Local above-ground persistence of vascular plants: Life-history trade-offs and environmental constraints

Questions: 1. Which plant traits and habitat characteristics best explain local above-ground persistence of vascular plant species and 2. Is there a trade-off between local above-ground persistence and the ability for seed dispersal and below-ground persistence in the soil seed bank? Locations: 845 long-term permanent plots in terrestrial habitats across the Netherlands. Methods: We analysed the local above-ground persistence of vascular plants in permanent plots (monitored once a year for ca. 16 year) with respect to functional traits and habitat preferences using survival statistics (Kaplan-Meier analysis and Cox' regression). These methods account for censored data and are rarely used in vegetation ecology. Results: Local above-ground persistence is determined by both functional traits (especially the ability to form long-lived clonal connections) and habitat preferences (especially nutrient requirements). Above-ground persistence is negatively related to the ability for dispersal by wind and to the ability to accumulate a long-term persistent soil seed bank (‘dispersal through time’) and is positively related to the ability for dispersal by water. Conclusions: Most species have a half-life expectation over 15 years, which may contribute to time lags after changes in habitat quality or -configuration (‘extinction debt’). There is evidence for a trade-off relationship between local above-ground persistence and below-ground seed persistence, while the relationship with dispersal in space is vector specific. The rate of species turnover increases with productivity. Nomenclature: van der Meijden (1990).