Endemic plants of the Indian peninsular savannas

Biodiversity of tropical grasslands and savannas (tropical grassy biomes;
TGBs) remains poorly documented compared to tropical forests. This is in
part due to the misplaced notion of TGBs being anthropogenic forest
derivatives that support negligible biodiversity and endemism. For the
Indian savannas, the legacy of colonial forestry has led to their
misinterpretation as anthropogenic wastelands of low conservation value.
One key assumption underlying the devaluation of Indian savannas against
Indian forests is the presumed absence of endemic species. Through a
systematic review, we test this assumption by collating data of plants
endemic to the peninsular-Indian savannas and analyse their
spatio-temporal discovery patterns. We found that the Indian savannas
contain 206 endemic plant species, of which 43% were described in the last
two decades. Spatial discovery patterns revealed two species-discovery
hotspots, the eastern edge of the Western Ghats Mountains and the Eastern
Ghats Mountains. Years taken for an endemic plant species to be described
was positively related to latitude and elevation of the type-locality, and
negatively to range size and plant height. Our results of an exponential
rise in the endemic plant discovery run counter to the assumption of
Indian savannas supporting no endemic plants. Our findings have important
implications on future plant discoveries by predicting most endemics
awaiting discovery are likely to be short-statured, range-restricted, and
occupy higher latitudes and elevations. The presence of endemic plants
calls for abandoning the outdated colonial-era view of Indian savannas
being low conservation-value ecosystems and revising conservation policies
to better protect these ancient ecosystems.