Plant community responses to experimental warming across the tundra biome

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Walker, Marilyn D, Wahren, C Henrik, Hollister, Robert D, Henry, Greg H R, Ahlquist, Lorraine E, Alatalo, Juha M, Bret-Harte, M Syndonia, Calef, Monika P, Callaghan, Terry V, Carroll, Amy B, Epstein, Howard E, Jonsdottir, Ingibjorg S, Klein, Julia A, Magnussonm, Borgbor, Molau, Ulf, Oberbauer, Steven F, Rewa, Steven P, Robinson, Clare H, Shaver, Gaius R, Suding, Katharine N, Thompson, Catharine C, Tolvanen, Anne, Totland, Orjan, Turner, P Lee, Tweedie, Craig E, Webber, Patrick J, Wookey, Philip
• Other Authors: University of Alaska Fairbanks, La Trobe University, Grand Valley State University, University of British Columbia, Florida International University, University of Gothenburg, Swedish Polar Research Secretariat, University of Virginia, University Centre in Svalbard, Colorado State University, Icelandic Institute of Natural History, Michigan State University, King's College London, Marine Biological Laboratory, University of California, Olympic National Park, Finnish Forest Research Institute, Norwegian University of Life Sciences, University of Colorado, University of Texas, El Paso, Biological and Environmental Sciences, orcid:0000-0001-5957-6424
• Format: Article in Journal/Newspaper
• Language: English
• Published: US National Academy of Sciences 2006
• Subjects: Arctic and alpine ecosystems; Biodiversity; Climate change; Vegetation change; Tundra ecology; Plants; Effects of global warming on; Climatic changes Environmental aspects; Arctic; Global warming; Tundra
• Online Access: http://hdl.handle.net/1893/884; https://doi.org/10.1073/pnas.0503198103; http://dspace.stir.ac.uk/bitstream/1893/884/1/ITEX_PNAS%20%282006%29%20hi%20res.pdf

Recent observations of changes in some tundra ecosystems appear to be responses to a warming climate. Several experimental studies have shown that tundra plants and ecosystems can respond strongly to environmental change, including warming; however, most studies were limited to a single location and were of short duration and based on a variety of experimental designs. In addition, comparisons among studies are difficult because a variety of techniques have been used to achieve experimental warming and different measurements have been used to assess responses. We used metaanalysis on plant community measurements from standardized warming experiments at 11 locations across the tundra biome involved in the International Tundra Experiment. The passive warming treatment increased plant level air temperature by 1–3°C, which is in the range of predicted and observed warming or tundra regions. Responses were rapid and detected in whole plant communities after only two growing seasons. Overall, warming increased height and cover of deciduous shrubs and graminoids, decreased cover of mosses and lichens, and decreased species diversity and evenness. These results predict that warming will cause a decline in biodiversity across a wide variety of tundra, at least in the short term. They also provide rigorous experimental evidence that recently observed increases in shrub cover in many tundra regions are in response to climate warming. These changes have important implications for processes and interactions within tundra ecosystems and between tundra and the atmosphere.