No lasting effects of a severe drought event on plant community composition in experimental grassland

Abstract

The effect of severe drought in the summer 2018 on the plant community composition and overall diversity was investigated in a replicated long-term grassland experiment where nitrogen availability was manipulated. The possible plant community response to the drought and the possible role of selected plant traits were investigated using model-based ordination techniques, which were tailored to the sampled pin-point cover data. Contrary to our prior expectation, that the severe drought had lasting effects on the plant community, we could not detect any significant effects of the severe drought on the plant community composition or Hill–Shannon diversity the following year and 3 years later. Furthermore, we did not detect any significant mediating effect of nitrogen on the possible effects of severe drought. The possible reasons for the observed high resistance of the grassland community to the severe drought event are discussed. Lasting effects of drought on plant communities cannot be predicted from observations during or immediately after the drought.