Pinus roxburghii (Chir Pine) belonging to family Pinaceae, is native to the tropical forests of Himachal Pradesh which is being commercially tapped for oleoresin in India. Resin industry, which use oleoresin as a raw material is one of the foremost industry thriving on this product and has got an ever increasing importance in our national economy. Keeping in view the value and importance of oleoresin, progeny trial was conducted to evaluate the oleoresin yielding potential of half-sib progenies of Chir Pine. Experiment was laid out in the main campus area of Dr Y.S. Parmar University of Horticulture and Forestry, Nauni, Solan (HP) and data was collected on oleoresin yield at the end of season. The trees of progenies having more than 30 cm dbh were segregated for oleoresin tapping experiment. In total, 22 out of 60 progenies had minimum one tree above 30 cm dbh in at least two replications. Hence, these progenies were selected for oleoresin tapping. The method employed for oleoresin collection was borehole method. The data pertaining to the oleoresin yield from different selected progenies revealed significant differences. The maximum oleoresin yield (625.00g/season) was noticed in Kaldoo-P3 and minimum in Rakni-P8 (130.00 g/season).

In the present study, we examined the species composition of Himalayan Chir Pine forest (Pinus roxburghii Sargent) at different altitudes between 1000-1600m asl, considering three altitudinal gradients viz., A1(Lower altitude: 1000-1200m); A2(Middle altitude: 1200-1400m); A3(Higher altitude: 1400-1600m) in the Western Himalayas. In this study, a total of 50 species were recorded, of which 9 were trees, 15 shrubs, 26 herbs. Herb plant richness (in number) showed a diminishing trend with altitude whereas shrub species remain same for low and mid altitudes with slight drop in high altitudes and the tree species richness remain constant for all the altitudes. Many types of environmental changes (altitudes, slopes, aspect, temperature, precipitation etc.) influence the processes that can both augment or erode diversity. The study suggests that species distribution, presence of the particular species (species composition) and number of species present (species richness) are largely regulated by altitudes and other climatic + topographic factors.

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