Inselberg, taxa, environment data for Inselberg floristics exemplify coast to inland OCBIL transition in a global diversity hotspot



We examined floristics of granitoid inselbergs in the hitherto poorly documented southeastern region of the Southwest Australian Floristic Region (SWAFR) and adjacent Great Western Woodlands, addressing several hypotheses of OCBIL theory. We found exceptional taxon richness (1,550 taxa on 89 inselbergs, with 58 well-sampled inselbergs and 1493 taxa chosen for detailed analyses). Granite inselberg endemism declines towards the arid inland, though taxon richness does not. OCBILs are likely found up to 500 km inland, not ca. 300 km as previously hypothesized. Hybrids are extremely rare on the 58 inselbergs analysed, whereas rare species, including singletons, are abundant. Conversely, exotic weeds are less common than in the whole SWAFR flora (8.2% vs 12.8%). Granite plant communities are distributed in parallel bands to the south coast, approximating the general transition from the Esperance and Boylya Floristic Districts across the SWAFR boundary north into the Arid Zone’s Great Western Woodlands. Positive correlations exist between several plant life forms and inselberg area, save for geophytes. There is a decrease from the coast inland for most life forms, except for annual and graminoid herbs that increase in taxa inland. Thus, inselberg floristics exemplify the coast-to-inland OCBIL transition in this global biodiversity hotspot.,Random stratified walks on inselbergs collecting every plant species encountered from sheet granite, herbfields, shrublands, woodlands and forests, gnammas (rock pools), seeps, adjacent salt lakes or freshwater pools, shaded rock ledges, crevices, boulders. Assembled into taxon lists x inselberg.
Date made available9 Oct 2020

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