Spatial Interpolation of Carbon Stock: A Case Study from the Western Ghats Biodiversity Hotspot, India

Background

This study in the Anamalai Hills of the Western Ghats estimates the biomass and carbon stock of major tropical forest types in India and attempts to identify suitable interpolation techniques to map carbon stock.

Research Goals & Methods

During 2005–2006, circular plots of 10-m radius were laid every 200 m along transects stratified by vegetation type and all woody plants with ≥ 10 cm DBH were identified to species level and measured. Biomass was calculated using allometric equations developed specifically for use in evergreen and deciduous forests of the Western Ghats. Nine different land-cover classes were identified using fieldwork and images from Indian Remote Sensing Satellite P6 LISS III and forest area statistics were derived from supervised classification. Vegetation and landcover type mapping using the IRS P6 LISS III data showed the area is dominated by deciduous forest (487.6 km2) and evergreen forest (230.2 km2).

Conclusions & Takeaways

The average values of the carbon stock in the whole of Anamalai Wildlife Sanctuary was 84 t/ha. Evergreen forest had a high amount of biomass (236.8 t/ha) whereas thorny scrub had a low biomass (32.23 t/ha). Total carbon stock across all forest types was 6.44 Mt of carbon. The authors found Kriging to be the best method for spatial interpolation of carbon stock, in comparison with IDW and polynomial using parameters derived from semivariograms.