Soil respiration response to climate change in Pacific Northwest prairies is mediated by a regional Mediterranean climate gradient

• DOI: 10.1111/gcb.12732
• Publication Date: 2014-09-10T07:27:50Z
• Authors: Lorien L. Reynolds; Bart R. Johnson; Laurel Pfeifer‐Me...; Scott D. Bridgham
• Keywords: Soil respiration

Abstract Soil respiration is expected to increase with rising global temperatures but the degree of response may depend on soil moisture and other local factors. Experimental climate change studies from single sites cannot discern whether an observed site‐dependent or generalizable. To deconvolve site‐specific vs. regional climatic controls, we examined for 18 months along a 520 km gradient in three Pacific Northwest, USA prairies that represents increasingly severe Mediterranean conditions north south. At each site implemented fully factorial combination 2.5–3 °C warming 20% added precipitation intensity. The was driven primarily by latitudinal not Warming increased at all during when limiting. However, these gains were offset reductions seasonal transitions summer drought due lengthened periods limitation. this varied north–south such 2011 cumulative annual 28.6% northern site, 13.5% central southern site. Precipitation also stimulated more frequently south, consistent duration best predictors nonlinear models Normalized Difference Vegetation Index ( NDVI ), antecedent moisture, temperature provided biased results high low respiration. effective integrator differences plant productivity terms their combined effects Our suggest limitation can effect respiration, greater growing‐season would constrain responses warming.