OOS 48 - Effects of Winter Climate Change and Soil Frost on Carbon and Nitrogen Dynamics in Terrestrial Ecosystems

Friday, August 7, 2009: 8:00 AM-11:30 AM
Mesilla, Albuquerque Convention Center
Pamela H. Templer, Boston University
Joshua P. Schimel, University of California, Santa Barbara
Climate warming effects in the winter are significant and are likely to become stronger. In high elevation and high latitudes environments, such as the Arctic, biological activity continues in frozen soil. However, this activity is extremely temperature-sensitive, and small increases in soil temperature can have large effects on biological processes. Conversely and surprisingly, warmer air temperatures in the temperate zone, such as Northeastern North America, may result in colder soils. In these areas, warmer winters result in a loss of the insulating snowpack (Hayhoe et al. 2006). With the snowpack as a good insulator, soils may remain thawed, but a loss in snowpack depth and duration can increase soil frost. Seasonally frozen ground is widespread, occupying approximately 55% of the exposed land surface in the Northern Hemisphere (Zhang et al. 2004). Therefore, changes in the depth and duration of frozen ground have the potential to affect the hydrology, biology and chemistry of ecosystems across broad regions. Variation in wintertime conditions can have a substantial influence on ecosystem processes by affecting the physical properties of soils, as well as plant and microbial activity. Recent research focused on the impacts of soil freezing and thawing on plant and microbial processes have produced a wealth of data on the impacts of changes in snowpack on alpine tundra, arctic tundra and northeastern forest ecosystems. Although studies have examined the impact of soil freezing on plant and microbial activity in these terrestrial ecosystems, there have been few attempts at cross-site syntheses. Here we propose to lead an organized oral session at the 2009 Ecological Society of America meeting to bring together ecosystem-scale experiments across a wide geographic range of ecosystem types. Our session will include two types of talks. The first set will showcase key ecosystem types and novel techniques and the second set will focus on synthesis across studies. Through these topics, we will address questions about the effects of winter climate change on the hydrology, biology and chemistry of tundra and forest ecosystems.
8:00 AM
 Effects of winter climate change and soil frost on forest nutrient retention and productivity in northeastern U.S. forest ecosystems
Pamela H. Templer, Boston University; John Campbell, United States Department of Agriculture Forest Service; Andrew B. Reinmann, Boston University; Anne M. Socci, Boston University
8:20 AM
 Winter climate change and soil nitrogen dynamics: A synthesis of experimental approaches in a temperate old field
Hugh A. L. Henry, University of Western Ontario; Terrence H. Bell, Université de Montréal; Amy C. Elliott, University of Western Ontario; Germaine Joseph, University of Western Ontario; Michelle M. Turner, University of Western Ontario
8:40 AM
 Using natural climate gradients to study winter climate change
Peter M. Groffman, Cary Institute of Ecosystem Studies; Janet P. Hardy, Cold Regions Research and Engineering Laboratory; Melany C. Fisk, Miami University of Ohio; Timothy J. Fahey, Cornell University; Charles T. Driscoll, Syracuse University
9:20 AM
 Changes in microbial physiology and community structure along seasonal and altitudinal gradients: Implications for soil respiration
David A. Lipson, San Diego State University; Russell K. Monson, University of Arizona; Steven K. Schmidt, University of Colorado; Michael N. Weintraub, University of Toledo
9:40 AM
9:50 AM
 A comparison of active-layer and permafrost microbial community responses to freeze-thaw stress: Can microbes adapt to changing climates?
Jessica G. Ernakovich, Colorado State University; Sarah J. Berg, Colorado State University; Alisa R. Challenger, Colorado State University; Kenneth F. Reardon, Colorado State University; Matthew D. Wallenstein, Colorado State University
10:10 AM
 Winter microbial carbon metabolism and community composition in Alaskan tundra soil
Shawna McMahon, Colorado State University; Matthew D. Wallenstein, Colorado State University; Joshua P. Schimel, University of California, Santa Barbara
10:30 AM
 Five years of winter climate change-related research in the Canadian low arctic: What have we learned?
Paul Grogan, Queen's University; Kate M. Buckeridge, University of California, Santa Barbara
10:50 AM
 Snowmelt causes pulse emissions of CO2 to the atmosphere
Ben Sullivan, The University of Montana; Sabina Dore, Northern Arizona University; Stephen C. Hart, University of California; Mario C. Montes-Helu, Northern Arizona University; Thomas E. Kolb, Northern Arizona University
See more of: Organized Oral Session
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