Project: Identifying the areas for grassland restoration and invasive tree species mapping using hyperspatial and spectral satellite data in the Palani, Anaimalai and Nilgiri hills.
Description: Tropical montane grasslands, including shola grasslands of the Western Ghats have been lost to exotic trees invasion at a rapid pace. The shola grasslands are extremely important because many endemic and endangered species exist here. Also, these shola grasslands support downstream ecosystems as most of the south Indian rivers originate in this habitat. These habitats are thus significant for water security. In the nineteenth century a number of invasive exotic trees were established in the montane grasslands. Since then, although planting stopped, invasion from exotic trees is rapidly moving into protected areas - the last remaining montane grassland patches. Our previous research (Arasumani et al. 2018, Arasumani et al. 2019) employing NASA Landsat satellite imageries, demonstrated that 23% (340 Km2) of the montane grasslands were lost to the exotic trees within five decades. This shola grassland loss reduced the population of endangered and endemic species of the Western Ghats, especially Nilgiri Pipit, Nilgiri Thar, and probably several frog species. Now, we primarily need to conserve the last remaining montane grasslands of the Western Ghats; but for that, there is a need to distinguish the specific type of exotic tree species to establish the direction of the invasive fronts moving into the montane grasslands. The state High Court of Tamil Nadu has an open Public Interest Litigation case directing the Forest Department to cut back exotic trees and restore native habitats. Conservationists suggest that the most urgent conservation action should include containing the invasion front, securing existing grasslands. Given the large-scale fragmentation of grasslands and the multiple-invasion fronts, conservation managers lack spatial information of areas with young invasion-front to prioritize action. This project will create maps of different exotic species types and areas for grassland restoration.
Some parts of this project are at different stages of completion
Study site: Palani, Anaimalai and Nilgiri hills.
Funding: National Geographic Society, IISER Tirupati, MoEF.
* Arasumani M., Danish Khan, C.K. Vishnudas, M. Muthukumar, Milind Bunyan*, V.V. Robin*. 2019. Invasion compounds and ecosystem-wide loss to afforestation in the tropical grasslands of the Shola Sky Island. Biological Conservation. 230 (2019) 141-150. 10.1016/j.biocon. 2018.12.019. *Equal authors.
* Arasumani M., Danish Khan, Arundhati Das, Ian Lockwood, Robert Stewart, Ravi A Kiran, M. Muthukumar, Milind Bunyan*, V.V. Robin*. 2018. Not seeing the grass for the trees: Timber plantations and agriculture shrink tropical montane grassland by two-thirds over four decades in the Palani Hills, a Western Ghats Sky Island. PLoS ONE 10.1371/journal.pone.0190003