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  • 1. Adolf, Carole
    et al.
    Wunderle, Stefan
    Colombaroli, Daniele
    Weber, Helga
    Gobet, Erika
    Heiri, Oliver
    van Leeuwen, Jacqueline F. N.
    Bigler, Christian
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Connor, Simon E.
    Galka, Mariusz
    La Mantia, Tommaso
    Makhortykh, Sergey
    Svitavska-Svobodova, Helena
    Vanniere, Boris
    Tinner, Willy
    The sedimentary and remote-sensing reflection of biomass burning in Europe2018Ingår i: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238, Vol. 27, nr 2, s. 199-212Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aim: We provide the first European-scale geospatial training set relating the charcoal signal in surface lake sediments to fire parameters (number, intensity and area) recorded by satellite moderate resolution imaging spectroradiometer (MODIS) sensors. Our calibration is intended for quantitative reconstructions of key fire-regime parameters by using sediment sequences of microscopic (MIC from pollen slides, particles 10-500 mu m) and macroscopic charcoal (MAC from sieves, particles > 100 mu m). Location: North-south and east-west transects across Europe, covering the mediterranean, temperate, alpine, boreal and steppe biomes. Time period: Lake sediments and MODIS active fire and burned area products were collected for the years 2012-2015. Methods: Cylinder sediment traps were installed in lakes to annually collect charcoal particles in sediments. We quantitatively assessed the relationships between MIC and MAC influx (particles/cm(2)/year) and the MODIS-derived products to identify source areas of charcoal and the extent to which lake-sediment charcoal is linked to fire parameters across the continent. Results: Source area of sedimentary charcoal was estimated to a 40-km radius around sites for both MIC and MAC particles. Fires occurred in grasslands and in forests, with grass morphotypes of MAC accurately reflecting the burned fuel-type. Despite the lack of local fires around the sites, MAC influx levels reached those reported for local fires. Both MIC and MAC showed strong and highly significant relationships with the MODIS-derived fire parameters, as well as with climatic variation along a latitudinal temperature gradient. Main conclusions: MIC and MAC are suited to quantitatively reconstructing fire number and fire intensity on a regional scale. However, burned area may only be estimated using MAC. Local fires may be identified by using several lines of evidence, e.g. analysis of large particles (> 600 mu m), magnetic susceptibility and sedimentological data. Our results offer new insights and applications to quantitatively reconstruct fires and to interpret available sedimentary charcoal records.

  • 2. Barrio, I. C.
    et al.
    Bueno, C. G.
    Gartzia, M.
    Soininen, E. M.
    Christie, K. S.
    Speed, J. D. M.
    Ravolainen, V. T.
    Forbes, B. C.
    Gauthier, G.
    Horstkotte, Tim
    Hoset, K. S.
    Høye, T. T.
    Jónsdóttir, I. S.
    Lévesque, E.
    Mörsdorf, M. A.
    Olofsson, Johan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Wookey, P. A.
    Hik, D. S.
    Biotic interactions mediate patterns of herbivore diversity in the Arctic2016Ingår i: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238, Vol. 25, nr 9, s. 1108-1118Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aim: Understanding the forces shaping biodiversity patterns, particularly for groups of organisms with key functional roles, will help predict the responses of ecosystems to environmental changes. Our aim was to evaluate the relative role of different drivers in shaping the diversity patterns of vertebrate herbivores, a group of organisms exerting a strong trophic influence in terrestrial Arctic ecosystems. This biome, traditionally perceived as homogeneous and low in biodiversity, includes wide variation in biotic and physical conditions and is currently undergoing major environmental change. Location: The Arctic (including the High Arctic, Low Arctic and Subarctic) MethodsWe compiled available data on vertebrate (birds and mammals) herbivore distribution at a pan-Arctic scale, and used eight variables that represent the most relevant hypotheses for explaining patterns of species richness. We used range maps rasterized on a 100kmx100km equal-area grid to analyse richness patterns of all vertebrate herbivore species combined, and birds and mammalian herbivores separately. Results: Overall, patterns of herbivore species richness in the Arctic were positively related to plant productivity (measured using the normalized difference vegetation index) and to the species richness of predators. Greater species richness of herbivores was also linked to areas with a higher mean annual temperature. Species richness of avian and mammalian herbivores were related to the distance from the coast, with the highest avian richness in coastal areas and mammalian richness peaking further inland. Main conclusions: Herbivore richness in the Arctic is most strongly linked to primary productivity and the species richness of predators. Our results suggest that biotic interactions, with either higher or lower trophic levels or both, can drive patterns of species richness at a biome-wide scale. Rapid ongoing environmental changes in the Arctic are likely to affect herbivore diversity through impacts on both primary productivity and changes in predator communities via range expansion of predators from lower latitudes.

  • 3. Bjorkman, Anne D.
    et al.
    Myers-Smith, Isla H.
    Elmendorf, Sarah C.
    Normand, Signe
    Thomas, Haydn J. D.
    Alatalo, Juha M.
    Alexander, Heather
    Anadon-Rosell, Alba
    Angers-Blondin, Sandra
    Bai, Yang
    Baruah, Gaurav
    te Beest, Mariska
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Environmental Sciences, Copernicus Institute of Sustainable Development, Utrecht University, Utrecht, The Netherlands.
    Berner, Logan
    Bjork, Robert G.
    Blok, Daan
    Bruelheide, Helge
    Buchwal, Agata
    Buras, Allan
    Carbognani, Michele
    Christie, Katherine
    Collier, Laura S.
    Cooper, Elisabeth J.
    Cornelissen, J. Hans C.
    Dickinson, Katharine J. M.
    Dullinger, Stefan
    Elberling, Bo
    Eskelinen, Anu
    Forbes, Bruce C.
    Frei, Esther R.
    Iturrate-Garcia, Maitane
    Good, Megan K.
    Grau, Oriol
    Green, Peter
    Greve, Michelle
    Grogan, Paul
    Haider, Sylvia
    Hajek, Tomas
    Hallinger, Martin
    Happonen, Konsta
    Harper, Karen A.
    Heijmans, Monique M. P. D.
    Henry, Gregory H. R.
    Hermanutz, Luise
    Hewitt, Rebecca E.
    Hollister, Robert D.
    Hudson, James
    Huelber, Karl
    Iversen, Colleen M.
    Jaroszynska, Francesca
    Jimenez-Alfaro, Borja
    Johnstone, Jill
    Jorgensen, Rasmus Halfdan
    Kaarlejarvi, Elina
    Klady, Rebecca
    Klimesova, Jitka
    Korsten, Annika
    Kuleza, Sara
    Kulonen, Aino
    Lamarque, Laurent J.
    Lantz, Trevor
    Lavalle, Amanda
    Lembrechts, Jonas J.
    Levesque, Esther
    Little, Chelsea J.
    Luoto, Miska
    Macek, Petr
    Mack, Michelle C.
    Mathakutha, Rabia
    Michelsen, Anders
    Milbau, Ann
    Molau, Ulf
    Morgan, John W.
    Morsdorf, Martin Alfons
    Nabe-Nielsen, Jacob
    Nielsen, Sigrid Scholer
    Ninot, Josep M.
    Oberbauer, Steven F.
    Olofsson, Johan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Onipchenko, Vladimir G.
    Petraglia, Alessandro
    Pickering, Catherine
    Prevey, Janet S.
    Rixen, Christian
    Rumpf, Sabine B.
    Schaepman-Strub, Gabriela
    Semenchuk, Philipp
    Shetti, Rohan
    Soudzilovskaia, Nadejda A.
    Spasojevic, Marko J.
    Speed, James David Mervyn
    Street, Lorna E.
    Suding, Katharine
    Tape, Ken D.
    Tomaselli, Marcello
    Trant, Andrew
    Treier, Urs A.
    Tremblay, Jean-Pierre
    Tremblay, Maxime
    Venn, Susanna
    Virkkala, Anna-Maria
    Vowles, Tage
    Weijers, Stef
    Wilmking, Martin
    Wipf, Sonja
    Zamin, Tara
    Tundra Trait Team: a database of plant traits spanning the tundra biome2018Ingår i: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238, Vol. 27, nr 12, s. 1402-1411Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Motivation: The Tundra Trait Team (TTT) database includes field‐based measurements of key traits related to plant form and function at multiple sites across the tundra biome. This dataset can be used to address theoretical questions about plant strategy and trade‐offs, trait–environment relationships and environmental filtering, and trait variation across spatial scales, to validate satellite data, and to inform Earth system model parameters.

    Main types of variable contained: The database contains 91,970 measurements of 18 plant traits. The most frequently measured traits (> 1,000 observations each) include plant height, leaf area, specific leaf area, leaf fresh and dry mass, leaf dry matter content, leaf nitrogen, carbon and phosphorus content, leaf C:N and N:P, seed mass, and stem specific density.

    Spatial location and grain: Measurements were collected in tundra habitats in both the Northern and Southern Hemispheres, including Arctic sites in Alaska, Canada, Greenland, Fennoscandia and Siberia, alpine sites in the European Alps, Colorado Rockies, Caucasus, Ural Mountains, Pyrenees, Australian Alps, and Central Otago Mountains (New Zealand), and sub‐Antarctic Marion Island. More than 99% of observations are georeferenced.

    Time period and grain: All data were collected between 1964 and 2018. A small number of sites have repeated trait measurements at two or more time periods.

    Major taxa and level of measurement: Trait measurements were made on 978 terrestrial vascular plant species growing in tundra habitats. Most observations are on individuals (86%), while the remainder represent plot or site means or maximums per species.

    Software format: csv file and GitHub repository with data cleaning scripts in R; contribution to TRY plant trait database (www.try-db.org) to be included in the next version release.

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  • 4. De Frenne, P
    et al.
    Kolb, A
    Verheyen, K
    Brunet, J
    Chabrerie, O
    Decocq, G
    Diekmann, M
    Eriksson, O
    Heinken, T
    Hermy, M
    Jõgar, Ü
    Stanton, S
    Zindel, Renate
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Zobel, M
    Graae, BJ
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Unraveling the effects of temperature, latitude and local environment on the reproduction of six forest herbs.2009Ingår i: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238, Vol. 18, nr 6, s. 641-651Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aim To investigate the effect of temperature, latitude and local environment on the reproductive traits of widespread perennial forest herbs to better understand the potential impacts of rising temperatures on their population dynamics and colonization capacities.

    Location Six regions along a latitudinal gradient from France to Sweden.

    Methods Within each region, we collected data from three to five populations of up to six species. For each species, several variables were recorded in each region (temperature, latitude) and population (local abiotic and biotic environmental variables), and seed production and germination were estimated. Resource investment in reproduction (RIR) was quantified as seed number × seed mass, while germinable seed output (GSO) was expressed as seed number × germination percentage. We performed linear regression and mixed effect models to investigate the effects of temperature (growing degree hours), latitude and local abiotic and biotic environment on RIR and GSO.

    Results Temperature and latitude explained most of the variation in RIR and GSO for early flowering species with a northerly distribution range edge (Anemone nemorosa, Paris quadrifolia and Oxalis acetosella). Reproduction of the more southerly distributed species (Brachypodium sylvaticum, Circaea lutetiana and Primula elatior), in contrast, was independent of temperature/latitude. In the late summer species, B. sylvaticum and C. lutetiana, variation in RIR and GSO was best explained by local environmental variables, while none of the investigated variables appeared to be related to reproduction in P. elatior.

    Main conclusions We showed that reproduction of only two early flowering, northerly distributed species was related to temperature. This suggests that the potential reproductive response of forest herbs to climate warming partly depends on their phenology and distribution, but also that the response is to some extent species dependent. These findings should be taken into account when predictions about future shifts in distribution range are made.

  • 5.
    Kadoya, Taku
    et al.
    Biodiversity Division, National Institute for Environmental Studies, Tsukuba, Japan; Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan.
    Nilsson, Karin A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Kelly, Jocelyn
    Department of Integrative Biology, University of Guelph, ON, Guelph, Canada.
    Bartley, Timothy J.
    Department of Integrative Biology, University of Guelph, ON, Guelph, Canada; Department of Biology, University of Toronto Mississauga, ON, Mississauga, Canada.
    Säterberg, Torbjörn
    Department of Aquatic Resources, Swedish University of Agricultural Sciences, Öregrund, Sweden.
    Guzzo, Matthew M.
    Department of Integrative Biology, University of Guelph, ON, Guelph, Canada.
    Esch, Ellen
    Department of Integrative Biology, University of Guelph, ON, Guelph, Canada.
    Koide, Dai
    Biodiversity Division, National Institute for Environmental Studies, Tsukuba, Japan.
    Matsuzaki, Shin-ichiro S.
    Biodiversity Division, National Institute for Environmental Studies, Tsukuba, Japan.
    Terui, Akira
    Department of Biology, University of North Carolina Greensboro, NC, Greensboro, United States.
    Akasaka, Munemitsu
    Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu, Japan; Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan.
    MacDougall, Andrew S.
    Department of Integrative Biology, University of Guelph, ON, Guelph, Canada.
    Common processes drive metacommunity structure in freshwater fish2024Ingår i: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aim: Environmental change affects metacommunity structure both directly—via abiotic factors and dispersal that affect species occurrence—and indirectly—via complex interactions among co-occurring species. We examined how the three main metacommunity factors—environmental conditions, spatial processes and species associations—affect metacommunity structure and whether responses are predictable in real-world systems by using novel methods to disentangle the drivers.

    Location: Eastern Asia, northern Europe and central North America.

    Time period: Contemporary.

    Major taxa studied: Freshwater fish. Methods: We used a dataset of freshwater fish species occurrences in temperate lakes in three countries in different biogeographic regions. We analysed co-occurrence patterns by using a joint species distribution model.

    Results: We demonstrated that environmental processes are the main drivers of species' distribution and diversity, suggesting that future climate change (anthropogenic alteration of abiotic factors) will heavily influence the structure of metacommunities. We also showed that spatial processes and species interactions mediated the influence of environmental processes, especially at the lake level.

    Main conclusions: Our results indicate that ongoing changes in metacommunity structure are modulated not only by the direct impacts of shifting abiotic factors but also by indirect effects of species interactions. Our global analysis indicates that even under the current high rate of environmental change, an identifiable set of underlying processes can be used to predict impacts of this change on metacommunity structure.

  • 6. Lapierre, Jean-Francois
    et al.
    Collins, Sarah M.
    Seekell, David A.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Climate Impacts Research Centre, Umeå University, Abisko, Sweden.
    Cheruvelil, Kendra Spence
    Tan, Pang-Ning
    Skaff, Nicholas K.
    Taranu, Zofia E.
    Fergus, C. Emi
    Soranno, Patricia A.
    Similarity in spatial structure constrains ecosystem relationships: Building a macroscale understanding of lakes2018Ingår i: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238, Vol. 27, nr 10, s. 1251-1263Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aim: We aimed to measure the dominant spatial patterns in ecosystem properties (such as nutrients and measures of primary production) and the multi‐scaled geographical driver variables of these properties and to quantify how the spatial structure of pattern in all of these variables influences the strength of relationships among them.

    Location and time period: We studied > 8,500 lakes in a 1.8 million km2 area of Northeast U.S.A. Data comprised 10‐year medians (2002–2011) for measured ecosystem properties, long‐term climate averages and recent land use/land cover variables.

    Major taxa studied: We focused on ecosystem properties at the base of aquatic food webs, including concentrations of nutrients and algal pigments that are proxies of pri -mary productivity.

    Methods: We quantified spatial structure in ecosystem properties and their geograph-ical driver variables using distance‐based Moran eigenvector maps (dbMEMs). We then compared the similarity in spatial structure for all pairs of variables with the cor -relation between variables to illustrate how spatial structure constrains relationships among ecosystem properties.

    Results: The strength of spatial structure decreased in order for climate, land cover/use, lake ecosystem properties and lake and landscape morphometry. Having a compa -rable spatial structure is a necessary condition to observe a strong relationship be -tween a pair of variables, but not a sufficient one; variables with very different spatial structure are never strongly correlated. Lake ecosystem properties tended to have an intermediary spatial structure compared with that of their main drivers, probably be -cause climate and landscape variables with known ecological links induce spatial patterns.

    Main conclusions: Our empirical results describe inherent spatial constraints that dic -tate the expected relationships between ecosystem properties and their geographical drivers at macroscales. Our results also suggest that understanding the spatial scales at which ecological processes operate is necessary to predict the effects of multi‐scaled environmental changes on ecosystem properties.

  • 7.
    Leuzinger, S
    et al.
    School of Applied Sciences, Auckland University of Technology, Auckland, 1142, New Zealand .
    Manusch, C
    Department of Environmental Systems Science, Institute of Terrestrial Ecosystems, ETH Zurich, Forest Ecology, Universitätstrasse 16, Zurich, 8092, Switzerland .
    Bugmann, H
    Department of Environmental Systems Science, Institute of Terrestrial Ecosystems, ETH Zurich, Forest Ecology, Universitätstrasse 16, Zurich, 8092, Switzerland .
    Wolf, Annett
    A sink-limited growth model improves biomass estimation along boreal and alpine tree lines2013Ingår i: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238, Vol. 22, nr 8, s. 924-932Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aim: Despite increasing evidence for plant growth often being limited by sink (meristem) activity rather than source (photosynthesis) activity, all currently available dynamic global vegetation models (DGVMs) simulate plant growth via source-limited processes. For a given climatic region, this may lead to an overestimation of carbon stock per unit surface area, particularly if a model fails to correctly predict forest cover. Our aim is to improve the Lund-Potsdam-Jena (LPJ) DGVM by replacing the source-limited (SoL) tree growth algorithm by a sink-limited (SiL) one. Location: Our analysis focuses on the cold tree line at high latitudes and altitudes. We study two altitudinal transects in the Swiss Alps and the northern tree line. Methods: We limit annual net primary productivity of the LPJ DGVM by an algorithm based on the annual sum of growing degree-days (GDD), assuming that maximum plant growth is reached asymptotically with increasing GDD. Results: Comparing simulation results with observational data, we show that the locations of both the northern and the alpine tree line are estimated more accurately when using a SiL algorithm than when using the commonly employed SoL algorithm. Also, simulated carbon stocks decrease in a more realistic manner towards the tree line when the SiL algorithm is used. This has far-reaching implications for estimating and projecting present and future carbon stocks in temperature-limited ecosystems. Main conclusions: In the range of 60-80°N over Europe and Asia, carbon stored in vegetation is estimated to be c. 50% higher in the LPJ standard version (LPJ-SoL) compared with LPJ-SiL, resulting in a global difference in estimated biomass of 25 Pg (c. 5% of the global terrestrial standing biomass). Similarly, the simulated elevation of the upper tree line in the European Alps differs by c. 400m between the two model versions, thus implying an additional overestimation of carbon stored in mountain forests around the world.

  • 8. Plue, Jan
    et al.
    De Frenne, Pieter
    Acharya, Kamal
    Brunet, Jorg
    Chabrerie, Olivier
    Decocq, Guillaume
    Diekmann, Martin
    Graae, Bente J.
    Heinken, Thilo
    Hermy, Martin
    Kolb, Annette
    Lemke, Isgard
    Liira, Jaan
    Naaf, Tobias
    Shevtsova, Anna
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Verheyen, Kris
    Wulf, Monika
    Cousins, Sara A. O.
    Climatic control of forest herb seed banks along a latitudinal gradient2013Ingår i: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238, Vol. 22, nr 10, s. 1106-1117Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aim Seed banks are central to the regeneration strategy of many plant species. Any factor altering seed bank density thus affects plant regeneration and population dynamics. Although seed banks are dynamic entities controlled by multiple environmental drivers, climatic factors are the most comprehensive, but still poorly understood. This study investigates how climatic variation structures seed production and resulting seed bank patterns. Location Temperate forests along a 1900km latitudinal gradient in north-western (NW) Europe. Methods Seed production and seed bank density were quantified in 153 plots along the gradient for four forest herbs with different seed longevity: Geum urbanum, Milium effusum, Poa nemoralis and Stachys sylvatica. We tested the importance of climatic and local environmental factors in shaping seed production and seed bank density. Results Seed production was determined by population size, and not by climatic factors. G.urbanum and M.effusum seed bank density declined with decreasing temperature (growing degree days) and/or increasing temperature range (maximum-minimum temperature). P.nemoralis and S.sylvatica seed bank density were limited by population size and not by climatic variables. Seed bank density was also influenced by other, local environmental factors such as soil pH or light availability. Different seed bank patterns emerged due to differential seed longevities. Species with long-lived seeds maintained constant seed bank densities by counteracting the reduced chance of regular years with high seed production at colder northern latitudes. Main conclusions Seed bank patterns show clear interspecific variation in response to climate across the distribution range. Not all seed banking species may be as well equipped to buffer climate change via their seed bank, notably in short-term persistent species. Since the buffering capacity of seed banks is key to species persistence, these results provide crucial information to advance climatic change predictions on range shifts, community and biodiversity responses.

  • 9.
    Rodríguez-Castañeda, Genoveva
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Ecology and Evolution Department, Stony Brook University, Stony Brook, NY, USA.
    The world and its shades of green: a meta-analysis on trophic cascades across temperature and precipitation gradients2013Ingår i: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238, Vol. 22, nr 1, s. 118-130Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aim: To assess effects of current global temperature and precipitation gradients on the trophic function of plant-herbivore-predator interactions. Specifically, I study effects of climatic gradients on factors that control herbivore abundances: top-down, bottom-up trophic cascades and plant defences. I include predictions of climate change on shifts in trophic function, under the assumption that temperature and precipitation affect the physiology and performance of plants, herbivores and predators.

    Location: Global.

    Methods: A search of the relevant experiments on trophic interactions was conducted using the Web of Science and Scielo databases. Strength of trophic interactions from each experiment was studied by the calculation of the log ratio effect size (Ln R) of the control and experimental means. Each study was georeferenced and mean annual temperature (MAT) and total annual precipitation (TAP) were determined for each study location. Effect size of trophic interaction studies across the world were correlated with these environmental variables.

    Results: In total, 387 effect sizes were extracted from the literature. With the exception of bottom-up trophic cascades, trophic interactions and factors controlling herbivore abundance exhibited significant linear or quadratic relationships with either temperature or precipitation gradients: plant growth, predation and the effect of plant defence on herbivores increased with temperature. In contrast, plant growth and herbivory increased with precipitation across ecosystems. Finally, top-down trophic cascades increased towards the extremes of MAT and TAP gradients.

    Main conclusions: This study shows climatic gradients not only affect species geographic distributions and physiological tolerance but also the strength of their trophic functionality. This is especially true for the main biotic controls of herbivore populations (i.e. predation, top-down trophic cascades and plant defences). These results suggest future climate change will cause shifts in the strength of trophic interactions, resulting in increased or reduced population control of herbivores across global ecosystems.

  • 10. Thomas, H. J. D.
    et al.
    Myers-Smith, I. H.
    Bjorkman, A. D.
    Elmendorf, S. C.
    Blok, D.
    Cornelissen, J. H. C.
    Forbes, B. C.
    Hollister, R. D.
    Normand, S.
    Prevey, J. S.
    Rixen, C.
    Schaepman-Strub, G.
    Wilmking, M.
    Wipf, S.
    Cornwell, W. K.
    Kattge, J.
    Goetz, S. J.
    Guay, K. C.
    Alatalo, J. M.
    Anadon-Rosell, A.
    Angers-Blondin, S.
    Berner, L. T.
    Bjork, R. G.
    Buchwal, A.
    Buras, A.
    Carbognani, M.
    Christie, K.
    Collier, L. Siegwart
    Cooper, E. J.
    Eskelinen, A.
    Frei, E. R.
    Grau, O.
    Grogan, P.
    Hallinger, M.
    Heijmans, M. M. P. D.
    Hermanutz, L.
    Hudson, J. M. G.
    Huelber, K.
    Iturrate-Garcia, M.
    Iversen, C. M.
    Jaroszynska, F.
    Johnstone, J. F.
    Kaarlejärvi, Elina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Department of Biology, Vrije Universiteit Brussel (VUB), Brussels, Belgium; Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.
    Kulonen, A.
    Lamarque, L. J.
    Levesque, E.
    Little, C. J.
    Michelsen, A.
    Milbau, A.
    Nabe-Nielsen, J.
    Nielsen, S. S.
    Ninot, J. M.
    Oberbauer, S. F.
    Olofsson, Johan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Onipchenko, V. G.
    Petraglia, A.
    Rumpf, S. B.
    Semenchuk, P. R.
    Soudzilovskaia, N. A.
    Spasojevic, M. J.
    Speed, J. D. M.
    Tape, K. D.
    te Beest, Mariska
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Environmental Sciences, Copernicus Institute of Sustainable Development, Utrecht University, Utrecht, The Netherlands.
    Tomaselli, M.
    Trant, A.
    Treier, U. A.
    Venn, S.
    Vowles, T.
    Weijers, S.
    Zamin, T.
    Atkin, O. K.
    Bahn, M.
    Blonder, B.
    Campetella, G.
    Cerabolini, B. E. L.
    Chapin, F. S. , I I I
    Dainese, M.
    de Vries, F. T.
    Diaz, S.
    Green, W.
    Jackson, R. B.
    Manning, P.
    Niinemets, U.
    Ozinga, W. A.
    Penuelas, J.
    Reich, P. B.
    Schamp, B.
    Sheremetev, S.
    van Bodegom, P. M.
    Traditional plant functional groups explain variation in economic but not size-related traits across the tundra biome2019Ingår i: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238, Vol. 28, nr 2, s. 78-95Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aim: Plant functional groups are widely used in community ecology and earth system modelling to describe trait variation within and across plant communities. However, this approach rests on the assumption that functional groups explain a large proportion of trait variation among species. We test whether four commonly used plant functional groups represent variation in six ecologically important plant traits.

    Location: Tundra biome.

    Time period: Data collected between 1964 and 2016.

    Major taxa studied: 295 tundra vascular plant species.

    Methods: We compiled a database of six plant traits (plant height, leaf area, specific leaf area, leaf dry matter content, leaf nitrogen, seed mass) for tundra species. We examined the variation in species-level trait expression explained by four traditional functional groups (evergreen shrubs, deciduous shrubs, graminoids, forbs), and whether variation explained was dependent upon the traits included in analysis. We further compared the explanatory power and species composition of functional groups to alternative classifications generated using post hoc clustering of species-level traits.

    Results: Traditional functional groups explained significant differences in trait expression, particularly amongst traits associated with resource economics, which were consistent across sites and at the biome scale. However, functional groups explained 19% of overall trait variation and poorly represented differences in traits associated with plant size. Post hoc classification of species did not correspond well with traditional functional groups, and explained twice as much variation in species-level trait expression.

    Main conclusions: Traditional functional groups only coarsely represent variation in well-measured traits within tundra plant communities, and better explain resource economic traits than size-related traits. We recommend caution when using functional group approaches to predict tundra vegetation change, or ecosystem functions relating to plant size, such as albedo or carbon storage. We argue that alternative classifications or direct use of specific plant traits could provide new insights for ecological prediction and modelling.

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  • 11. Wasof, Safaa
    et al.
    Lenoir, Jonathan
    Aarrestad, Per Arild
    Alsos, Inger Greve
    Armbruster, W. Scott
    Austrheim, Gunnar
    Bakkestuen, Vegar
    Birks, H. John B.
    Bråthen, Kari Anne
    Broennimann, Olivier
    Brunet, Jörg
    Bruun, Hans Henrik
    Dahlberg, Carl Johan
    Diekmann, Martin
    Dullinger, Stefan
    Dynesius, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Ejrnaes, Rasmus
    Gegout, Jean-Claude
    Graae, Bente Jessen
    Grytnes, John-Arvid
    Guisan, Antoine
    Hylander, Kristoffer
    Jonsdottir, Ingibjörg S.
    Kapfer, Jutta
    Klanderud, Kari
    Luoto, Miska
    Milbau, Ann
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Moora, Mari
    Nygaard, Bettina
    Odland, Arvid
    Pauli, Harald
    Ravolainen, Virve
    Reinhardt, Stefanie
    Sandvik, Sylvi Marlen
    Schei, Fride Hoistad
    Speed, James D. M.
    Svenning, Jens-Christian
    Thuiller, Wilfried
    Tveraabak, Liv Unn
    Vandvik, Vigdis
    Velle, Liv Guri
    Virtanen, Risto
    Vittoz, Pascal
    Willner, Wolfgang
    Wohlgemuth, Thomas
    Zimmermann, Niklaus E.
    Zobel, Martin
    Decocq, Guillaume
    Disjunct populations of European vascular plant species keep the same climatic niches2015Ingår i: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238, Vol. 24, nr 12, s. 1401-1412Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aim Previous research on how climatic niches vary across species ranges has focused on a limited number of species, mostly invasive, and has not, to date, been very conclusive. Here we assess the degree of niche conservatism between distant populations of native alpine plant species that have been separated for thousands of years. Location European Alps and Fennoscandia. Methods Of the studied pool of 888 terrestrial vascular plant species occurring in both the Alps and Fennoscandia, we used two complementary approaches to test and quantify climatic-niche shifts for 31 species having strictly disjunct populations and 358 species having either a contiguous or a patchy distribution with distant populations. First, we used species distribution modelling to test for a region effect on each species' climatic niche. Second, we quantified niche overlap and shifts in niche width (i.e. ecological amplitude) and position (i.e. ecological optimum) within a bi-dimensional climatic space. Results Only one species (3%) of the 31 species with strictly disjunct populations and 58 species (16%) of the 358 species with distant populations showed a region effect on their climatic niche. Niche overlap was higher for species with strictly disjunct populations than for species with distant populations and highest for arctic-alpine species. Climatic niches were, on average, wider and located towards warmer and wetter conditions in the Alps. Main conclusion Climatic niches seem to be generally conserved between populations that are separated between the Alps and Fennoscandia and have probably been so for 10,000-15,000 years. Therefore, the basic assumption of species distribution models that a species' climatic niche is constant in space and time-at least on time scales 104 years or less-seems to be largely valid for arctic-alpine plants.

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