Upper forest line change in the Nepal Himalayas

Keywords: Climate Change, Forest Line, Landcover, Nepal Himalayas
Session Type: Virtual Paper Abstract
Day: Friday
Session Start / End Time: 2/25/2022 11:20 AM (Eastern Time (US & Canada)) - 2/25/2022 12:40 PM (Eastern Time (US & Canada))
Room: Virtual 2

Abstract

The upper forest line represents the high elevational limit of closed-canopy forest. Natural forest lines are climate-sensitive, and studies have documented higher elevational shifts of forest lines in some regions as temperature increases due to climate change. However, many areas with insufficient studies still need more data for accurate confirmations. This study selected Nepal’s five protected areas – Makalu Barun National Park, Langtang National Park, Annapurna Conservation Area, Dhorpatan Hunting Reserve, and Api Nampa Conservation Area to map and track forest lines change in the recent decades. We used Landsat-based landcover maps, Google Earth images, and Digital Elevation Model (DEM) to identify historical and current forest lines. We generated slope, aspect, and Topographic Position Index (TPI) from DEM to understand the association with the upper forest line. The upper limit of the forest line ranges from 3500 to 4200 m, and the forest line elevation of eastern Nepal is generally higher than western Nepal. Topographic variables such as slope and aspect and anthropogenic activities such as proximity to settlements and grazing areas are the major controlling factors of the spatial pattern of the upper forest line. The findings can contribute towards future forest line monitoring in response to climate change, track the rate of shift, and identify the future forest expansion sites.