Anthropogenic disturbances alter community structure in the forests of Kashmir Himalaya

Abstract

Both natural and anthropogenic disturbances are key drivers of forest dynamics that alter species composition and diversity, which in turn determine the successional trajectory of the forests. The present study aimed to investigate the community composition, population structure and regeneration status of tree species in relation to anthropogenic disturbances in temperate pure coniferous forests of Kashmir Himalaya. Comparable forest sites with varying degree of disturbance were selected and the regeneration status of the tree species was determined by measuring the population size of seedlings and saplings. The seedling, sapling and tree density were significantly greater in the less disturbed (LD) sites as compared to the highly disturbed sites (HD). Moreover, the LD sites showed highest frequency of lower tree girth classes, resulting in the formation of an inverse J-shaped curve, while as the HD sites showed unimodal distribution with maximum number of individuals in higher girth classes. Such a shift in forest structure from inverse J-shaped to unimodal distribution alters the niche space and facilitates the colonization of non-resident oak species (Quercus baloot, Q. incana), which otherwise are component of relatively low-altitude mixed temperate forests of the region. The results of the present study provide baseline ecological indicators in characterizing and quantifying the human-driven changes in forest composition and structure; and can help in developing scientifically-informed policy tools for the effective management and ecological restoration of human-modified forest landscapes in this Himalayan region.