Abstract

The present study was conducted at two different ecosystems that is, 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 whereas forest site is located inside the National Park and is protected. The study was done on seasonal basis and the average results revealed comparatively more or equal values of diversity (H′) for both sites (site I = 2.435 and site II = 2.395) while dominance index showed higher value at site I (average = 0.147). The richness index (average = 3.842) and equability index (average = 0.90) both showed higher value at site II. Seasonal trend of Shannon diversity (site I = 3.03, site II = 2.87), richness index (site I = 3.70, site II = 5.83) and evenness or equability index (0.94, site I and II) depicted highest value during summer season whereas lowest variation in Shannon diversity and richness index was observed in winter season at both sites. However, dominance index was recorded lowest in summer season at both sites (site I = 0.06 and site II = 0.07) hence inversely related to diversity (H′). The frequently occurred dominant species during prominent seasons based on importance value (IV) wereCynodon dactylon, Salvia moorcroftiana and Thymus serphyllum at site I and Fragaria nubicola, Galinsoga parviflora, Stipa sibirica and Viola indica at site II. The abundance to frequency ratio (A/F) indicated most of the species performed contagious pattern of distribution.

Key words: Biodiversity, community structure, seasons, species, grazing.