Vegetation dynamics of several little disturbed temperate forests in east Central Nepal

This study analyzes seven little disturbed stands of temperate forest located at Bakum Ghyang monastery, 40 km north-northeast of Kathmandu, in northern Sindhu Palchok District, Nepal. The stands were 1,200 m(2) in area, located on homogeneous sites of a west-facing slope between 2,400 and 2,900 m. Elevation, aspect, slope angle, and topographic position were measured at each plot. The diameters and heights of all trees and saplings in the plots were measured, identified to species, and evaluated for cutting or lopping. Small seedlings were counted in ten randomly located subplots. Stands were ordinated with Detrended Correspondence Analysis and axes correlated with environmental variables. Three of the stands, on lower elevation or more mesic sites, were dominated by Quercus oxyodon and four by Tsuga dumosa. The more remote stands had small amounts of fodder lopping and livestock browsing. The first and second ordination axes correlated highly with elevation and aspect, respectively. Mesic Q. oxyodon stands had Q. lamellosa and several species of the Lauraceae. Q. semecarpifolia and Rhododendron arboreum were second and third most important species on Tsuga dominated southwest-facing stands. In the highest stand Abies spectabilis was almost as important as Tsuga. The only major canopy dominant which seemed to be regenerating sufficiently to maintain its population structure was Tsuga dumosa. In view of the poor Quercus regeneration in the areas with little human activity, I hypothesize that Quercus species are unable to reproduce in individual treefall gaps, but need more severe disturbances, probably from intense ground fires and mass wasting.