Session 2D Lectures by Fellows/Associates

The paradox of forest-grassland mosaics: revisiting the ‘one climate-one biome’ paradigm

The ‘one climate-one biome’ paradigm – the idea that each biome occupies a unique area of climate space such that the dominant or ‘climax’ vegetation of a region can be predicted based on local climate alone – has been a cornerstone of traditional ecological thought. However, many ecosystems display ‘bi-stability’ where two different biomes occur under the same climatic conditions. Forest-grassland mosaics, such as the shola-grassland complexes of the Western Ghats, are a classic example of this phenomenon wherein both forest and grassland patches, with abrupt boundaries between the two, co-occur in the landscape. Here, I leverage recent experiments carried out in the montane shola-grassland mosaics of the Nilgiris in the Western Ghats to assess the role of different biotic and abiotic drivers in maintaining these mosaics, and discuss the potential impacts of future climatic changes on the ecological integrity of these unique ecosystems.