The relationship between vegetation, plant functional diversity and environment on rock outcrops in the Western Ghats, India

Abstract

Background: Rock outcrops support specialist plant communities that are often adapted to highly seasonal climates and heterogeneous soil cover. However, the relationship between environmental parameters and plant functional types remains unexplored in many regions of the world, including the Northern Western Ghats (NWG) in India. Aims: In the present work, we characterised the vegetation of high and low elevation rock outcrops in the NWG, and investigate the relationship between plant functional types and environmental variables. Methods: Vegetation surveys were conducted on 16 high elevation and 14 low elevation sites using a transect and quadrat method. Floristic data were used to calculate plant diversity and plant functional type abundance. The relationship between vegetation and climatic (temperature, precipitation) and soil (soil carbon and nitrogen) variables was explored using cluster and ordination analysis. Results: Rock outcrop sites were grouped into two clusters based on elevation, distance from the sea and mean diurnal range. Plant functional type abundance was related to macro-environmental variables such as temperature, precipitation and soil nutrients such as carbon and nitrogen. Conclusions: We inferred that the distribution and dominance of different plant functional types in the NWG are related to primarily by elevation (a proxy for temperature) and distance from the sea.