Wednesday, August 4, 2010: 1:30 PM-5:00 PM
317-318, David L Lawrence Convention Center
OOS 35 - Soil Moisture as an Integrating Factor Determining Grassland/Old Field Responses to Global Warming
The effect and impact of current and projected climate change on ecosystem distribution, function, and services is a topic of international concern and wide public interest. In recent years, advances in the effectiveness and availability of field technology have enabled us to start conducting manipulative climate change experiments in the field. Recognizing that soil water is a critical factor affecting the distribution and functioning of vegetation globally, it is not surprising that many global change experiments have focused on soil water dynamics and how they are influenced by warming, elevated levels of CO2, nitrogen additions, and/or altered precipitation dynamics to explain ecosystem responses. In this session, we will review salient findings from several field grassland/old field global change experiments to evaluate the extent to which changes in soil water dynamics provide a common mechanistic link in their respective responses to global warming, primarily, as well as other factors. By considering experiments across a gradient from semi-arid to humid systems, including some experiments with precipitation manipulations, we will also investigate how responses to warming interact with precipitation dynamics to affect critical ecosystem responses, from nutrient cycling to plant species responses. The presenters will present data from five different global warming studies (the Boston Area Climate Experiment; the Oklahoma Global Climate Change Experiment; the Prairie Heating and CO2 Enrichment Experiment; the T-FACE experiment in the Qinahai-Tibet grassland; and the Jasper Ridge Global Change Experiment). The climate change experiments each use infra-red warming treatments, and range in start dates from 1998 to 2008. The talks in the organized session will be arranged from microbial to ecosystem scales to highlight the direct and indirect (water relations) effects of warming on soil nutrient cycling, soil respiration, photosynthesis and NPP, plant productivity and grazing, ecosystem C exchange. The session will culminate in a talk summarizing modeling results for ecosystem carbon and water dynamics for the five study sites represented within this session. In synthesizing results from both experimental manipulations and terrestrial ecosystem modeling, we hope to achieve a mechanistic understanding of the direct and indirect effects of warming, which transcends individual ecosystems/sites and can be applied to broader spatial scales.
Organizer:Susanne S. Hoeppner, Purdue University
Co-organizers:Jack A. Morgan, USDA-ARS
Jana L. Heisler-White, University of Wyoming
Moderator:Jack A. Morgan, USDA-ARS
1:30 PMOOS 35-1Precipitation patterns affect soil water content and ecosystem water balance in grasslands in North America
Kerry M. Byrne, Colorado State University, William K. Lauenroth, University of Wyoming, Peter B. Adler, Utah State University
1:50 PMOOS 35-2Does process-based soil water modeling of sagebrush steppe inform climate envelopes
Daniel R. Schlaepfer, University of Wyoming, William K. Lauenroth, University of Wyoming, John B. Bradford, USDA Forest Service
2:10 PMOOS 35-3Impacts of altered rainfall timing and warming in a mesic grassland ecosystem
John M. Blair, Kansas State University, Philip A. Fay, USDA, Agricultural Research Service, Alan K. Knapp, Colorado State University, Melinda D. Smith, Yale University, Scott L. Collins, University of New Mexico
2:30 PMOOS 35-4Variations in temperature sensitivities of soil and microbial respiration: Implications for climate-carbon modeling
Vidya Suseela, Purdue University, Jeffrey S. Dukes, Purdue University, Richard Conant, Colorado State University, Matthew D. Wallenstein, Colorado State University
2:50 PMOOS 35-5The effects of warming and precipitation change on photosynthesis and plant primary production in a New England old-field community
Susanne S. Hoeppner, Purdue University, Nicholas G. Smith, Purdue University, Jeffrey S. Dukes, Purdue University, Vikki Rodgers, Babson College, Michael Daley, Lasell College
3:10 PM Break
3:20 PMOOS 35-6CANCELLED - Mechanisms on the responses of ANPP to warming with grazing on the Tibetan plateau
Shiping Wang, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Guangping Xu, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Jichuang Duan, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Yichao Rui, University of Graduate, Chinese Academy of Sciences, Zhenhua Zhang, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xiaofeng Chang, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Caiyun Luo, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Yigang Hu, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Yanfen Wang, University of Graduate, Chinese Academy of Sciences, Xinquan Zhao, Northwest Institute of Plateau Biology, Chinese Academy of Sciences
3:40 PMOOS 35-7Ecosystem carbon exchange in response to climate warming: short vs long term
Shuli Niu, University of Oklahoma, Xiaolei Yan, University of Oklahoma, Yiqi Luo, University of Oklahoma
4:00 PMOOS 35-8Persistent ecosystem carbon loss under elevated CO2 and warming is driven by enhanced rates of ecosystem respiration at the PHACE experiment, Wyoming
Elise G. Pendall, University of Wyoming, Jana L. Heisler-White, University of Wyoming, David G. Williams, University of Wyoming, Jack A. Morgan, USDA-ARS, Daniel R. LeCain, USDA-ARS, Yolima Carrillo, University of Wyoming
4:20 PMOOS 35-9Modeled effect of warming on ecosystem carbon and water dynamics within grassland/old-field ecosystems along a moisture gradient
Jana L. Heisler-White, University of Wyoming, Jack Morgan, USDA-ARS, William J. Parton, Colorado State University, John M. Blair, Kansas State University, Nona R. Chiariello, Stanford University, Jeffrey S. Dukes, Purdue University, Philip A. Fay, USDA, Agricultural Research Service, Christopher B. Field, Carnegie Institution of Washington, Susanne S. Hoeppner, Purdue University, Mark Hovenden, University of Tasmania, Alan K. Knapp, Colorado State University, Yiqi Luo, University of Oklahoma, Shuli Niu, University of Oklahoma, Elise Pendall, University of Wyoming, Vidya Suseela, Purdue University
4:40 PMOOS 35-10Grassland conversion in relation to the onset of drought in a multi-factor global change experiment
Nona R. Chiariello, Stanford University, Todd Tobeck, Carnegie Institution for Science, Yuka Otsuki Estrada, Carnegie Institution for Science, Christopher B. Field, Carnegie Institution for Science

See more of Organized Oral Session

See more of The 95th ESA Annual Meeting (August 1 -- 6, 2010)