Fine‐grain beta diversity of Palaearctic grassland vegetation

Questions Which environmental factors influence fine-grain beta diversity of vegetation and do they vary among taxonomic groups? Location Palaearctic biogeographic realm. Methods We extracted 4,654 nested-plot series with at least four different grain sizes between 0.0001 m² 1,024 from the GrassPlot database, covering a wide range grassland other open habitat types. derived extensive structural information for these series. For each groups (vascular plants, bryophytes, lichens, all), we calculated slope parameter (z-value) power law species–area relationship (SAR), as measure. tested whether z-values differed respect to gradients (latitude, elevation, macroclimate), ecological (site) characteristics (several stress–productivity, disturbance heterogeneity measures, including land use) alpha (c-value SAR). Results Mean were highest intermediate vascular plants lowest bryophytes. Bivariate regressions against variables had rather low predictive (mean R² = 0.07 less taxa). strongest predictors herb layer cover (negative), elevation (positive), rock stone (positive) c-value (U-shaped). All metrics related use (fertilization, livestock grazing, mowing, burning, decrease in naturalness) led z-values. Other little or no impact on The patterns lichens all taxa combined similar but weaker than those plants. Conclusions conclude that productivity has negative positive effects z-values, while effect varies depending type intensity. These differences can be explained via drivers mean occupancy species, which is mathematically linked diversity.