Tropical Plant Research

C. M. Sharma, Ashish K. Mishra*, Om Prakash, Suchita Dimri and Pratibha Baluni

Abstract:
Mechanism to maintain species coexistence in ridge top due to drastic climatic variation could be assessed by their forest structure and composition studies. Variations in forest composition, structure and their regeneration status are described here for four different ridge top sites of the Garhwal Himalaya. A total of 2439 individuals were recorded in the study area which belonged to 17 tree species in 16 genus and 9 families. The most abundant family was Pinaceae whereas Ericaceae and Rosaceae were found as co-dominant families. Simpson dominance value was highest on Sukhee top (0.84), moderate in Harshil (0.76) whereas lowest in Raithal (0.65). The total stem density was highest (710 stems ha^-1) at the Harshil and lowest (552 stems ha^-1) at the Sukhee top, and for total basal cover, the highest value (92.07 m².ha^-1) was recorded in Dharali whereas the lowest value (75.18 m².ha^-1) was found at Harshil ridge top. Importance Value Index showed that Abies spectabilis, Betula utilis, Cedrus deodara,Pinus wallichiana, Acer caesium and Quercus semecarpifolia are the dominant species of the ridge tops. Taxus baccata, Acer acuminatum, Aesculus indica, Juglans regia, Ilex dipyrena and Sorbus cuspidata were reported with poor regeneration status. The study seeks to understand the current forest composition of the ridge top but also may be helpful in predicting their adaptation to the climatic changes.