Fine-grain beta diversity in Palaearctic open vegetation: variability within and between biomes and vegetation types

Aims : To quantify how fine-grain (within-plot) beta diversity differs among biomes and vegetation types. Study area 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 spanning broad geographic ecological gradients. Next, we calculated slope parameter ( z -value) of power-law species–area relationship (SAR) to use as a measure multiplicative diversity. did this separately for vascular plants, bryophytes lichens three groups combined (complete vegetation). then tested whether -values differed biomes, ecological-physiognomic types coarse fine levels phytosociological classes. Results found that varied significantly The explanatory power species richness was highest followed by complete vegetation, lichens. Within each group, explained variance increased typological resolution. In adjusted R 2 0.14 but reached 0.50 Among mean were particularly high in Subtropics winter rain (Mediterranean biome) Dry tropics subtropics. Natural grasslands had higher than secondary grasslands. Alpine Mediterranean whereas managed benign soil climate conditions saline communities characterised low -values. Conclusions study relating units, distinct patterns. As explain conceptual figure, these can be related ultimate drivers, such productivity, stress disturbance, which influence via multiple pathways. provided means, medians quantiles wide range entities provide benchmarks local continental studies, while calling additional data under-represented units. Syntaxonomic references Mucina et al. (2016) classes occurring Europe; Ermakov (2012) restricted Asia. Abbreviations ANOVA = analysis variance; EDGG Eurasian Grassland Group; SAR species-area relationship.