Fine-scale South African bee distribution

Fine-scale bee species distribution models: Hotspots of richness and endemism in South Africa with species-area comparisons
Annalie Melin, CM. Beale, JC. Manning, JF. Colville 2024
https://doi.org/10.1111/icad.12715

Abstract
1 While global patterns of bee diversity have been modelled, our understanding of fine-scale regional patterns is more limited, particularly for under-sampled regions such as Africa. South Africa is among the exceptions on the African continent; its bee fauna (ca. 1253 species) has been well collected and documented, including mass digitising of its natural history collections. It is a region with high floral diversity, high habitat heterogeneity and variable rainfall seasonality.
2 Here, we combine a South African bee species distributional database (877 bee species) with a geospatial modelling approach to determine fine-scale (~11 × 11 km grid cell resolution) hotspots of bee species richness, endemism and range-restricted species.
3 Our analyses, based on the probabilities of occurrence surfaces for each species across 108,803 two-minute grid cells, reveal three bee hotspots of richness: Winter rainfall, Aseasonal rainfall and Early-to-late summer rainfall. These hotspots contain large numbers of endemic and geographically restricted taxa. Hotspots with particularly high bee diversity include the Fynbos, Succulent Karoo and Desert biomes; the latter showing 6–20 times more species per unit area than other biomes. Our results conform with global species-area patterns: areas of higher-than-expected bee density are largely concentrated in Mediterranean and arid habitats.
4 This study further enhances our knowledge in identifying regional and global hotspots of richness and endemism for a keystone group of insects and enabling these to be accounted for when setting conservation priorities.

South African bee richness hotspots at a ~11 × 11 km grid cell resolution

Richness and endemism by Biome:
Biomes Richness (Endemics)
Savanna 712 (215)
Fynbos 698 (233)
Grassland 687 (221)
Succulent Karoo 674 (222)
Nama-Karoo 650 (200)
Albany Thicket 594 (183)
Desert 330 (114)

Relationship between area and the number of bee species - see the paper for details.

Posted on February 9, 2024 11:42 AM by tonyrebelo