ATREE’s research in the ASSAR consortium is situated in the semi-arid part of the Moyar and Bhavani rivers located upstream of the Bhavanisagar Reservoir. The Moyar-Bhavanisub-region lies in the central and south central regions of Tamil Nadu, which are predominantly arid plains and receive relatively lower rainfall than the eastern and northern parts of the state. Annual rainfall varies from 500-700 mm, but rainfall in the contributing catchment can be as high as 3000 mm annually.

Along with diverse wildlife and physiographic features, the landscape has very high human density and a long history of human use.This area has diverse indigenous tribal communities such as the Kurumbas, Sholigas and Irulas as well a large population of scheduled castes. These communities often live in or on the boundaries of protected areas and depend on non-timber forest produce (NTFP)to supplement agricultural incomes.Other major livelihood activities include agriculture (especially on the western part) and pastoralism with communitiesliving adjacent to the BhavanisagarReservoir practicing fishing also.

Understanding trends in semi-arid ecosystems
Forested and natural ecosystems in the semi-arid Moyar-Bhavani sub-region consist of a mixture of sub-tropical hill forests along the hill slopes, riparian forests along the Moyar River and savanna and dry thorn forests in the valley.Research within these natural ecosystems will focus on understanding the impacts of climate change and climate variability on vegetative cover and productivity. This area is also threatened by invasive species including Prosopis and Lantana, which have proliferated recently. We intend to document the spread of these invasives to understand characteristics of invaded habitat, and predict areas of future invasion. Non-timber forest produce (NTFP) often forms a significant portion of the income generated by communities living in these ecosystems. Our research will investigate trends in these species and their response to climatic stressors and other disturbances (e.g. fire and invasive species).

Agriculturein the Moyar-Bhavani
Major crops grown in the Moyar-Bhavanisub-region include cholam(sorghum) and sugarcane (in Coimbatore), finger millet, maize and sesame (in Erode); with cropping intensity reported to be as high as 105%. The BhavaniBasin is primarily irrigated by the canal irrigation systems, which are maintained by government-financed watershed development programs. Despite the higher productivity associated with irrigation sourced from tank systems, the area under tank irrigation is currently lower than those irrigated by canals. Further, a considerable reduction in crop area, yield, and agricultural income in the Bhavani basin due to water scarcity has been reported.Agriculture in the Moyar basin is primarily semi-arid (rainfed) in nature and is characterized by low productivity and high risk due to the low amounts of rainfall and small land holdings. More recently however, there has been a recent shift to water-intensive crops that depend heavily on groundwater resources.

Livestock and fisheries in the Moyar-Bhavani
As with other semi-arid regions, livestock and allied sectors are crucial sources of livelihood in the Moyar-Bhavani and serve as an important risk spreading mechanism, often by buffering agricultural losses.Nevertheless, changing patterns of vegetation in common property pastoralist lands and reducing water resources, pose an imminent risk to pastoralism. Climate change is also likely to increase heat stress and disease susceptibility particularly among non-indigenous cattle breeds. The Bhavanisagar Reservoir within the Moyar-Bhavaniprovides livelihood opportunities to fishing communities in the region. These communities hold traditional rights for fishing in the reservoir granted to them by the Fisheries Department. However, fluctuating market dynamics, pollution in the reservoir and uncertain impacts of climate change on fish stock threaten the livelihood of these communities.