GUPTA, N.K.SANYAM2017-01-042017-01-04201247850http://krishikosh.egranth.ac.in/handle/1/94317ABSTRACT The present investigation entitled, “Studies on biomass partitioning and soil enrichment in plantations of different tree species under mid hill conditions of Himachal Pradesh” was carried out during the year 2011-2012 at five sites under five species viz. Quercus leucotrichophora, Pinus roxburghii, Eucalyptus tereticornis, Melia azedarach and Ulmus villosa with 5cm interval in four diameter classes (5 to10cm to >20cm), raised by the department of Silviculture and Agroforestry, Dr. Y. S. Parmar University of Horticulture and Forestry, Nauni(Solan), Himachal Pradesh. The various observations regarding different growth parameters, standing volume, green and dry biomass were taken from the randomly selected trees (30% of the total population). The different tree growth parameters increased with increase in diameter in all the species. The data on various growth parameters were used for variability analysis and correlation study. Among crown characters, crown area, crown width, crown height and crown length showed significant differences within four diameter classes in all the species. All the tree parameters showed statistically significant variation except diameter at breast height and collar diameter for all the species. Stem volume of sample trees increased with increase in diameter. Stem volume was significantly correlated with all the tree growth parameters and high correlation coefficient was observed between all the tree growth parameters. For estimation of volume, diameter as independent variable remained best estimator using power function while form factor and tree height showed mixed results with power, exponential and polynomial functions. Similar results were obtained in case of estimation of branch (green and dry) biomass with branch length and branch diameter where power, exponential and polynomial functions gave the maximum value of adjusted R2. Studies on biomass partitioning were also done to find out contribution of different plant parts (stem, branch+twig, leaves) towards total biomass and their per cent contribution was also calculated. Melia azedarach was having maximum green as well as dry biomass. Soil parameters generally showed decreasing trend with increase in depth except exchangeable calcium and magnesium. The solar flux and LAI varied with age and species.enThesis