Increased plant productivity in Alaskan tundra as a result of experimental warming of soil and permafrost

作者：Susan M. Natali, Edward A. G. Schuur, Rachel L. Rubin · 发表于：Journal of Ecology · 年份：2011 · DOI：10.1111/j.1365-2745.2011.01925.x · 被引用次数：371 · 研究领域：Climate change and permafrost、Cryospheric studies and observations、Geology and Paleoclimatology Research

Summary 1. The response of northern tundra plant communities to warming temperatures is of critical concern because permafrost ecosystems play a key role in global carbon (C) storage, and climate‐induced ecological shifts in the plant community will affect the transfer of carbon‐dioxide between biological and atmospheric pools. 2. This study, which focuses on the response of tundra plant growth and phenology to experimental warming, was conducted at the Carbon in Permafrost Experimental Heating Research project, located in the northern foothills of the Alaska Range. We used snow fences coupled with spring snow removal to increase deep‐soil temperatures and thaw depth (winter warming), and open‐top chambers to increase summer air temperatures (summer warming). 3. Winter warming increased wintertime soil temperature (5–40 cm) by 2.3 °C, resulting in a 10% increase in growing season thaw depth. Summer warming significantly increased growing season air temperature; peak temperature differences occurred near midday when summer warming plots were approximately 1.0 °C warmer than ambient plots. 4. Changes in the soil environment as a result of winter warming treatment resulted in a 20% increase in above‐ground biomass and net primary productivity (ANPP), while there was no detected summer warming effect on ecosystem‐level ANPP or biomass. Both summer and winter warming extended the growing season through earlier bud break and delayed senescence, despite equivalent snow‐free days acr...