Recurrent summer drought affects biomass production and community composition independently of snowmelt manipulation in alpine grassland

Abstract Earlier snowmelt and more frequent summer drought due to climate warming are considered particularly influential for extratropical alpine plants, which adapted a short growing season high water availability. Here, we explored the combined effects of two drivers with field experiment in late‐successional grassland Swiss Alps (2500 m a.s.l.) over 6–7 years. We advanced delayed by removing adding snow experimental plots prior natural 7 years this treatment 5 10 weeks 6 measured plant biomass formation, community composition ecosystem respiration, monitored soil moisture as well temperature. Natural dates varied 42 days across Snow manipulations 4.6 8.0 on average but did not affect annual growth (peak biomass) above‐ nor below‐ground. Interactions between were nonsignificant, implying that independent snowmelt. Drought reduced total above‐ground 10‐week 16 ± 7% years, while 5‐week lowered last year only. This decline was accountable sensitivity production few forb graminoid species. In contrast, dominant sedge Carex curvula , whose proportion cover increased from 36% controls 48% drought. Below‐ground slightly under (5‐week only), resulting higher root mass fraction (both treatments). Despite continued respiration 13%–23% per season, assessed nine times during three seasons. Since than 85% stemmed below‐ground activities roots drought, assume microorganisms heavily constrained treatments. Synthesis. conclude timing is unrelated productivity, recurrent will shift allocation shoots typical grassland, potential implications grazers also nutrient carbon cycling. Species‐specific drought‐sensitivity considerably alter