Characterizing fragmentation trends of the Himalayan forests in the Kumaon region of Uttarakhand, India

- Forests in the central Himalayan regions are rapidly transforming
- We identified regions of forest loss and deforestation over the time span of 25 years using Landsat archive
- We quantified anthropogenic and natural components of forest fragmentation in the central Himalayan region
- The results showed distinguishing underlying mechanisms that trigger forest fragmentation at different altitudes
- Our results offer great potential in developing land management plans and forest conservation policies

Forest fragmentation is a major conservation issue, which includes interdependent components of forest loss and changes in their spatial patterns. Over the years, the Himalayan forests have experienced major changes, but data and documentation on patterns and causes of forest fragmentation are limited. In this study, we analyzed temporal changes (1990-2014) of forest loss and fragmentation using Landsat imageries in the Kumaon division of Uttarakhand state, India. To assess mechanisms causing forest fragmentation, we investigated changes in following quantitative parameters describing forest fragmentation: (i) forest area density (Pf), (ii) overall forest connectivity (Pff), (iii) anthropogenic fragmentation (Pfa), and (iv) natural fragmentation (Pfn). We found that this region is undergoing intensive forest fragmentation, shifting from forest-dominated landscapes to fragmented forests intermixed with agricultural lands and urban settlements. Overall, intact forest patches decreased between 1990 and 2009 (1442 km2), followed by a small gain from 2009 to 2014 (260 km2). In lower altitudes, anthropogenic activities caused fragmentation; while in higher altitudes, fragmentation can be attributed to natural causes. All districts within the region show a decreasing trend of forest cover area, with the highest rate of forest cover loss for the low-lying district of Udham Singh Nagar and the lowest rate for the high-lying district of Bageshwar. This trend can be associated with increasing population density in low-lying districts than high-lying districts. Our results emphasize on delineating spatial trends of forest loss and fragmentation to support the identification of conservation sites. The findings can further help in developing forest policies for maintaining local livelihood options in the Himalayan region.

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