CATKIN MATURATION TIMING AND SEED GERMINATION IN BETULA UTILIS (D. DON) IN THE WESTERN HIMALAYAN TREELINE AREA OF UTTARAKHAND

Abstract

B. utilis is the only broad leaved angiosperm tree species in the Himalayas which dominates an extensive area at subalpine altitudes. Lack of sufficient regeneration is a major problem in B. utilis and has been declared endemic in many states of India. Very few studies on seeds and none on maturity indices of B. utilis have been conducted particularly in the treeline areas on Indian Himalayan region. The aim of the present study was to assess the seed/catkin maturity time and seed germination status of B. utilis in treeline areas. The study site was located at 30°49´22˝N and 79°21´4 7˝E between 3340 and 3560m elevation in the western Himalayan region of Uttarakhand. Physical parameters, catkin size, number of catkin, weight of catkin and mass of catkin were taken and germination was carried out in a dual chamber seed germinator for each collection date in laboratory. The tree density of B. utilis was 100 ind ha-1. The mean catkin size between first and last collection varied from 60.24±0.29 to 114.90±1.62, the change in catkin weight was 13.60 and 11.33 g during the collection period. The mass per 100 catkins during study varied between 16.30±0.74 and 33.27±0.14 g. Maximum germination 25.67±0.67% occurred when the catkin moisture content was 31.60±1.55%. At the treeline areas B. utilis is struggling for survival, growth and regeneration due to harsh climatic conditions and excessive anthropogenic pressure in the form of heavy grazing. The species requires proper conservation and management strategy, so that the seedlings and saplings could survive and replace adult trees in future. The present study is useful for assessing the exact catkin maturation time of the species for future multiplication of the species in nurseries.