Land snail biogeography and endemism in south-eastern Africa: Implications for the Maputaland-Pondoland-Albany biodiversity hotspot

along the coastal belt and the cyclical expansion and contraction of forests over geological time [57, 78–80], contrasting with the more homogeneous savanna in Bushveld province, grass- lands in Highveld province, and the lower Karoo in the southern escarpment subdominion. The refugial role played by the patchy distribution of forests during the Pleistocene climatic cycles with corresponding expansions and retractions [78, 80, 81] are presumed to have shaped the present-day malacofauna of the area (see Fig 4D). The repeated isolation of once linked forest patches may have contributed to rapid diversification and increased narrow endemism Fig 6. Biotic elements of land snails in south-eastern Africa. (a) First two dimensions of the nonmetric multidimensional scaling of the distribution ranges of land snails of south-eastern Africa based on their incidence in pre-defined operational geographic units (Fig 1). Biotic elements found by PRABCLUS are denoted by 1–9; N = noise component. (b) Distribution maps of the nine biotic elements of the land snail fauna of south-eastern Africa. Four different shadings from light to dark indicate the areas where >30%, >45%, >60% and >100% of the species of each element are present. The MPA hotspot boundary is reprinted from Hoffman et al. [26] (public domain). https://doi.org/10.1371/journal.pone.0248040.g006 PLOS ONE Land snail endemism in the Maputaland-Pondoland-Albany biodiversity hotspot PLOS ONE | https://doi.org/10.1371/journal.pone.0248040 March 4, 2021 14 / 26