On the relationships between plant species richness and the environment: a case study in Eastern Ghats, India

Many places of the earth support high plant species richness, but emphasis is given to biodiversity hotspots with rich endemic species under threats of destruction by anthropogenic interventions. This definitely underplays species conservation at several places significant for optimisation of preserving natural ecosystems. Here we explore influences of climate, physiography and disturbance on plant species richness of the Eastern Ghats. We focus on the implications of water-energy dynamics and climatic heterogeneity on community distribution. Initially, 26-environmental variables were considered for the study, but eight least correlated variables viz., aspect, human appropriation of net primary productivity, global human footprint, mean annual temperature, mean annual precipitation, precipitation of driest quarter, terrain ruggedness index and temperature seasonality were utilised for further analysis. A total of 1670 species from 2274 sampling locations of 22564 records were examined using canonical correspondence analysis (CCA) and decision trees. Water-energy dynamics broadly regulates plant richness, with significant influence of mean annual precipitation and temperature. Precipitation of the driest quarter is the most significant factor in describing plant richness, indicating the availability of water during the dry period is crucial. The rise in temperature is likely to deteriorate further, where temperature seasonality is significant. Temperature seasonality determines thermal variability and assesses the intensity of climate change impacts on plant richness. The study offers ecological insights for successful conservation and management planning for the sustenance of the Eastern Ghats' rich biodiversity.