Threat evaluation for biodiversity conservation of forest ecosystems using geospatial techniques: a case study of Odisha, India.
Up-scaling the evaluation of threat status of biodiversity from species to ecosystem level has remained for long a research challenge in global conservation science. To meet this challenge, the present study makes an attempt toward actionable conservation prescription and assigning a threat category scheme for forest ecosystems. The scheme sets the quantitative criteria for evaluation of cumulative anthropogenic threats in grid cells, such as deforestation, degradation, fragmentation, forest fires and biological invasions. Adopting the convention of IUCN, five conservation status categories (i.e. Critically Endangered, Endangered, Vulnerable, Near Threatened, Least Concern) have been similarly adopted for the forest ecosystems facing these threats. The operational success of this scheme of threat categories at ecosystem level has been strengthened by remote sensing and field data generated for the forest ecosystems of Odisha, India. The threat category status of the forest ecosystems were identified by creating grids (5 km × 5 km) in GIS and assigned the degree of the threats for each grid. The database on deforestation was generated using topographical maps of 1935 and remote sensing data of 1975 and 2010. The degradation in forest ecosystems have been assessed based on the change in forest canopy closure, fragmentation pattern, forest fire distribution and impact of biological invasions. The analysis for conservation priority hotspots complements an assessment of the threatened ecosystems undergoing remarkable level of multiple threats. Areas under the danger of cumulative anthropogenic threats would have a higher priority. 5.8% grids of existing forest had included under the category of conservation priority hotspot-I, followed by 12.4% in conservation priority hotspot-II, and 12.5% in conservation priority hotspot-III. An integrated approach involving the cumulative anthropogenic threat indicators have been found to be the most appropriate tool to empirically evaluate the threat status of the forest ecosystems. Finally, identification of ecosystems especially those facing increasing extinction risks, as attempted in the present study, can help in devising an appropriate policy and management agenda for the conservation and sustainable use of biodiversity.