Low-altitude mountains are important centres of diversity in landscapes with little topographic variation. Topographic variables and biotic factors (soil depth and vegetation) were important in predicting current distributions of Ornduffia calthifolia and O. marchantii in the low-altitude Porongorup Range region of the Southwest Australian Floristic Region biodiversity hotspot.
Keppel et al. deduce from species distribution modelling approaches that both species are likely to severely contract under a milder RCP2.6 climatic projection (2 °C of warming), but are unlikely to persist if warming is more severe (RCP4.5). The Porongurup mountain range constitutes an important refugium for O. calthifolia and O. marchantii, but this valuable and protective site of endemic richness may be severely threatened if global warming exceeds 2 °C.
This article is part of the AoB Special Issue on Endemism Hotspots as Climate Change Refugia, which is free access for a couple of months, then behind the paywall for a while before being free access after February 2017.
Keppel, G., Robinson, T. P., Wardell-Johnson, G. W., Yates, C. J., Van Niel, K. P., Byrne, M., & Schut, A. G. T. (2016). A low-altitude mountain range as an important refugium for two narrow endemics in the Southwest Australian Floristic Region biodiversity hotspot. Annals of Botany, 119(2), 289–300. https://doi.org/10.1093/aob/mcw182