Decline in large-seeded species in Danish grasslands over an eight-year period

Abstract

A time-series analysis of cover data from 236 Danish grassland sites demonstrated community selection on seed mass. Across four grassland habitat types and during an eight-year period there was a significant decline in large-seeded species. In the analysis, the continuous seed size variable was used to group plant species into functional types. This method was chosen in order to account for the sampling process of the abundance data, and is in contrast to most other analyses of trait selection, where the community weighted mean of the traits is used as the dependent variable. Generally, little is known on the causes for seed size community selection in semi-natural grasslands that are not subjected to successional processes.