CONE MATURATION TIMING AND SEED GERMINATION IN PINUS ROXBURGHII (SERG.) IN THE CENTRAL HIMALAYAN REGION OF UTTARAKHAND, INDIAAmit Mittal, Nandan Singh, Ashish Tewari and Shruti Shah
The Himalayan forests are severally affected by several biotic and abiotic disturbance. These disturbances are affecting the stability of the ecosystem and the recurrent fire and grazing are adversely affecting the regeneration of tree species, seed maturation process which contribute to the establishment of the ideal time to harvest when seeds have a better physiological quality for germination. The study site was located at 29o23/15â N and of 79o30/38â E between 1720 and 1810 msl elevation in the central Himalayan region of Uttarakhand. Germination was carried out in a dual chamber seed germinator for each collection date in laboratory. The tree density of Pinus roxburghii was 295 and 855 ind ha-1. The mean cone size between first and last collection varied from 74.92Â±2.8 and 202.1Â±5.7cm2. The weight of 100 seeds between first and final collection was 8.34Â±0.05 to 12.84Â±0.09g. Maximum germination 81.3Â±1.45% occurred when the seed moisture content was 21.67Â±0.58%. The natural regeneration of this species is good but the fire is the main cause of death of seedlings.