Climate change and land use in Sagarmatha National Park, Nepal
The goal of our work in the Himalayas is to document changes in high mountain ecosystems as they respond to the integrated effects of multiple stressors, including human land use decisions and climate variability and change. We work to identify and analyze patterns of land use and land cover change through time within the Everest region of the Central Himalayas and to determine how management systems and anthropogenic activities are affecting conservation efforts in these protected areas and the livelihood systems at their fringes.
We use satellite imagery to calculate vegetation indices and land cover trajectories for different vegetation covers in stratified elevation zones. To date we have collected over 850 ground reference data points. Opportunistic and systematic field interviews are also conducted by our Nepali colleagues to elicit people’s perception on causes and consequences of land cover changes as well.
The total acreage classified as Forest declined by approximately ten percent over the past 40 years. However, this figure masks the true rate of forest loss because of the spatial pattern - in the lower elevations where humans can easily access timber, there is a near total loss of forest cover and a large increase in grass cover, but in higher, more remote locations, there is an increase in vegetative productivity as the climate warms and growing season lengthens. The pattern of disturbance is most pronounced in the valleys with easiest access and thus highest human usage. However, in the high elevations, there is a large increase in area classified as forest or woodland as trees move into former shrub/grasslands and as grass moves into former glaciated lands.
While our findings are largely preliminary and our interdisciplinary work in the region is ongoing, we can surmise that social factors including political conflict, the difficulty to enforce park management strategies, increasing tourist demand, and consequent natural resources exploitation contribute to explaining some of the changes and conversions in forested area. It appears that proximal and distal human-induced changes might be overwhelming any potentially beneficial climate change impacts on growing conditions or the length of the growing season and subsequent high elevation regreening. The ACSP will continue working in these harsh but beautiful environments and we welcome collaborators from varied disciplines as this work requires a healthy dose of interdisciplinarity in addition to land change scientists.