Response of soil respiration under different mycorrhizal strategies to precipitation and temperature

Abstract

The symbiotic associations between plant roots and mycorrhizal fungi are almost ubiquitous. These interactions can produce a large amount of soil respiration (R s ) and respond strongly to such climatic changes as temperature and precipitation. The objective of the present study was to explore how interannual variations in environmental factors (i.e., temperature and precipitation) and biotic factors (leaf area index, LAI) influence soil respiration and its temperature sensitivity (appar - ent Q 10 ) in global forest ecosystems that are classified by the mycorrhizae of the dominant plants. Based on a global forest database, the mycorrhizal strategy of tree species over 200 site-years was determined. The R s on the global scale was largely controlled by temperature. When the mycorrhizal strategy was considered, the re- sponses of the R s to the mean annual temperature (MAT), mean annual precipitation (MAP) and LAI were highly variable among different mycorrhizal strategies. For example, the R s was explained mainly by the LAI for arbuscular mycorrhizal (AM) and AM+ ectomycorrhizal (ECM) types and by the MAT for ECM and ECM+EEM (ectendomycorrhizal) +NM (non-mycorrhizal) types. The apparent Q 10 of the R s was not significantly different. This study was the first to evaluate the influence of differ - ent mycorrhizal strategies on forest R s on the global scale. The mycorrhizal strategy plays an important role in the interpretation of the current soil respiration data.