Timing of drought in the growing season and strong legacy effects determine the annual productivity of temperate grasses in a changing climate

Abstract. The frequency of extreme weather events, such as droughts, is assumed to increase and lead alterations in ecosystem productivity thus the terrestrial carbon cycle. Although grasslands typically show reduced response drought, effects drought on grassland have been shown vary strongly. Here we tested, a 2-year field experiment, if resistance recovery grasses varies throughout growing season timing influences drought-induced reductions annual aboveground net primary production (ANPP) grasses. For experiment grew six temperate perennial C3 grass species cultivars pure stands. were cut times during subject 10 week treatments that occurred either spring, summer or fall. Averaged across all grasses, losses spring smaller (?20 % ?51 %) than fall (?77 ?87 %). This suggests higher when plants are their reproductive stage highest. After release from found no prolonged suppression growth. In contrast, post-drought growth rates formerly drought-stressed swards outperformed control swards. strong overcompensation after resulted relatively small overall ANPP ranged ?4 ?14 not affected by event. summary, our results (i) increased phenological highest; (ii) positive legacy indicate high potential drought; (iii) can compensate for immediate total biomass significant extent.