Talk, 56th Annual Symposium of the International Association for Vegetation Science, Tartu, Estonia: 2013-06-26 - 2013-06-30
The interrelationship between biodiversity and ecosystem functions such as productivity was mainly focused on various aspects of alpha-diversity. Besides species richness, functional diversity such as the number of functional groups was measured and related for instance to biomass. Most of the ground-breaking studies and experiments were affected in temperate grasslands. Central European grasslands are known to exhibit enormous species richness at small scales (Wilson et al. 2012). In these ecosystems, and especially in managed hay meadows, small scale units of vegetation may vary in species composition and functional traits. In addition to plot-related values at the level of one square meter, spatial heterogeneity within communities plays a major role for the performance of grasslands, which can be taken again as a case study for general traits of ecosystems. In grasslands small-scale differences in species composi - tion may reflect previous disturbances, local soil specifics, and the legacy of individual species and populations. Following a standard protocol for coordinated biodiversity assessments (see also Fraser et al. 2013), we recorded species identity and biomass at the site level (six sites with 8 × 8 m each) and within sites at the plot level (one square meter). We focus on 6 sites in Northern Bavaria. All sites are located near Bayreuth within less than 5 km in distance. Climatic conditions are comparable. Precipitation reaches about 700 mm p.a. and annual temperatures are 8 °C in average. The plots of this study are located in close vicinity to the former BIODEPTH plots in Bayreuth, where impor - tant studies on the biodiversity – ecosystem functioning debate were carried out (Hector et al. 1999). Current studies on the succession of these experimental plots have shown strong individual behaviour on near-by plots on the same substrate (Kreyling et al. 2011). Here, we analyze the spatial patterns of beta-diversity in extensively used grasslands (no fertilization, one to two har - vests per year). Two replicates were installed on low fertile, intermediate and high fertile sites, each. Fertility, however, is driven by the substrate and water availability only, not by anthropogenic fertilizer input. In addition, we relate the intrinsic floristic heterogeneity of the vegetation to fertility gradients. The aim of this study is developing approaches for heterogeneity measures in coordinated biodiversity experiments.