Comparative Study of Herbaceous Vegetation in Lower Dachigam National Park, Kashmir Himalaya, India

摘要

The present study was conducted to estimate the variation in herbaceous community features in terms of diversity, species richness and distribution pattern in the two different ecosystems i.e., site I (pastureland) and site II (forest) in the lower Dachigam National Park of Kashmir, Himalaya. The pasture site is located outside the National Park and is under grazing were as forest site is located inside the National Park and is protected. The study was done on seasonal basis and the results revealedhigher trend for diversity (H') at both sites during summer season (site I = 3.03, site II =2.92). However, dominance index was inversely related to diversity index(H') (site I = 0.06 and site II = 0.07). Richness index showed maximum value in spring (4.12, site II) and summer (3.70, site I). Equability or evenness index obtained higher value in summer (0.94, site I) and winter (0.96, site II). Comparatively on an average site II showed higher trend in Shannon diversity (site I = 2.435, site II = 2.655), richness index (site I = 2.652, site II = 3.297) and equability index (site I = 0.852, site II = 0.915). The frequently occurred dominant species during prominent season based on IVI at site I were Cynodon dactylon, Salvia moorcroftiana and Thymus serphyllum at site II were Arthraxon prinoides, Fragaria nubicola, Poa annua, Poa sp. and Viola indica. The abundance to frequency ratio (A/F) indicated most of the species performed contiguous pattern of distribution. A seasonal picture depicted contagious>random distribution pattern while regular distribution was reported almost negligible. The study concluded that seasons have great influence on species diversity. During spring and summer season an increase in species diversity was observed which declined as autumn and winter approached mainly due to dry environmental conditions, slow growth rate and other climatic factors.