Emerging ecological and environmental hazards in the Himalayas

The Himalayas are at the forefront of hazards related to climate change as well as other global change drivers such as land-use and land-cover change including complex interactions between diverse drivers.

Scientists, civil society organizations and local communities have identified key issues related to how specific Himalayan ecosystems are responding to these drivers including episodes of greening and browning of vegetation as well spread of Pine and the retreat of Oak forests, higher incidence of forest fire due to changes in winter rainfall and summer heat.

Using evidence from multi-decadal time-series of remotely sensed data on state of vegetation combined with climate data and measurements and observations from instrumented catchments we now have insights on the greening and browning of vegetation at larger scales and the comparative ecohydrological response of Pine and Oak dominated catchments at finer scales.   The Himalayas show elevation specific patterns of greening and browning trends that differ across the Himalayas from west to east.  Pine dominated catchments seem to have lower levels and temporally homogeneous soil moisture profiles as well as higher evapotranspiration and lower discharge regimes compared to Oak dominated catchments.  We discuss the implications of the evidence for biodiversity and ecosystem services under emerging and future climate change.