Low elevation riparian forests found within the Middle Hills of Nepal are both essential biological habitats and important resources for local subsistence farmers. Forming networks of habitat patches within the primarily agricultural matrix of the Middle Hills, these forests are repositories of a rich biological diversity. Dynamics of forest change along riparian corridors were investigated within the newly established Makalu Barun National Park and Conservation Area (MBCA) of eastern Nepal, based on a comparison of remote sensing data over a 20-year interval. Multispectral analysis and a supervised classification of Landsat TM (1992) and Landsat MSS (1972) data estimate approximately 7000 ha of low elevation riparian forests within the study area. Change detection analysis estimates based on the respective supervised classifications reveal little significant change in extent of the tropical and subtropical zone riparian forests. More impact was evident toward the upper elevational limits of the study area. A 4% (approximately 300 ha) loss of cover within areas previously designated as forest is estimated. For all areas in the study area, a net loss of forest of 11% is estimated. Land use is shown to be highly dynamic, with significant internal trading between land use classes. The important role of riparian corridors in biodiversity conservation within the Middle Hills of east Nepal is discussed. Further research on biodiversity within these patches and a specific recognition of the value of remnant riparian forests within the landscape and rural economy are required if conservation goals for the eastern Nepal Himalaya are to be met.
