Post-drought rewetting triggers substantial K release and shifts in leaf stoichiometry in managed and abandoned mountain grasslands

Background and aim When soil is rewetted after drought, typically a transient pulse of mineralization and other microbial processes occur. This “Birch effect” translates into a temporarily elevated soil carbon dioxide efflux (SCE) and may alter nutrient availability. While rewetting effects on SCE have been frequently studied, effects on soil nutrient supply have rarely been considered despite potential relevance for plant nutrition during post-drought recovery.