Seed maturation timing in Quercus leucotrichophora A. camus along an altitudinal gradient in Uttarakhand Himalaya

Abstract

Quercus leucotrichophora A. Camus is a dominant forest forming species in Central Himalayan region between 1600 and 2100 m elevation. The species is under severe anthropogenic pressure and failing to regenerate in its natural environment. Climatic irregularities may further aggravate the problem as acorn ripening time may shift. Acorns of Q. leucotrichophora were collected from three sites located along the altitudinal limits of the species to determine the acorn maturation time. Across the sites the mean weight of acorns between the first and final collection ranged from 9.3±2.2 gm to 21.6±2.1. Inspite of variation in moisture content initial germination commenced at the same time across the sites. Maximum acorn germination was between 56.7±1.2 and 59.6±0.6. The mean acorn size was larger at the lower elevation site than higher elevation site across the collection dates. The change in acorn colour from green to dark brown, the removal of acorns cap with ease and acorn moisture content between 36.4±0.8 – 37.6±1.2 at the time of maximum germination appear to be reliable indication of maturity. Comparison with an earlier study indicates that acorns are now maturing earlier which can be severely affects its regeneration potential.