plants mediate the sensitivity of soil respiration to rainfall植物对降雨对土壤呼吸的敏感性分析.pdfVIP

Ecosystems (2011) 14: 156–167 DOI: 10.1007/s10021-010-9401-y 2010 Springer Science+Business Media, LLC Plants Mediate the Sensitivity of Soil Respiration to Rainfall Variability Zachary T. Aanderud,1,2 Donald R. Schoolmaster Jr.,1 and Jay T. Lennon1,3* 1W. K. Kellogg Biological Station, Michigan State University, 3700 East Gull Lake Drive, Hickory Corners, Michigan 49060, USA; 2Department of Plant and Wildlife Sciences, Brigham Young University, 489 WIDB, Provo, Utah 84602, USA; 3Department of Microbiology and Molecular Genetics, Michigan State University, Hickory Corners, Michigan 49060, USA ABSTRACT Soil respiration from grasslands plays a critical role of soil respiration to both moisture and tempera- in determining carbon dioxide (CO2) feedbacks ture. Using time-series multiple regression, we between soils and the atmosphere. In these often found that plants dampened the sensitivity of res- mesic systems, soil moisture and temperature tend piration to moisture under high variability rainfall to co-regulate soil respiration. Increasing variance treatments, which may reflect the relative stability of rainfall patterns may alter aboveground–below- of root contributions to total soil respiration. In ground interactions and have important implica- contrast, plants increased the sensitivity of respi- tions for the sensitivity of soil respiration to ration to temperature under low variability rainfall fluctuations in moisture and temperature. We treatment suggesting that the environmental con- conducted a set of field experiments to evaluate the trols on soil CO2 dynamics in mesic habitats may be