Diversity, spatial distribution and biomass patterns in oak and pine forest community along altitudinal gradient in Paddar range of Kishtwar forest division, northwestern Himalaya

This study explores the phytosociological dynamics of forest vegetation and biomass patterns in selected oak and pine forests of north-western Himalaya spanning an altitudinal range of 1650-2500 meters. The trees density varied between 126 to 214 trees/ha while the density of forest floor vegetation was 214.32 and 126.71/m² in oak and pine forests respectively. Herb species richness was slightly higher (23)in the oak forest compared to the pine forest (19). Asteraceae family dominated oak forest whereas Poaceae dominated pine forest stand representing 7 species at each site. The Shannon-Weiner index (H') was maximum for oak forest (3.79) and concentration of dominance (Cd) and evenness (J') were also maximum for oak forest (0.27) and pine forest (0.90) respectively. Simpson diversity was 0.86 in oak and 0.91 in pine forests. Contagious distribution patterns were observed for most species in both study sites. The forest floor biomass was 497.38 g/m² in oak and 412.79 g/m² in pine stands during the study period (2022-2023) with the rainy season contributing to the maximum biomass whereaswinter season attributed to decrease in biomass at both sites.