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.

Land use and climate change impacts on distribution of plant species of conservation value in Eastern Ghats, India: a simulation study.

Effective monitoring of the current status of species distributions and predicting future distributions are very important for conservation practices at the ecosystem and species levels. The human population, land use, and climate are important factors that influence the distributions of species. Even though future simulations have many uncertainties, such studies can provide a means of obtaining species distributions, range shifts, and food production and help mitigation and adaptation planning. Here, we simulate the population, land use/land cover and species distributions in the Eastern Ghats, India. A MaxEnt species distribution model was used to simulate the potential habitats of a group of endemic (28 species found in this region) and rare, endangered, and threatened (RET) (22 species found in this region) plant species on the basis of IPCC AR5 scenarios developed for 2050 and 2070. Simulations of populations in 2050 indicate that they will increase at a rate of 1.12% relative to the base year, 2011. These increases in population create a demand for more land for settlement and food productions. Land use land cover (LULC) simulations show an increase in built-up land from 3665.00 km2 in 2015 to 3989.56 km2 by 2050. There is a minor increase of 0.04% in the area under agriculture in 2050 compared with 2015. On the other hand, the habitat simulations show that the combined effects of climate and land use change have a greater influence on the decline of potential distributions of species. Climate change and the prevailing rate of LULC change will reduce the extents of the habitats of endemic and RET species (~ 60% and ~ 40%, respectively). The Eastern Ghats have become extensively fragmented due to human activities and have become a hotspot of endemic and RET species loss. Climate and LULC change will enhance the species loss and ecosystem services.

Dynamics and determinants of land change in India: integrating satellite data with village socioeconomics.

We examine the dynamics and spatial determinants of land change in India by integrating decadal land cover maps (1985-1995-2005) from a wall-to-wall analysis of Landsat images with spatiotemporal socioeconomic database for ~630,000 villages in India. We reinforce our results through collective evidence from synthesis of 102 case studies that incorporate field knowledge of the causes of land change in India. We focus on cropland-fallow land conversions, and forest area changes (excludes non-forest tree categories including commercial plantations). We show that cropland to fallow conversions are prominently associated with lack of irrigation and capital, male agricultural labor shortage, and fragmentation of land holdings. We find gross forest loss is substantial and increased from ~23,810 km2 (1985-1995) to ~25,770 km2 (1995-2005). The gross forest gain also increased from ~6000 km2 (1985-1995) to ~7440 km2 (1995-2005). Overall, India experienced a net decline in forest by ~18,000 km2 (gross loss-gross gain) consistently during both decades. We show that the major source of forest loss was cropland expansion in areas of low cropland productivity (due to soil degradation and lack of irrigation), followed by industrial development and mining/quarrying activities, and excessive economic dependence of villages on forest resources.