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We present a field study on the drought effects on total soil respiration (SR_t) and its components, i.e., “autotrophic” (SR_a: by roots/mycorrhizosphere) and “heterotrophic” respiration (SR_h: by microorganisms and soil fauna in bulk soil), in a mature European beech/Norway spruce forest. SR_a and SR_h were distinguished underneath groups of beech and spruce trees using the root exclusion method. Seasonal courses of SR_a and SR_h were studied from 2002 to 2004, with the summer of 2003 being extraordinarily warm and dry in Central Europe. We (1) analyzed the soil temperature (T _s) and moisture sensitivity of SR_a and SR_h underneath both tree species, and (2) examined whether drought caused differential decline of SR_a between spruce and beech. Throughout the study period, SR_a of beech accounted for 45–55% of SR_t, independent of the soil water regime; in contrast, SR_a was …