Dynamics of plant bioresources in Western Himalayan region of India - watershed based study.
The dynamics of plant bioresources including agriculture is different in the hills from those in the plains. The agriculture and forestry are the two major land use types and play an important role in providing food and livelihood security. The structure of vegetation for trees and shrubs layer was moderately instable and uneven as few species such as Acacia catechu, Lantana camara, Carissa spinarium in Mandhala; Quercus leucotrichophora, Pinus roxburghii, Myrsine africana in Moolbari, and Salix denticulata, Pinus wattichiana and Picea smithiana in Megad dominated the vegetation. Species richness was high at lower altitudes and low as we go higher. The distribution of species was mainly contiguous, however, few species showed random and regular distribution. Agricultural patterns have changed from traditional and subsistence to modern, which are primarily monoculture of high-valued cash crops. This has enhanced farm incomes but at the same time led to severe genetic erosion of traditional crops and varieties. Several development factors coupled with emerging climate change like erratic rain and snowfall patterns, flash floods, depletion of top soil and groundwater, destruction of natural habitat, wildlife menace, infestation of land through invasive alien weeds, low productivity, abandonment of agricultural lands have emerged as serious threats to the dynamics of hill agro-ecosystems.