016] [Indexed: 11/18/2022] Open
Abstract
Global temperature increases are significantly altering species distributions and the structure of ecological communities. However, the impact of temperature increases on multi- species interactions is poorly understood. We used an ant-Hemiptera-plant interaction to examine the potential outcomes of predicted temperature increases for each partner and for the availability of honeydew, a keystone resource in many forest ecosystems. We re-created this interaction in growth cabinets using predicted mean summer temperatures for Melbourne, Australia, for the years 2011 (23°C), 2050 (25°C) and 2100 (29°C), respectively, under an unmitigated greenhouse gas emission scenario. Plant growth and ant foraging activities increased, while scale insect growth, abundance and size, honeydew standing crop per tree and harvesting by ants decreased at 29°C, relative to lower temperatures (23 and 25°C). This led to decreased scale insect infestations of plants and reduced honeydew standing crop per tree at the highest temperature. At all temperatures, honeydew standing crop was lower when ants harvested the honeydew from scale insects, but the impact of ant harvesting was particularly significant at 29°C, where combined effects of temperature and ants reduced honeydew standing crop to below detectable levels. Although temperature increases in the next 35 years will have limited effects on this system, by the end of this century, warmer temperatures may cause the availability of honeydew to decline. Decline of honeydew may have far-reaching trophic effects on honeydew and ant-mediated interactions. However, field-based studies that consider the full complexity of ecosystems may be required to elucidate these impacts.
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Affiliation(s)
- Katayo Sagata
- Department of Zoology, La Trobe University, Melbourne, VIC 3086, Australia
- Papua New Guinea Institute of Biological Research, Goroka, Eastern Highlands Province, Papua New Guinea
| | - Heloise Gibb
- Department of Zoology, La Trobe University, Melbourne, VIC 3086, Australia
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204
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Manish K, Telwala Y, Nautiyal DC, Pandit MK. Modelling the impacts of future climate change on plant communities in the Himalaya: a case study from Eastern Himalaya, India. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s40808-016-0163-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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205
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Mundra S, Halvorsen R, Kauserud H, Bahram M, Tedersoo L, Elberling B, Cooper EJ, Eidesen PB. Ectomycorrhizal and saprotrophic fungi respond differently to long-term experimentally increased snow depth in the High Arctic. Microbiologyopen 2016; 5:856-869. [PMID: 27255701 PMCID: PMC5061721 DOI: 10.1002/mbo3.375] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 04/11/2016] [Accepted: 04/18/2016] [Indexed: 11/24/2022] Open
Abstract
Changing climate is expected to alter precipitation patterns in the Arctic, with consequences for subsurface temperature and moisture conditions, community structure, and nutrient mobilization through microbial belowground processes. Here, we address the effect of increased snow depth on the variation in species richness and community structure of ectomycorrhizal (ECM) and saprotrophic fungi. Soil samples were collected weekly from mid‐July to mid‐September in both control and deep snow plots. Richness of ECM fungi was lower, while saprotrophic fungi was higher in increased snow depth plots relative to controls. [Correction added on 23 September 2016 after first online publication: In the preceding sentence, the richness of ECM and saprotrophic fungi were wrongly interchanged and have been fixed in this current version.] ECM fungal richness was related to soil NO3‐N, NH4‐N, and K; and saprotrophic fungi to NO3‐N and pH. Small but significant changes in the composition of saprotrophic fungi could be attributed to snow treatment and sampling time, but not so for the ECM fungi. Delayed snow melt did not influence the temporal variation in fungal communities between the treatments. Results suggest that some fungal species are favored, while others are disfavored resulting in their local extinction due to long‐term changes in snow amount. Shifts in species composition of fungal functional groups are likely to affect nutrient cycling, ecosystem respiration, and stored permafrost carbon.
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Affiliation(s)
- Sunil Mundra
- The University Centre in Svalbard, P.O. Box 156, NO-9171, Longyearbyen, Norway. , .,Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, P.O. Box 1066, Blindern, NO-0316, Oslo, Norway. ,
| | - Rune Halvorsen
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Håvard Kauserud
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, P.O. Box 1066, Blindern, NO-0316, Oslo, Norway
| | - Mohammad Bahram
- Institute of Ecology and Earth Sciences, Tartu University, 14A Ravila, 50411, Tartu, Estonia.,Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, SE 75236, Uppsala, Sweden
| | - Leho Tedersoo
- Natural History Museum, University of Tartu, 14A Ravila, 50411, Tartu, Estonia
| | - Bo Elberling
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, DK-1350, Copenhagen, Denmark
| | - Elisabeth J Cooper
- Department of Arctic and Marine Biology, Institute of Biosciences Fisheries and Economics, UiT The Arctic University of Norway, N-9037, Tromsø, Norway
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206
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Winkler DE, Chapin KJ, Kueppers LM. Soil moisture mediates alpine life form and community productivity responses to warming. Ecology 2016; 97:1553-1563. [DOI: 10.1890/15-1197.1] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 01/04/2016] [Accepted: 01/11/2016] [Indexed: 11/18/2022]
Affiliation(s)
- Daniel E. Winkler
- School of Engineering University of California, Merced 5200 North Lake Road Merced CA 95343 USA
| | - Kenneth J. Chapin
- Department of Ecology and Evolutionary Biology University of California, Los Angeles 612 Charles E. Young Drive East Los Angeles CA 90095‐7246 USA
| | - Lara M. Kueppers
- Sierra Nevada Research Institute University of California, Merced 5200 North Lake Road Merced CA 95343 USA
- Climate and Ecosystem Sciences Division Lawrence Berkeley National Laboratory One Cyclotron Road Berkeley CA 94720 USA
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207
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Spectral determination of concentrations of functionally diverse pigments in increasingly complex arctic tundra canopies. Oecologia 2016; 182:85-97. [PMID: 27193900 DOI: 10.1007/s00442-016-3646-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 04/28/2016] [Indexed: 10/21/2022]
Abstract
As the Arctic warms, tundra vegetation is becoming taller and more structurally complex, as tall deciduous shrubs become increasingly dominant. Emerging studies reveal that shrubs exhibit photosynthetic resource partitioning, akin to forests, that may need accounting for in the "big leaf" net ecosystem exchange models. We conducted a lab experiment on sun and shade leaves from S. pulchra shrubs to determine the influence of both constitutive (slowly changing bulk carotenoid and chlorophyll pools) and facultative (rapidly changing xanthophyll cycle) pigment pools on a suite of spectral vegetation indices, to devise a rapid means of estimating within canopy resource partitioning. We found that: (1) the PRI of dark-adapted shade leaves (PRIo) was double that of sun leaves, and that PRIo was sensitive to variation among sun and shade leaves in both xanthophyll cycle pool size (V + A + Z) (r (2) = 0.59) and Chla/b (r (2) = 0.64); (2) A corrected PRI (difference between dark and illuminated leaves, ΔPRI) was more sensitive to variation among sun and shade leaves in changes to the epoxidation state of their xanthophyll cycle pigments (dEPS) (r (2) = 0.78, RMSE = 0.007) compared to the uncorrected PRI of illuminated leaves (PRI) (r (2) = 0.34, RMSE = 0.02); and (3) the SR680 index was correlated with each of (V + A + Z), lutein, bulk carotenoids, (V + A + Z)/(Chla + b), and Chla/b (r (2) range = 0.52-0.69). We suggest that ΔPRI be employed as a proxy for facultative pigment dynamics, and the SR680 for the estimation of constitutive pigment pools. We contribute the first Arctic-specific information on disentangling PRI-pigment relationships, and offer insight into how spectral indices can assess resource partitioning within shrub tundra canopies.
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208
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Livensperger C, Steltzer H, Darrouzet-Nardi A, Sullivan PF, Wallenstein M, Weintraub MN. Earlier snowmelt and warming lead to earlier but not necessarily more plant growth. AOB PLANTS 2016; 8:plw021. [PMID: 27075181 PMCID: PMC4866651 DOI: 10.1093/aobpla/plw021] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/14/2016] [Indexed: 05/09/2023]
Abstract
Climate change over the past ∼50 years has resulted in earlier occurrence of plant life-cycle events for many species. Across temperate, boreal and polar latitudes, earlier seasonal warming is considered the key mechanism leading to earlier leaf expansion and growth. Yet, in seasonally snow-covered ecosystems, the timing of spring plant growth may also be cued by snowmelt, which may occur earlier in a warmer climate. Multiple environmental cues protect plants from growing too early, but to understand how climate change will alter the timing and magnitude of plant growth, experiments need to independently manipulate temperature and snowmelt. Here, we demonstrate that altered seasonality through experimental warming and earlier snowmelt led to earlier plant growth, but the aboveground production response varied among plant functional groups. Earlier snowmelt without warming led to early leaf emergence, but often slowed the rate of leaf expansion and had limited effects on aboveground production. Experimental warming alone had small and inconsistent effects on aboveground phenology, while the effect of the combined treatment resembled that of early snowmelt alone. Experimental warming led to greater aboveground production among the graminoids, limited changes among deciduous shrubs and decreased production in one of the dominant evergreen shrubs. As a result, we predict that early onset of the growing season may favour early growing plant species, even those that do not shift the timing of leaf expansion.
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Affiliation(s)
- Carolyn Livensperger
- Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO 80523, USA
| | - Heidi Steltzer
- Biology Department, Fort Lewis College, Durango, CO 81301, USA
| | | | - Patrick F Sullivan
- Environment and Natural Resources Institute, University of Alaska Anchorage, Anchorage, AK 99508, USA
| | - Matthew Wallenstein
- Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO 80523, USA
| | - Michael N Weintraub
- Department of Environmental Sciences, University of Toledo, Toledo, OH 43606, USA
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209
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Sandström P, Cory N, Svensson J, Hedenås H, Jougda L, Borchert N. On the decline of ground lichen forests in the Swedish boreal landscape: Implications for reindeer husbandry and sustainable forest management. AMBIO 2016; 45:415-29. [PMID: 26754169 PMCID: PMC4824705 DOI: 10.1007/s13280-015-0759-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 05/04/2015] [Accepted: 12/14/2015] [Indexed: 05/06/2023]
Abstract
Lichens are a bottleneck resource for circumpolar populations of reindeer, and as such, for reindeer husbandry as an indigenous Sami land-use tradition in northern Sweden. This study uses ground lichen data and forest information collected within the Swedish National Forest Inventory since 1953, on the scale of northern Sweden. We found a 71 % decline in the area of lichen-abundant forests over the last 60 years. A decline was observed in all regions and age classes and especially coincided with a decrease of >60 year old, open pine forests, which was the primary explanatory factor in our model. The effects of reindeer numbers were inconclusive in explaining the decrease in lichen-abundant forest. The role that forestry has played in causing this decline can be debated, but forestry can have a significant role in reversing the trend and improving ground lichen conditions.
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Affiliation(s)
- Per Sandström
- Department of Forest Resource Management, Faculty of Forest Sciences, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden.
| | - Neil Cory
- Department of Forest Resource Management, Faculty of Forest Sciences, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden
| | - Johan Svensson
- Department of Wildlife, Fish and Environmental Studies, Faculty of Forest Sciences, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden
| | - Henrik Hedenås
- Department of Forest Resource Management, Faculty of Forest Sciences, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden
| | - Leif Jougda
- Swedish Forest Agency, Volgsjövägen 27, 912 34, Vilhelmina, Sweden
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210
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Olsen SL, Töpper JP, Skarpaas O, Vandvik V, Klanderud K. From facilitation to competition: temperature-driven shift in dominant plant interactions affects population dynamics in seminatural grasslands. GLOBAL CHANGE BIOLOGY 2016; 22:1915-1926. [PMID: 26845378 DOI: 10.1111/gcb.13241] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 01/22/2016] [Accepted: 01/25/2016] [Indexed: 06/05/2023]
Abstract
Biotic interactions are often ignored in assessments of climate change impacts. However, climate-related changes in species interactions, often mediated through increased dominance of certain species or functional groups, may have important implications for how species respond to climate warming and altered precipitation patterns. We examined how a dominant plant functional group affected the population dynamics of four co-occurring forb species by experimentally removing graminoids in seminatural grasslands. Specifically, we explored how the interaction between dominants and subordinates varied with climate by replicating the removal experiment across a climate grid consisting of 12 field sites spanning broad-scale temperature and precipitation gradients in southern Norway. Biotic interactions affected population growth rates of all study species, and the net outcome of interactions between dominants and subordinates switched from facilitation to competition with increasing temperature along the temperature gradient. The impacts of competitive interactions on subordinates in the warmer sites could primarily be attributed to reduced plant survival. Whereas the response to dominant removal varied with temperature, there was no overall effect of precipitation on the balance between competition and facilitation. Our findings suggest that global warming may increase the relative importance of competitive interactions in seminatural grasslands across a wide range of precipitation levels, thereby favouring highly competitive dominant species over subordinate species. As a result, seminatural grasslands may become increasingly dependent on disturbance (i.e. traditional management such as grazing and mowing) to maintain viable populations of subordinate species and thereby biodiversity under future climates. Our study highlights the importance of population-level studies replicated under different climatic conditions for understanding the underlying mechanisms of climate change impacts on plants.
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Affiliation(s)
- Siri L Olsen
- Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, N-1432, Ås, Norway
- Norwegian Institute for Nature Research, Gaustadalléen 21, N-0349, Oslo, Norway
| | - Joachim P Töpper
- Faculty of Engineering and Science, Sogn og Fjordane University College, P.O. Box 133, N-6851, Sogndal, Norway
- Department of Biology, University of Bergen, P.O. Box 7803, N-5020, Bergen, Norway
| | - Olav Skarpaas
- Norwegian Institute for Nature Research, Gaustadalléen 21, N-0349, Oslo, Norway
| | - Vigdis Vandvik
- Department of Biology, University of Bergen, P.O. Box 7803, N-5020, Bergen, Norway
| | - Kari Klanderud
- Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, N-1432, Ås, Norway
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211
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Whiteley JA, Gonzalez A. Biotic nitrogen fixation in the bryosphere is inhibited more by drought than warming. Oecologia 2016; 181:1243-58. [DOI: 10.1007/s00442-016-3601-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 03/03/2016] [Indexed: 11/30/2022]
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212
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Examination of Surface Temperature Modification by Open-Top Chambers along Moisture and Latitudinal Gradients in Arctic Alaska Using Thermal Infrared Photography. REMOTE SENSING 2016. [DOI: 10.3390/rs8010054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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213
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Newaz MS, Dang QL, Man R. Morphological Response of Jack Pine to the Interactive Effects of Carbon Dioxide, Soil Temperature and Photoperiod. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/ajps.2016.76083] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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214
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The role of summer precipitation and summer temperature in establishment and growth of dwarf shrub Betula nana in northeast Siberian tundra. Polar Biol 2015. [DOI: 10.1007/s00300-015-1847-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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215
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Declining resilience of ecosystem functions under biodiversity loss. Nat Commun 2015; 6:10122. [PMID: 26646209 PMCID: PMC4686828 DOI: 10.1038/ncomms10122] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 11/03/2015] [Indexed: 11/08/2022] Open
Abstract
The composition of species communities is changing rapidly through drivers such as habitat loss and climate change, with potentially serious consequences for the resilience of ecosystem functions on which humans depend. To assess such changes in resilience, we analyse trends in the frequency of species in Great Britain that provide key ecosystem functions—specifically decomposition, carbon sequestration, pollination, pest control and cultural values. For 4,424 species over four decades, there have been significant net declines among animal species that provide pollination, pest control and cultural values. Groups providing decomposition and carbon sequestration remain relatively stable, as fewer species are in decline and these are offset by large numbers of new arrivals into Great Britain. While there is general concern about degradation of a wide range of ecosystem functions, our results suggest actions should focus on particular functions for which there is evidence of substantial erosion of their resilience. Global change may affect the resilience of ecosystem functions by altering community composition. Here, Oliver et al. show that in Great Britain since the 1970s there have been significant net declines among animal species that provide key ecosystem functions such as pollination and pest control.
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216
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Provencher-Nolet L, Bernier M, Lévesque E. Quantification des changements récents à l'écotone forêt-toundra à partir de l'analyse numérique de photographies aériennes. ECOSCIENCE 2015. [DOI: 10.2980/21-(3-4)-3715] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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217
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Bowden JJ, Buddle CM. Determinants of ground-dwelling spider assemblages at a regional scale in the Yukon Territory, Canada. ECOSCIENCE 2015. [DOI: 10.2980/17-3-3308] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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218
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Khorsand Rosa R, Oberbauer SF, Starr G, Parker La Puma I, Pop E, Ahlquist L, Baldwin T. Plant phenological responses to a long-term experimental extension of growing season and soil warming in the tussock tundra of Alaska. GLOBAL CHANGE BIOLOGY 2015; 21:4520-32. [PMID: 26183112 DOI: 10.1111/gcb.13040] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 06/29/2015] [Indexed: 05/27/2023]
Abstract
Climate warming is strongly altering the timing of season initiation and season length in the Arctic. Phenological activities are among the most sensitive plant responses to climate change and have important effects at all levels within the ecosystem. We tested the effects of two experimental treatments, extended growing season via snow removal and extended growing season combined with soil warming, on plant phenology in tussock tundra in Alaska from 1995 through 2003. We specifically monitored the responses of eight species, representing four growth forms: (i) graminoids (Carex bigellowii and Eriophorum vaginatum); (ii) evergreen shrubs (Ledum palustre, Cassiope tetragona, and Vaccinium vitis-idaea); (iii) deciduous shrubs (Betula nana and Salix pulchra); and (iv) forbs (Polygonum bistorta). Our study answered three questions: (i) Do experimental treatments affect the timing of leaf bud break, flowering, and leaf senescence? (ii) Are responses to treatments species-specific and growth form-specific? and (iii) Which environmental factors best predict timing of phenophases? Treatment significantly affected the timing of all three phenophases, although the two experimental treatments did not differ from each other. While phenological events began earlier in the experimental plots relative to the controls, duration of phenophases did not increase. The evergreen shrub, Cassiope tetragona, did not respond to either experimental treatment. While the other species did respond to experimental treatments, the total active period for these species did not increase relative to the control. Air temperature was consistently the best predictor of phenology. Our results imply that some evergreen shrubs (i.e., C. tetragona) will not capitalize on earlier favorable growing conditions, putting them at a competitive disadvantage relative to phenotypically plastic deciduous shrubs. Our findings also suggest that an early onset of the growing season as a result of decreased snow cover will not necessarily result in greater tundra productivity.
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Affiliation(s)
- Roxaneh Khorsand Rosa
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
| | - Steven F Oberbauer
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
| | - Gregory Starr
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, 35487, USA
| | - Inga Parker La Puma
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
- Rutgers University, New Brunswick, NJ, 08901, USA
| | - Eric Pop
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
- Bay Area Air Quality Management District, San Francisco, CA, 94109, USA
| | - Lorraine Ahlquist
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
- Parsons Brinckerhoff, San Diego, CA, 92101, USA
| | - Tracey Baldwin
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
- NEON, Inc., Boulder, CO, 80301, USA
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219
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Ropars P, Lévesque E, Boudreau S. Shrub densification heterogeneity in subarctic regions: the relative influence of historical and topographic variables. ECOSCIENCE 2015. [DOI: 10.1080/11956860.2015.1107262] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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220
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Little CJ, Jägerbrand AK, Molau U, Alatalo JM. Community and species-specific responses to simulated global change in two subarctic-alpine plant communities. Ecosphere 2015. [DOI: 10.1890/es14-00427.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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221
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Shen M, Piao S, Dorji T, Liu Q, Cong N, Chen X, An S, Wang S, Wang T, Zhang G. Plant phenological responses to climate change on the Tibetan Plateau: research status and challenges. Natl Sci Rev 2015. [DOI: 10.1093/nsr/nwv058] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Phenology studies the cycle of events in nature that are initiated and driven by an annually recurring environment. Plant phenology is expected to be one of the most sensitive and easily observable natural indicators of climate change. On the Tibetan Plateau (TP), an accelerated warming since the mid-1980s has resulted in significant environmental changes. These new conditions are accompanied by phenological changes that are characterized by considerable spatiotemporal heterogeneity. Satellite remote sensing observed widespread advance in the start of the plant growing season across the plateau during the 1980s and 1990s but substantial delay over 2000–2011 in the southwest although it continued to advance in the northeast regions of the TP. Both observational studies and controlled experiments have revealed, to some extent, the positive role of higher preseason temperature and even more precipitation in advancing the leaf onset and first flowering date of the TP. However, a number of rarely visited research issues that are essential for understanding the role of phenology in ecosystem responses and feedback processes to climate change remain to be solved. Our review recommends that addressing the following questions should be a high priority. How did other phenological events change, such as flowering and fruiting phenology? What are the influences from environmental changes other than temperature and precipitation, including human activities such as grazing? What are the genetic and physiological bases of plants phenological responses? How does phenological change influence ecosystem structure and function at different scales and feedback to the climate system? Investigating these research questions requires, first of all, new data of the associated environmental variables, and consistent and reliable phenological observation using different methodologies (i.e. in situ observations and remote sensing).
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Affiliation(s)
- Miaogen Shen
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China
| | - Shilong Piao
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China
- College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Tsechoe Dorji
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Qiang Liu
- College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Nan Cong
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaoqiu Chen
- College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Shuai An
- College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Shiping Wang
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China
| | - Tao Wang
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Gengxin Zhang
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
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222
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Schollert M, Kivimäenpää M, Valolahti HM, Rinnan R. Climate change alters leaf anatomy, but has no effects on volatile emissions from Arctic plants. PLANT, CELL & ENVIRONMENT 2015; 38:2048-60. [PMID: 25737381 DOI: 10.1111/pce.12530] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 02/20/2015] [Accepted: 02/23/2015] [Indexed: 05/22/2023]
Abstract
Biogenic volatile organic compound (BVOC) emissions are expected to change substantially because of the rapid advancement of climate change in the Arctic. BVOC emission changes can feed back both positively and negatively on climate warming. We investigated the effects of elevated temperature and shading on BVOC emissions from arctic plant species Empetrum hermaphroditum, Cassiope tetragona, Betula nana and Salix arctica. Measurements were performed in situ in long-term field experiments in subarctic and high Arctic using a dynamic enclosure system and collection of BVOCs into adsorbent cartridges analysed by gas chromatography-mass spectrometry. In order to assess whether the treatments had resulted in anatomical adaptations, we additionally examined leaf anatomy using light microscopy and scanning electron microscopy. Against expectations based on the known temperature and light-dependency of BVOC emissions, the emissions were barely affected by the treatments. In contrast, leaf anatomy of the studied plants was significantly altered in response to the treatments, and these responses appear to differ from species found at lower latitudes. We suggest that leaf anatomical acclimation may partially explain the lacking treatment effects on BVOC emissions at plant shoot-level. However, more studies are needed to unravel why BVOC emission responses in arctic plants differ from temperate species.
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Affiliation(s)
- Michelle Schollert
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen Ø, 2100, Denmark
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen K, 1350, Denmark
| | - Minna Kivimäenpää
- Department of Environmental Science, University of Eastern Finland, Kuopio, 70211, Finland
| | - Hanna M Valolahti
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen Ø, 2100, Denmark
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen K, 1350, Denmark
| | - Riikka Rinnan
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen Ø, 2100, Denmark
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen K, 1350, Denmark
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223
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Jacques MH, Lapointe L, Rice K, Montgomery RA, Stefanski A, Reich PB. Responses of two understory herbs, Maianthemum canadense and Eurybia macrophylla, to experimental forest warming: early emergence is the key to enhanced reproductive output. AMERICAN JOURNAL OF BOTANY 2015; 102:1610-24. [PMID: 26451035 DOI: 10.3732/ajb.1500046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 09/11/2015] [Indexed: 05/22/2023]
Abstract
PREMISE OF THE STUDY Understory herbs might be the most sensitive plant form to global warming in deciduous forests, yet they have been little studied in the context of climate change. METHODS A field experiment set up in Minnesota, United States simulated global warming in a forest setting and provided the opportunity to study the responses of Maianthemum canadense and Eurybia macrophylla in their natural environment in interaction with other components of the ecosystem. Effects of +1.7° and +3.4°C treatments on growth, reproduction, phenology, and gas exchange were evaluated along with treatment effects on light, water, and nutrient availability, potential drivers of herb responses. KEY RESULTS Overall, growth and gas exchanges of these two species were modestly affected by warming. They emerged up to 16 (E. macrophylla) to 17 d (M. canadense) earlier in the heated plots than in control plots, supporting early-season carbon gain under high light conditions before canopy closure. This additional carbon gain in spring likely supported reproduction. Eurybia macrophylla only flowered in the heated plots, and both species had some aspect of reproduction that was highest in the +1.7°C treatment. The reduced reproductive effort in the +3.4°C plots was likely due to reduced soil water availability, counteracting positive effects of warming. CONCLUSIONS Global warming might improve fitness of herbaceous species in deciduous forests, mainly by advancing their spring emergence. However, other impacts of global warming such as drier soils in the summer might partly reduce the carbon gain associated with early emergence.
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Affiliation(s)
- Marie-Hélène Jacques
- Département de biologie and Centre d'étude de la forêt, Université Laval, Québec City, QC, Canada, G1V 0A6
| | - Line Lapointe
- Département de biologie and Centre d'étude de la forêt, Université Laval, Québec City, QC, Canada, G1V 0A6
| | - Karen Rice
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota 55108 USA
| | - Rebecca A Montgomery
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota 55108 USA
| | - Artur Stefanski
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota 55108 USA
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota 55108 USA Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, New South Wales, Australia
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224
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Ylänne H, Stark S, Tolvanen A. Vegetation shift from deciduous to evergreen dwarf shrubs in response to selective herbivory offsets carbon losses: evidence from 19 years of warming and simulated herbivory in the subarctic tundra. GLOBAL CHANGE BIOLOGY 2015; 21:3696-3711. [PMID: 25950664 DOI: 10.1111/gcb.12964] [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: 01/16/2015] [Accepted: 04/06/2015] [Indexed: 06/04/2023]
Abstract
Selective herbivory of palatable plant species provides a competitive advantage for unpalatable plant species, which often have slow growth rates and produce slowly decomposable litter. We hypothesized that through a shift in the vegetation community from palatable, deciduous dwarf shrubs to unpalatable, evergreen dwarf shrubs, selective herbivory may counteract the increased shrub abundance that is otherwise found in tundra ecosystems, in turn interacting with the responses of ecosystem carbon (C) stocks and CO2 balance to climatic warming. We tested this hypothesis in a 19-year field experiment with factorial treatments of warming and simulated herbivory on the dominant deciduous dwarf shrub Vaccinium myrtillus. Warming was associated with a significantly increased vegetation abundance, with the strongest effect on deciduous dwarf shrubs, resulting in greater rates of both gross ecosystem production (GEP) and ecosystem respiration (ER) as well as increased C stocks. Simulated herbivory increased the abundance of evergreen dwarf shrubs, most importantly Empetrum nigrum ssp. hermaphroditum, which led to a recent shift in the dominant vegetation from deciduous to evergreen dwarf shrubs. Simulated herbivory caused no effect on GEP and ER or the total ecosystem C stocks, indicating that the vegetation shift counteracted the herbivore-induced C loss from the system. A larger proportion of the total ecosystem C stock was found aboveground, rather than belowground, in plots treated with simulated herbivory. We conclude that by providing a competitive advantage to unpalatable plant species with slow growth rates and long life spans, selective herbivory may promote aboveground C stocks in a warming tundra ecosystem and, through this mechanism, counteract C losses that result from plant biomass consumption.
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Affiliation(s)
- Henni Ylänne
- Department of Ecology, University of Oulu, P.O. Box 3000, Oulu, FI-90014, Finland
- Arctic Centre, University of Lapland, P.O. Box 122, Rovaniemi, FI-96101, Finland
| | - Sari Stark
- Arctic Centre, University of Lapland, P.O. Box 122, Rovaniemi, FI-96101, Finland
| | - Anne Tolvanen
- Natural Resources Institute Finland (Luke), P.O. Box 413, Oulu, FI-90014, Finland
- Thule Institute, University of Oulu, P.O. Box 7300, Oulu, FI-90014, Finland
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225
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Kopp CW, Cleland EE. A Range-Expanding Shrub Species Alters Plant Phenological Response to Experimental Warming. PLoS One 2015; 10:e0139029. [PMID: 26402617 PMCID: PMC4581864 DOI: 10.1371/journal.pone.0139029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 09/07/2015] [Indexed: 11/19/2022] Open
Abstract
Shifts in plant species phenology (the timing of life-history events such as flowering) have been observed worldwide in concert with rising global temperatures. While most species display earlier phenology with warming, there is large variation among, and even within, species in phenological sensitivity to rising temperatures. Other indirect effects of climate change, such as shifting species composition and altered species interactions, may also be contributing to shifting plant phenology. Here, we describe how experimental warming and the presence of a range-expanding species, sagebrush (Artemisia rothrockii), interact to influence the flowering phenology (day of first and peak flowering) and production (number of flowers) of an alpine cushion plant, Trifolium andersonii, in California's White Mountains. Both first flowering and peak flowering were strongly accelerated by warming, but not when sagebrush was present. Warming significantly increased flower production of T. andersonii, but less so in the presence of sagebrush. A shading treatment delayed phenology and lowered flower production, suggesting that shading may be the mechanism by which sagebrush presence delayed flowering of the understory species. This study demonstrates that species interactions can modify phenological responses to climate change, and suggests that indirect effects of rising temperatures arising from shifting species ranges and altered species interactions may even exceed the direct effects of rising temperatures on phenology.
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Affiliation(s)
- Christopher W. Kopp
- The Biodiversity Research Centre, The University of British Columbia, Vancouver, Canada
- * E-mail:
| | - Elsa E. Cleland
- Ecology, Behavior & Evolution Section, Division of Biological Sciences, University of California San Diego, San Diego, United States of America
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226
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Pointing SB, Burkhard Büdel, Convey P, Gillman LN, Körner C, Leuzinger S, Vincent WF. Biogeography of photoautotrophs in the high polar biome. FRONTIERS IN PLANT SCIENCE 2015; 6:692. [PMID: 26442009 PMCID: PMC4566839 DOI: 10.3389/fpls.2015.00692] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 08/21/2015] [Indexed: 11/19/2023]
Abstract
The global latitudinal gradient in biodiversity weakens in the high polar biome and so an alternative explanation for distribution of Arctic and Antarctic photoautotrophs is required. Here we identify how temporal, microclimate and evolutionary drivers of biogeography are important, rather than the macroclimate features that drive plant diversity patterns elsewhere. High polar ecosystems are biologically unique, with a more central role for bryophytes, lichens and microbial photoautotrophs over that of vascular plants. Constraints on vascular plants arise mainly due to stature and ontogenetic barriers. Conversely non-vascular plant and microbial photoautotroph distribution is correlated with favorable microclimates and the capacity for poikilohydric dormancy. Contemporary distribution also depends on evolutionary history, with adaptive and dispersal traits as well as legacy influencing biogeography. We highlight the relevance of these findings to predicting future impacts on diversity of polar photoautotrophs and to the current status of plants in Arctic and Antarctic conservation policy frameworks.
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Affiliation(s)
- Stephen B. Pointing
- Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of Technology, Auckland, New Zealand
| | - Burkhard Büdel
- Department of Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Peter Convey
- British Antarctic Survey, NERC, Cambridge, UK
- National Antarctic Research Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Len N. Gillman
- Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of Technology, Auckland, New Zealand
| | | | - Sebastian Leuzinger
- Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of Technology, Auckland, New Zealand
| | - Warwick F. Vincent
- Centre d’\Études Nordiques and Département de Biologie, Université Laval, Québec, QC, Canada
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227
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Kaarlejärvi E, Hoset KS, Olofsson J. Mammalian herbivores confer resilience of Arctic shrub-dominated ecosystems to changing climate. GLOBAL CHANGE BIOLOGY 2015; 21:3379-3388. [PMID: 25967156 DOI: 10.1111/gcb.12970] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 04/13/2015] [Accepted: 05/01/2015] [Indexed: 06/04/2023]
Abstract
Climate change is resulting in a rapid expansion of shrubs in the Arctic. This expansion has been shown to be reinforced by positive feedbacks, and it could thus set the ecosystem on a trajectory toward an alternate, more productive regime. Herbivores, on the other hand, are known to counteract the effects of simultaneous climate warming on shrub biomass. However, little is known about the impact of herbivores on resilience of these ecosystems, that is, the capacity of a system to absorb disturbance and still remain in the same regime, retaining the same function, structure, and feedbacks. Here, we investigated how herbivores affect resilience of shrub-dominated systems to warming by studying the change of shrub biomass after a cessation of long-term experimental warming in a forest-tundra ecotone. As predicted, warming increased the biomass of shrubs, and in the absence of herbivores, shrub biomass in tundra continued to increase 4 years after cessation of the artificial warming, indicating that positive effects of warming on plant growth may persist even over a subsequent colder period. Herbivores contributed to the resilience of these systems by returning them back to the original low-biomass regime in both forest and tundra habitats. These results support the prediction that higher shrub biomass triggers positive feedbacks on soil processes and microclimate, which enable maintaining the rapid shrub growth even in colder climates. Furthermore, the results show that in our system, herbivores facilitate the resilience of shrub-dominated ecosystems to climate warming.
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Affiliation(s)
- Elina Kaarlejärvi
- Department of Ecology and Environmental Sciences, University of Umeå, SE-90187, Umeå, Sweden
| | - Katrine S Hoset
- Section of Ecology, Department of Biology, University of Turku, FI-20014, Turku, Finland
| | - Johan Olofsson
- Department of Ecology and Environmental Sciences, University of Umeå, SE-90187, Umeå, Sweden
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228
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Ferrari A, Hagedorn F, Niklaus PA. Experimental soil warming and cooling alters the partitioning of recent assimilates: evidence from a 14C-labelling study at the alpine treeline. Oecologia 2015; 181:25-37. [DOI: 10.1007/s00442-015-3427-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 08/07/2015] [Indexed: 10/23/2022]
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229
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Loiseau N, Gaertner JC. Indices for assessing coral reef fish biodiversity: the need for a change in habits. Ecol Evol 2015; 5:4018-27. [PMID: 26445656 PMCID: PMC4588647 DOI: 10.1002/ece3.1619] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 06/24/2015] [Accepted: 06/25/2015] [Indexed: 11/12/2022] Open
Abstract
We present the first representative and quantified overview of the indices used worldwide for assessing the biodiversity of coral reef fishes. On this basis, we discuss the suitability and drawbacks of the indices most widely used in the assessment of coral fish biodiversity. An extensive and systematic survey of the literature focused on coral reef fish biodiversity was conducted from 1990 up to the present. We found that the multicomponent aspect of biodiversity, which is considered as a key feature of biodiversity for numerous terrestrial and marine ecosystems, has been poorly taken into account in coral reef fish studies. Species richness is still strongly dominant while other diversity components, such as functional diversity, are underestimated even when functional information is available. We also demonstrate that the reason for choosing particular indices is often unclear, mainly based on empirical rationales and/or the reproduction of widespread habits, but generally with no clear relevance with regard to the aims of the studies. As a result, the most widely used indices (species richness, Shannon, etc.) would appear to be poorly suited to meeting the main challenges facing the monitoring of coral reef fish biodiversity in the future. Our results clearly show that coral reef scientists should rather take advantage of the multicomponent aspect of biodiversity. To facilitate this approach, we propose general guidelines to serve as a basis for the selection of indices that provide complementary and relevant information for monitoring the response of coral reef fish biodiversity in the face of structuring factors (natural or anthropic). The aim of these guidelines was to achieve a better match between the properties of the selected indices and the context of each study (e.g. expected effect of the main structuring factors, nature of data available).
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Affiliation(s)
- Nicolas Loiseau
- University of French Polynesia - UMR-241 EIO (UPF IRD Ifremer ILM) Papeete French Polynesia
| | - Jean-Claude Gaertner
- Institut de Recherche pour le Développement (IRD) - UMR-241 EIO (UPF IRD Ifremer ILM) Laboratoire d'Excellence Corail - Papeete Papeete French Polynesia
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230
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Geml J, Morgado LN, Semenova TA, Welker JM, Walker MD, Smets E. Long-term warming alters richness and composition of taxonomic and functional groups of arctic fungi. FEMS Microbiol Ecol 2015; 91:fiv095. [PMID: 26253509 DOI: 10.1093/femsec/fiv095] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2015] [Indexed: 11/13/2022] Open
Abstract
Fungi, including symbionts, pathogens and decomposers, play crucial roles in community dynamics and nutrient cycling in terrestrial ecosystems. Despite their ecological importance, the response of most arctic fungi to climate warming is unknown, so are their potential roles in driving the observed and predicted changes in tundra communities. We carried out deep DNA sequencing of soil samples to study the long-term effects of experimental warming on fungal communities in dry heath and moist tussock tundra in Arctic Alaska. The data presented here indicate that fungal community composition responds strongly to warming in the moist tundra, but not in the dry tundra. While total fungal richness was not significantly affected by warming, there were clear correlations among operational taxonomic unit richness of various ecological and taxonomic groups and long-term warming. Richness of ectomycorrhizal, ericoid mycorrhizal and lichenized fungi generally decreased with warming, while richness of saprotrophic, plant and animal pathogenic, and root endophytic fungi tended to increase in the warmed plots. More importantly, various taxa within these functional guilds followed opposing trends that highlight the importance of species-specific responses to warming. We recommend that species-level ecological differences be taken into account in climate change and nutrient cycling studies that involve arctic fungi.
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Affiliation(s)
- József Geml
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA Leiden, the Netherlands Faculty of Science, Leiden University, PO Box 9502, 2300 RA Leiden, the Netherlands
| | - Luis N Morgado
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA Leiden, the Netherlands
| | - Tatiana A Semenova
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA Leiden, the Netherlands Faculty of Science, Leiden University, PO Box 9502, 2300 RA Leiden, the Netherlands
| | - Jeffrey M Welker
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508, USA
| | | | - Erik Smets
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA Leiden, the Netherlands Faculty of Science, Leiden University, PO Box 9502, 2300 RA Leiden, the Netherlands Plant Conservation and Population Biology, KU Leuven, Kasteelpark Arenberg 31, Box 2437, 3001 Leuven, Belgium
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231
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Yandow LH, Chalfoun AD, Doak DF. Climate Tolerances and Habitat Requirements Jointly Shape the Elevational Distribution of the American Pika (Ochotona princeps), with Implications for Climate Change Effects. PLoS One 2015; 10:e0131082. [PMID: 26244851 PMCID: PMC4526653 DOI: 10.1371/journal.pone.0131082] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 05/28/2015] [Indexed: 11/19/2022] Open
Abstract
Some of the most compelling examples of ecological responses to climate change are elevational range shifts of individual species, which have been observed throughout the world. A growing body of evidence, however, suggests substantial mediation of simple range shifts due to climate change by other limiting factors. Understanding limiting factors for a species within different contexts, therefore, is critical for predicting responses to climate change. The American pika (Ochotona princeps) is an ideal species for investigating distributions in relation to climate because of their unusual and well-understood natural history as well as observed shifts to higher elevation in parts of their range. We tested three hypotheses for the climatic or habitat characteristics that may limit pika presence and abundance: summer heat, winter snowpack, and forage availability. We performed these tests using an index of pika abundance gathered in a region where environmental influences on pika distribution have not been well-characterized. We estimated relative pika abundance via scat surveys and quantified climatic and habitat characteristics across two North-Central Rocky Mountain Ranges, the Wind River and Bighorn ranges in Wyoming, USA. Pika scat density was highest at mid-elevations and increased linearly with forage availability in both ranges. Scat density also increased with temperatures conducive to forage plant growth, and showed a unimodal relationship with the number of days below -5°C, which is modulated by insulating snowpack. Our results provide support for both the forage availability and winter snowpack hypotheses. Especially in montane systems, considering the context-dependent nature of climate effects across regions and elevations as well as interactions between climatic and other critical habitat characteristics, will be essential for predicting future species distributions.
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Affiliation(s)
- Leah H. Yandow
- Department of Zoology and Physiology, University of Wyoming, 1000 East University Avenue, Laramie, Wyoming, 82071, United States of America
- Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology (3166), University of Wyoming, 1000 East University Avenue, Laramie, Wyoming, 82071, United States of America
- * E-mail:
| | - Anna D. Chalfoun
- U.S. Geological Survey Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology (3166), University of Wyoming, 1000 East University Avenue, Laramie, Wyoming, 82071, United States of America
| | - Daniel F. Doak
- Department of Zoology and Physiology, University of Wyoming, 1000 East University Avenue, Laramie, Wyoming, 82071, United States of America
- Environmental Studies Program, University of Colorado Boulder, 1201 17 St., 397 UCB, Boulder, Colorado, 80309, United States of America
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232
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Classen AT, Sundqvist MK, Henning JA, Newman GS, Moore JAM, Cregger MA, Moorhead LC, Patterson CM. Direct and indirect effects of climate change on soil microbial and soil microbial-plant interactions: What lies ahead? Ecosphere 2015. [DOI: 10.1890/es15-00217.1] [Citation(s) in RCA: 337] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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233
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Stark S, Väisänen M, Ylänne H, Julkunen-Tiitto R, Martz F. Decreased phenolic defence in dwarf birch (Betula nana) after warming in subarctic tundra. Polar Biol 2015. [DOI: 10.1007/s00300-015-1758-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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234
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Orsenigo S, Abeli T, Rossi G, Bonasoni P, Pasquaretta C, Gandini M, Mondoni A. Effects of Autumn and Spring Heat Waves on Seed Germination of High Mountain Plants. PLoS One 2015; 10:e0133626. [PMID: 26197387 PMCID: PMC4509759 DOI: 10.1371/journal.pone.0133626] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 06/30/2015] [Indexed: 11/19/2022] Open
Abstract
Alpine plants are considered to be particularly vulnerable to climate change and related extreme episodes, such as heat waves. Despite growing interest in the impact of heat waves on alpine plants, knowledge about their effects on regeneration is still fragmentary. Recruitment from seeds will be crucial for the successful migration and survival of these species and will play a key role in their future adaptation to climate change. In this study, we assessed the impacts of heat waves on the seed germination of 53 high mountain plants from the Northern Apennines (Italy). The seeds were exposed to laboratory simulations of three seasonal temperature treatments, derived from real data recorded at a meteorological station near the species growing site, which included two heat wave episodes that occurred both in spring 2003 and in autumn 2011. Moreover, to consider the effect of increasing drought conditions related to heat waves, seed germination was also investigated under four different water potentials. In the absence of heat waves, seed germination mainly occurred in spring, after seeds had experienced autumn and winter seasons. However, heat waves resulted in a significant increase of spring germination in c. 30% of the species and elicited autumn germination in 50%. When heat waves were coupled with drought, seed germination decreased in all species, but did not stop completely. Our results suggest that in the future, heat waves will affect the germination phenology of alpine plants, especially conditionally dormant and strictly cold-adapted chorotypes, by shifting the emergence time from spring to autumn and by increasing the proportion of emerged seedlings. The detrimental effects of heat waves on recruitment success is less likely to be due to the inhibition of seed germination per se, but rather due to seedling survival in seasons, and temperature and water conditions that they are not used to experiencing. Changes in the proportion and timing of emergence suggest that there may be major implications for future plant population size and structure.
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Affiliation(s)
- Simone Orsenigo
- Department of Earth and Environmental Sciences, University of Pavia, Pavia, Italy
| | - Thomas Abeli
- Department of Earth and Environmental Sciences, University of Pavia, Pavia, Italy
| | - Graziano Rossi
- Department of Earth and Environmental Sciences, University of Pavia, Pavia, Italy
| | - Paolo Bonasoni
- Institute of Atmospheric Sciences and Climate, Bologna, Italy
| | | | | | - Andrea Mondoni
- Department of Earth and Environmental Sciences, University of Pavia, Pavia, Italy
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235
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Klanderud K, Vandvik V, Goldberg D. The Importance of Biotic vs. Abiotic Drivers of Local Plant Community Composition Along Regional Bioclimatic Gradients. PLoS One 2015; 10:e0130205. [PMID: 26091266 PMCID: PMC4474800 DOI: 10.1371/journal.pone.0130205] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 05/17/2015] [Indexed: 11/18/2022] Open
Abstract
We assessed if the relative importance of biotic and abiotic factors for plant community composition differs along environmental gradients and between functional groups, and asked which implications this may have in a warmer and wetter future. The study location is a unique grid of sites spanning regional-scale temperature and precipitation gradients in boreal and alpine grasslands in southern Norway. Within each site we sampled vegetation and associated biotic and abiotic factors, and combined broad- and fine-scale ordination analyses to assess the relative explanatory power of these factors for species composition. Although the community responses to biotic and abiotic factors did not consistently change as predicted along the bioclimatic gradients, abiotic variables tended to explain a larger proportion of the variation in species composition towards colder sites, whereas biotic variables explained more towards warmer sites, supporting the stress gradient hypothesis. Significant interactions with precipitation suggest that biotic variables explained more towards wetter climates in the sub alpine and boreal sites, but more towards drier climates in the colder alpine. Thus, we predict that biotic interactions may become more important in alpine and boreal grasslands in a warmer future, although more winter precipitation may counteract this trend in oceanic alpine climates. Our results show that both local and regional scales analyses are needed to disentangle the local vegetation-environment relationships and their regional-scale drivers, and biotic interactions and precipitation must be included when predicting future species assemblages.
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Affiliation(s)
- Kari Klanderud
- Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
- Biology Department, University of Bergen, Bergen, Norway
| | - Vigdis Vandvik
- Biology Department, University of Bergen, Bergen, Norway
| | - Deborah Goldberg
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
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236
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Legault G, Cusa M. Temperature and delayed snowmelt jointly affect the vegetative and reproductive phenologies of four sub-Arctic plants. Polar Biol 2015. [DOI: 10.1007/s00300-015-1736-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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237
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Effects of climate change on plant population growth rate and community composition change. PLoS One 2015; 10:e0126228. [PMID: 26039073 PMCID: PMC4454569 DOI: 10.1371/journal.pone.0126228] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 03/31/2015] [Indexed: 11/25/2022] Open
Abstract
The impacts of climate change on forest community composition are still not well known. Although directional trends in climate change and community composition change were reported in recent years, further quantitative analyses are urgently needed. Previous studies focused on measuring population growth rates in a single time period, neglecting the development of the populations. Here we aimed to compose a method for calculating the community composition change, and to testify the impacts of climate change on community composition change within a relatively short period (several decades) based on long-term monitoring data from two plots—Dinghushan Biosphere Reserve, China (DBR) and Barro Colorado Island, Panama (BCI)—that are located in tropical and subtropical regions. We proposed a relatively more concise index, Slnλ, which refers to an overall population growth rate based on the dominant species in a community. The results indicated that the population growth rate of a majority of populations has decreased over the past few decades. This decrease was mainly caused by population development. The increasing temperature had a positive effect on population growth rates and community change rates. Our results promote understanding and explaining variations in population growth rates and community composition rates, and are helpful to predict population dynamics and population responses to climate change.
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238
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Sweet SK, Griffin KL, Steltzer H, Gough L, Boelman NT. Greater deciduous shrub abundance extends tundra peak season and increases modeled net CO2 uptake. GLOBAL CHANGE BIOLOGY 2015; 21:2394-409. [PMID: 25556338 DOI: 10.1111/gcb.12852] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 11/18/2014] [Indexed: 05/24/2023]
Abstract
Satellite studies of the terrestrial Arctic report increased summer greening and longer overall growing and peak seasons since the 1980s, which increases productivity and the period of carbon uptake. These trends are attributed to increasing air temperatures and reduced snow cover duration in spring and fall. Concurrently, deciduous shrubs are becoming increasingly abundant in tundra landscapes, which may also impact canopy phenology and productivity. Our aim was to determine the influence of greater deciduous shrub abundance on tundra canopy phenology and subsequent impacts on net ecosystem carbon exchange (NEE) during the growing and peak seasons in the arctic foothills region of Alaska. We compared deciduous shrub-dominated and evergreen/graminoid-dominated community-level canopy phenology throughout the growing season using the normalized difference vegetation index (NDVI). We used a tundra plant-community-specific leaf area index (LAI) model to estimate LAI throughout the green season and a tundra-specific NEE model to estimate the impact of greater deciduous shrub abundance and associated shifts in both leaf area and canopy phenology on tundra carbon flux. We found that deciduous shrub canopies reached the onset of peak greenness 13 days earlier and the onset of senescence 3 days earlier compared to evergreen/graminoid canopies, resulting in a 10-day extension of the peak season. The combined effect of the longer peak season and greater leaf area of deciduous shrub canopies almost tripled the modeled net carbon uptake of deciduous shrub communities compared to evergreen/graminoid communities, while the longer peak season alone resulted in 84% greater carbon uptake in deciduous shrub communities. These results suggest that greater deciduous shrub abundance increases carbon uptake not only due to greater leaf area, but also due to an extension of the period of peak greenness, which extends the period of maximum carbon uptake.
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Affiliation(s)
- Shannan K Sweet
- Lamont-Doherty Earth Observatory, Department of Earth and Environmental Sciences, Columbia University, Palisades, NY, 10964, USA
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239
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Zhang C, Wang LL, Yang YP, Duan YW. Flower evolution of alpine forbs in the open top chambers (OTCs) from the Qinghai-Tibet Plateau. Sci Rep 2015; 5:10254. [PMID: 25998558 PMCID: PMC4441194 DOI: 10.1038/srep10254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 04/08/2015] [Indexed: 11/22/2022] Open
Abstract
Effects of global changes on biodiversity have been paid more and more attention world widely, and the open top chambers (OTCs) are the most common tools to study the effects of climatic warming on plant diversity. However, it remains unclear how flowers evolve under environmental changes, which could help us to understand the changes of plant diversity in the OTCs. We compared the insect diversity and pollen:ovule (P/O) ratio of eight outcrossing species with different life histories inside and outside the OTCs on the Qinghai-Tibet Plateau, to examine the effects induced by OTCs on the evolution of floral traits. In the OTCs, P/O ratio decreased in annuals, but increased in perennials, indicating an overall trend toward selfing in annuals. We found that the insect diversity differed significantly inside and outside the OTCS, with decreases of dipteran insects and bees. We concluded that changes of P/O ratio in the studied plant species might result from pollination failure, which might be the results of mismatch between flowering time and pollinator activities. We also suggested annuals might be in a more extinction risk than perennials in OTCs, if strong inbreeding depression occurs in these annual outcrossing plants.
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Affiliation(s)
- Chan Zhang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Plant Germplasm and Genomics Center, the Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Graduate University of the Chinese Academy of Sciences, Beijing 100049, Beijing, P. R. China
| | - Lin-Lin Wang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Plant Germplasm and Genomics Center, the Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
| | - Yong-Ping Yang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Plant Germplasm and Genomics Center, the Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
| | - Yuan-Wen Duan
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Plant Germplasm and Genomics Center, the Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
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240
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241
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Dawes MA, Philipson CD, Fonti P, Bebi P, Hättenschwiler S, Hagedorn F, Rixen C. Soil warming and CO2 enrichment induce biomass shifts in alpine tree line vegetation. GLOBAL CHANGE BIOLOGY 2015; 21:2005-21. [PMID: 25471674 DOI: 10.1111/gcb.12819] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 11/18/2014] [Indexed: 05/26/2023]
Abstract
Responses of alpine tree line ecosystems to increasing atmospheric CO2 concentrations and global warming are poorly understood. We used an experiment at the Swiss tree line to investigate changes in vegetation biomass after 9 years of free air CO2 enrichment (+200 ppm; 2001-2009) and 6 years of soil warming (+4 °C; 2007-2012). The study contained two key tree line species, Larix decidua and Pinus uncinata, both approximately 40 years old, growing in heath vegetation dominated by dwarf shrubs. In 2012, we harvested and measured biomass of all trees (including root systems), above-ground understorey vegetation and fine roots. Overall, soil warming had clearer effects on plant biomass than CO2 enrichment, and there were no interactive effects between treatments. Total plant biomass increased in warmed plots containing Pinus but not in those with Larix. This response was driven by changes in tree mass (+50%), which contributed an average of 84% (5.7 kg m(-2) ) of total plant mass. Pinus coarse root mass was especially enhanced by warming (+100%), yielding an increased root mass fraction. Elevated CO2 led to an increased relative growth rate of Larix stem basal area but no change in the final biomass of either tree species. Total understorey above-ground mass was not altered by soil warming or elevated CO2 . However, Vaccinium myrtillus mass increased with both treatments, graminoid mass declined with warming, and forb and nonvascular plant (moss and lichen) mass decreased with both treatments. Fine roots showed a substantial reduction under soil warming (-40% for all roots <2 mm in diameter at 0-20 cm soil depth) but no change with CO2 enrichment. Our findings suggest that enhanced overall productivity and shifts in biomass allocation will occur at the tree line, particularly with global warming. However, individual species and functional groups will respond differently to these environmental changes, with consequences for ecosystem structure and functioning.
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Affiliation(s)
- Melissa A Dawes
- WSL Institute for Snow and Avalanche Research - SLF, Flüelastrasse 11, CH-7260, Davos Dorf, Switzerland; Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
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242
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Ernst CM, Buddle CM. Drivers and Patterns of Ground-Dwelling Beetle Biodiversity across Northern Canada. PLoS One 2015; 10:e0122163. [PMID: 25901996 PMCID: PMC4406721 DOI: 10.1371/journal.pone.0122163] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 02/05/2015] [Indexed: 11/23/2022] Open
Abstract
Many macroecological patterns of biodiversity, including the relationship between latitude and species richness, are well-described. Data collected in a repeatable, standardized manner can advance the discipline beyond the description of patterns and be used to elucidate underlying mechanisms. Using standardized field methods and a hyper-diverse focal taxon, viz. Coleoptera, we aim to (1) describe large-scale latitudinal patterns of taxonomic diversity, functional diversity, and assemblage structure across northern Canada, and (2) determine which climatic, spatial, and habitat variables best explain these patterns. We collected terrestrial beetles at twelve locations in the three northernmost ecoclimatic zones in North America: north boreal, subarctic, and high arctic (51-81°N, 60-138°W). After identifying beetles and assigning them to a functional group, we assessed latitudinal trends for multiple diversity indices using linear regression and visualized spatial patterns of assemblage structure with multivariate ordinations. We used path analysis to test causal hypotheses for species and functional group richness, and we used a permutational approach to assess relationships between assemblage structure and 20 possible climatic and environmental mechanisms. More than 9,000 beetles were collected, representing 464 species and 18 functional groups. Species and functional diversity have significant negative relationships with latitude, which are likely explained by the mediating effects of temperature, precipitation, and plant height. Assemblages within the same ecoclimatic zone are similar, and there is a significant relationship between assemblage structure and latitude. Species and functional assemblage structure are significantly correlated with many of the same climatic factors, particularly temperature maxima and minima. At a large spatial extent, the diversity and assemblage structure of northern beetles show strong latitudinal gradients due to the mediating effects of climate, particularly temperature. Northern arthropod assemblages present significant opportunities for biodiversity research and conservation efforts, and their sensitivity to climate make them ideal targets for long-term terrestrial diversity monitoring.
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Affiliation(s)
- Crystal M. Ernst
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Christopher M. Buddle
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
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243
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Wang Z, Li Y, Hao X, Zhao M, Han G. Responses of plant community coverage to simulated warming and nitrogen addition in a desert steppe in Northern China. Ecol Res 2015. [DOI: 10.1007/s11284-015-1265-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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244
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Hollister RD, May JL, Kremers KS, Tweedie CE, Oberbauer SF, Liebig JA, Botting TF, Barrett RT, Gregory JL. Warming experiments elucidate the drivers of observed directional changes in tundra vegetation. Ecol Evol 2015; 5:1881-95. [PMID: 26140204 PMCID: PMC4485969 DOI: 10.1002/ece3.1499] [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: 02/12/2015] [Revised: 02/23/2015] [Accepted: 03/10/2015] [Indexed: 11/11/2022] Open
Abstract
Few studies have clearly linked long-term monitoring with in situ experiments to clarify potential drivers of observed change at a given site. This is especially necessary when findings from a site are applied to a much broader geographic area. Here, we document vegetation change at Barrow and Atqasuk, Alaska, occurring naturally and due to experimental warming over nearly two decades. An examination of plant cover, canopy height, and community indices showed more significant differences between years than due to experimental warming. However, changes with warming were more consistent than changes between years and were cumulative in many cases. Most cases of directional change observed in the control plots over time corresponded with a directional change in response to experimental warming. These included increases in canopy height and decreases in lichen cover. Experimental warming resulted in additional increases in evergreen shrub cover and decreases in diversity and bryophyte cover. This study suggests that the directional changes occurring at the sites are primarily due to warming and indicates that further changes are likely in the next two decades if the regional warming trend continues. These findings provide an example of the utility of coupling in situ experiments with long-term monitoring to accurately document vegetation change in response to global change and to identify the underlying mechanisms driving observed changes.
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Affiliation(s)
- Robert D Hollister
- Biology Department, Grand Valley State University 1 Campus Drive, Allendale, Michigan, 49401
| | - Jeremy L May
- Biology Department, Grand Valley State University 1 Campus Drive, Allendale, Michigan, 49401 ; Department of Biological Sciences, Florida International University 11200 SW 8th Street, Miami, Florida, 33199
| | - Kelseyann S Kremers
- Biology Department, Grand Valley State University 1 Campus Drive, Allendale, Michigan, 49401 ; Department of Biological Sciences, University of Notre Dame Notre Dame, Indiana, 46556
| | - Craig E Tweedie
- Department of Biology, University of Texas at El Paso El Paso, Texas, 79968
| | - Steven F Oberbauer
- Department of Biological Sciences, Florida International University 11200 SW 8th Street, Miami, Florida, 33199
| | - Jennifer A Liebig
- Biology Department, Grand Valley State University 1 Campus Drive, Allendale, Michigan, 49401
| | - Timothy F Botting
- Biology Department, Grand Valley State University 1 Campus Drive, Allendale, Michigan, 49401
| | - Robert T Barrett
- Biology Department, Grand Valley State University 1 Campus Drive, Allendale, Michigan, 49401
| | - Jessica L Gregory
- Biology Department, Grand Valley State University 1 Campus Drive, Allendale, Michigan, 49401
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245
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Boelman NT, Gough L, Wingfield J, Goetz S, Asmus A, Chmura HE, Krause JS, Perez JH, Sweet SK, Guay KC. Greater shrub dominance alters breeding habitat and food resources for migratory songbirds in Alaskan arctic tundra. GLOBAL CHANGE BIOLOGY 2015; 21:1508-20. [PMID: 25294359 DOI: 10.1111/gcb.12761] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 09/30/2014] [Indexed: 05/12/2023]
Abstract
Climate warming is affecting the Arctic in multiple ways, including via increased dominance of deciduous shrubs. Although many studies have focused on how this vegetation shift is altering nutrient cycling and energy balance, few have explicitly considered effects on tundra fauna, such as the millions of migratory songbirds that breed in northern regions every year. To understand how increasing deciduous shrub dominance may alter breeding songbird habitat, we quantified vegetation and arthropod community characteristics in both graminoid and shrub dominated tundra. We combined measurements of preferred nest site characteristics for Lapland longspurs (Calcarius lapponicus) and Gambel's White-crowned sparrows (Zonotrichia leucophrys gambelii) with modeled predictions for the distribution of plant community types in the Alaskan arctic foothills region for the year 2050. Lapland longspur nests were found in sedge-dominated tussock tundra where shrub height does not exceed 20 cm, whereas White-crowned sparrows nested only under shrubs between 20 cm and 1 m in height, with no preference for shrub species. Shrub canopies had higher canopy-dwelling arthropod availability (i.e. small flies and spiders) but lower ground-dwelling arthropod availability (i.e. large spiders and beetles). Since flies are the birds' preferred prey, increasing shrubs may result in a net enhancement in preferred prey availability. Acknowledging the coarse resolution of existing tundra vegetation models, we predict that by 2050 there will be a northward shift in current White-crowned sparrow habitat range and a 20-60% increase in their preferred habitat extent, while Lapland longspur habitat extent will be equivalently reduced. Our findings can be used to make first approximations of future habitat change for species with similar nesting requirements. However, we contend that as exemplified by this study's findings, existing tundra modeling tools cannot yet simulate the fine-scale habitat characteristics that are critical to accurately predicting future habitat extent for many wildlife species.
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Affiliation(s)
- Natalie T Boelman
- Lamont-Doherty Earth Observatory, and Department of Earth and Environmental Sciences, Columbia University, Palisades, NY, 10964, USA
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246
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Pattison RR, Jorgenson JC, Raynolds MK, Welker JM. Trends in NDVI and Tundra Community Composition in the Arctic of NE Alaska Between 1984 and 2009. Ecosystems 2015. [DOI: 10.1007/s10021-015-9858-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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247
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Jägerbrand AK, Alatalo JM. Effects of human trampling on abundance and diversity of vascular plants, bryophytes and lichens in alpine heath vegetation, Northern Sweden. SPRINGERPLUS 2015; 4:95. [PMID: 25774335 PMCID: PMC4353821 DOI: 10.1186/s40064-015-0876-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 02/05/2015] [Indexed: 11/10/2022]
Abstract
This study investigated the effects of human trampling on cover, diversity and species richness in an alpine heath ecosystem in northern Sweden. We tested the hypothesis that proximity to trails decreases plant cover, diversity and species richness of the canopy and the understory. We found a significant decrease in plant cover with proximity to the trail for the understory, but not for the canopy level, and significant decreases in the abundance of deciduous shrubs in the canopy layer and lichens in the understory. Proximity also had a significant negative impact on species richness of lichens. However, there were no significant changes in species richness, diversity or evenness of distribution in the canopy or understory with proximity to the trail. While not significant, liverworts, acrocarpous and pleurocarpous bryophytes tended to have contrasting abundance patterns with differing proximity to the trail, indicating that trampling may cause shifts in dominance hierarchies of different groups of bryophytes. Due to the decrease in understory cover, the abundance of litter, rock and soil increased with proximity to the trail. These results demonstrate that low-frequency human trampling in alpine heaths over long periods can have major negative impacts on lichen abundance and species richness. To our knowledge, this is the first study to demonstrate that trampling can decrease species richness of lichens. It emphasises the importance of including species-level data on non-vascular plants when conducting studies in alpine or tundra ecosystems, since they often make up the majority of species and play a significant role in ecosystem functioning and response in many of these extreme environments.
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Affiliation(s)
- Annika K Jägerbrand
- VTI, Swedish National Road and Transport Research Institute, Box 55685, 102 15 Stockholm, Sweden
| | - Juha M Alatalo
- Department of Ecology and Genetics, Uppsala University, Campus Gotland, SE-621 67 Visby, Sweden
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248
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Contrasting growth responses of dominant peatland plants to warming and vegetation composition. Oecologia 2015; 178:141-51. [DOI: 10.1007/s00442-015-3254-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 01/28/2015] [Indexed: 10/24/2022]
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249
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Bragazza L, Bardgett RD, Mitchell EAD, Buttler A. Linking soil microbial communities to vascular plant abundance along a climate gradient. THE NEW PHYTOLOGIST 2015; 205:1175-1182. [PMID: 25348596 DOI: 10.1111/nph.13116] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 09/20/2014] [Indexed: 06/04/2023]
Abstract
The ongoing expansion of shrub cover in response to climate change represents a unique opportunity to explore the link between soil microbial communities and vegetation changes. This link is particularly important in peatlands where shrub expansion is expected to feed back negatively on the carbon sink capacity of these ecosystems. Microbial community structure and function were measured seasonally in four peatlands located along an altitude gradient representing a natural gradient of climate and associated vascular plant abundance. We show that increased soil temperature and reduced water content are associated with greater vascular plant biomass, in particular that of ericoids, and that this, in turn, is correlated with greater microbial biomass. More specifically, microbial community structure is characterized by an increasing dominance of fungi over bacteria with improved soil oxygenation. We also found that the carbon and nitrogen stoichiometry of microbial biomass differs in relation to soil microbial community structure and that this is ultimately associated with a different investment in extracellular enzymatic activity. Our findings highlight the fact that the determination of the structural identity of microbial communities can help to explain the biogeochemical dynamics of organic matter and provide a better understanding of ecosystem response to environmental changes.
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Affiliation(s)
- Luca Bragazza
- WSL Swiss Federal Institute for Forest, Snow and Landscape Research, Site Lausanne, Station 2, CH-1015, Lausanne, Switzerland
- Laboratory of Ecological Systems (ECOS), École Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Station 2, CH-1015, Lausanne, Switzerland
- Department of Life Science and Biotechnologies, University of Ferrara, Corso Ercole I d'Este 32, I-44121, Ferrara, Italy
| | - Richard D Bardgett
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Manchester, M13 9PT, UK
| | - Edward A D Mitchell
- Laboratory of Soil Biology, University of Neuchatel, Rue Emile-Argand 11, CH-2000, Neuchatel, Switzerland
- Jardin Botanique de Neuchâtel, Chemin du Perthuis-du-Sault 58, CH-2000, Neuchatel, Switzerland
| | - Alexandre Buttler
- WSL Swiss Federal Institute for Forest, Snow and Landscape Research, Site Lausanne, Station 2, CH-1015, Lausanne, Switzerland
- Laboratory of Ecological Systems (ECOS), École Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Station 2, CH-1015, Lausanne, Switzerland
- Laboratoire de Chrono-Environnement, UMR 6249 CNRS - INRA, Université de Franche-Comté, Besançon, France
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Marshall KE, Baltzer JL. Decreased competitive interactions drive a reverse species richness latitudinal gradient in subarctic forests. Ecology 2015; 96:461-70. [DOI: 10.1890/14-0717.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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