1
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Famiglietti CA, Worden M, Anderegg LDL, Konings AG. Impacts of climate timescale on the stability of trait-environment relationships. THE NEW PHYTOLOGIST 2024; 241:2423-2434. [PMID: 38037289 DOI: 10.1111/nph.19416] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 11/02/2023] [Indexed: 12/02/2023]
Abstract
Predictive relationships between plant traits and environmental factors can be derived at global and regional scales, informing efforts to reorient ecological models around functional traits. However, in a changing climate, the environmental variables used as predictors in such relationships are far from stationary. This could yield errors in trait-environment model predictions if timescale is not accounted for. Here, the timescale dependence of trait-environment relationships is investigated by regressing in situ trait measurements of specific leaf area, leaf nitrogen content, and wood density on local climate characteristics summarized across several increasingly long timescales. We identify contrasting responses of leaf and wood traits to climate timescale. Leaf traits are best predicted by recent climate timescales, while wood density is a longer term memory trait. The use of sub-optimal climate timescales reduces the accuracy of the resulting trait-environment relationships. This study concludes that plant traits respond to climate conditions on the timescale of tissue lifespans rather than long-term climate normals, even at large spatial scales where multiple ecological and physiological mechanisms drive trait change. Thus, determining trait-environment relationships with temporally relevant climate variables may be critical for predicting trait change in a nonstationary climate system.
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Affiliation(s)
| | - Matthew Worden
- Department of Earth System Science, Stanford University, Stanford, CA, 94305, USA
| | - Leander D L Anderegg
- Department of Ecology, Evolution, & Marine Biology, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Alexandra G Konings
- Department of Earth System Science, Stanford University, Stanford, CA, 94305, USA
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2
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Dinh KV, Albini D, Orr JA, Macaulay SJ, Rillig MC, Borgå K, Jackson MC. Winter is coming: Interactions of multiple stressors in winter and implications for the natural world. GLOBAL CHANGE BIOLOGY 2023; 29:6834-6845. [PMID: 37776127 DOI: 10.1111/gcb.16956] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 09/10/2023] [Indexed: 10/01/2023]
Abstract
Winter is a key driver of ecological processes in freshwater, marine and terrestrial ecosystems, particularly in higher latitudes. Species have evolved various adaptive strategies to cope with food limitations and the cold and dark wintertime. However, human-induced climate change and other anthropogenic stressors are impacting organisms in winter in unpredictable ways. In this paper, we show that global change experiments investigating multiple stressors have predominantly been conducted during summer months. However, effects of anthropogenic stressors sometimes differ between winter and other seasons, necessitating comprehensive investigations. Here, we outline a framework for understanding the different effects of anthropogenic stressors in winter compared to other seasons and discuss the primary mechanisms that will alter ecological responses of organisms (microbes, animals and plants). For instance, while the magnitude of some anthropogenic stressors can be greater in winter than in other seasons (e.g. some pollutants), others may alleviate natural winter stress (e.g. warmer temperatures). These changes can have immediate, delayed or carry-over effects on organisms during winter or later seasons. Interactions between stressors may also vary with season. We call for a renewed research direction focusing on multiple stressor effects on winter ecology and evolution to fully understand, and predict, how ecosystems will fare under changing winters. We also argue the importance of incorporating the interactions of anthropogenic stressors with winter into ecological risk assessments, management and conservation efforts.
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Affiliation(s)
- Khuong V Dinh
- Section for Aquatic Biology and Toxicology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Dania Albini
- Department of Biology, University of Oxford, Oxford, UK
| | - James A Orr
- Department of Biology, University of Oxford, Oxford, UK
| | | | - Matthias C Rillig
- Plant Ecology, Institut für Biologie, Freie Universität Berlin, Berlin, Germany
- Berlin-Brandenburg-Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
| | - Katrine Borgå
- Section for Aquatic Biology and Toxicology, Department of Biosciences, University of Oslo, Oslo, Norway
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3
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Harning DJ, Sacco S, Anamthawat-Jónsson K, Ardenghi N, Thordarson T, Raberg JH, Sepúlveda J, Geirsdóttir Á, Shapiro B, Miller GH. Delayed postglacial colonization of Betula in Iceland and the circum North Atlantic. eLife 2023; 12:RP87749. [PMID: 37955570 PMCID: PMC10642962 DOI: 10.7554/elife.87749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023] Open
Abstract
As the Arctic continues to warm, woody shrubs are expected to expand northward. This process, known as 'shrubification,' has important implications for regional biodiversity, food web structure, and high-latitude temperature amplification. While the future rate of shrubification remains poorly constrained, past records of plant immigration to newly deglaciated landscapes in the Arctic may serve as useful analogs. We provide one new postglacial Holocene sedimentary ancient DNA (sedaDNA) record of vascular plants from Iceland and place a second Iceland postglacial sedaDNA record on an improved geochronology; both show Salicaceae present shortly after deglaciation, whereas Betulaceae first appears more than 1000 y later. We find a similar pattern of delayed Betulaceae colonization in eight previously published postglacial sedaDNA records from across the glaciated circum North Atlantic. In nearly all cases, we find that Salicaceae colonizes earlier than Betulaceae and that Betulaceae colonization is increasingly delayed for locations farther from glacial-age woody plant refugia. These trends in Salicaceae and Betulaceae colonization are consistent with the plant families' environmental tolerances, species diversity, reproductive strategies, seed sizes, and soil preferences. As these reconstructions capture the efficiency of postglacial vascular plant migration during a past period of high-latitude warming, a similarly slow response of some woody shrubs to current warming in glaciated regions, and possibly non-glaciated tundra, may delay Arctic shrubification and future changes in the structure of tundra ecosystems and temperature amplification.
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Affiliation(s)
- David J Harning
- Institute of Arctic and Alpine Research, University of Colorado BoulderBoulderUnited States
| | - Samuel Sacco
- Department of Ecology and Evolutionary Biology, University of California Santa CruzSanta CruzUnited States
| | | | - Nicolò Ardenghi
- Institute of Arctic and Alpine Research, University of Colorado BoulderBoulderUnited States
| | - Thor Thordarson
- Faculty of Earth Sciences, University of IcelandReykjavikIceland
| | - Jonathan H Raberg
- Institute of Arctic and Alpine Research, University of Colorado BoulderBoulderUnited States
| | - Julio Sepúlveda
- Institute of Arctic and Alpine Research, University of Colorado BoulderBoulderUnited States
- Department of Geological Sciences, University of Colorado BoulderBoulderUnited States
| | | | - Beth Shapiro
- Department of Ecology and Evolutionary Biology, University of California Santa CruzSanta CruzUnited States
| | - Gifford H Miller
- Institute of Arctic and Alpine Research, University of Colorado BoulderBoulderUnited States
- Department of Geological Sciences, University of Colorado BoulderBoulderUnited States
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4
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Oberhuber W, Dobler AL, Heinzle T, Scandurra F, Gruber A, Wieser G. Climate Overrides the Influence of Microsite Conditions on Radial Growth of the Tall Multi-Stemmed Shrub Alnus alnobetula at Treeline. PLANTS (BASEL, SWITZERLAND) 2023; 12:1708. [PMID: 37111935 PMCID: PMC10143859 DOI: 10.3390/plants12081708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/13/2023] [Accepted: 04/17/2023] [Indexed: 06/19/2023]
Abstract
Green alder (Alnus alnobetula), a tall multi-stemmed deciduous shrub, is widespread at high elevations in the Central European Alps. Its growth form frequently leads to asymmetric radial growth and anomalous growth ring patterns, making development of representative ring-width series a challenge. In order to assess the variability among radii of one shoot, among shoots belonging to one stock and among stocks, 60 stem discs were sampled at treeline on Mt. Patscherkofel (Tyrol, Austria). Annual increments were measured along 188 radii and analyzed in terms of their variability by applying dendrochronological techniques. Results revealed a high agreement in ring-width variation among radii of one shoot, among shoots of one stock and largely among stocks from different sites, confirming the pronounced limitation of radial stem growth by climate forcing at the alpine treeline. In contrast to this, a high variability in both absolute growth rates and long-term growth trends was found, which we attribute to different microsite conditions and disturbances. These factors also override climate control of radial growth under growth-limiting environmental conditions. Based on our findings we provide recommendations for the number of samples needed to carry out inter- and intra-annual studies of radial growth in this multi-stemmed clonal shrub.
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5
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Leng R, Harrison S, Anderson K. Himalayan alpine ecohydrology: An urgent scientific concern in a changing climate. AMBIO 2023; 52:390-410. [PMID: 36324019 PMCID: PMC9755440 DOI: 10.1007/s13280-022-01792-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/22/2022] [Accepted: 08/31/2022] [Indexed: 06/16/2023]
Abstract
Climate change is projected to have important impacts on snow and vegetation distribution in global mountains. Despite this, the coupling of ecological shifts and hydrological processes within alpine zones has not attracted significant scientific attention. As the largest and one of the most climatically sensitive mountain systems, we argue that Himalayan alpine ecohydrological processes require urgent scientific attention because up to 1.6 billion people rely on water supplies from the mountains. We review studies from global mountain systems to highlight the importance of considering ecohydrological impacts within Himalayan alpine zones (4100-6000 m.a.s.l), explaining mechanisms for interactions between snow and dwarf plants. Our findings highlight the paucity of monitoring stations within Himalayan alpine systems. We suggest that it is likely that alpine ecological shifts will impact hydrological processes, but we found that specific mechanisms and functional relationships are missing for Himalayan systems, so the strength and direction of ecohydrological relationships is currently unknown. We advocate for more purposeful and widespread monitoring efforts below glaciers and above the treeline, calling for new experiments to query the role of small plants within the Himalayan alpine hydrological system. We outline the need for community engagement with alpine ecohydrological experiments, and we explain how new snow and vegetation products derived from remote sensing observations have the potential to improve scientific understanding of the interacting effects of warming and ecohydrological factors in this sensitive region.
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Affiliation(s)
- Ruolin Leng
- Department of Geography, University of Exeter, Cornwall Campus, Penryn, TR10 9FE Cornwall UK
- Environment and Sustainability Institute, University of Exeter, Cornwall Campus, Penryn,, TR10 9FE Cornwall UK
| | - Stephan Harrison
- Department of Geography, University of Exeter, Cornwall Campus, Penryn, TR10 9FE Cornwall UK
- Environment and Sustainability Institute, University of Exeter, Cornwall Campus, Penryn,, TR10 9FE Cornwall UK
| | - Karen Anderson
- Department of Geography, University of Exeter, Cornwall Campus, Penryn, TR10 9FE Cornwall UK
- Environment and Sustainability Institute, University of Exeter, Cornwall Campus, Penryn,, TR10 9FE Cornwall UK
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6
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Ray PM, Bret-Harte MS. Cryocampsis: a biophysical freeze-bending response of shrubs and trees under snow loads. PNAS NEXUS 2022; 1:pgac131. [PMID: 36714826 PMCID: PMC9802243 DOI: 10.1093/pnasnexus/pgac131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 07/21/2022] [Indexed: 02/01/2023]
Abstract
We report a biophysical mechanism, termed cryocampsis (Greek cryo-, cold, + campsis, bending), that helps northern shrubs bend downward under a snow load. Subfreezing temperatures substantially increase the downward bending of cantilever-loaded branches of these shrubs, while allowing them to recover their summer elevation after thawing and becoming unloaded. This is counterintuitive, because biological materials (including branches that show cryocampsis) generally become stiffer when frozen, so should flex less, rather than more, under a given bending load. Cryocampsis involves straining of the cell walls of a branch's xylem (wood), and depends upon the branch being hydrated. Among woody species tested, cryocampsis occurs in almost all Arctic, some boreal, only a few temperate and Mediterranean, and no tropical woody species that we have tested. It helps cold-winter climate shrubs reversibly get, and stay, below the snow surface, sheltering them from winter weather and predation hazards. This should be advantageous, because Arctic shrub bud winter mortality significantly increases if their shoots are forcibly kept above the snow surface. Our observations reveal a physically surprising behavior of biological materials at subfreezing temperatures, and a previously unrecognized mechanism of woody plant adaptation to cold-winter climates. We suggest that cryocampsis' mechanism involves the movement of water between cell wall matrix polymers and cell lumens during freezing, analogous to that of frost-heave in soils or rocks.
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Affiliation(s)
| | - M Syndonia Bret-Harte
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
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7
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Boyle JS, Angers-Blondin S, Assmann JJ, Myers-Smith IH. Summer temperature—but not growing season length—influences radial growth of Salix arctica in coastal Arctic tundra. Polar Biol 2022. [DOI: 10.1007/s00300-022-03074-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
AbstractArctic climate change is leading to an advance of plant phenology (the timing of life history events) with uncertain impacts on tundra ecosystems. Although the lengthening of the growing season is thought to lead to increased plant growth, we have few studies of how plant phenology change is altering tundra plant productivity. Here, we test the correspondence between 14 years of Salix arctica phenology data and radial growth on Qikiqtaruk–Herschel Island, Yukon Territory, Canada. We analysed stems from 28 individuals using dendroecology and linear mixed-effect models to test the statistical power of growing season length and climate variables to individually predict radial growth. We found that summer temperature best explained annual variation in radial growth. We found no strong evidence that leaf emergence date, earlier leaf senescence date, or total growing season length had any direct or lagged effects on radial growth. Radial growth was also not explained by interannual variation in precipitation, MODIS surface greenness (NDVI), or sea ice concentration. Our results demonstrate that at this site, for the widely distributed species S. arctica, temperature—but not growing season length—influences radial growth. These findings challenge the assumption that advancing phenology and longer growing seasons will increase the productivity of all plant species in Arctic tundra ecosystems.
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8
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Domine F, Fourteau K, Picard G, Lackner G, Sarrazin D, Poirier M. Permafrost cooled in winter by thermal bridging through snow-covered shrub branches. NATURE GEOSCIENCE 2022; 15:554-560. [PMID: 35845978 PMCID: PMC9279148 DOI: 10.1038/s41561-022-00979-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
Considerable expansion of shrubs across the Arctic tundra has been observed in recent decades. These shrubs are thought to have a warming effect on permafrost by increasing snowpack thermal insulation, thereby limiting winter cooling and accelerating thaw. Here, we use ground temperature observations and heat transfer simulations to show that low shrubs can actually cool the ground in winter by providing a thermal bridge through the snowpack. Observations from unmanipulated herb tundra and shrub tundra sites on Bylot Island in the Canadian high Arctic reveal a 1.21 °C cooling effect between November and February. This is despite a snowpack that is twice as insulating in shrubs. The thermal bridging effect is reversed in spring when shrub branches absorb solar radiation and transfer heat to the ground. The overall thermal effect is likely to depend on snow and shrub characteristics and terrain aspect. The inclusion of these thermal bridging processes into climate models may have an important impact on projected greenhouse gas emissions by permafrost.
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Affiliation(s)
- Florent Domine
- Takuvik Joint International Laboratory, Université Laval (Canada) and CNRS-INSU (France), Québec, Canada
- Centre d’Études Nordiques, Université Laval, Québec, Canada
- Department of Chemistry, Université Laval, Québec, Canada
| | - Kévin Fourteau
- Université Grenoble Alpes, Université Toulouse, Météo-France, CNRS, CNRM, Centre d’Études de la Neige, Grenoble, France
| | - Ghislain Picard
- Université Grenoble Alpes, CNRS, IRD, Grenoble INP, IGE, Grenoble, France
| | - Georg Lackner
- Takuvik Joint International Laboratory, Université Laval (Canada) and CNRS-INSU (France), Québec, Canada
- Centre d’Études Nordiques, Université Laval, Québec, Canada
- Department of Civil and Water Engineering, Université Laval, Québec, Canada
| | - Denis Sarrazin
- Centre d’Études Nordiques, Université Laval, Québec, Canada
| | - Mathilde Poirier
- Centre d’Études Nordiques, Université Laval, Québec, Canada
- Department of Biology, Université Laval, Québec, Canada
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9
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Huebner DC, Buchwal A, Bret‐Harte MS. Retrogressive thaw slumps in the Alaskan Low Arctic may influence tundra shrub growth more strongly than climate. Ecosphere 2022. [DOI: 10.1002/ecs2.4106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Diane C. Huebner
- Institute of Arctic Biology/Department of Biology and Wildlife University of Alaska Fairbanks Fairbanks Alaska USA
| | - Agata Buchwal
- Institute of Geoecology and Geoinformation Adam Mickiewicz University Poznań Poland
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10
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Stunz E, Fetcher N, Lavretsky P, Mohl JE, Tang J, Moody ML. Landscape Genomics Provides Evidence of Ecotypic Adaptation and a Barrier to Gene Flow at Treeline for the Arctic Foundation Species Eriophorum vaginatum. FRONTIERS IN PLANT SCIENCE 2022; 13:860439. [PMID: 35401613 PMCID: PMC8987161 DOI: 10.3389/fpls.2022.860439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
Global climate change has resulted in geographic range shifts of flora and fauna at a global scale. Extreme environments, like the Arctic, are seeing some of the most pronounced changes. This region covers 14% of the Earth's land area, and while many arctic species are widespread, understanding ecotypic variation at the genomic level will be important for elucidating how range shifts will affect ecological processes. Tussock cottongrass (Eriophorum vaginatum L.) is a foundation species of the moist acidic tundra, whose potential decline due to competition from shrubs may affect ecosystem stability in the Arctic. We used double-digest Restriction Site-Associated DNA sequencing to identify genomic variation in 273 individuals of E. vaginatum from 17 sites along a latitudinal gradient in north central Alaska. These sites have been part of 30 + years of ecological research and are inclusive of a region that was part of the Beringian refugium. The data analyses included genomic population structure, demographic models, and genotype by environment association. Genome-wide SNP investigation revealed environmentally associated variation and population structure across the sampled range of E. vaginatum, including a genetic break between populations north and south of treeline. This structure is likely the result of subrefugial isolation, contemporary isolation by resistance, and adaptation. Forty-five candidate loci were identified with genotype-environment association (GEA) analyses, with most identified genes related to abiotic stress. Our results support a hypothesis of limited gene flow based on spatial and environmental factors for E. vaginatum, which in combination with life history traits could limit range expansion of southern ecotypes northward as the tundra warms. This has implications for lower competitive attributes of northern plants of this foundation species likely resulting in changes in ecosystem productivity.
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Affiliation(s)
- Elizabeth Stunz
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, United States
| | - Ned Fetcher
- Institute for Environmental Science and Sustainability, Wilkes University, Wilkes-Barre, PA, United States
| | - Philip Lavretsky
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, United States
| | - Jonathon E. Mohl
- Department of Mathematical Sciences, Border Biomedical Research Center, University of Texas at El Paso, El Paso, TX, United States
| | - Jianwu Tang
- Marine Biological Laboratory, The Ecosystems Center, Woods Hole, MA, United States
| | - Michael L. Moody
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, United States
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11
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Chardon NI, Nabe‐Nielsen J, Assmann JJ, Dyrholm Jacobsen IB, Guéguen M, Normand S, Wipf S. High resolution species distribution and abundance models cannot predict separate shrub datasets in adjacent Arctic fjords. DIVERS DISTRIB 2022. [DOI: 10.1111/ddi.13498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- Nathalie Isabelle Chardon
- Biodiversity Research Centre University of British Columbia Vancouver British Columbia Canada
- WSL Institute for Snow and Avalanche Research Davos Dorf Switzerland
- Department of Biology Aarhus University Aarhus C Denmark
| | | | | | | | - Maya Guéguen
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc CNRS, LECA Laboratoire d’Ecologie Alpine Grenoble France
| | - Signe Normand
- Department of Biology Aarhus University Aarhus C Denmark
| | - Sonja Wipf
- Swiss National Park Chastè Planta‐Wildenberg Zernez Switzerland
- Climate Change, Extremes and Natural Hazards in Alpine Regions Research Centre CERC Davos Dorf Switzerland
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12
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Pang G, Chen D, Wang X, Lai HW. Spatiotemporal variations of land surface albedo and associated influencing factors on the Tibetan Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 804:150100. [PMID: 34517323 DOI: 10.1016/j.scitotenv.2021.150100] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 08/16/2021] [Accepted: 08/30/2021] [Indexed: 06/13/2023]
Abstract
Land surface albedo plays a crucial role in the land surface energy budget and climate. This paper identified the spatiotemporal variations of surface albedo on the Tibetan Plateau (TP) from 1982 to 2015, and quantified the relationships between the spatial and temporal patterns of the albedo and associated influencing factors (snow cover, vegetation, and soil moisture) on the seasonal and interannual basis using satellite products and reanalysis data. It was determined that the albedo presented a distinct spatial variability, with high values in mountainous areas and low values on the southeastern TP. Spatially, average albedo exhibited a positive correlation with snow cover and negative correlations with vegetation and soil moisture. Average albedo over the whole TP had a clear seasonal cycle with a peak in winter and a minimum value in summer, which is dictated by seasonal changes in snow and vegetation covers. Annual average albedo exhibited a weakly downward trend, which was mainly contributed by a significant decrease in summer, pointing to the important role in vegetation dynamics for temporal change of the albedo. On the regional basis, interannual variation of albedo was more responsive to snow cover over the snow- and vegetation-coexisting area than the snow-covered area, and to changes in Normalized Difference Vegetation Index (NDVI) over the vegetation-covered area than the snow- and vegetation-coexisting area; albedo had a weakly negative correlation with soil moisture over bare soil. Furthermore, our results indicated that snow cover was the dominant factor for albedo change on mountainous areas, and vegetation change predominated the variation of albedo on the eastern, southern, and northwestern TP. Specifically, variations in snow cover contributed more than those of vegetation to the interannual albedo variation over the Three Rivers Headwater Region. These results would be beneficial for better understanding the climate and eco-environment changes over the TP.
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Affiliation(s)
- Guojin Pang
- Faculty of Geomatics, Lanzhou Jiaotong University, Lanzhou 730070, China; Regional Climate Group, Department of Earth Sciences, University of Gothenburg, Gothenburg 40530, Sweden; National-Local Joint Engineering Research Center of Technologies and Applications for National Geographic State Monitoring, Lanzhou 730070, China; Gansu Provincial Engineering Laboratory for National Geographic State Monitoring, Lanzhou 730070, China
| | - Deliang Chen
- Regional Climate Group, Department of Earth Sciences, University of Gothenburg, Gothenburg 40530, Sweden.
| | - Xuejia Wang
- State Key Laboratory of Cryospheric Science/Yulong Snow Mountain Cryosphere and Sustainable Development Field Observation and Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730030, China.
| | - Hui-Wen Lai
- Regional Climate Group, Department of Earth Sciences, University of Gothenburg, Gothenburg 40530, Sweden
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13
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Broadbent AAD, Bahn M, Pritchard WJ, Newbold LK, Goodall T, Guinta A, Snell HSK, Cordero I, Michas A, Grant HK, Soto DX, Kaufmann R, Schloter M, Griffiths RI, Bardgett RD. Shrub expansion modulates belowground impacts of changing snow conditions in alpine grasslands. Ecol Lett 2021; 25:52-64. [PMID: 34708508 DOI: 10.1111/ele.13903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/18/2021] [Accepted: 10/06/2021] [Indexed: 11/28/2022]
Abstract
Climate change is disproportionately impacting mountain ecosystems, leading to large reductions in winter snow cover, earlier spring snowmelt and widespread shrub expansion into alpine grasslands. Yet, the combined effects of shrub expansion and changing snow conditions on abiotic and biotic soil properties remains poorly understood. We used complementary field experiments to show that reduced snow cover and earlier snowmelt have effects on soil microbial communities and functioning that persist into summer. However, ericaceous shrub expansion modulates a number of these impacts and has stronger belowground effects than changing snow conditions. Ericaceous shrub expansion did not alter snow depth or snowmelt timing but did increase the abundance of ericoid mycorrhizal fungi and oligotrophic bacteria, which was linked to decreased soil respiration and nitrogen availability. Our findings suggest that changing winter snow conditions have cross-seasonal impacts on soil properties, but shifts in vegetation can modulate belowground effects of future alpine climate change.
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Affiliation(s)
- Arthur A D Broadbent
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
| | - Michael Bahn
- Institut für Ökologie, Universität Innsbruck, Innsbruck, Austria
| | - William J Pritchard
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
| | | | - Tim Goodall
- UK Centre for Ecology & Hydrology, Wallingford, Oxfordshire, UK
| | - Andrew Guinta
- Institut für Ökologie, Universität Innsbruck, Innsbruck, Austria
| | - Helen S K Snell
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
| | - Irene Cordero
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
| | - Antonios Michas
- Research Unit for Comparative Microbiome Analysis, Helmholtz Zentrum München, Neuherberg, Germany.,Chair for Soil Science, Technical University of Munich, Freising, Germany
| | - Helen K Grant
- National Environmental Isotope Facility, UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Lancaster, UK
| | - David X Soto
- National Environmental Isotope Facility, UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Lancaster, UK
| | - Rüdiger Kaufmann
- Institut für Ökologie, Universität Innsbruck, Innsbruck, Austria
| | - Michael Schloter
- Research Unit for Comparative Microbiome Analysis, Helmholtz Zentrum München, Neuherberg, Germany.,Chair for Soil Science, Technical University of Munich, Freising, Germany
| | - Robert I Griffiths
- UK Centre for Ecology & Hydrology, Environment Centre Wales, Gwynedd, UK
| | - Richard D Bardgett
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
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14
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Muntjewerf L, Sacks WJ, Lofverstrom M, Fyke J, Lipscomb WH, Ernani da Silva C, Vizcaino M, Thayer‐Calder K, Lenaerts JTM, Sellevold R. Description and Demonstration of the Coupled Community Earth System Model v2 - Community Ice Sheet Model v2 (CESM2-CISM2). JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS 2021; 13:e2020MS002356. [PMID: 34434489 PMCID: PMC8365656 DOI: 10.1029/2020ms002356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 05/06/2021] [Accepted: 05/21/2021] [Indexed: 06/13/2023]
Abstract
Earth system/ice-sheet coupling is an area of recent, major Earth System Model (ESM) development. This work occurs at the intersection of glaciology and climate science and is motivated by a need for robust projections of sea-level rise. The Community Ice Sheet Model version 2 (CISM2) is the newest component model of the Community Earth System Model version 2 (CESM2). This study describes the coupling and novel capabilities of the model, including: (1) an advanced energy-balance-based surface mass balance calculation in the land component with downscaling via elevation classes; (2) a closed freshwater budget from ice sheet to the ocean from surface runoff, basal melting, and ice discharge; (3) dynamic land surface types; and (4) dynamic atmospheric topography. The Earth system/ice-sheet coupling is demonstrated in a simulation with an evolving Greenland Ice Sheet (GrIS) under an idealized high CO2 scenario. The model simulates a large expansion of ablation areas (where surface ablation exceeds snow accumulation) and a large increase in surface runoff. This results in an elevated freshwater flux to the ocean, as well as thinning of the ice sheet and area retreat. These GrIS changes result in reduced Greenland surface albedo, changes in the sign and magnitude of sensible and latent heat fluxes, and modified surface roughness and overall ice sheet topography. Representation of these couplings between climate and ice sheets is key for the simulation of ice and climate interactions.
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Affiliation(s)
- Laura Muntjewerf
- Department of Geoscience and Remote SensingDelft University of TechnologyDelftThe Netherlands
| | - William J. Sacks
- Climate and Global Dynamics LaboratoryNational Center for Atmospheric ResearchBoulderCOUSA
| | | | - Jeremy Fyke
- Associated Engineering Group LtdCalgaryABCanada
| | - William H. Lipscomb
- Climate and Global Dynamics LaboratoryNational Center for Atmospheric ResearchBoulderCOUSA
| | | | - Miren Vizcaino
- Department of Geoscience and Remote SensingDelft University of TechnologyDelftThe Netherlands
| | | | - Jan T. M. Lenaerts
- Department of Atmospheric and Oceanic SciencesUniversity of Colorado BoulderBoulderCOUSA
| | - Raymond Sellevold
- Department of Geoscience and Remote SensingDelft University of TechnologyDelftThe Netherlands
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15
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Crump SE, Fréchette B, Power M, Cutler S, de Wet G, Raynolds MK, Raberg JH, Briner JP, Thomas EK, Sepúlveda J, Shapiro B, Bunce M, Miller GH. Ancient plant DNA reveals High Arctic greening during the Last Interglacial. Proc Natl Acad Sci U S A 2021; 118:e2019069118. [PMID: 33723011 PMCID: PMC8020792 DOI: 10.1073/pnas.2019069118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Summer warming is driving a greening trend across the Arctic, with the potential for large-scale amplification of climate change due to vegetation-related feedbacks [Pearson et al., Nat. Clim. Chang. (3), 673-677 (2013)]. Because observational records are sparse and temporally limited, past episodes of Arctic warming can help elucidate the magnitude of vegetation response to temperature change. The Last Interglacial ([LIG], 129,000 to 116,000 y ago) was the most recent episode of Arctic warming on par with predicted 21st century temperature change [Otto-Bliesner et al., Philos. Trans. A Math. Phys. Eng. Sci. (371), 20130097 (2013) and Post et al., SciAdv (5), eaaw9883 (2019)]. However, high-latitude terrestrial records from this period are rare, so LIG vegetation distributions are incompletely known. Pollen-based vegetation reconstructions can be biased by long-distance pollen transport, further obscuring the paleoenvironmental record. Here, we present a LIG vegetation record based on ancient DNA in lake sediment and compare it with fossil pollen. Comprehensive plant community reconstructions through the last and current interglacial (the Holocene) on Baffin Island, Arctic Canada, reveal coherent climate-driven community shifts across both interglacials. Peak LIG warmth featured a ∼400-km northward range shift of dwarf birch, a key woody shrub that is again expanding northward. Greening of the High Arctic-documented here by multiple proxies-likely represented a strong positive feedback on high-latitude LIG warming. Authenticated ancient DNA from this lake sediment also extends the useful preservation window for the technique and highlights the utility of combining traditional and molecular approaches for gleaning paleoenvironmental insights to better anticipate a warmer future.
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Affiliation(s)
- Sarah E Crump
- Institute of Arctic and Alpine Research and Department of Geological Sciences, University of Colorado, Boulder, CO 80303;
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064
| | - Bianca Fréchette
- Geotop, Université du Québec à Montréal, Montréal, H2L 2C4, Canada
| | - Matthew Power
- Trace and Environmental DNA Laboratory, School of Molecular and Life Sciences, Curtin University, 6845 Bentley, Australia
| | - Sam Cutler
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064
| | - Gregory de Wet
- Institute of Arctic and Alpine Research and Department of Geological Sciences, University of Colorado, Boulder, CO 80303
- Department of Geosciences, Smith College, Northampton, MA 01063
| | - Martha K Raynolds
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775
| | - Jonathan H Raberg
- Institute of Arctic and Alpine Research and Department of Geological Sciences, University of Colorado, Boulder, CO 80303
| | - Jason P Briner
- Department of Geology, University at Buffalo, Buffalo, NY 14260
| | | | - Julio Sepúlveda
- Institute of Arctic and Alpine Research and Department of Geological Sciences, University of Colorado, Boulder, CO 80303
| | - Beth Shapiro
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064
- HHMI, University of California, Santa Cruz, CA 95064
| | - Michael Bunce
- Trace and Environmental DNA Laboratory, School of Molecular and Life Sciences, Curtin University, 6845 Bentley, Australia
- New Zealand Environment Protection Authority, 6011 Wellington, New Zealand
| | - Gifford H Miller
- Institute of Arctic and Alpine Research and Department of Geological Sciences, University of Colorado, Boulder, CO 80303
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16
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Abstract
AbstractThe eastern Canadian Subarctic and Arctic are experiencing significant environmental change with widespread implications for the people, plants, and animals living there. In this study, we integrate 10 years of research at the Nakvak Brook watershed in Torngat Mountains National Park of Canada, northern Labrador, to assess the sensitivity of ecological and geomorphological systems to regional climate warming. A time series of the Normalized Difference Vegetation Index indicates that the area has undergone a significant greening trend over the past four decades. Analyses of shrub cross sections suggest that greening has been caused by a combination of rapid establishment and growth that began in the late 1990’s and coincided with warmer growing season temperatures. Recent (2010–2015) vegetation change has been subtle and heavily moderated by soil moisture status. Plant canopy height is greater in wet areas and has an insulating effect on ground surface temperatures during the winter, a consequence of snow trapping by shrub canopies. Observations of subsurface conditions indicate that the study site is best characterized as having discontinuous near-surface permafrost. The importance of subsurface conditions for above-ground vegetation depends on the geomorphological context, with plants in wet areas underlain by fine materials being the most likely to be growth-limited by permafrost, thus being potential hot-spots for future change. With the expectation of sustained climate change, loss of adjacent sea ice, and proximity to the forest-tundra ecotone, it is likely that the Torngat Mountains will continue to be an area of rapid environmental change in the coming decades.
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17
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Wang K, Jafarov E, Overeem I. Sensitivity evaluation of the Kudryavtsev permafrost model. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 720:137538. [PMID: 32143043 DOI: 10.1016/j.scitotenv.2020.137538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/22/2020] [Accepted: 02/23/2020] [Indexed: 06/10/2023]
Abstract
Modeling is an important way to assess current and future permafrost spatial distribution and dynamics, especially in data poor areas like the Arctic region. Here, we evaluate a physics-based analytical model, Kudryavtsev's active layer model, which is widely used because it has relatively few data requirements. This model was recently incorporated into a component modeling toolbox, allowing for coupled modeling of permafrost and geomorphic processes over geological timescales. However, systematic quantitative assessment of the influence of its controlling parameters on permafrost temperature and active layer thickness predictions has not been undertaken before. We investigate the sensitivity of the Kudryavtsev's active layer model by Monte Carlo simulations to generate probability distributions for input parameters and compare predictions with a comprehensive benchmark dataset of in-situ permafrost observations over entire Alaska. Predicted permafrost surface temperature is highly dependent on mean annual air temperature (r = 0.78 on average), annual temperature amplitude (-0.41), and winter-averaged snow thickness (0.30). Uncertainty of predicted permafrost temperature is relatively small (RMSE = 1 °C), when air temperature and snow depth are well constrained. Similarly, RMSE between simulated and observed ALT at stations is ~0.08 m. However, under given air temperature and snow conditions, soil water content bias can significantly affect modeled active layer thickness (RMSE = 0.1 m or 40% of the observed active layer thickness). If soil water content has a large bias, improvements in other parameters may not significantly improve the active layer predictions of the Kudryavtsev's model.
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Affiliation(s)
- Kang Wang
- School of Geographic Sciences, East China Normal University, Shanghai 200241, China; CSDMS, Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO 80309, USA; Department of Geological Sciences, University of Colorado Boulder, Boulder, CO 80309, USA.
| | - Elchin Jafarov
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Irina Overeem
- CSDMS, Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO 80309, USA; Department of Geological Sciences, University of Colorado Boulder, Boulder, CO 80309, USA
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18
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Bjorkman AD, García Criado M, Myers-Smith IH, Ravolainen V, Jónsdóttir IS, Westergaard KB, Lawler JP, Aronsson M, Bennett B, Gardfjell H, Heiðmarsson S, Stewart L, Normand S. Status and trends in Arctic vegetation: Evidence from experimental warming and long-term monitoring. AMBIO 2020; 49:678-692. [PMID: 30929249 PMCID: PMC6989703 DOI: 10.1007/s13280-019-01161-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 02/04/2019] [Accepted: 02/14/2019] [Indexed: 05/20/2023]
Abstract
Changes in Arctic vegetation can have important implications for trophic interactions and ecosystem functioning leading to climate feedbacks. Plot-based vegetation surveys provide detailed insight into vegetation changes at sites around the Arctic and improve our ability to predict the impacts of environmental change on tundra ecosystems. Here, we review studies of changes in plant community composition and phenology from both long-term monitoring and warming experiments in Arctic environments. We find that Arctic plant communities and species are generally sensitive to warming, but trends over a period of time are heterogeneous and complex and do not always mirror expectations based on responses to experimental manipulations. Our findings highlight the need for more geographically widespread, integrated, and comprehensive monitoring efforts that can better resolve the interacting effects of warming and other local and regional ecological factors.
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Affiliation(s)
- Anne D. Bjorkman
- Senckenberg Gesellschaft für Naturforschung, Biodiversity and Climate Research Centre (SBiK-F), Frankfurt, Germany
- Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | | | | | | | | | | | - James P. Lawler
- Inventory and Monitoring Program, U.S. National Park Service, Anchorage, Alaska USA
| | - Mora Aronsson
- Swedish Species Information Centre, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Bruce Bennett
- Yukon Conservation Data Centre, Whitehorse, Yukon Canada
| | - Hans Gardfjell
- Department of Forest Resource Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Starri Heiðmarsson
- Akureyri Division, Icelandic Institute of Natural History, Borgir vid Nordurslod, 600 Akureyri, Iceland
| | - Laerke Stewart
- Arctic Ecosystem Ecology, Department of Bioscience, Aarhus University, Roskilde, Denmark
| | - Signe Normand
- Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Aarhus, Denmark
- Arctic Research Center, Department of Bioscience, Aarhus University, Ny Munkegade 114-116, 8000 Århus, Denmark
- Center for Biodiversity Dynamic in a Changing World (BIOCHANGE), Department of Bioscience, Aarhus University, Ny Munkegade 114-116, 8000 Århus, Denmark
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19
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Climate Warming Persistence Triggered Tree Ingression After Shrub Encroachment in a High Alpine Tundra. Ecosystems 2020. [DOI: 10.1007/s10021-020-00495-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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20
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Crump SE, Miller GH, Power M, Sepúlveda J, Dildar N, Coghlan M, Bunce M. Arctic shrub colonization lagged peak postglacial warmth: Molecular evidence in lake sediment from Arctic Canada. GLOBAL CHANGE BIOLOGY 2019; 25:4244-4256. [PMID: 31603617 DOI: 10.1111/gcb.14836] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 08/08/2019] [Indexed: 12/29/2022]
Abstract
Arctic shrubification is an observable consequence of climate change, already resulting in ecological shifts and global-scale climate feedbacks including changes in land surface albedo and enhanced evapotranspiration. However, the rate at which shrubs can colonize previously glaciated terrain in a warming world is largely unknown. Reconstructions of past vegetation dynamics in conjunction with climate records can provide critical insights into shrubification rates and controls on plant migration, but paleoenvironmental reconstructions based on pollen may be biased by the influx of exotic pollen to tundra settings. Here, we reconstruct past plant communities using sedimentary ancient DNA (sedaDNA), which has a more local source area than pollen. We additionally reconstruct past temperature variability using bacterial cell membrane lipids (branched glycerol dialkyl glycerol tetraethers) and an aquatic productivity indicator (biogenic silica) to evaluate the relative timing of postglacial ecological and climate changes at a lake on southern Baffin Island, Arctic Canada. The sedaDNA record tightly constrains the colonization of dwarf birch (Betula, a thermophilous shrub) to 5.9 ± 0.1 ka, ~3 ka after local deglaciation as determined by cosmogenic 10 Be moraine dating and >2 ka later than Betula pollen is recorded in nearby lake sediment. We then assess the paleovegetation history within the context of summer temperature and find that paleotemperatures were highest prior to 6.3 ka, followed by cooling in the centuries preceding Betula establishment. Together, these molecular proxies reveal that Betula colonization lagged peak summer temperatures, suggesting that inefficient dispersal, rather than climate, may have limited Arctic shrub migration in this region. In addition, these data suggest that pollen-based climate reconstructions from high latitudes, which rely heavily on the presence and abundance of pollen from thermophilous taxa like Betula, can be compromised by both exotic pollen fluxes and vegetation migration lags.
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Affiliation(s)
- Sarah E Crump
- Institute of Arctic and Alpine Research and Department of Geological Sciences, University of Colorado Boulder, Boulder, CO, USA.,Organic Geochemistry Laboratory, University of Colorado Boulder, Boulder, CO, USA
| | - Gifford H Miller
- Institute of Arctic and Alpine Research and Department of Geological Sciences, University of Colorado Boulder, Boulder, CO, USA.,Trace and Environmental DNA (TrEnD) Laboratory, School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia
| | - Matthew Power
- Trace and Environmental DNA (TrEnD) Laboratory, School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia
| | - Julio Sepúlveda
- Institute of Arctic and Alpine Research and Department of Geological Sciences, University of Colorado Boulder, Boulder, CO, USA.,Organic Geochemistry Laboratory, University of Colorado Boulder, Boulder, CO, USA
| | - Nadia Dildar
- Institute of Arctic and Alpine Research and Department of Geological Sciences, University of Colorado Boulder, Boulder, CO, USA.,Organic Geochemistry Laboratory, University of Colorado Boulder, Boulder, CO, USA
| | - Megan Coghlan
- Trace and Environmental DNA (TrEnD) Laboratory, School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia
| | - Michael Bunce
- Trace and Environmental DNA (TrEnD) Laboratory, School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia
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21
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Göckede M, Kwon MJ, Kittler F, Heimann M, Zimov N, Zimov S. Negative feedback processes following drainage slow down permafrost degradation. GLOBAL CHANGE BIOLOGY 2019; 25:3254-3266. [PMID: 31241797 PMCID: PMC6851682 DOI: 10.1111/gcb.14744] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 06/03/2019] [Accepted: 06/17/2019] [Indexed: 05/31/2023]
Abstract
The sustainability of the vast Arctic permafrost carbon pool under climate change is of paramount importance for global climate trajectories. Accurate climate change forecasts, therefore, depend on a reliable representation of mechanisms governing Arctic carbon cycle processes, but this task is complicated by the complex interaction of multiple controls on Arctic ecosystem changes, linked through both positive and negative feedbacks. As a primary example, predicted Arctic warming can be substantially influenced by shifts in hydrologic regimes, linked to, for example, altered precipitation patterns or changes in topography following permafrost degradation. This study presents observational evidence how severe drainage, a scenario that may affect large Arctic areas with ice-rich permafrost soils under future climate change, affects biogeochemical and biogeophysical processes within an Arctic floodplain. Our in situ data demonstrate reduced carbon losses and transfer of sensible heat to the atmosphere, and effects linked to drainage-induced long-term shifts in vegetation communities and soil thermal regimes largely counterbalanced the immediate drainage impact. Moreover, higher surface albedo in combination with low thermal conductivity cooled the permafrost soils. Accordingly, long-term drainage effects linked to warming-induced permafrost degradation hold the potential to alleviate positive feedbacks between permafrost carbon and Arctic warming, and to slow down permafrost degradation. Self-stabilizing effects associated with ecosystem disturbance such as these drainage impacts are a key factor for predicting future feedbacks between Arctic permafrost and climate change, and, thus, neglect of these mechanisms will exaggerate the impacts of Arctic change on future global climate projections.
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Affiliation(s)
| | - Min Jung Kwon
- Max Planck Institute for BiogeochemistryJenaGermany
- Korea Polar Research InstituteIncheonSouth Korea
| | | | - Martin Heimann
- Max Planck Institute for BiogeochemistryJenaGermany
- Institute for Atmospheric and Earth System Research (INAR)/PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Nikita Zimov
- North‐East Scientific Station, Pacific Institute for Geography, Far‐East Branch, Russian Academy of SciencesCherskiiRussia
| | - Sergey Zimov
- North‐East Scientific Station, Pacific Institute for Geography, Far‐East Branch, Russian Academy of SciencesCherskiiRussia
- Far Eastern Federal UniversityVladivostokRussia
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22
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Wallace CA, Baltzer JL. Tall Shrubs Mediate Abiotic Conditions and Plant Communities at the Taiga–Tundra Ecotone. Ecosystems 2019. [DOI: 10.1007/s10021-019-00435-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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23
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Myers-Smith IH, Thomas HJD, Bjorkman AD. Plant traits inform predictions of tundra responses to global change. THE NEW PHYTOLOGIST 2019; 221:1742-1748. [PMID: 30444539 DOI: 10.1111/nph.15592] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 09/21/2018] [Indexed: 06/09/2023]
Abstract
Contents Summary 1742 I. Introduction 1742 II. The global context of tundra trait variation 1743 III. The current state of knowledge on trait change in the tundra biome 1744 IV. The links between traits and ecosystem functions 1744 V. Future priorities for tundra trait research 1746 VI. Conclusions 1746 References 1747 SUMMARY: In the rapidly warming tundra biome, plant traits provide an essential link between ongoing vegetation change and feedbacks to key ecosystem functions. However, only recently have comprehensive trait data been compiled for tundra species and sites, allowing us to assess key elements of functional responses to global change. In this review, we summarize trait-based research in tundra ecosystems, with a focus on three components: plant trait variation and how it compares with global patterns; shifts in community-level traits in response to environmental change; and the use of traits to understand and predict ecosystem function. Quantifying patterns and trends in plant traits will allow us to better project the consequences of environmental change for the ecology and functioning of tundra ecosystems.
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Affiliation(s)
| | - Haydn J D Thomas
- School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3FF, UK
| | - Anne D Bjorkman
- Senckenberg Gesellschaft für Naturforschung, Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, Frankfurt, Germany
- Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Ny Munkegade 114-116, DK-8000, Aarhus C, Denmark
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24
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Ray PM, Bret-Harte MS. Elastic and Irreversible Bending of Tree and Shrub Branches Under Cantilever Loads. FRONTIERS IN PLANT SCIENCE 2019; 10:59. [PMID: 30804957 PMCID: PMC6370663 DOI: 10.3389/fpls.2019.00059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 01/16/2019] [Indexed: 06/09/2023]
Abstract
Tree and shrub branches subjected to cantilever loads such as intercepted snowfall undergo, in addition to the familiar instantaneous elastic bending, a conspicuous retarded-elastic bending, which is commonly 30-50% of their instantaneous bending and occasionally even more. The resultant bending creep that occurs after loading also often includes a slow, time-dependent irreversible bending. These phenomena occur quite generally among woody plants of different major biomes, taxonomic groups, and structural types. We give some of branch bending viscoelasticity's basic physical properties such as load dependence and stress relaxation. These properties belong to the secondary walls of branches' xylem (wood) cells; some properties differ notably from those reported for primary cell walls, a difference for which we propose explanations. A method for separating the overlapping time courses of retarded-elastic and time-dependent irreversible bending shows that multiple retarded-elastic ("Kelvin") elements of branches span a wide range of retardation times (a retardation spectrum, approximate examples of which we calculate), and that irreversible bending can occur in different cases either only in the first few h after loading, or more extensively through 24 h, or (rarely) for several days. A separate time-independent irreversible bending, permanent set, involving a substantial yield stress, also occurs. In three species of shrubs rapid irreversible bending began only several (up to 24) h after loading, implying an unusual kind of viscoelasticity. Deductions from the dynamics of bending suggest that retarded elasticity can help protect branches against breakage by wind gusts during storms. Irreversible bending probably contributes both to the form that tree and shrub crowns develop over the long term, involving progressive increase in the downward curvature and/or inclination of branches, and also to certain other, more specialized, developmental changes.
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Affiliation(s)
- Peter M. Ray
- Department of Biological Sciences, Stanford University, Stanford, CA, United States
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States
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25
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The Role of Climate and Land Use in the Changes in Surface Albedo Prior to Snow Melt and the Timing of Melt Season of Seasonal Snow in Northern Land Areas of 40°N–80°N during 1982–2015. REMOTE SENSING 2018. [DOI: 10.3390/rs10101619] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The rapid warming of the Northern Hemisphere high latitudes and the observed changes in boreal forest areas affect the global surface albedo and climate. This study looks at the trends in the timing of the snow melt season as well as the albedo levels before and after the melt season in Northern Hemisphere land areas between 40°N and 80°N over the years 1982 to 2015. The analysis is based on optical satellite data from the Advanced Very High Resolution Radiometer (AVHRR). The results show that the changes in surface albedo already begin before the start of the melt season. These albedo changes are significant (the mean of absolute change is 4.4 albedo percentage units per 34 years). The largest absolute changes in pre-melt-season albedo are concentrated in areas of the boreal forest, while the pre-melt albedo of tundra remains unchanged. Trends in melt season timing are consistent over large areas. The mean of absolute change of start date of melt season is 11.2 days per 34 years, 10.6 days for end date of melt season and 14.8 days for length of melt season. The changes result in longer and shorter melt seasons, as well as changed timing of the melt, depending on the area. The albedo levels preceding the onset of melt and start of the melt season correlate with climatic parameters (air temperature, precipitation, wind speed). The changes in albedo are more closely linked to changes in vegetation, whereas the changes in melt season timing are linked to changes in climate.
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26
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Bjorkman AD, Myers-Smith IH, Elmendorf SC, Normand S, Rüger N, Beck PSA, Blach-Overgaard A, Blok D, Cornelissen JHC, Forbes BC, Georges D, Goetz SJ, Guay KC, Henry GHR, HilleRisLambers J, Hollister RD, Karger DN, Kattge J, Manning P, Prevéy JS, Rixen C, Schaepman-Strub G, Thomas HJD, Vellend M, Wilmking M, Wipf S, Carbognani M, Hermanutz L, Lévesque E, Molau U, Petraglia A, Soudzilovskaia NA, Spasojevic MJ, Tomaselli M, Vowles T, Alatalo JM, Alexander HD, Anadon-Rosell A, Angers-Blondin S, Beest MT, Berner L, Björk RG, Buchwal A, Buras A, Christie K, Cooper EJ, Dullinger S, Elberling B, Eskelinen A, Frei ER, Grau O, Grogan P, Hallinger M, Harper KA, Heijmans MMPD, Hudson J, Hülber K, Iturrate-Garcia M, Iversen CM, Jaroszynska F, Johnstone JF, Jørgensen RH, Kaarlejärvi E, Klady R, Kuleza S, Kulonen A, Lamarque LJ, Lantz T, Little CJ, Speed JDM, Michelsen A, Milbau A, Nabe-Nielsen J, Nielsen SS, Ninot JM, Oberbauer SF, Olofsson J, Onipchenko VG, Rumpf SB, Semenchuk P, Shetti R, Collier LS, Street LE, Suding KN, Tape KD, Trant A, Treier UA, Tremblay JP, Tremblay M, Venn S, Weijers S, Zamin T, Boulanger-Lapointe N, Gould WA, Hik DS, Hofgaard A, Jónsdóttir IS, Jorgenson J, Klein J, Magnusson B, Tweedie C, Wookey PA, Bahn M, Blonder B, van Bodegom PM, Bond-Lamberty B, Campetella G, Cerabolini BEL, Chapin FS, Cornwell WK, Craine J, Dainese M, de Vries FT, Díaz S, Enquist BJ, Green W, Milla R, Niinemets Ü, Onoda Y, Ordoñez JC, Ozinga WA, Penuelas J, Poorter H, Poschlod P, Reich PB, Sandel B, Schamp B, Sheremetev S, Weiher E. Plant functional trait change across a warming tundra biome. Nature 2018; 562:57-62. [PMID: 30258229 DOI: 10.1038/s41586-018-0563-7] [Citation(s) in RCA: 208] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 08/08/2018] [Indexed: 11/09/2022]
Abstract
The tundra is warming more rapidly than any other biome on Earth, and the potential ramifications are far-reaching because of global feedback effects between vegetation and climate. A better understanding of how environmental factors shape plant structure and function is crucial for predicting the consequences of environmental change for ecosystem functioning. Here we explore the biome-wide relationships between temperature, moisture and seven key plant functional traits both across space and over three decades of warming at 117 tundra locations. Spatial temperature-trait relationships were generally strong but soil moisture had a marked influence on the strength and direction of these relationships, highlighting the potentially important influence of changes in water availability on future trait shifts in tundra plant communities. Community height increased with warming across all sites over the past three decades, but other traits lagged far behind predicted rates of change. Our findings highlight the challenge of using space-for-time substitution to predict the functional consequences of future warming and suggest that functions that are tied closely to plant height will experience the most rapid change. They also reveal the strength with which environmental factors shape biotic communities at the coldest extremes of the planet and will help to improve projections of functional changes in tundra ecosystems with climate warming.
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Affiliation(s)
- Anne D Bjorkman
- School of GeoSciences, University of Edinburgh, Edinburgh, UK. .,Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Aarhus, Denmark. .,Senckenberg Gesellschaft für Naturforschung, Biodiversity and Climate Research Centre (BiK-F), Frankfurt, Germany.
| | | | - Sarah C Elmendorf
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA.,National Ecological Observatory Network, Boulder, CO, USA.,Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO, USA
| | - Signe Normand
- Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Aarhus, Denmark.,Arctic Research Center, Department of Bioscience, Aarhus University, Aarhus, Denmark.,Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Nadja Rüger
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.,Smithsonian Tropical Research Institute, Balboa, Panama
| | - Pieter S A Beck
- European Commission, Joint Research Centre, Directorate D - Sustainable Resources, Bio-Economy Unit, Ispra, Italy
| | - Anne Blach-Overgaard
- Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Aarhus, Denmark.,Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Daan Blok
- Department of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden
| | - J Hans C Cornelissen
- Systems Ecology, Department of Ecological Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Bruce C Forbes
- Arctic Centre, University of Lapland, Rovaniemi, Finland
| | - Damien Georges
- School of GeoSciences, University of Edinburgh, Edinburgh, UK.,International Agency for Research in Cancer, Lyon, France
| | - Scott J Goetz
- School of Informatics, Computing and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Kevin C Guay
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA
| | - Gregory H R Henry
- Department of Geography, University of British Columbia, Vancouver, British Columbia, Canada
| | | | | | - Dirk N Karger
- Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | - Jens Kattge
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.,Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Peter Manning
- Senckenberg Gesellschaft für Naturforschung, Biodiversity and Climate Research Centre (BiK-F), Frankfurt, Germany
| | - Janet S Prevéy
- WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland
| | - Christian Rixen
- WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland
| | - Gabriela Schaepman-Strub
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | | | - Mark Vellend
- Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Martin Wilmking
- Institute of Botany and Landscape Ecology, Greifswald University, Greifswald, Germany
| | - Sonja Wipf
- WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland
| | - Michele Carbognani
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Luise Hermanutz
- Department of Biology, Memorial University, St. John's, Newfoundland and Labrador, Canada
| | - Esther Lévesque
- Département des Sciences de l'environnement et Centre d'études nordiques, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Ulf Molau
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Alessandro Petraglia
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Nadejda A Soudzilovskaia
- Environmental Biology Department, Institute of Environmental Sciences, Leiden University, Leiden, The Netherlands
| | - Marko J Spasojevic
- Department of Evolution, Ecology and Organismal Biology, University of California Riverside, Riverside, CA, USA
| | - Marcello Tomaselli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Tage Vowles
- Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Juha M Alatalo
- Department of Biological and Environmental Sciences, Qatar University, Doha, Qatar
| | - Heather D Alexander
- Department of Forestry, Forest and Wildlife Research Center, Mississippi State University, Mississippi State, MS, USA
| | - Alba Anadon-Rosell
- Institute of Botany and Landscape Ecology, Greifswald University, Greifswald, Germany.,Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain.,Biodiversity Research Institute, University of Barcelona, Barcelona, Spain
| | | | - Mariska Te Beest
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden.,Environmental Sciences, Copernicus Institute of Sustainable Development, Utrecht University, Utrecht, The Netherlands
| | - Logan Berner
- School of Informatics, Computing and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
| | - Robert G Björk
- Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden.,Gothenburg Global Biodiversity Centre, Göteborg, Sweden
| | - Agata Buchwal
- Institute of Geoecology and Geoinformation, Adam Mickiewicz University, Poznan, Poland.,Department of Biological Sciences, University of Alaska, Anchorage, Anchorage, AK, USA
| | - Allan Buras
- Forest Ecology and Forest Management, Wageningen University and Research, Wageningen, The Netherlands
| | | | - Elisabeth J Cooper
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Stefan Dullinger
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
| | - Bo Elberling
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Anu Eskelinen
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.,Department of Physiological Diversity, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany.,Department of Ecology and Genetics, University of Oulu, Oulu, Finland
| | - Esther R Frei
- Department of Geography, University of British Columbia, Vancouver, British Columbia, Canada.,Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | - Oriol Grau
- Global Ecology Unit, CREAF-CSIC-UAB, Cerdanyola del Vallès, Spain.,CREAF, Cerdanyola del Vallès, Spain
| | - Paul Grogan
- Department of Biology, Queen's University, Kingston, Ontario, Canada
| | - Martin Hallinger
- Biology Department, Swedish Agricultural University (SLU), Uppsala, Sweden
| | - Karen A Harper
- Biology Department, Saint Mary's University, Halifax, Nova Scotia, Canada
| | - Monique M P D Heijmans
- Plant Ecology and Nature Conservation Group, Wageningen University and Research, Wageningen, The Netherlands
| | - James Hudson
- British Columbia Public Service, Surrey, British Columbia, Canada
| | - Karl Hülber
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
| | - Maitane Iturrate-Garcia
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Colleen M Iversen
- Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Francesca Jaroszynska
- WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland.,Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - Jill F Johnstone
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Rasmus Halfdan Jørgensen
- Forest and Landscape College, Department of Geosciences and Natural Resource Management, University of Copenhagen, Nødebo, Denmark
| | - Elina Kaarlejärvi
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden.,Department of Biology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Rebecca Klady
- Department of Forest Resources Management, Faculty of Forestry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sara Kuleza
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Aino Kulonen
- WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland
| | - Laurent J Lamarque
- Département des Sciences de l'environnement et Centre d'études nordiques, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Trevor Lantz
- School of Environmental Studies, University of Victoria, Victoria, British Columbia, Canada
| | - Chelsea J Little
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Department of Aquatic Ecology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dubendorf, Switzerland
| | - James D M Speed
- NTNU University Museum, Norwegian University of Science and Technology, Trondheim, Norway
| | - Anders Michelsen
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark.,Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Ann Milbau
- Research Institute for Nature and Forest (INBO), Brussels, Belgium
| | | | - Sigrid Schøler Nielsen
- Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Josep M Ninot
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain.,Biodiversity Research Institute, University of Barcelona, Barcelona, Spain
| | - Steven F Oberbauer
- Department of Biological Sciences, Florida International University, Miami, FL, USA
| | - Johan Olofsson
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
| | | | - Sabine B Rumpf
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
| | - Philipp Semenchuk
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT-The Arctic University of Norway, Tromsø, Norway.,Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
| | - Rohan Shetti
- Institute of Botany and Landscape Ecology, Greifswald University, Greifswald, Germany
| | - Laura Siegwart Collier
- Department of Biology, Memorial University, St. John's, Newfoundland and Labrador, Canada
| | - Lorna E Street
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | - Katharine N Suding
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - Ken D Tape
- Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Andrew Trant
- Department of Biology, Memorial University, St. John's, Newfoundland and Labrador, Canada.,School of Environment, Resources and Sustainability, University of Waterloo, Waterloo, Ontario, Canada
| | - Urs A Treier
- Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Aarhus, Denmark.,Arctic Research Center, Department of Bioscience, Aarhus University, Aarhus, Denmark.,Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Jean-Pierre Tremblay
- Département de biologie, Centre d'études nordiques and Centre d'étude de la forêt, Université Laval, Quebec City, Québec, Canada
| | - Maxime Tremblay
- Département des Sciences de l'environnement et Centre d'études nordiques, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Susanna Venn
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria, Australia
| | - Stef Weijers
- Department of Geography, University of Bonn, Bonn, Germany
| | - Tara Zamin
- Department of Biology, Queen's University, Kingston, Ontario, Canada
| | | | - William A Gould
- USDA Forest Service International Institute of Tropical Forestry, Río Piedras, Puerto Rico
| | - David S Hik
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | | | - Ingibjörg S Jónsdóttir
- Faculty of Life and Environmental Sciences, University of Iceland, Reykjavík, Iceland.,University Centre in Svalbard, Longyearbyen, Norway
| | - Janet Jorgenson
- Arctic National Wildlife Refuge, US Fish and Wildlife Service, Fairbanks, AK, USA
| | - Julia Klein
- Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO, USA
| | | | | | - Philip A Wookey
- Biology and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Michael Bahn
- Institute of Ecology, University of Innsbruck, Innsbruck, Austria
| | - Benjamin Blonder
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK.,Rocky Mountain Biological Laboratory, Crested Butte, CO, USA
| | - Peter M van Bodegom
- Institute of Environmental Sciences, Leiden University, Leiden, The Netherlands
| | - Benjamin Bond-Lamberty
- Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, MD, USA
| | - Giandiego Campetella
- School of Biosciences and Veterinary Medicine, Plant Diversity and Ecosystems Management Unit, University of Camerino, Camerino, Italy
| | | | - F Stuart Chapin
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - William K Cornwell
- School of Biological, Earth and Environmental Sciences, Ecology and Evolution Research Centre, UNSW Sydney, Sydney, New South Wales, Australia
| | | | - Matteo Dainese
- Institute for Alpine Environment, Eurac Research, Bolzano, Italy
| | - Franciska T de Vries
- School of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
| | - Sandra Díaz
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), CONICET and FCEFyN, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Brian J Enquist
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA.,The Santa Fe Institute, Santa Fe, NM, USA
| | - Walton Green
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Ruben Milla
- Área de Biodiversidad y Conservación. Departamento de Biología, Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos, Madrid, Spain
| | - Ülo Niinemets
- Estonian University of Life Sciences, Tartu, Estonia
| | - Yusuke Onoda
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | | | - Wim A Ozinga
- Team Vegetation, Forest and Landscape Ecology, Wageningen Environmental Research (Alterra), Wageningen, The Netherlands.,Institute for Water and Wetland Research, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Josep Penuelas
- CREAF, Cerdanyola del Vallès, Spain.,Global Ecology Unit CREAF-CSIC-UAB, Consejo Superior de Investigaciones Cientificas, Bellaterra, Spain
| | - Hendrik Poorter
- Plant Sciences (IBG-2), Forschungszentrum Jülich GmbH, Jülich, Germany.,Department of Biological Sciences, Macquarie University, North Ryde, New South Wales, Australia
| | - Peter Poschlod
- Ecology and Conservation Biology, Institute of Plant Sciences, University of Regensburg, Regensburg, Germany
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St. Paul, MN, USA.,Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Brody Sandel
- Department of Biology, Santa Clara University, Santa Clara, CA, USA
| | - Brandon Schamp
- Department of Biology, Algoma University, Sault Ste. Marie, Ontario, Canada
| | | | - Evan Weiher
- Department of Biology, University of Wisconsin - Eau Claire, Eau Claire, WI, USA
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27
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Interdependent Dynamics of LAI-Albedo across the Roofing Landscapes: Mongolian and Tibetan Plateaus. REMOTE SENSING 2018. [DOI: 10.3390/rs10071159] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The Mongolian Plateau (MP) and Tibetan Plateau (TP) have experienced higher-than-global average warming in recent decades, resulting in many significant changes in ecosystem structure and function. Among them are the leaf area index (LAI) and albedo, which play a fundamental role in understanding many causes and consequences of land surface processes and climate. Here, we focused on the spatiotemporal changes of LAI, albedo, and their spatiotemporal relationships on the two roofing landscapes in Eurasia. Based on the MODIS products, we investigated the spatiotemporal changes of albedo(VIS, NIR and SHO) and LAI from 2000 through 2016. We found that there existed a general negative logarithmic relationship between LAI and three measures of albedo on both plateaus. No significant relationship was found for LAI-albedoNIR on the TP, due to more complex land surface canopy characteristics affected by the NIR reflection there. During 2000–2016, overall, annual mean LAI increased significantly by 119.40 × 103 km2 on the MP and by 28.35 × 103 km2 on the TP, while the decreased areas for annual mean albedoVIS were 585.59 × 103 km2 and 235.73 × 103 km2 on the MP and TP, respectively. More importantly, the LAI-albedo relationships varied substantially across the space and over time, with mismatches found in some parts of the landscapes. Substantial additional efforts with observational and/or experimental investigations are needed to explore the underlying mechanisms responsible for these relationships, including the influences of vegetation characteristics and disturbances.
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28
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Frei ER, Bianchi E, Bernareggi G, Bebi P, Dawes MA, Brown CD, Trant AJ, Mamet SD, Rixen C. Biotic and abiotic drivers of tree seedling recruitment across an alpine treeline ecotone. Sci Rep 2018; 8:10894. [PMID: 30022032 PMCID: PMC6052039 DOI: 10.1038/s41598-018-28808-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 06/29/2018] [Indexed: 11/19/2022] Open
Abstract
Treeline responses to climate change ultimately depend on successful seedling recruitment, which requires dispersal of viable seeds and establishment of individual propagules in novel environments. In this study, we evaluated the effects of several abiotic and biotic drivers of early tree seedling recruitment across an alpine treeline ecotone. In two consecutive years, we sowed seeds of low- and high-elevation provenances of Larix decidua (European larch) and Picea abies (Norway spruce) below, at, and above the current treeline into intact vegetation and into open microsites with artificially removed surface vegetation, as well as into plots protected from seed predators and herbivores. Seedling emergence and early establishment in treatment and in control plots were monitored over two years. Tree seedling emergence occurred at and several hundred metres above the current treeline when viable seeds and suitable microsites for germination were available. However, dense vegetation cover at lower elevations and winter mortality at higher elevations particularly limited early recruitment. Post-dispersal predation, species, and provenance also affected emergence and early establishment. This study demonstrates the importance of understanding multiple abiotic and biotic drivers of early seedling recruitment that should be incorporated into predictions of treeline dynamics under climate change.
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Affiliation(s)
- Esther R Frei
- WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, 7260, Davos Dorf, Switzerland. .,Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903, Birmensdorf, Switzerland.
| | - Eva Bianchi
- WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, 7260, Davos Dorf, Switzerland.,Institute of Terrestrial Ecosystems, Department of Environmental Systems Science, ETH Zurich, Universitätstrasse 22, 8092, Zurich, Switzerland
| | - Giulietta Bernareggi
- WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, 7260, Davos Dorf, Switzerland.,Dipartimento di Bioscienze, Università di Parma, Parco Area delle Scienze 11/A, 43124, Parma, Italy
| | - Peter Bebi
- WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, 7260, Davos Dorf, Switzerland
| | - Melissa A Dawes
- WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, 7260, Davos Dorf, Switzerland.,Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903, Birmensdorf, Switzerland
| | - Carissa D Brown
- Department of Geography, Memorial University, 230 Elizabeth Avenue, St John's, NL, A1B 3X9, Canada
| | - Andrew J Trant
- School of Environment, Resources and Sustainability, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada
| | - Steven D Mamet
- Department of Soil Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, S7N 5A8, Canada
| | - Christian Rixen
- WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, 7260, Davos Dorf, Switzerland
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29
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Jespersen RG, Leffler AJ, Oberbauer SF, Welker JM. Arctic plant ecophysiology and water source utilization in response to altered snow: isotopic (δ18O and δ2H) evidence for meltwater subsidies to deciduous shrubs. Oecologia 2018; 187:1009-1023. [DOI: 10.1007/s00442-018-4196-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 06/05/2018] [Indexed: 11/29/2022]
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30
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Lemay MA, Provencher-Nolet L, Bernier M, Lévesque E, Boudreau S. Spatially explicit modeling and prediction of shrub cover increase near Umiujaq, Nunavik. ECOL MONOGR 2018. [DOI: 10.1002/ecm.1296] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Marc-André Lemay
- Département de biologie; Université Laval; 1045 avenue de la Médecine Québec Quebec G1V 0A6 Canada
- Centre d’études nordiques; Université Laval; 2405 rue de la Terrasse Québec Quebec G1V 0A6 Canada
| | - Laurence Provencher-Nolet
- Centre d’études nordiques; Université Laval; 2405 rue de la Terrasse Québec Quebec G1V 0A6 Canada
- Institut national de la recherche scientifique-Centre Eau Terre Environnement; 490 rue de la Couronne Québec Quebec G1K 9A9 Canada
| | - Monique Bernier
- Centre d’études nordiques; Université Laval; 2405 rue de la Terrasse Québec Quebec G1V 0A6 Canada
- Institut national de la recherche scientifique-Centre Eau Terre Environnement; 490 rue de la Couronne Québec Quebec G1K 9A9 Canada
| | - Esther Lévesque
- Centre d’études nordiques; Université Laval; 2405 rue de la Terrasse Québec Quebec G1V 0A6 Canada
- Département des sciences de l'environnement; Université du Québec à Trois-Rivières; 3351 boulevard des Forges, CP 500 Trois-Rivières Quebec G9A 5H7 Canada
| | - Stéphane Boudreau
- Département de biologie; Université Laval; 1045 avenue de la Médecine Québec Quebec G1V 0A6 Canada
- Centre d’études nordiques; Université Laval; 2405 rue de la Terrasse Québec Quebec G1V 0A6 Canada
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31
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Tomiolo S, Ward D. Soil properties and climate mediate the effects of biotic interactions on the performance of a woody range expander. Ecosphere 2018. [DOI: 10.1002/ecs2.2186] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Sara Tomiolo
- Department of Biological Sciences Kent State University Cunningham Hall Kent Ohio 44242 USA
| | - David Ward
- Department of Biological Sciences Kent State University Cunningham Hall Kent Ohio 44242 USA
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32
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Träger S, Milbau A, Wilson SD. Potential contributions of root decomposition to the nitrogen cycle in arctic forest and tundra. Ecol Evol 2018; 7:11021-11032. [PMID: 29299278 PMCID: PMC5743615 DOI: 10.1002/ece3.3522] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 09/17/2017] [Accepted: 09/21/2017] [Indexed: 12/01/2022] Open
Abstract
Plant contributions to the nitrogen (N) cycle from decomposition are likely to be altered by vegetation shifts associated with climate change. Roots account for the majority of soil organic matter input from vegetation, but little is known about differences between vegetation types in their root contributions to nutrient cycling. Here, we examine the potential contribution of fine roots to the N cycle in forest and tundra to gain insight into belowground consequences of the widely observed increase in woody vegetation that accompanies climate change in the Arctic. We combined measurements of root production from minirhizotron images with tissue analysis of roots from differing root diameter and color classes to obtain potential N input following decomposition. In addition, we tested for changes in N concentration of roots during early stages of decomposition, and investigated whether vegetation type (forest or tundra) affected changes in tissue N concentration during decomposition. For completeness, we also present respective measurements of leaves. The potential N input from roots was twofold greater in forest than in tundra, mainly due to greater root production in forest. Potential N input varied with root diameter and color, but this variation tended to be similar in forest and tundra. As for roots, the potential N input from leaves was significantly greater in forest than in tundra. Vegetation type had no effect on changes in root or leaf N concentration after 1 year of decomposition. Our results suggest that shifts in vegetation that accompany climate change in the Arctic will likely increase plant‐associated potential N input both belowground and aboveground. In contrast, shifts in vegetation might not alter changes in tissue N concentration during early stages of decomposition. Overall, differences between forest and tundra in potential contribution of decomposing roots to the N cycle reinforce differences between habitats that occur for leaves.
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Affiliation(s)
- Sabrina Träger
- Department of Botany Institute of Ecology and Earth Sciences University of Tartu Tartu Estonia
| | - Ann Milbau
- Research Institute for Nature and Forest INBO Brussels Belgium.,Department of Ecology and Environmental Science Climate Impacts Research Centre Umeå University Abisko Sweden
| | - Scott D Wilson
- Department of Ecology and Environmental Science Climate Impacts Research Centre Umeå University Abisko Sweden.,Department of Biology University of Regina Regina SK Canada
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Vowles T, Gunnarsson B, Molau U, Hickler T, Klemedtsson L, Björk RG. Expansion of deciduous tall shrubs but not evergreen dwarf shrubs inhibited by reindeer in Scandes mountain range. THE JOURNAL OF ECOLOGY 2017; 105:1547-1561. [PMID: 29200500 PMCID: PMC5697633 DOI: 10.1111/1365-2745.12753] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 01/12/2017] [Indexed: 06/02/2023]
Abstract
One of the most palpable effects of warming in Arctic ecosystems is shrub expansion above the tree line. However, previous studies have found that reindeer can influence plant community responses to warming and inhibit shrubification of the tundra.We revisited grazed (ambient) and ungrazed study plots (exclosures), at the southern as well as the northern limits of the Swedish alpine region, to study long-term grazing effects and vegetation changes in response to increasing temperatures between 1995 and 2011, in two vegetation types (shrub heath and mountain birch forest).In the field layer at the shrub heath sites, evergreen dwarf shrubs had increased in cover from 26% to 49% but were unaffected by grazing. Deciduous dwarf and tall shrubs also showed significant, though smaller, increases over time. At the birch forest sites, the increase was similar for evergreen dwarf shrubs (20-48%) but deciduous tall shrubs did not show the same consistent increase over time as in the shrub heath.The cover and height of the shrub layer were significantly greater in exclosures at the shrub heath sites, but no significant treatment effects were found on species richness or diversity.July soil temperatures and growing season thawing degree days (TDD) were higher in exclosures at all but one site, and there was a significant negative correlation between mean shrub layer height and soil TDD at the shrub heath sites. Synthesis. This study shows that shrub expansion is occurring rapidly in the Scandes mountain range, both above and below the tree line. Tall, deciduous shrubs had benefitted significantly from grazing exclosure, both in terms of cover and height, which in turn lowered summer soil temperatures. However, the overriding vegetation shift across our sites was the striking increase in evergreen dwarf shrubs, which were not influenced by grazing. As the effects of an increase in evergreen dwarf shrubs and more recalcitrant plant litter may to some degree counteract some of the effects of an increase in deciduous tall shrubs, herbivore influence on shrub interactions is potentially of great importance for shaping arctic shrub expansion and its associated ecosystem effects.
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Affiliation(s)
- Tage Vowles
- Department of Biological and Environmental SciencesUniversity of GothenburgBox 46140530GöteborgSweden
| | - Bengt Gunnarsson
- Department of Biological and Environmental SciencesUniversity of GothenburgBox 46140530GöteborgSweden
| | - Ulf Molau
- Department of Biological and Environmental SciencesUniversity of GothenburgBox 46140530GöteborgSweden
| | - Thomas Hickler
- Senckenberg Biodiversity & Climate Research Centre Bik FSenckenberganalge 25D‐60325FrankfurtGermany
- Department of Physical GeographyGoethe University FrankfurtAltenhöferallee 1D‐60438FrankfurtGermany
| | - Leif Klemedtsson
- Department of Earth SciencesUniversity of GothenburgBox 46040530GöteborgSweden
| | - Robert G. Björk
- Department of Earth SciencesUniversity of GothenburgBox 46040530GöteborgSweden
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Regional Quantitative Cover Mapping of Tundra Plant Functional Types in Arctic Alaska. REMOTE SENSING 2017. [DOI: 10.3390/rs9101024] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Tian L, Chen J, Zhang Y. Growing season carries stronger contributions to albedo dynamics on the Tibetan plateau. PLoS One 2017; 12:e0180559. [PMID: 28886037 PMCID: PMC5590739 DOI: 10.1371/journal.pone.0180559] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 06/16/2017] [Indexed: 11/19/2022] Open
Abstract
The Tibetan Plateau has experienced higher-than-global-average climate warming in recent decades, resulting in many significant changes in ecosystem structure and function. Among them is albedo, which bridges the causes and consequences of land surface processes and climate. The plateau is covered by snow/ice and vegetation in the non-growing season (nGS) and growing season (GS), respectively. Based on the MODIS products, we investigated snow/ice cover and vegetation greenness in relation to the spatiotemporal changes of albedo on the Tibetan Plateau from 2000 through 2013. A synchronous relationship was found between the change in GSNDVI and GSalbedo over time and across the Tibetan landscapes. We found that the annual average albedo had a decreasing trend, but that the albedo had slightly increased during the nGS and decreased during the GS. Across the landscapes, the nGSalbedo fluctuated in a synchronous pattern with snow/ice cover. Temporally, monthly snow/ice coverage also had a high correspondence with albedo, except in April and October. We detected clear dependencies of albedo on elevation. With the rise in altitude, the nGSalbedo decreased below 4000 m, but increased for elevations of 4500-5500 m. Above 5500 m, the nGSalbedo decreased, which was in accordance with the decreased amount of snow/ice coverage and the increased soil moisture on the plateau. More importantly, the decreasing albedo in the most recent decade appeared to be caused primarily by lowered growing season albedo.
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Affiliation(s)
- Li Tian
- Qianyanzhou Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
- Lhasa station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
- * E-mail:
| | - Jiquan Chen
- CGCEO and Department of Geography, Environment, and Spatial Sciences, Michigan State University, East Lansing, Michigan, United States of America
| | - Yangjian Zhang
- Lhasa station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
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Seasonal and Long-Term Changes to Active-Layer Temperatures after Tall Shrubland Expansion and Succession in Arctic Tundra. Ecosystems 2017. [DOI: 10.1007/s10021-017-0165-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Swift RJ, Rodewald AD, Senner NR. Breeding habitat of a declining shorebird in a changing environment. Polar Biol 2017. [DOI: 10.1007/s00300-017-2101-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Wang Z, Erb AM, Schaaf CB, Sun Q, Liu Y, Yang Y, Shuai Y, Casey KA, Román MO. Early spring post-fire snow albedo dynamics in high latitude boreal forests using Landsat-8 OLI data. REMOTE SENSING OF ENVIRONMENT 2016; 185:71-83. [PMID: 29769751 PMCID: PMC5952213 DOI: 10.1016/j.rse.2016.02.059] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Taking advantage of the improved radiometric resolution of Landsat-8 OLI which, unlike previous Landsat sensors, does not saturate over snow, the progress of fire recovery progress at the landscape scale (< 100m) is examined. High quality Landsat-8 albedo retrievals can now capture the true reflective and layered character of snow cover over a full range of land surface conditions and vegetation densities. This new capability particularly improves the assessment of post-fire vegetation dynamics across low- to high- burn severity gradients in Arctic and boreal regions in the early spring, when the albedos during recovery show the greatest variation. We use 30 m resolution Landsat-8 surface reflectances with concurrent coarser resolution (500m) MODIS high quality full inversion surface Bidirectional Reflectance Distribution Functions (BRDF) products to produce higher resolution values of surface albedo. The high resolution full expression shortwave blue sky albedo product performs well with an overall RMSE of 0.0267 between tower and satellite measures under both snow-free and snow-covered conditions. While the importance of post-fire albedo recovery can be discerned from the MODIS albedo product at regional and global scales, our study addresses the particular importance of early spring post-fire albedo recovery at the landscape scale by considering the significant spatial heterogeneity of burn severity, and the impact of snow on the early spring albedo of various vegetation recovery types. We found that variations in early spring albedo within a single MODIS gridded pixel can be larger than 0.6. Since the frequency and severity of wildfires in Arctic and boreal systems is expected to increase in the coming decades, the dynamics of albedo in response to these rapid surface changes will increasingly impact the energy balance and contribute to other climate processes and physical feedback mechanisms. Surface radiation products derived from Landsat-8 data will thus play an important role in characterizing the carbon cycle and ecosystem processes of high latitude systems.
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Affiliation(s)
- Zhuosen Wang
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- School for the Environment, University of Massachusetts Boston, Boston, MA, USA
- NASA Postdoctoral Program Fellow, Goddard Space Flight Center, Greenbelt, MD, USA
| | - Angela M. Erb
- School for the Environment, University of Massachusetts Boston, Boston, MA, USA
| | - Crystal B. Schaaf
- School for the Environment, University of Massachusetts Boston, Boston, MA, USA
| | - Qingsong Sun
- School for the Environment, University of Massachusetts Boston, Boston, MA, USA
| | - Yan Liu
- School for the Environment, University of Massachusetts Boston, Boston, MA, USA
| | - Yun Yang
- United States Department of Agriculture, Agricultural Research Service, MD, USA
| | - Yanmin Shuai
- School for the Environment, University of Massachusetts Boston, Boston, MA, USA
| | - Kimberly A. Casey
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA
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Williamson SN, Barrio IC, Hik DS, Gamon JA. Phenology and species determine growing-season albedo increase at the altitudinal limit of shrub growth in the sub-Arctic. GLOBAL CHANGE BIOLOGY 2016; 22:3621-3631. [PMID: 27158930 DOI: 10.1111/gcb.13297] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 03/02/2016] [Accepted: 03/18/2016] [Indexed: 06/05/2023]
Abstract
Arctic warming is resulting in reduced snow cover and increased shrub growth, both of which have been associated with altered land surface-atmospheric feedback processes involving sensible heat flux, ground heat flux and biogeochemical cycling. Using field measurements, we show that two common Arctic shrub species (Betula glandulosa and Salix pulchra), which are largely responsible for shrub encroachment in tundra, differed markedly in albedo and that albedo of both species increased as growing season progressed when measured at their altitudinal limit. A moveable apparatus was used to repeatedly measure albedo at six precise spots during the summer of 2012, and resampled in 2013. Contrary to the generally accepted view of shrub-covered areas having low albedo in tundra, full-canopy prostrate B. glandulosa had almost the highest albedo of all surfaces measured during the peak of the growing season. The higher midsummer albedo is also evident in localized MODIS albedo aggregated from 2000 to 2013, which displays a similar increase in growing-season albedo. Using our field measurements, we show the ensemble summer increase in tundra albedo counteracts the generalized effect of earlier spring snow melt on surface energy balance by approximately 40%. This summer increase in albedo, when viewed in absolute values, is as large as the difference between the forest and tundra transition. These results indicate that near future (<50 years) changes in growing-season albedo related to Arctic vegetation change are unlikely to be particularly large and might constitute a negative feedback to climate warming in certain circumstances. Future efforts to calculate energy budgets and a sensible heating feedback in the Arctic will require more detailed information about the relative abundance of different ground cover types, particularly shrub species and their respective growth forms and phenology.
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Affiliation(s)
- Scott N Williamson
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada.
| | - Isabel C Barrio
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - David S Hik
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - John A Gamon
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB, T6G 2E3, Canada
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Moss Mediates the Influence of Shrub Species on Soil Properties and Processes in Alpine Tundra. PLoS One 2016; 11:e0164143. [PMID: 27760156 PMCID: PMC5070840 DOI: 10.1371/journal.pone.0164143] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 09/20/2016] [Indexed: 11/30/2022] Open
Abstract
In tundra ecosystems, bryophytes influence soil processes directly and indirectly through interactions with overstory shrub species. We experimentally manipulated moss cover and measured seasonal soil properties and processes under two species of deciduous shrubs with contrasting canopy structures, Salix planifolia pulchra and Betula glandulosa-nana complex. Soil properties (seasonal temperature, moisture and C:N ratios) and processes (seasonal litter decomposition and soil respiration) were measured over twelve months. Shrub species identity had the largest influence on summer soil temperatures and soil respiration rates, which were higher under Salix canopies. Mosses were associated with lower soil moisture irrespective of shrub identity, but modulated the effects of shrubs on winter soil temperatures and soil C:N ratios so that moss cover reduced differences in soil winter temperatures between shrub species and reduced C:N ratios under Betula but not under Salix canopies. Our results suggest a central role of mosses in mediating soil properties and processes, with their influence depending on shrub species identity. Such species-dependent effects need to be accounted for when forecasting vegetation dynamics under ongoing environmental changes.
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Lutz DA, Burakowski EA, Murphy MB, Borsuk ME, Niemiec RM, Howarth RB. Trade-offs between three forest ecosystem services across the state of New Hampshire, USA: timber, carbon, and albedo. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:146-161. [PMID: 27039516 DOI: 10.1890/14-2207] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Forests are more frequently being managed to store and sequester carbon for the purposes of climate change mitigation. Generally, this practice involves long-term conservation of intact mature forests and/or reductions in the frequency and intensity of timber harvests. However, incorporating the influence of forest surface albedo often suggests that long rotation lengths may not always be optimal in mitigating climate change in forests characterized by frequent snowfall. To address this, we investigated trade-offs between three ecosystem services: carbon storage, albedo-related radiative forcing, and timber provisioning. We calculated optimal rotation length at 498 diverse Forest Inventory and Analysis forest sites in the state of New Hampshire, USA. We found that the mean optimal rotation lengths across all sites was 94 yr (standard deviation of sample means = 44 yr), with a large cluster of short optimal rotation lengths that were calculated at high elevations in the White Mountain National Forest. Using a regression tree approach, we found that timber growth, annual storage of carbon, and the difference between annual albedo in mature forest vs. a post-harvest landscape were the most important variables that influenced optimal rotation. Additionally, we found that the choice of a baseline albedo value for each site significantly altered the optimal rotation lengths across all sites, lowering the mean rotation to 59 yr with a high albedo baseline, and increasing the mean rotation to 112 yr given a low albedo baseline. Given these results, we suggest that utilizing temperate forests in New Hampshire for climate mitigation purposes through carbon storage and the cessation of harvest is appropriate at a site-dependent level that varies significantly across the state.
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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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Tape KD, Lord R, Marshall HP, Ruess RW. Snow-mediated ptarmigan browsing and shrub expansion in arctic Alaska. ECOSCIENCE 2015. [DOI: 10.2980/17-2-3323] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Mitchell JS, Ruess RW. Seasonal patterns of climate controls over nitrogen fixation byAlnus viridissubsp.fruticosain a secondary successional chronosequence in interior Alaska. ECOSCIENCE 2015. [DOI: 10.2980/16-3-3236] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Initial Stages of Tundra Shrub Litter Decomposition May Be Accelerated by Deeper Winter Snow But Slowed Down by Spring Warming. Ecosystems 2015. [DOI: 10.1007/s10021-015-9924-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Buma B, Barrett TM. Spatial and topographic trends in forest expansion and biomass change, from regional to local scales. GLOBAL CHANGE BIOLOGY 2015; 21:3445-3454. [PMID: 25726931 DOI: 10.1111/gcb.12915] [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: 12/30/2014] [Accepted: 02/19/2015] [Indexed: 06/04/2023]
Abstract
Natural forest growth and expansion are important carbon sequestration processes globally. Climate change is likely to increase forest growth in some regions via CO2 fertilization, increased temperatures, and altered precipitation; however, altered disturbance regimes and climate stress (e.g. drought) will act to reduce carbon stocks in forests as well. Observations of asynchrony in forest change is useful in determining current trends in forest carbon stocks, both in terms of forest density (e.g. Mg ha(-1) ) and spatially (extent and location). Monitoring change in natural (unmanaged) areas is particularly useful, as while afforestation and recovery from historic land use are currently large carbon sinks, the long-term viability of those sinks depends on climate change and disturbance dynamics at their particular location. We utilize a large, unmanaged biome (>135 000 km(2) ) which spans a broad latitudinal gradient to explore how variation in location affects forest density and spatial patterning: the forests of the North American temperate rainforests in Alaska, which store >2.8 Pg C in biomass and soil, equivalent to >8% of the C in contiguous US forests. We demonstrate that the regional biome is shifting; gains exceed losses and are located in different spatio-topographic contexts. Forest gains are concentrated on northerly aspects, lower elevations, and higher latitudes, especially in sheltered areas, whereas loss is skewed toward southerly aspects and lower latitudes. Repeat plot-scale biomass data (n = 759) indicate that within-forest biomass gains outpace losses (live trees >12.7 cm diameter, 986 Gg yr(-1) ) on gentler slopes and in higher latitudes. This work demonstrates that while temperate rainforest dynamics occur at fine spatial scales (<1000 m(2) ), the net result of thousands of individual events is regionally patterned change. Correlations between the disturbance/establishment imbalance and biomass accumulation suggest the potential for relatively rapid biome shifts and biomass changes.
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Affiliation(s)
- Brian Buma
- University of Alaska Southeast, 11120 Glacier Highway, Juneau, AK, 99801, USA
| | - Tara M Barrett
- Pacific Northwest Research Station, USDA Forest Service, 1133 N. Western Ave., Wenatchee, WA, 98801, USA
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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: 60] [Impact Index Per Article: 6.7] [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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Hollesen J, Buchwal A, Rachlewicz G, Hansen BU, Hansen MO, Stecher O, Elberling B. Winter warming as an important co-driver for Betula nana growth in western Greenland during the past century. GLOBAL CHANGE BIOLOGY 2015; 21:2410-23. [PMID: 25788025 PMCID: PMC4657495 DOI: 10.1111/gcb.12913] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 02/05/2015] [Accepted: 02/14/2015] [Indexed: 05/09/2023]
Abstract
Growing season conditions are widely recognized as the main driver for tundra shrub radial growth, but the effects of winter warming and snow remain an open question. Here, we present a more than 100 years long Betula nana ring-width chronology from Disko Island in western Greenland that demonstrates a highly significant and positive growth response to both summer and winter air temperatures during the past century. The importance of winter temperatures for Betula nana growth is especially pronounced during the periods from 1910-1930 to 1990-2011 that were dominated by significant winter warming. To explain the strong winter importance on growth, we assessed the importance of different environmental factors using site-specific measurements from 1991 to 2011 of soil temperatures, sea ice coverage, precipitation and snow depths. The results show a strong positive growth response to the amount of thawing and growing degree-days as well as to winter and spring soil temperatures. In addition to these direct effects, a strong negative growth response to sea ice extent was identified, indicating a possible link between local sea ice conditions, local climate variations and Betula nana growth rates. Data also reveal a clear shift within the last 20 years from a period with thick snow depths (1991-1996) and a positive effect on Betula nana radial growth, to a period (1997-2011) with generally very shallow snow depths and no significant growth response towards snow. During this period, winter and spring soil temperatures have increased significantly suggesting that the most recent increase in Betula nana radial growth is primarily triggered by warmer winter and spring air temperatures causing earlier snowmelt that allows the soils to drain and warm quicker. The presented results may help to explain the recently observed 'greening of the Arctic' which may further accelerate in future years due to both direct and indirect effects of winter warming.
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Affiliation(s)
- Jørgen Hollesen
- Center for Permafrost (CENPERM), Department of Geoscience and Natural Resource Management, University of CopenhagenØster Voldgade 10, DK-1350, Copenhagen, Denmark
- Department of Conservation and Natural Sciences, National Museum of Denmark, I.C. ModewegsvejBrede, DK-2800, Lyngby, Denmark
| | - Agata Buchwal
- Institute of Geoecology and Geoinformation, Adam Mickiewicz UniversityDziegielowa 27, 61-680, Poznan, Poland
- Department of Biological Sciences, University of Alaska Anchorage, Ecosystem and Biomedical Lab3151 Alumni Loop, Anchorage, AK 99508, USA
| | - Grzegorz Rachlewicz
- Institute of Geoecology and Geoinformation, Adam Mickiewicz UniversityDziegielowa 27, 61-680, Poznan, Poland
| | - Birger U Hansen
- Center for Permafrost (CENPERM), Department of Geoscience and Natural Resource Management, University of CopenhagenØster Voldgade 10, DK-1350, Copenhagen, Denmark
| | - Marc O Hansen
- Center for Permafrost (CENPERM), Department of Geoscience and Natural Resource Management, University of CopenhagenØster Voldgade 10, DK-1350, Copenhagen, Denmark
| | - Ole Stecher
- Arctic Station, University of CopenhagenQeqertarsuaq, Greenland
| | - Bo Elberling
- Center for Permafrost (CENPERM), Department of Geoscience and Natural Resource Management, University of CopenhagenØster Voldgade 10, DK-1350, Copenhagen, Denmark
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Morgado LN, Semenova TA, Welker JM, Walker MD, Smets E, Geml J. Summer temperature increase has distinct effects on the ectomycorrhizal fungal communities of moist tussock and dry tundra in Arctic Alaska. GLOBAL CHANGE BIOLOGY 2015; 21:959-72. [PMID: 25156129 PMCID: PMC4322476 DOI: 10.1111/gcb.12716] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 07/19/2014] [Accepted: 07/28/2014] [Indexed: 05/22/2023]
Abstract
Arctic regions are experiencing the greatest rates of climate warming on the planet and marked changes have already been observed in terrestrial arctic ecosystems. While most studies have focused on the effects of warming on arctic vegetation and nutrient cycling, little is known about how belowground communities, such as fungi root-associated, respond to warming. Here, we investigate how long-term summer warming affects ectomycorrhizal (ECM) fungal communities. We used Ion Torrent sequencing of the rDNA internal transcribed spacer 2 (ITS2) region to compare ECM fungal communities in plots with and without long-term experimental warming in both dry and moist tussock tundra. Cortinarius was the most OTU-rich genus in the moist tundra, while the most diverse genus in the dry tundra was Tomentella. On the diversity level, in the moist tundra we found significant differences in community composition, and a sharp decrease in the richness of ECM fungi due to warming. On the functional level, our results indicate that warming induces shifts in the extramatrical properties of the communities, where the species with medium-distance exploration type seem to be favored with potential implications for the mobilization of different nutrient pools in the soil. In the dry tundra, neither community richness nor community composition was significantly altered by warming, similar to what had been observed in ECM host plants. There was, however, a marginally significant increase in OTUs identified as ECM fungi with the medium-distance exploration type in the warmed plots. Linking our findings of decreasing richness with previous results of increasing ECM fungal biomass suggests that certain ECM species are favored by warming and may become more abundant, while many other species may go locally extinct due to direct or indirect effects of warming. Such compositional shifts in the community might affect nutrient cycling and soil organic C storage.
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Affiliation(s)
- Luis N Morgado
- Naturalis Biodiversity CenterP.O. Box 9517, Leiden, RA, 2300, The Netherlands
| | - Tatiana A Semenova
- Naturalis Biodiversity CenterP.O. Box 9517, Leiden, RA, 2300, The Netherlands
- Faculty of Science, Leiden UniversityP.O. Box 9502, Leiden, RA, 2300, The Netherlands
| | - Jeffrey M Welker
- Department of Biological Sciences, University of Alaska AnchorageAnchorage, USA
| | | | - Erik Smets
- Naturalis Biodiversity CenterP.O. Box 9517, Leiden, RA, 2300, The Netherlands
- Faculty of Science, Leiden UniversityP.O. Box 9502, Leiden, RA, 2300, The Netherlands
- Plant Conservation and Population Biology, KU LeuvenKasteelpark Arenberg 31, Box 2437, Leuven, 3001, Belgium
| | - József Geml
- Naturalis Biodiversity CenterP.O. Box 9517, Leiden, RA, 2300, The Netherlands
- Faculty of Science, Leiden UniversityP.O. Box 9502, Leiden, RA, 2300, The Netherlands
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Gill H, Lantz T. A Community-Based Approach to Mapping Gwich'in Observations of Environmental Changes in the Lower Peel River Watershed, NT. J ETHNOBIOL 2014. [DOI: 10.2993/0278-0771-34.3.294] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Harneet Gill
- University of Victoria, School of Environmental Studies, P.O. Box 1700, STN CSC, Victoria, British Columbia, Canada V8W 2Y2
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