Session

Assessing biodiversity requires considering various aspects, including the multiple facets of biodiversity and the spatial scale at which it is measured. Whether different biodiversity facets exhibit the same patterns across spatial scales for various vegetation types remains unclear. We aimed to observe patterns of biodiversity changes across scales and facets in different grassland types. Specifically, we asked: 1) How does biodiversity change in different grassland types across scales from the perspective of different facets of biodiversity? 2) Can hotspots at smaller scales become coldspots at larger scales, and vice versa? 3) Are there situations where a vegetation type is rich in one biodiversity facet but not in others? 4) What causes shifts in biodiversity richness: rare or common species? We used a dataset of nested-plot series of grasslands in Ukraine, with seven grain sizes ranging from 0.001 to 100 m², and assessed metrics of taxonomic, phylogenetic, and functional diversity. By considering species presence/absence and relative cover in the community, we evaluated the influence of common and rare species. Our results showed various shifts in hotspots and coldspots for different facets of biodiversity and grassland types across spatial scales. This was particularly evident for functional diversity, where communities were poor at small scales but rich at larger scales in meso-xeric grasslands and vice versa in steppe depressions. We also observed the significant role of rare species in biodiversity rankings. Incorporating multiple facets of biodiversity and varying spatial scales is important for accurately assessing biodiversity and prioritizing grassland conservation efforts.