Case Study #3 - Land cover classification of Tumkur district using Google Earth Engine
Aim: To identify the highly suitable habitat for Vateria indica L. using ensemble species distribution modelling for conservation purposes.
The Vateria indica, L, is an endemic species to Western ghats. Vateria Indica is widely used in Ayurveda, Siddha, Unani, Folk medicines and it is highly traded species. A slow-growing species, found primarily in the west coast evergreen forests, and also occasionally in secondary evergreen dipterocarp forest in the south. IUCN has categorised this species as Critically Endangered A1cd ver 2.3 (accessed on 24-Mar-2018)
Ensemble Species Distribution Modelling: For ensemble modelling in present climatic conditions we selected Ten modelling techniques Viz., Artificial Neural Networks (ANN), Classification Tree Analysis (CTA), Flexible Discriminant Analysis (FDA), Generalized Additive Models (GAM), Generalized Boosted Models (GBM), Generalized Linear Models (GLM), Multivariate Adaptive Regression Splines (MARS), Random Forests (RF) and Surface Range Envelope (SRE) and Maximum Entropy (MaxEnt) approach using Biomod2 package implemented in R. The final Ensemble SDM obtaining by calculating median of probabilities.
To do ensemble modeling we used following bioclimatic variables.
Bio1 (Annual Mean Temperature)
Bio2 (Mean Diurnal Range)
Bio12 (Annual Precipitation)
Bio14 (Precipitation of Driest Month)
Bio18 (Precipitation of Warmest Quarter)
The Ensemble model was evaluated by receiver operating curve (ROC). The Ensemble model had mean AUC value of 0.992 indicating that model has preformed well. In this study, we found that Bio12, Bio14, and Bio18 are the top three contributors in model building. The ensemble results also showed that there is a large range of highly suitable habitat for Vateria indica is found between 15.113° N to 8.060° N and 73.547° E to 77.577° E (See figure Ensemble Species Distribution model) which is partially protected and the area of PA's should be increased to prevent the species from extinction.