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Thakur D, Altman J, Jandová V, Fibich P, Münzbergová Z, Doležal J. Global warming alters Himalayan alpine shrub growth dynamics and climate sensitivity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:170252. [PMID: 38253093 DOI: 10.1016/j.scitotenv.2024.170252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 01/15/2024] [Accepted: 01/16/2024] [Indexed: 01/24/2024]
Abstract
Global climate change is having significant effects on plant growth patterns and mountain plants can be particularly vulnerable to accelerated warming. Rising temperatures are releasing plants from cold limitation, such as at high elevations and latitudes, but can also induce drought limitation, as documented for trees from lower elevations and latitudes. Here we test these predictions using a unique natural experiment with Himalayan alpine shrub Rhododendron anthopogon and its growth responses to changing climate over a large portion of its latitudinal and elevational ranges, including steep precipitation and temperature gradients. We determined growth dynamics during the last three decades, representing period of accelerated warming, using annual radial growth increments for nine populations growing on both wet and warm southern localities and drier and cold northern localities in the Himalayas along elevation gradients encompassing the lower and upper species range limits. A significant growth increase over past decades was observed after controlling for confounding effect of shrub age and microsites. However, the magnitude of increase varied among populations. Particularly, populations situated in the lower elevation of the northernmost (cold and dry) locality exhibited most substantial growth enhancement. The relationship between growth variability and climate varied among populations, with the populations from the coldest location displaying the strongest responsiveness to increasing minimum temperatures during July. Minimum temperatures of April and August were the most important factor limiting the growth across most populations. Potential warming-induced drought limitation had no significant impact on growth variation in any part of the species geographic range. Overall, our findings indicate that plant growth is continuously increasing in recent decades and growth-climate relationships are not consistent across populations, with populations from the coldest and wettest localities showing stronger responses. The observed patterns suggest that dwarf-shrubs benefit from ongoing warming, leading to increased shrubification of high elevation alpine ecosystems.
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Affiliation(s)
- Dinesh Thakur
- Institute of Botany of the Czech Academy of Sciences, Zámek 1, 252 43, Průhonice, Czechia.
| | - Jan Altman
- Institute of Botany of the Czech Academy of Sciences, Zámek 1, 252 43, Průhonice, Czechia; Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 165 21 Prague, Czechia
| | - Veronika Jandová
- Institute of Botany of the Czech Academy of Sciences, Zámek 1, 252 43, Průhonice, Czechia; Department of Botany, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czechia
| | - Pavel Fibich
- Institute of Botany of the Czech Academy of Sciences, Zámek 1, 252 43, Průhonice, Czechia; Department of Botany, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czechia
| | - Zuzana Münzbergová
- Institute of Botany of the Czech Academy of Sciences, Zámek 1, 252 43, Průhonice, Czechia; Department of Botany, Faculty of Science, Charles University, Albertov 6, 128 00, Prague, Czechia
| | - Jiří Doležal
- Institute of Botany of the Czech Academy of Sciences, Zámek 1, 252 43, Průhonice, Czechia; Department of Botany, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czechia
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2
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Power CC, Normand S, von Arx G, Elberling B, Corcoran D, Krog AB, Bouvin NK, Treier UA, Westergaard-Nielsen A, Liu Y, Prendin AL. No effect of snow on shrub xylem traits: Insights from a snow-manipulation experiment on Disko Island, Greenland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:169896. [PMID: 38185160 DOI: 10.1016/j.scitotenv.2024.169896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 12/18/2023] [Accepted: 01/02/2024] [Indexed: 01/09/2024]
Abstract
Widespread shrubification across the Arctic has been generally attributed to increasing air temperatures, but responses vary across species and sites. Wood structures related to the plant hydraulic architecture may respond to local environmental conditions and potentially impact shrub growth, but these relationships remain understudied. Using methods of dendroanatomy, we analysed shrub ring width (RW) and xylem anatomical traits of 80 individuals of Salix glauca L. and Betula nana L. at a snow manipulation experiment in Western Greenland. We assessed how their responses differed between treatments (increased versus ambient snow depth) and soil moisture regimes (wet and dry). Despite an increase in snow depth due to snow fences (28-39 %), neither RW nor anatomical traits in either species showed significant responses to this increase. In contrast, irrespective of the snow treatment, the xylem specific hydraulic conductivity (Ks) and earlywood vessel size (LA95) for the study period were larger in S. glauca (p < 0.1, p < 0.01) and B. nana (p < 0.01, p < 0.001) at the wet than the dry site, while both species had larger vessel groups at the dry than the wet site (p < 0.01). RW of B. nana was higher at the wet site (p < 0.01), but no differences were observed for S. glauca. Additionally, B. nana Ks and LA95 showed different trends over the study period, with decreases observed at the dry site (p < 0.001), while for other responses no difference was observed. Our results indicate that, taking into account ontogenetic and allometric trends, hydraulic related xylem traits of both species, along with B. nana growth, were influenced by soil moisture. These findings suggest that soil moisture regime, but not snow cover, may determine xylem responses to future climate change and thus add to the heterogeneity of Arctic shrub dynamics, though more long-term species- and site- specific studies are needed.
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Affiliation(s)
- Candice C Power
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark.
| | - Signe Normand
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark; SustainScapes - Center for Sustainable Landscapes under Global Change, Aarhus University, Denmark
| | - Georg von Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Bo Elberling
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark; Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - Derek Corcoran
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark; SustainScapes - Center for Sustainable Landscapes under Global Change, Aarhus University, Denmark
| | - Amanda B Krog
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark
| | | | - Urs Albert Treier
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark; SustainScapes - Center for Sustainable Landscapes under Global Change, Aarhus University, Denmark
| | - Andreas Westergaard-Nielsen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark; Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - Yijing Liu
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - Angela L Prendin
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark; Department of Land Environment Agriculture and Forestry (TeSAF), University of Padova, Legnaro, Italy
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3
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Gałka M, Diaconu AC, Cwanek A, Hedenäs L, Knorr KH, Kołaczek P, Łokas E, Obremska M, Swindles GT, Feurdean A. Climate-induced hydrological fluctuations shape Arctic Alaskan peatland plant communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167381. [PMID: 37769738 DOI: 10.1016/j.scitotenv.2023.167381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 09/23/2023] [Accepted: 09/24/2023] [Indexed: 10/03/2023]
Abstract
Rapidly increasing temperatures in high-latitude regions are causing major changes in wetland ecosystems. To assess the impact of concomitant hydroclimatic fluctuations, mineral deposition, and autogenous succession on the rate and direction of changing arctic plant communities in Arctic Alaska, we conducted detailed palaeoecological analyses using plant macrofossil, pollen, testate amoebae, elemental analyses, and radiocarbon and lead (210Pb) dating on two replicate monoliths from a peatland that developed in a river valley on the northern foothills of the Books Range. We observed an expansion of Sphagnum populations and vascular plants preferring dry habitats, such as Sphagnum warnstorfii, Sphagnum teres/squarrosum, Polytrichum strictum, Aulacomnium palustre and Salix sp., in recent decades between 2000 and 2015 CE, triggered by an increase in temperature and deepening water tables. Deepening peatland water tables became accentuated over the last two decades, when it reached its lowest point in the last 700 years. Conversely, a higher water-table between ca. 1500 and 1950 CE led to a recession of Sphagnum communities and an expansion of sedges. The almost continuous supply of mineral matter during this time led to a dominance of minerotrophic plant communities, although with varying species composition throughout the study period. The replicate cores show similar patterns, but nuanced differences are also visible, depicting fine spatial scale differences particularly in peat-forming plant distribution and the different timings of their presence. In conclusion, our study provides valuable insights into the impact of hydroclimatic fluctuations on peatland vegetation in Arctic Alaska, highlighting their tendency to dry out in recent decades. It also highlights the importance of river valley peatlands in paleoenvironmental reconstructions.
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Affiliation(s)
- Mariusz Gałka
- University of Lodz, Faculty of Biology and Environmental Protection, Department of Biogeography, Paleoecology and Nature Conservation, Banacha 1/3, 90-237 Łodz, Poland.
| | | | - Anna Cwanek
- Department of Mass Spectrometry, The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
| | - Lars Hedenäs
- Swedish Museum of Natural History, Department of Botany, Stockholm, Sweden
| | - Klaus-Holger Knorr
- University of Münster, Institute of Landscape Ecology, Ecohydrology & Biogeochemistry Group, Heisenbergstr 2, 48149 Münster, Germany
| | - Piotr Kołaczek
- Climate Change Ecology Research Unit, Adam Mickiewicz University, Poznań, B. Krygowskiego 10, 61-680 Poznań, Poland
| | - Edyta Łokas
- Department of Mass Spectrometry, The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
| | - Milena Obremska
- Institute of Geological Sciences, Polish Academy of Sciences, Twarda 51/55, 00-818 Warsaw, Poland
| | - Graeme T Swindles
- Geography, School of Natural and Built Environment, Queen's University Belfast, Belfast, UK; Ottawa-Carleton Geoscience Centre and Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada
| | - Angelica Feurdean
- Babes-Bolyai University, Department of Geology, Cluj-Napoca, Romania; Goethe University, Institute of Physical Geography, Frankfurt am Main, Germany
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4
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Frigo D, Eggertsson Ó, Prendin AL, Dibona R, Unterholzner L, Carrer M. Growth form and leaf habit drive contrasting effects of Arctic amplification in long-lived woody species. GLOBAL CHANGE BIOLOGY 2023; 29:5896-5907. [PMID: 37526296 DOI: 10.1111/gcb.16895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 07/15/2023] [Indexed: 08/02/2023]
Abstract
Current global change is inducing heterogeneous warming trends worldwide, with faster rates at higher latitudes in the Northern Hemisphere. Consequently, tundra vegetation is experiencing an increase in growth rate and uneven but expanding distribution. Yet, the drivers of this heterogeneity in woody species responses are still unclear. Here, applying a retrospective approach and focusing on long-term responses, we aim to get insight into growth trends and climate sensitivity of long-lived woody species belonging to different functional types with contrasting growth forms and leaf habits (shrub vs. tree and deciduous vs. evergreen). A total of 530 samples from 7 species (common juniper, dwarf birch, woolly willow, Norway spruce, lodgepole pine, rowan, and downy birch) were collected in 10 sites across Iceland. We modelled growth trends and contrasted yearly ring-width measurements, filtering in high- and low-frequency components, with precipitation, land- and sea-surface temperature records (1967-2018). Shrubs and trees showed divergent growth trends, with shrubs closely tracking the recent warming, whereas trees, especially broadleaved, showed strong fluctuations but no long-term growth trends. Secondary growth, particularly the high-frequency component, was positively correlated with summer temperatures for most of the species. On the contrary, growth responses to sea surface temperature, especially in the low frequency, were highly diverging between growth forms, with a strong positive association for shrubs and a negative for trees. Within comparable vegetation assemblage, long-lived woody species could show contrasting responses to similar climatic conditions. Given the predominant role of oceanic masses in shaping climate patterns in the Arctic and Low Arctic, further investigations are needed to deepen the knowledge on the complex interplay between coastal tundra ecosystems and land-sea surface temperature dynamics.
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Affiliation(s)
- Davide Frigo
- Department of Land Environment Agriculture and Forestry, University of Padova, Legnaro, Italy
| | | | - Angela Luisa Prendin
- Department of Land Environment Agriculture and Forestry, University of Padova, Legnaro, Italy
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Raffaella Dibona
- Department of Land Environment Agriculture and Forestry, University of Padova, Legnaro, Italy
| | - Lucrezia Unterholzner
- Department of Land Environment Agriculture and Forestry, University of Padova, Legnaro, Italy
- Chair of Forest Growth and Woody Biomass Production, TU Dresden, Tharandt, Germany
| | - Marco Carrer
- Department of Land Environment Agriculture and Forestry, University of Padova, Legnaro, Italy
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5
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Zona D, Lafleur PM, Hufkens K, Gioli B, Bailey B, Burba G, Euskirchen ES, Watts JD, Arndt KA, Farina M, Kimball JS, Heimann M, Göckede M, Pallandt M, Christensen TR, Mastepanov M, López‐Blanco E, Dolman AJ, Commane R, Miller CE, Hashemi J, Kutzbach L, Holl D, Boike J, Wille C, Sachs T, Kalhori A, Humphreys ER, Sonnentag O, Meyer G, Gosselin GH, Marsh P, Oechel WC. Pan-Arctic soil moisture control on tundra carbon sequestration and plant productivity. GLOBAL CHANGE BIOLOGY 2023; 29:1267-1281. [PMID: 36353841 PMCID: PMC10099953 DOI: 10.1111/gcb.16487] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 09/16/2022] [Accepted: 10/05/2022] [Indexed: 05/26/2023]
Abstract
Long-term atmospheric CO2 concentration records have suggested a reduction in the positive effect of warming on high-latitude carbon uptake since the 1990s. A variety of mechanisms have been proposed to explain the reduced net carbon sink of northern ecosystems with increased air temperature, including water stress on vegetation and increased respiration over recent decades. However, the lack of consistent long-term carbon flux and in situ soil moisture data has severely limited our ability to identify the mechanisms responsible for the recent reduced carbon sink strength. In this study, we used a record of nearly 100 site-years of eddy covariance data from 11 continuous permafrost tundra sites distributed across the circumpolar Arctic to test the temperature (expressed as growing degree days, GDD) responses of gross primary production (GPP), net ecosystem exchange (NEE), and ecosystem respiration (ER) at different periods of the summer (early, peak, and late summer) including dominant tundra vegetation classes (graminoids and mosses, and shrubs). We further tested GPP, NEE, and ER relationships with soil moisture and vapor pressure deficit to identify potential moisture limitations on plant productivity and net carbon exchange. Our results show a decrease in GPP with rising GDD during the peak summer (July) for both vegetation classes, and a significant relationship between the peak summer GPP and soil moisture after statistically controlling for GDD in a partial correlation analysis. These results suggest that tundra ecosystems might not benefit from increased temperature as much as suggested by several terrestrial biosphere models, if decreased soil moisture limits the peak summer plant productivity, reducing the ability of these ecosystems to sequester carbon during the summer.
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Affiliation(s)
- Donatella Zona
- Department BiologySan Diego State UniversitySan DiegoCaliforniaUSA
- School of BiosciencesUniversity of SheffieldSheffieldUK
| | - Peter M. Lafleur
- School of the EnvironmentTrent UniversityPeterboroughOntarioCanada
| | | | - Beniamino Gioli
- National Research Council (CNR)Institute of BioEconomy (IBE)FlorenceItaly
| | - Barbara Bailey
- Department of Mathematics and Statistics, San Diego State UniversitySan DiegoCaliforniaUSA
| | - George Burba
- LI‐COR BiosciencesLincolnNebraskaUSA
- The Robert B. Daugherty Water for Food Global Institute and School of Natural ResourcesUniversity of NebraskaLincolnNebraskaUSA
| | | | - Jennifer D. Watts
- Woodwell Climate Research CenterFalmouthMassachusettsUSA
- W.A. Franke College of Forestry & ConservationThe University of MontanaMissoulaMontanaUSA
| | - Kyle A. Arndt
- Woodwell Climate Research CenterFalmouthMassachusettsUSA
| | - Mary Farina
- Woodwell Climate Research CenterFalmouthMassachusettsUSA
| | - John S. Kimball
- W.A. Franke College of Forestry & ConservationThe University of MontanaMissoulaMontanaUSA
| | - Martin Heimann
- Max Planck Institute for BiogeochemistryJenaGermany
- Faculty of Science, Institute for Atmospheric and Earth System Research (INAR) / Physics, University of HelsinkiHelsinkiFinland
| | | | | | - Torben R. Christensen
- Department of Ecoscience, Arctic Research CentreAarhus UniversityRoskildeDenmark
- Oulanka Research StationOulu UniversityKuusamoFinland
| | - Mikhail Mastepanov
- Department of Ecoscience, Arctic Research CentreAarhus UniversityRoskildeDenmark
- Oulanka Research StationOulu UniversityKuusamoFinland
| | - Efrén López‐Blanco
- Department of Ecoscience, Arctic Research CentreAarhus UniversityRoskildeDenmark
- Department of Environment and Minerals, Greenland Institute of Natural ResourcesNuukGreenland
| | | | - Roisin Commane
- Department of Earth and Environmental Sciences, Lamont‐Doherty Earth ObservatoryColumbia UniversityPalisadesNew YorkUSA
| | - Charles E. Miller
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCaliforniaUSA
| | - Josh Hashemi
- Department BiologySan Diego State UniversitySan DiegoCaliforniaUSA
- Environmental Meteorology, Institute of Earth and Environmental SciencesUniversity of FreiburgFreiburgGermany
| | - Lars Kutzbach
- Institute of Soil Science, Center for Earth System Research and Sustainability (CEN)Universität HamburgHamburgGermany
| | - David Holl
- Institute of Soil Science, Center for Earth System Research and Sustainability (CEN)Universität HamburgHamburgGermany
| | - Julia Boike
- Geography DepartmentHumboldt‐Universität zu BerlinBerlinGermany
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine ResearchPotsdamGermany
| | | | - Torsten Sachs
- GFZ German Research Centre for GeosciencesPotsdamGermany
| | - Aram Kalhori
- GFZ German Research Centre for GeosciencesPotsdamGermany
| | - Elyn R. Humphreys
- Department of Geography & Environmental StudiesCarleton UniversityOttawaOntarioCanada
| | - Oliver Sonnentag
- Département de GéographieUniversité de MontréalMontréalQuebecCanada
| | - Gesa Meyer
- Département de GéographieUniversité de MontréalMontréalQuebecCanada
| | | | - Philip Marsh
- Department of Geography and Environmental Studies, Wilfrid Laurier UniversityWaterlooOntarioCanada
| | - Walter C. Oechel
- Department BiologySan Diego State UniversitySan DiegoCaliforniaUSA
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6
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Power CC, Assmann JJ, Prendin AL, Treier UA, Kerby JT, Normand S. Improving ecological insights from dendroecological studies of Arctic shrub dynamics: Research gaps and potential solutions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 851:158008. [PMID: 35988628 DOI: 10.1016/j.scitotenv.2022.158008] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 08/01/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
Rapid climate change has been driving changes in Arctic vegetation in recent decades, with increased shrub dominance in many tundra ecosystems. Dendroecological observations of tundra shrubs can provide insight into current and past growth and recruitment patterns, both key components for understanding and predicting ongoing and future Arctic shrub dynamics. However, generalizing these dynamics is challenging as they are highly scale-dependent and vary among sites, species, and individuals. Here, we provide a perspective on how some of these challenges can be overcome. Based on a targeted literature search of dendrochronological studies from 2005 to 2022, we highlight five research gaps that currently limit dendro-based studies from revealing cross-scale ecological insight into shrub dynamics across the Arctic biome. We further discuss the related research priorities, suggesting that future studies could consider: 1) increasing focus on intra- and interspecific variation, 2) including demographic responses other than radial growth, 3) incorporating drivers, in addition to warming, at different spatial and temporal scales, 4) implementing systematic and unbiased sampling approaches, and 5) investigating the cellular mechanisms behind the observed responses. Focusing on these aspects in dendroecological studies could improve the value of the field for addressing cross-scale and plant community-framed ecological questions. We outline how this could be facilitated through the integration of community-based dendroecology and dendroanatomy with remote sensing approaches. Integrating new technologies and a more multidisciplinary approach in dendroecological research could provide key opportunities to close important knowledge gaps in our understanding of scale-dependencies, as well as intra- and inter-specific variation, in vegetation community dynamics across the Arctic tundra.
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Affiliation(s)
- Candice C Power
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Ny Munkegade 114-116, DK-8000 Aarhus C, Denmark; Center for Biodiversity Dynamics in a Changing World, Aarhus University, Ny Munkegade 114-116, DK-8000 Aarhus C, Denmark.
| | - Jakob J Assmann
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Ny Munkegade 114-116, DK-8000 Aarhus C, Denmark; Center for Biodiversity Dynamics in a Changing World, Aarhus University, Ny Munkegade 114-116, DK-8000 Aarhus C, Denmark
| | - Angela L Prendin
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Ny Munkegade 114-116, DK-8000 Aarhus C, Denmark; Center for Biodiversity Dynamics in a Changing World, Aarhus University, Ny Munkegade 114-116, DK-8000 Aarhus C, Denmark
| | - Urs A Treier
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Ny Munkegade 114-116, DK-8000 Aarhus C, Denmark; Center for Biodiversity Dynamics in a Changing World, Aarhus University, Ny Munkegade 114-116, DK-8000 Aarhus C, Denmark
| | - Jeffrey T Kerby
- Center for Biodiversity Dynamics in a Changing World, Aarhus University, Ny Munkegade 114-116, DK-8000 Aarhus C, Denmark; Aarhus Institute of Advanced Studies, Aarhus University, Høegh-Guldbergs Gade 6B, DK-8000 Aarhus C, Denmark
| | - Signe Normand
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Ny Munkegade 114-116, DK-8000 Aarhus C, Denmark; Center for Biodiversity Dynamics in a Changing World, Aarhus University, Ny Munkegade 114-116, DK-8000 Aarhus C, Denmark
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7
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Weijers S. Declining temperature and increasing moisture sensitivity of shrub growth in the Low-Arctic erect dwarf-shrub tundra of western Greenland. Ecol Evol 2022; 12:e9419. [PMID: 36381399 PMCID: PMC9637549 DOI: 10.1002/ece3.9419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 09/22/2022] [Accepted: 09/27/2022] [Indexed: 11/09/2022] Open
Abstract
Evergreen dwarf shrubs respond swiftly to warming in the cool and dry High Arctic, but their response in the warmer Low Arctic, where they are expected to be outcompeted by taller species under future warming, remains to be clarified. Here, 12,528 annual growth increments, covering 122 years (1893-2014), were measured of 764 branches from 25 individuals of the evergreen dwarf shrub Cassiope tetragona from a Low-Arctic erect dwarf-shrub tundra site in western Greenland. In addition, branch initiation and mortality frequency time series were developed. The influence of seasonal climate and correspondence with fluctuations in regional normalized difference vegetation index (NDVI), a satellite-proxy for vegetation productivity, were studied. Summer temperatures were the main driver of growth, while winter temperatures were the main non-summer-climate driver. During past and recent warm episodes, shrub growth diverged from summer temperatures. In recent decades, early summer precipitation has become the main growth-limiting factor for some individuals, likely through micro-topography-determined soil moisture availability, and more than half of the shrubs studied became irresponsive to summer temperatures. There was correspondence between climatic drivers, C. tetragona growth and branch initiation frequency, and satellite-observed vegetation productivity, suggesting the area's shrub-dominated tundra vegetation is limited by similar climatic factors. Winter warming events were likely the predominant cause of branch mortality, while branching increased after years with poor growth and cooler-than-average summers. These findings show that the erect dwarf-shrub tundra in the Low Arctic has already and will likely become decreasingly temperature- and increasingly moisture-limited and that winter warming supports shrub growth, but increased extreme winter warming event frequency may increase branch mortality and vegetation damage. Such counter-acting mechanisms could offer an explanation for the vegetation stability observed over large parts of the Arctic.
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Affiliation(s)
- Stef Weijers
- Department of GeographyUniversity of BonnBonnGermany
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8
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Alpine shrub growth follows bimodal seasonal patterns across biomes - unexpected environmental controls. Commun Biol 2022; 5:793. [PMID: 35933562 PMCID: PMC9357034 DOI: 10.1038/s42003-022-03741-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 07/20/2022] [Indexed: 11/29/2022] Open
Abstract
Under climate change, cold-adapted alpine ecosystems are turning into hotspots of warming. However, the complexity of driving forces of growth, associated biomass gain and carbon storage of alpine shrubs is poorly understood. We monitored alpine growth mechanisms of six common shrub species across contrasting biomes, Mediterranean and tundra, using 257 dendrometers, recording stem diameter variability at high temporal resolution. Linking shrub growth to on-site environmental conditions, we modelled intra-annual growth patterns based on distributed lag non-linear models implemented with generalized additive models. We found pronounced bimodal growth patterns across biomes, and counterintuitively, within the cold-adapted biome, moisture, and within the drought-adapted biome, temperature was crucial, with unexpected consequences. In a warmer world, the Mediterranean alpine might experience strong vegetation shifts, biomass gain and greening, while the alpine tundra might see less changes in vegetation patterns, minor modifications of biomass stocks and rather browning. Generalized additive models reveal an unexpected environmental control in shrub growth across biomes.
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9
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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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10
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Shrubification along Pipeline Corridors in Permafrost Regions. FORESTS 2022. [DOI: 10.3390/f13071093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Pipeline corridors have been rapidly increasing in length and density because of the ever growing demand for crude oil and natural gas resources in hydrocarbon-rich permafrost regions. Pipeline engineering activities have significant implications for the permafrost environment in cold regions. Along these pipeline corridors, the shrubification in the right-of-way (ROW) has been extensively observed during vegetation recovery. However, the hydrothermal mechanisms of this ROW shrubification have seldom been studied and thus remain poorly understood. This paper reviews more than 112 articles mainly published from 2000 to 2022 and focuses on the hydrothermal mechanisms of shrubification associated with environmental changes induced by the rapidly degrading permafrost from pipeline construction and around the operating pipelines under a warming climate. First, the shrubification from pipeline construction and operation and the ensuing vegetation clearance are featured. Then, key permafrost-related ROW shrubification mechanisms (e.g., from the perspectives of warmer soil, soil moisture, soil type, soil nutrients, topography and landscapes, and snow cover) are discussed. Other key influencing factors on these hydrothermal and other mechanisms are hierarchically documented as well. In the end, future research priorities are identified and proposed. We call for prioritizing more systematic and in-depth investigations and surveys, laboratory testing, long-term field monitoring, and numerical modeling studies of the ROW shrubification along oil and gas pipelines in permafrost regions, such as in boreal and arctic zones, as well as in alpine and high-plateau regions. This review can improve our understanding of shrubification mechanisms under pipeline disturbances and climate changes and help to better manage the ecological environment along pipeline corridors in permafrost regions.
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11
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From Intra-plant to Regional Scale: June Temperatures and Regional Climates Directly and Indirectly Control Betula nana Growth in Arctic Alaska. Ecosystems 2022. [DOI: 10.1007/s10021-022-00771-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractTundra shrubs reflect climate sensitivities in their growth-ring widths, yet tissue-specific shrub chronologies are poorly studied. Further, the relative importance of regional climate patterns that exert mesoscale precipitation and temperature influences on tundra shrub growth has been explored in only a few Arctic locations. Here, we investigate Betula nana growth-ring chronologies from adjacent dry heath and moist tussock tundra habitats in arctic Alaska in relation to local and regional climate. Mean shrub and five tissue-specific ring width chronologies were analyzed using serial sectioning of above- and below-ground shrub organs, resulting in 30 shrubs per site with 161 and 104 cross sections from dry and moist tundra, respectively. Betula nana growth-ring widths in both habitats were primarily related to June air temperature (1989–2014). The strongest relationships with air temperature were found for ‘Branch2’ chronologies (dry site: r = 0.78, June 16, DOY = 167; moist site: r = 0.75, June 9, DOY = 160). Additionally, below-ground chronologies (‘Root’ and ‘Root2’) from the moist site were positively correlated with daily mean air temperatures in the previous late-June (‘Root2’ chronology: r = 0.57, pDOY = 173). Most tissue-specific chronologies exhibited the strongest correlations with daily mean air temperature during the period between 8 and 20 June. Structural equation modeling indicated that shrub growth is indirectly linked to regional Arctic and Pacific Decadal Oscillation (AO and PDO) climate indices through their relation to summer sea ice extent and air temperature. Strong dependence of Betula nana growth on early growing season temperature indicates a highly coordinated allocation of resources to tissue growth, which might increase its competitive advantage over other shrub species under a rapidly changing Arctic climate.
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12
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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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13
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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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14
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Extremely wet summer events enhance permafrost thaw for multiple years in Siberian tundra. Nat Commun 2022; 13:1556. [PMID: 35322039 PMCID: PMC8943195 DOI: 10.1038/s41467-022-29248-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 02/24/2022] [Indexed: 11/09/2022] Open
Abstract
Permafrost thaw can accelerate climate warming by releasing carbon from previously frozen soil in the form of greenhouse gases. Rainfall extremes have been proposed to increase permafrost thaw, but the magnitude and duration of this effect are poorly understood. Here we present empirical evidence showing that one extremely wet summer (+100 mm; 120% increase relative to average June-August rainfall) enhanced thaw depth by up to 35% in a controlled irrigation experiment in an ice-rich Siberian tundra site. The effect persisted over two subsequent summers, demonstrating a carry-over effect of extremely wet summers. Using soil thermal hydrological modelling, we show that rainfall extremes delayed autumn freeze-up and rainfall-induced increases in thaw were most pronounced for warm summers with mid-summer precipitation rainfall extremes. Our results suggest that, with rainfall and temperature both increasing in the Arctic, permafrost will likely degrade and disappear faster than is currently anticipated based on rising air temperatures alone.
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15
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Raiho AM, Scharf HR, Roland CA, Swanson DK, Stehn SE, Hooten MB. Searching for refuge: A framework for identifying site factors conferring resistance to climate‐driven vegetation change. DIVERS DISTRIB 2022. [DOI: 10.1111/ddi.13492] [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)
- Ann M. Raiho
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado USA
| | - Henry R. Scharf
- Department of Mathematics and Statistics San Diego State University San Diego California USA
| | - Carl A. Roland
- Denali National Park and Preserve National Park Service Anchorage Alaska USA
| | | | - Sarah E. Stehn
- Denali National Park and Preserve National Park Service Anchorage Alaska USA
- Arctic Network National Park Service Anchorage Alaska USA
| | - Mevin B. Hooten
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado USA
- Department of Statistics Colorado State University Fort Collins Colorado USA
- Colorado Cooperative Fish and Wildlife Research Unit U.S. Geological Survey Fort Collins Colorado USA
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16
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Influences of summer warming and nutrient availability on Salix glauca L. growth in Greenland along an ice to sea gradient. Sci Rep 2022; 12:3077. [PMID: 35197470 PMCID: PMC8866482 DOI: 10.1038/s41598-022-05322-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 01/04/2022] [Indexed: 11/08/2022] Open
Abstract
The combined effects of climate change and nutrient availability on Arctic vegetation growth are poorly understood. Archaeological sites in the Arctic could represent unique nutrient hotspots for studying the long-term effect of nutrient enrichment. In this study, we analysed a time-series of ring widths of Salix glauca L. collected at nine archaeological sites and in their natural surroundings along a climate gradient in the Nuuk fjord region, Southwest Greenland, stretching from the edge of the Greenlandic Ice Sheet in the east to the open sea in the west. We assessed the temperature-growth relationship for the last four decades distinguishing between soils with past anthropogenic nutrient enrichment (PANE) and without (controls). Along the East-West gradient, the inner fjord sites showed a stronger temperature signal compared to the outermost ones. Individuals growing in PANE soils had wider ring widths than individuals growing in the control soils and a stronger climate-growth relation, especially in the inner fjord sites. Thereby, the individuals growing on the archaeological sites seem to have benefited more from the climate warming in recent decades. Our results suggest that higher nutrient availability due to past human activities plays a role in Arctic vegetation growth and should be considered when assessing both the future impact of plants on archaeological sites and the general greening in landscapes with contrasting nutrient availability.
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17
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Martin AC, Macias-Fauria M, Bonsall MB, Forbes BC, Zetterberg P, Jeffers ES. Common mechanisms explain nitrogen-dependent growth of Arctic shrubs over three decades despite heterogeneous trends and declines in soil nitrogen availability. THE NEW PHYTOLOGIST 2022; 233:670-686. [PMID: 34087005 DOI: 10.1111/nph.17529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 05/20/2021] [Indexed: 06/12/2023]
Abstract
Heterogeneity has been observed in the responses of Arctic shrubs to climate variability over recent decades, which may reflect landscape-scale variability in belowground resources. At a northern fringe of tall shrub expansion (Yuribei, Yamal Peninsula, Russia), we sought to determine the mechanisms relating nitrogen (N) limitation to shrub growth over decadal time. We analysed the ratio of 15 N to 14 N isotopes in wood rings of 10 Salix lanata individuals (399 measurements) to reconstruct annual point-based bioavailable N between 1980 and 2013. We applied a model-fitting/model-selection approach with a suite of competing ecological models to assess the most-likely mechanisms that explain each shrub's individual time-series. Shrub δ15 N time-series indicated declining (seven shrubs), increasing (two shrubs) and no trend (one shrub) in N availability. The most appropriate model for all shrubs included N-dependent growth of linear rather than saturating form. Inclusion of plant-soil feedbacks better explained ring width and δ15 N for eight of 10 individuals. Although N trajectories were individualistic, common mechanisms of varying strength confirmed the N-dependency of shrub growth. The linear mechanism may reflect intense scavenging of scarce N; the importance of plant-soil feedbacks suggests that shrubs subvert the microbial bottleneck by actively controlling their environment.
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Affiliation(s)
- Andrew C Martin
- Oxford Long-Term Ecology Laboratory, Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK
- Biogeosciences Lab, School of Geography and the Environment, University of Oxford, Oxford, OX1 3QY, UK
| | - Marc Macias-Fauria
- Biogeosciences Lab, School of Geography and the Environment, University of Oxford, Oxford, OX1 3QY, UK
| | - Michael B Bonsall
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK
| | - Bruce C Forbes
- Arctic Centre, University of Lapland, Pohjoisranta 4, Rovaniemi, 96100, Finland
| | - Pentti Zetterberg
- Department of Forest Sciences, University of Eastern Finland, Joensuu, 80101, Finland
| | - Elizabeth S Jeffers
- Oxford Long-Term Ecology Laboratory, Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK
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18
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Biophysical Determinants of Shifting Tundra Vegetation Productivity in the Beaufort Delta Region of Canada. Ecosystems 2022. [DOI: 10.1007/s10021-021-00725-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractTemperature increases across the circumpolar north have driven rapid increases in vegetation productivity, often described as ‘greening’. These changes have been widespread, but spatial variation in their pattern and magnitude suggests that biophysical factors also influence the response of tundra vegetation to climate warming. In this study, we used field sampling of soils and vegetation and random forests modeling to identify the determinants of trends in Landsat-derived Enhanced Vegetation Index, a surrogate for productivity, in the Beaufort Delta region of Canada between 1984 and 2016. This region has experienced notable change, with over 71% of the Tuktoyaktuk Coastlands and over 66% of the Yukon North Slope exhibiting statistically significant greening. Using both classification and regression random forests analyses, we show that increases in productivity have been more widespread and rapid at low-to-moderate elevations and in areas dominated by till blanket and glaciofluvial deposits, suggesting that nutrient and moisture availability mediate the impact of climate warming on tundra vegetation. Rapid greening in shrub-dominated vegetation types and observed increases in the cover of low and tall shrub cover (4.8% and 6.0%) also indicate that regional changes have been driven by shifts in the abundance of these functional groups. Our findings demonstrate the utility of random forests models for identifying regional drivers of tundra vegetation change. To obtain additional fine-grained insights on drivers of increased tundra productivity, we recommend future research combine spatially comprehensive time series satellite data (as used herein) with samples of high spatial resolution imagery and integrated field investigations.
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19
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Dobbert S, Pape R, Löffler J. Contrasting growth response of evergreen and deciduous arctic‐alpine shrub species to climate variability. Ecosphere 2021. [DOI: 10.1002/ecs2.3688] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Svenja Dobbert
- Department of Geography University of Bonn Meckenheimer Allee 166 Bonn D‐53115 Germany
| | - Roland Pape
- Department of Natural Sciences and Environmental Health University of South‐Eastern Norway Gullbringvegen 36 Bø N‐3800 Norway
| | - Jörg Löffler
- Department of Geography University of Bonn Meckenheimer Allee 166 Bonn D‐53115 Germany
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20
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Rapid Ecosystem Change at the Southern Limit of the Canadian Arctic, Torngat Mountains National Park. REMOTE SENSING 2021. [DOI: 10.3390/rs13112085] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Northern protected areas guard against habitat and species loss but are themselves highly vulnerable to environmental change due to their fixed spatial boundaries. In the low Arctic, Torngat Mountains National Park (TMNP) of Canada, widespread greening has recently occurred alongside warming temperatures and regional declines in caribou. Little is known, however, about how biophysical controls mediate plant responses to climate warming, and available observational data are limited in temporal and spatial scope. In this study, we investigated the drivers of land cover change for the 9700 km2 extent of the park using satellite remote sensing and geostatistical modelling. Random forest classification was used to hindcast and simulate land cover change for four different land cover types from 1985 to 2019 with topographic and surface reflectance imagery (Landsat archive). The resulting land cover maps, in addition to topographic and biotic variables, were then used to predict where future shrub expansion is likely to occur using a binomial regression framework. Land cover hindcasts showed a 235% increase in shrub and a 105% increase in wet vegetation cover from 1985/89 to 2015/19. Shrub cover was highly persistent and displaced wet vegetation in southern, low-elevation areas, whereas wet vegetation expanded to formerly dry, mid-elevations. The predictive model identified both biotic (initial cover class, number of surrounding shrub neighbors), and topographic variables (elevation, latitude, and distance to the coast) as strong predictors of future shrub expansion. A further 51% increase in shrub cover is expected by 2039/43 relative to 2014 reference data. Establishing long-term monitoring plots within TMNP in areas where rapid vegetation change is predicted to occur will help to validate remote sensing observations and will improve our understanding of the consequences of change for biotic and abiotic components of the tundra ecosystem, including important cultural keystone species.
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21
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Prendin AL, Carrer M, Bjerregaard Pedersen N, Normand S, Hollesen J, Treier UA, Pividori M, Garbrecht Thygesen L. Chemical signature of Eurois occulta L. outbreaks in the xylem cell wall of Salix glauca L. in Greenland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 764:144607. [PMID: 33387770 DOI: 10.1016/j.scitotenv.2020.144607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 11/29/2020] [Accepted: 12/17/2020] [Indexed: 06/12/2023]
Abstract
Insect defoliations are a major natural disturbance in high-latitude ecosystems and are expected to increase in frequency and severity due to current climatic change. Defoliations cause severe reductions in biomass and carbon investments that affect the functioning and productivity of tundra ecosystems. Here we combined dendro-anatomical analysis with chemical imaging to investigate the direct and lagged effects of insect outbreaks on carbon investment. We analysed the content of lignin vs. holocellulose, i.e. unspecified carbohydrates in xylem samples of Salix glauca L. collected at Iffiartarfik, Nuuk fjord, Greenland, featuring two outbreak events of the moth Eurois occulta L. Cross sections of the growth rings corresponding to both outbreaks ±3 years were analysed using confocal Raman imaging to identify possible chemical signatures related to insect defoliation on fibres, vessels, and ray parenchyma cells and to get insight into species-specific defence responses. Outbreak years with narrower rings and thinner fibre cell walls are accompanied by a change in the content of cell-wall polymers but not their underlying chemistry. Indeed, during the outbreaks the ratio between lignin and carbohydrates significantly increased in fibre but not vessel cell walls due to an increase in lignin content coupled with a reduced content of carbohydrates. Parenchyma cell walls and cell corners did not show any significant changes in the cell-wall biopolymer content. The selective adjustment of the cell-wall composition of fibres but not vessels under stressful conditions could be related to the plants priority to maintain an efficient hydraulic system rather than mechanical support. However, the higher lignin content of fibre cell walls formed during the outbreak events could increase mechanical stiffness to the thin walls by optimizing the available resources. Chemical analysis of xylem traits with Raman imaging is a promising approach to highlight hidden effects of defoliation otherwise overlooked with classical dendroecological methods.
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Affiliation(s)
- Angela Luisa Prendin
- University of Padova, TeSAF Department, Agripolis, Viale dell'Università, 16, 35020 Legnaro, PD, Italy; Aarhus University, Department of Biology, Ecoinformatics and Biodiversity, Ny Munkegade 116, building 1540, 8000 Aarhus C, Denmark.
| | - Marco Carrer
- University of Padova, TeSAF Department, Agripolis, Viale dell'Università, 16, 35020 Legnaro, PD, Italy.
| | | | - Signe Normand
- Aarhus University, Department of Biology, Ecoinformatics and Biodiversity, Ny Munkegade 116, building 1540, 8000 Aarhus C, Denmark; Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Ny Munkegade 116, building 1540, 8000 Aarhus C, Denmark.
| | - Jørgen Hollesen
- The National Museum of Denmark, Environmental Archaeology and Material Science, IC Modewegsvej, Brede, 2800 Kgs. Lyngby, Denmark.
| | - Urs Albert Treier
- Aarhus University, Department of Biology, Ecoinformatics and Biodiversity, Ny Munkegade 116, building 1540, 8000 Aarhus C, Denmark; Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Ny Munkegade 116, building 1540, 8000 Aarhus C, Denmark.
| | - Mario Pividori
- University of Padova, TeSAF Department, Agripolis, Viale dell'Università, 16, 35020 Legnaro, PD, Italy.
| | - Lisbeth Garbrecht Thygesen
- University of Copenhagen, Faculty of Science, Department of Geosciences and Natural Resource Management, Rolighedsvej 23, 1958 Frederiksberg C, Denmark.
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22
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Abstract
AbstractIn the tundra, woody plants are dispersing towards higher latitudes and altitudes due to increasingly favourable climatic conditions. The coverage and height of woody plants are increasing, which may influence the soils of the tundra ecosystem. Here, we use structural equation modelling to analyse 171 study plots and to examine if the coverage and height of woody plants affect the growing-season topsoil moisture and temperature (< 10 cm) as well as soil organic carbon stocks (< 80 cm). In our study setting, we consider the hierarchy of the ecosystem by controlling for other factors, such as topography, wintertime snow depth and the overall plant coverage that potentially influence woody plants and soil properties in this dwarf shrub-dominated landscape in northern Fennoscandia. We found strong links from topography to both vegetation and soil. Further, we found that woody plants influence multiple soil properties: the dominance of woody plants inversely correlated with soil moisture, soil temperature, and soil organic carbon stocks (standardised regression coefficients = − 0.39; − 0.22; − 0.34, respectively), even when controlling for other landscape features. Our results indicate that the dominance of dwarf shrubs may lead to soils that are drier, colder, and contain less organic carbon. Thus, there are multiple mechanisms through which woody plants may influence tundra soils.
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23
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Chen Y, Hu FS, Lara MJ. Divergent shrub-cover responses driven by climate, wildfire, and permafrost interactions in Arctic tundra ecosystems. GLOBAL CHANGE BIOLOGY 2021; 27:652-663. [PMID: 33216446 DOI: 10.1111/gcb.15451] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/26/2020] [Accepted: 11/14/2020] [Indexed: 05/22/2023]
Abstract
The expansion of shrubs across the Arctic tundra may fundamentally modify land-atmosphere interactions. However, it remains unclear how shrub expansion pattern is linked with key environmental drivers, such as climate change and fire disturbance. Here we used 40+ years of high-resolution (~1.0 m) aerial and satellite imagery to estimate shrub-cover change in 114 study sites across four burned and unburned upland (ice-poor) and lowland (ice-rich) tundra ecosystems in northern Alaska. Validated with data from four additional upland and lowland tundra fires, our results reveal that summer precipitation was the most important climatic driver (r = 0.67, p < 0.001), responsible for 30.8% of shrub expansion in the upland tundra between 1971 and 2016. Shrub expansion in the uplands was largely enhanced by wildfire (p < 0.001) and it exhibited positive correlation with fire severity (r = 0.83, p < 0.001). Three decades after fire disturbance, the upland shrub cover increased by 1077.2 ± 83.6 m2 ha-1 , ~7 times the amount identified in adjacent unburned upland tundra (155.1 ± 55.4 m2 ha-1 ). In contrast, shrub cover markedly decreased in lowland tundra after fire disturbance, which triggered thermokarst-associated water impounding and resulted in 52.4% loss of shrub cover over three decades. No correlation was found between lowland shrub cover with fire severity (r = 0.01). Mean summer air temperature (MSAT) was the principal factor driving lowland shrub-cover dynamics between 1951 and 2007. Warmer MSAT facilitated shrub expansion in unburned lowlands (r = 0.78, p < 0.001), but accelerated shrub-cover losses in burned lowlands (r = -0.82, p < 0.001). These results highlight divergent pathways of shrub-cover responses to fire disturbance and climate change, depending on near-surface permafrost and drainage conditions. Our study offers new insights into the land-atmosphere interactions as climate warming and burning intensify in high latitudes.
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Affiliation(s)
- Yaping Chen
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Feng Sheng Hu
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Geology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Biology, Washington University in Saint Louis, Saint Louis, MO, USA
- Department of Earth and Planetary Sciences, Washington University in Saint Louis, Saint Louis, MO, USA
| | - Mark J Lara
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Geography, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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24
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Abstract
Arctic sea ice extent (SIE) is declining at an accelerating rate with a wide range of ecological consequences. However, determining sea ice effects on tundra vegetation remains a challenge. In this study, we examined the universality or lack thereof in tundra shrub growth responses to changes in SIE and summer climate across the Pan-Arctic, taking advantage of 23 tundra shrub-ring chronologies from 19 widely distributed sites (56°N to 83°N). We show a clear divergence in shrub growth responses to SIE that began in the mid-1990s, with 39% of the chronologies showing declines and 57% showing increases in radial growth (decreasers and increasers, respectively). Structural equation models revealed that declining SIE was associated with rising air temperature and precipitation for increasers and with increasingly dry conditions for decreasers. Decreasers tended to be from areas of the Arctic with lower summer precipitation and their growth decline was related to decreases in the standardized precipitation evapotranspiration index. Our findings suggest that moisture limitation, associated with declining SIE, might inhibit the positive effects of warming on shrub growth over a considerable part of the terrestrial Arctic, thereby complicating predictions of vegetation change and future tundra productivity.
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25
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Andruko R, Danby R, Grogan P. Recent Growth and Expansion of Birch Shrubs Across a Low Arctic Landscape in Continental Canada: Are These Responses More a Consequence of the Severely Declining Caribou Herd than of Climate Warming? Ecosystems 2020; 23:1362-1379. [PMID: 33214772 PMCID: PMC7666286 DOI: 10.1007/s10021-019-00474-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 12/08/2019] [Indexed: 12/01/2022]
Abstract
The recent widespread expansion of deciduous shrubs across much of the Arctic has been largely attributed to climate warming. This study investigated decadal growth rates of dwarf birch (Betula glandulosa) across a low Arctic landscape in the continental interior of Canada. Detailed birch cover (100 m2 replicate plots) and individual shrub stature measurement datasets for five representative habitat-types were compared between 2006 and 2016, and evaluated in relation to environmental characteristics. Furthermore, dendrochronologically-based annual growth rates were assessed in relation to the 20-year climate record. Birch height, lateral dimensions, and patch groundcover all increased 20–25% relative to 2006 values, but these increases were similar among the habitat-types. Together, the limited evidence of recent warming at this site, the absence of significant habitat-type growth rate differences, and the lack of correlation between annual climate and stem secondary growth strongly suggest that climate change was not the principal cause. Instead, we propose that release from caribou impacts following the recent severe herd decline may explain the net shrub growth. Individual shrub growth rates were correlated with soil nutrient availability, but the latter was highly variable, suggesting that growth rates are primarily determined by fine-scale rather than habitat-scale spatial heterogeneity in nutrient supply. Together, our results demonstrate that birch growth has been enhanced across a variety of habitat-types in the Daring Lake landscape over the decade since 2006, and suggest that the recent severe caribou herd declines may be at least as significant as climate warming in driving birch shrub expansion in the Canadian central low Arctic.
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Affiliation(s)
- Rhett Andruko
- Department of Biology, Queen's University, Kingston, Ontario K7L 3N6 Canada
| | - Ryan Danby
- School of Environmental Studies, Queen's University, Kingston, Ontario K7L 3N6 Canada
| | - Paul Grogan
- Department of Biology, Queen's University, Kingston, Ontario K7L 3N6 Canada
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26
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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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27
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Higgens RF, Pries CH, Virginia RA. Trade-offs Between Wood and Leaf Production in Arctic Shrubs Along a Temperature and Moisture Gradient in West Greenland. Ecosystems 2020. [DOI: 10.1007/s10021-020-00541-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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28
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Le Moullec M, Sandal L, Grøtan V, Buchwal A, Hansen BB. Climate synchronises shrub growth across a high‐arctic archipelago: contrasting implications of summer and winter warming. OIKOS 2020. [DOI: 10.1111/oik.07059] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Mathilde Le Moullec
- Centre for Biodiversity Dynamics, Dept of Biology, Norwegian Univ. of Science and Technology Högskoleringen 5 NO‐7491 Trondheim Norway
| | - Lisa Sandal
- Centre for Biodiversity Dynamics, Dept of Biology, Norwegian Univ. of Science and Technology Högskoleringen 5 NO‐7491 Trondheim Norway
| | - Vidar Grøtan
- Centre for Biodiversity Dynamics, Dept of Biology, Norwegian Univ. of Science and Technology Högskoleringen 5 NO‐7491 Trondheim Norway
| | - Agata Buchwal
- Dept of Biological Sciences, Univ. of Alaska Anchorage AK USA
- Inst. of Geoecology and Geoinformation, Adam Mickiewicz Univ. Poznan Wielkopolskie Poland
| | - Brage Bremset Hansen
- Centre for Biodiversity Dynamics, Dept of Biology, Norwegian Univ. of Science and Technology Högskoleringen 5 NO‐7491 Trondheim Norway
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29
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Francon L, Corona C, Till-Bottraud I, Carlson BZ, Stoffel M. Some (do not) like it hot: shrub growth is hampered by heat and drought at the alpine treeline in recent decades. AMERICAN JOURNAL OF BOTANY 2020; 107:607-617. [PMID: 32239494 DOI: 10.1002/ajb2.1459] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 01/30/2020] [Indexed: 05/23/2023]
Abstract
PREMISE Mountain ecosystems are particularly sensitive to climate change. However, only a very small number of studies exist so far using annually resolved records of alpine plant growth spanning the past century. Here we aimed to identify the effects of heat waves and drought, driven by global warming, on annual radial growth of Rhododendron ferrugineum. METHODS We constructed two century-long shrub ring-width chronologies from R. ferrugineum individuals on two adjacent, north- and west-facing slopes in the southern French Alps. We analyzed available meteorological data (temperature, precipitation and drought) over the period 1960-2016. Climate-growth relationships were evaluated using bootstrapped correlation functions and structural equation models to identify the effects of rising temperature on shrub growth. RESULTS Analysis of meteorological variables during 1960-2016 revealed a shift in the late 1980s when heat waves and drought increased in intensity and frequency. In response to these extreme climate events, shrubs have experienced significant changes in their main limiting factors. Between 1960 and 1988, radial growth on both slopes was strongly controlled by the sum of growing degree days during the snow free period. Between 1989 and 2016, August temperature and drought have emerged as the most important. CONCLUSIONS Increasing air temperatures have caused a shift in the growth response of shrubs to climate. The recently observed negative effect of high summer temperature and drought on shrub growth can, however, be buffered by topographic variability, supporting the macro- and microrefugia hypotheses.
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Affiliation(s)
- Loïc Francon
- Université Clermont Auvergne, CNRS, GEOLAB, F-63000, Clermont-Ferrand, France
| | - Christophe Corona
- Université Clermont Auvergne, CNRS, GEOLAB, F-63000, Clermont-Ferrand, France
| | - Irène Till-Bottraud
- Université Clermont Auvergne, CNRS, GEOLAB, F-63000, Clermont-Ferrand, France
| | - Bradley Z Carlson
- Centre de Recherches sur les Ecosystèmes d'Altitude (CREA), Observatoire du Mont-Blanc, 74400, Chamonix, France
| | - Markus Stoffel
- Climate Change Impacts and Risks in the Anthropocene (C-CIA), Institute for Environmental Sciences, University of Geneva, Geneva, Switzerland
- Department of Earth Sciences, University of Geneva, Geneva, Switzerland
- Department F.-A. Forel for Environmental and Aquatic Sciences, University of Geneva, Geneva, Switzerland
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30
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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: 60] [Impact Index Per Article: 15.0] [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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31
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Myers‐Smith IH, Grabowski MM, Thomas HJD, Angers‐Blondin S, Daskalova GN, Bjorkman AD, Cunliffe AM, Assmann JJ, Boyle JS, McLeod E, McLeod S, Joe R, Lennie P, Arey D, Gordon RR, Eckert CD. Eighteen years of ecological monitoring reveals multiple lines of evidence for tundra vegetation change. ECOL MONOGR 2019. [DOI: 10.1002/ecm.1351] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Isla H. Myers‐Smith
- School of GeoSciences University of Edinburgh Edinburgh EH9 3FF United Kingdom
| | | | - Haydn J. D. Thomas
- School of GeoSciences University of Edinburgh Edinburgh EH9 3FF United Kingdom
| | | | | | - Anne D. Bjorkman
- School of GeoSciences University of Edinburgh Edinburgh EH9 3FF United Kingdom
- Section for Ecoinformatics & Biodiversity Department of Bioscience Aarhus University DK‐8000 Aarhus Denmark
| | - Andrew M. Cunliffe
- School of GeoSciences University of Edinburgh Edinburgh EH9 3FF United Kingdom
| | - Jakob J. Assmann
- School of GeoSciences University of Edinburgh Edinburgh EH9 3FF United Kingdom
| | - Joseph S. Boyle
- School of GeoSciences University of Edinburgh Edinburgh EH9 3FF United Kingdom
| | - Edward McLeod
- Department of Environment Yukon Parks–Inuvik Office Yukon Territorial Government Inuvik NWT X0E 0T0 Canada
| | - Samuel McLeod
- Department of Environment Yukon Parks–Inuvik Office Yukon Territorial Government Inuvik NWT X0E 0T0 Canada
| | - Ricky Joe
- Department of Environment Yukon Parks–Inuvik Office Yukon Territorial Government Inuvik NWT X0E 0T0 Canada
| | - Paden Lennie
- Department of Environment Yukon Parks–Inuvik Office Yukon Territorial Government Inuvik NWT X0E 0T0 Canada
| | - Deon Arey
- Department of Environment Yukon Parks–Inuvik Office Yukon Territorial Government Inuvik NWT X0E 0T0 Canada
| | - Richard R. Gordon
- Department of Environment Yukon Parks–Inuvik Office Yukon Territorial Government Inuvik NWT X0E 0T0 Canada
| | - Cameron D. Eckert
- Department of Environment Yukon Parks–Whitehorse Office Yukon Territorial Government Whitehorse Yukon Territory Y1A 2C6 Canada
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32
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Pastick NJ, Jorgenson MT, Goetz SJ, Jones BM, Wylie BK, Minsley BJ, Genet H, Knight JF, Swanson DK, Jorgenson JC. Spatiotemporal remote sensing of ecosystem change and causation across Alaska. GLOBAL CHANGE BIOLOGY 2019; 25:1171-1189. [PMID: 29808518 DOI: 10.1111/gcb.14279] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 01/25/2018] [Accepted: 03/09/2018] [Indexed: 05/19/2023]
Abstract
Contemporary climate change in Alaska has resulted in amplified rates of press and pulse disturbances that drive ecosystem change with significant consequences for socio-environmental systems. Despite the vulnerability of Arctic and boreal landscapes to change, little has been done to characterize landscape change and associated drivers across northern high-latitude ecosystems. Here we characterize the historical sensitivity of Alaska's ecosystems to environmental change and anthropogenic disturbances using expert knowledge, remote sensing data, and spatiotemporal analyses and modeling. Time-series analysis of moderate-and high-resolution imagery was used to characterize land- and water-surface dynamics across Alaska. Some 430,000 interpretations of ecological and geomorphological change were made using historical air photos and satellite imagery, and corroborate land-surface greening, browning, and wetness/moisture trend parameters derived from peak-growing season Landsat imagery acquired from 1984 to 2015. The time series of change metrics, together with climatic data and maps of landscape characteristics, were incorporated into a modeling framework for mapping and understanding of drivers of change throughout Alaska. According to our analysis, approximately 13% (~174,000 ± 8700 km2 ) of Alaska has experienced directional change in the last 32 years (±95% confidence intervals). At the ecoregions level, substantial increases in remotely sensed vegetation productivity were most pronounced in western and northern foothills of Alaska, which is explained by vegetation growth associated with increasing air temperatures. Significant browning trends were largely the result of recent wildfires in interior Alaska, but browning trends are also driven by increases in evaporative demand and surface-water gains that have predominately occurred over warming permafrost landscapes. Increased rates of photosynthetic activity are associated with stabilization and recovery processes following wildfire, timber harvesting, insect damage, thermokarst, glacial retreat, and lake infilling and drainage events. Our results fill a critical gap in the understanding of historical and potential future trajectories of change in northern high-latitude regions.
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Affiliation(s)
- Neal J Pastick
- Stinger Ghaffarian Technologies, Inc. (contractor to the U.S. Geological Survey), Sioux Falls, South Dakota
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota
| | | | - Scott J Goetz
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, Arizona
| | - Benjamin M Jones
- Alaska Science Center, U.S. Geological Survey, Anchorage, Alaska
| | - Bruce K Wylie
- Earth Resources Observation and Science Center, U.S. Geological Survey, Sioux Falls, South Dakota
| | - Burke J Minsley
- Crustal Geophysics and Geochemistry Science Center, U.S. Geological Survey, Denver, Colorado
| | - Hélène Genet
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska
| | - Joseph F Knight
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota
| | | | - Janet C Jorgenson
- Arctic National Wildlife Refuge, U.S. Fish and Wildlife Service, Fairbanks, Alaska
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33
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Buchwal A, Weijers S, Blok D, Elberling B. Temperature sensitivity of willow dwarf shrub growth from two distinct High Arctic sites. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2019; 63:167-181. [PMID: 30511167 DOI: 10.1007/s00484-018-1648-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 11/08/2018] [Accepted: 11/10/2018] [Indexed: 06/09/2023]
Abstract
The High Arctic region has experienced marked climate fluctuations within the past decades strongly affecting tundra shrub growth. However, the spatial variability in dwarf shrub growth responses in this remote region remains largely unknown. This study characterizes temperature sensitivity of radial growth of two willow dwarf shrub species from two distinct High Arctic sites. The dwarf shrub Salix arctica from Northern Greenland (82°N), which has a dry continental High Arctic climate, is linked with Salix polaris from central Svalbard (78° N), which experiences a more oceanic High Arctic climate with relatively mild winters. We found similar positive and significant relationships between annual growth of both Salix dwarf shrub species and July-August air temperatures (1960-2010), despite different temperature regimes and shrub growth rates at the two sites. Also, Salix dwarf shrub growth was significantly negatively correlated with Arctic and North Atlantic Oscillation (AO/NAO) indices; S. arctica from Northern Greenland was negatively correlated with previous autumn (AO index) and current summer AO and NAO indices, and S. polaris with the summer NAO index. The results highlight the importance of both local and regional climatic drivers for dwarf willow shrub growth in harsh polar desert habitats and are a step in the direction of identifying and scaling changes in plant growth across the High Arctic.
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Affiliation(s)
- Agata Buchwal
- Institute of Geoecology and Geoinformation, Adam Mickiewicz University, B. Krygowskiego 10, 61-680, Poznan, Poland.
| | - Stef Weijers
- Department of Geography, University of Bonn, Meckenheimer Allee 166, 53115, Bonn, Germany
| | - Daan Blok
- Department of Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, S-223 62, Lund, Sweden
| | - Bo Elberling
- Center for Permafrost (CENPERM), Department of Geoscience and Natural Resource Management, University of Copenhagen, Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen K, Denmark.
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34
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McPartland MY, Kane ES, Falkowski MJ, Kolka R, Turetsky MR, Palik B, Montgomery RA. The response of boreal peatland community composition and NDVI to hydrologic change, warming, and elevated carbon dioxide. GLOBAL CHANGE BIOLOGY 2019; 25:93-107. [PMID: 30295397 DOI: 10.1111/gcb.14465] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 09/07/2018] [Indexed: 06/08/2023]
Abstract
Widespread changes in arctic and boreal Normalized Difference Vegetation Index (NDVI) values captured by satellite platforms indicate that northern ecosystems are experiencing rapid ecological change in response to climate warming. Increasing temperatures and altered hydrology are driving shifts in ecosystem biophysical properties that, observed by satellites, manifest as long-term changes in regional NDVI. In an effort to examine the underlying ecological drivers of these changes, we used field-scale remote sensing of NDVI to track peatland vegetation in experiments that manipulated hydrology, temperature, and carbon dioxide (CO2 ) levels. In addition to NDVI, we measured percent cover by species and leaf area index (LAI). We monitored two peatland types broadly representative of the boreal region. One site was a rich fen located near Fairbanks, Alaska, at the Alaska Peatland Experiment (APEX), and the second site was a nutrient-poor bog located in Northern Minnesota within the Spruce and Peatland Responses Under Changing Environments (SPRUCE) experiment. We found that NDVI decreased with long-term reductions in soil moisture at the APEX site, coincident with a decrease in photosynthetic leaf area and the relative abundance of sedges. We observed increasing NDVI with elevated temperature at the SPRUCE site, associated with an increase in the relative abundance of shrubs and a decrease in forb cover. Warming treatments at the SPRUCE site also led to increases in the LAI of the shrub layer. We found no strong effects of elevated CO2 on community composition. Our findings support recent studies suggesting that changes in NDVI observed from satellite platforms may be the result of changes in community composition and ecosystem structure in response to climate warming.
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Affiliation(s)
- Mara Y McPartland
- Department of Geography, Environment and Society, University of Minnesota, Minneapolis, Minnesota
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota
| | - Evan S Kane
- School of Forest Resources and Environmental Sciences, Michigan Technological University, Houghton, Michigan
- Northern Research Station, USDA Forest Service, Houghton, Michigan
| | - Michael J Falkowski
- Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, Colorado
| | - Randy Kolka
- Northern Research Station, USDA Forest Service, Grand Rapids, Minnesota
| | - Merritt R Turetsky
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Brian Palik
- Northern Research Station, USDA Forest Service, Grand Rapids, Minnesota
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35
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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: 216] [Impact Index Per Article: 36.0] [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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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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Blok D, Faucherre S, Banyasz I, Rinnan R, Michelsen A, Elberling B. Contrasting above- and belowground organic matter decomposition and carbon and nitrogen dynamics in response to warming in High Arctic tundra. GLOBAL CHANGE BIOLOGY 2018; 24:2660-2672. [PMID: 29235209 DOI: 10.1111/gcb.14017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 11/29/2017] [Indexed: 06/07/2023]
Abstract
Tundra regions are projected to warm rapidly during the coming decades. The tundra biome holds the largest terrestrial carbon pool, largely contained in frozen permafrost soils. With warming, these permafrost soils may thaw and become available for microbial decomposition, potentially providing a positive feedback to global warming. Warming may directly stimulate microbial metabolism but may also indirectly stimulate organic matter turnover through increased plant productivity by soil priming from root exudates and accelerated litter turnover rates. Here, we assess the impacts of experimental warming on turnover rates of leaf litter, active layer soil and thawed permafrost sediment in two high-arctic tundra heath sites in NE-Greenland, either dominated by evergreen or deciduous shrubs. We incubated shrub leaf litter on the surface of control and warmed plots for 1 and 2 years. Active layer soil was collected from the plots to assess the effects of 8 years of field warming on soil carbon stocks. Finally, we incubated open cores filled with newly thawed permafrost soil for 2 years in the active layer of the same plots. After field incubation, we measured basal respiration rates of recovered thawed permafrost cores in the lab. Warming significantly reduced litter mass loss by 26% after 1 year incubation, but differences in litter mass loss among treatments disappeared after 2 years incubation. Warming also reduced litter nitrogen mineralization and decreased the litter carbon to nitrogen ratio. Active layer soil carbon stocks were reduced 15% by warming, while soil dissolved nitrogen was reduced by half in warmed plots. Warming had a positive legacy effect on carbon turnover rates in thawed permafrost cores, with 10% higher respiration rates measured in cores from warmed plots. These results demonstrate that warming may have contrasting effects on above- and belowground tundra carbon turnover, possibly governed by microbial resource availability.
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Affiliation(s)
- Daan Blok
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
- Department of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden
| | - Samuel Faucherre
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Imre Banyasz
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Riikka Rinnan
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - 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
| | - Bo Elberling
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
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38
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Elevation modulates how Arctic arthropod communities are structured along local environmental gradients. Polar Biol 2017. [DOI: 10.1007/s00300-017-2204-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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