29 - Assessing linkages between land use and biodiversity: A case study from the Eastern Himalayas using low-cost, high-return survey technology

Summary

To assess the impacts of global change and to sustainably manage biodiversity requires access to baseline data that can be used effectively by planners and resource managers. Too often, the high cost and severe logistical constraints associated with traditional methods of natural resource surveys limit the availability of such data. To address this problem, we present an alternative, low-cost, high-return, and readily transferable methodology that utilizes both ground-based and remotely sensed data. We illustrate this approach using results from an initial biodiversity baseline study of a proposed strategic conservation ‘hotspot’: the North Bank Landscape (NBL) of the Brahmaputra River in the eastern Himalayan foothills, which includes parts of Assam, Arunachal Pradesh, North Bengal, and Bhutan. The NBL contains significant populations of Asian elephants, tigers, clouded leopards, golden langurs, and other rare and endangered fauna. Following a brief training course in survey methodology, 14 trainees conducted a gradient-based (gradsect) survey of vascular plant species, plant functional types (PFTs), vegetation structure, site physical features, and mammalian habitat along a georeferenced land-use intensity gradient within the NBL. We found that plant species and PFT diversity were highly correlated with vegetation structure, which was, in turn, closely associated with mammalian habitat. This correlation provided a set of indicators for assessing and forecasting the impact of land use on both plant and animal biodiversity. The value of these indicators was further reinforced though their highly significant correlation with satellite imagery, which enhanced their potential for mapping habitat on a regional as well as local scale. Spatial modelling of the gradient-based survey locations revealed a high level of regional environmental representativeness. Our results from the field survey in India show that, compared with similarly sampled forested landscapes recorded so far in 20 countries, the NBL is second to the world’s richest hotspot (Sumatra) in plant species diversity and comparable in PFT diversity and Plant Functional Complexity (PFC). While the results satisfy key criteria for listing the NBL as a global hotspot, the generic, low-cost methodology has wider implications for assessing the impact of global change on biodiversity.