Structure and Composition of Vegetation and Status of Invasion in Different Forest Types of Western Himalaya

Abstract

Present study deals with qualitative and quantitative assessment of vegetation in four most dominated forest types of western Himalaya, Sal (Shorea robusta) forest, Chir-Pine (Pinus roxburghii) forest, Banj-oak (Quercus leucotrichophora), and Deodar forest (Cedrus deodara) between 600 to 2100 m asl elevation. These forests serve the lifeline for local communities for their daily sustenance. A total of 336 species belonging to 277 genera and 98 families were recoded from study area. Total basal cover (TBC) ranged between 24.05 to 35.15 m² ha^-1, Tree density ranged from 472 to 1068, shrub’s density varied between 1930 to 4080 whereas herbs ranged from 53600 to 80008 individual per hectare. Maximum tree density was recorded (1068 ind. ha^-1) at the oak stand and minimum (472 ind. ha^-1) recorded at the Sal forest. Species richness, Shannon-Wiener diversity index and TBC increase from Sal to oak forest. It was observed that temperate oak forests in study area comprised higher diversity and species richness at tree, shrub and herb layer, Sal forest depicted higher regeneration. Major invasive species in study area were Lantana camara, Ageratina adenophora, Ageratum conyzoides and Parthenium hysterophorous. In present study, Ageratina adenophora recorded an elevation of about 2100m asl, which is the alarming sign for local biodiversity and may cause a serious threat to Himalayan biodiversity.