A matter of time: Recovery of plant species diversity in wild plant communities at declining nitrogen deposition

Aim: High levels of nitrogen deposition have been responsible for important losses of plant species diversity. It is often assumed that reduction of ammonia and nitrogen oxide emissions will result in the recovery of the former biodiversity. In Western Europe N deposition peaked between 1980 and 1988 and declined thereafter. In a 60-year experiment in hay meadows we tested the hypothesis that increasing and declining nitrogen deposition had negative, respectively, positive effects on plant species diversity.

Location: Wageningen, The Netherlands

Method: Duplicated plots received different fertilization treatments from 1958 onwards (control, Ca, K, P, PK, N, NPK). Productivity, soil pH and species composition were measured at regular intervals. In the control plots the correlations between N deposition, diversity, production and soil acidification were analysed. Subsequently, we tested whether the treatment effects (e.g., N addition and liming) confirmed the hypothesized interactio...