Heat affected cone bursting in various provenances of Pinus roxburghii from Garhwal Himalaya

Abstract

All over the world the dominance of pines and fire-returns intervals in the forests are positively correlated. The relation is not simply between pines and the presence of fire, but between tolerance limits of pines and the heat generated through natural fire regimes. The long needle pine maintains a continuous fuel bed across the forest floor, which creates most favourable circumstances for the incidence of wild land fires. The chirpine forests are particularly extending in Himalaya, because the species is fire hardy and inextricably linked with forest fires. In its development from a seedling through sapling and pole sizes over the first 25 years of its life, the Pinus may survive as many as 10 fires [1]. Pines have therefore, specilized, unusual adaptations to a range of high frequency, low-intensity fires, which is responsible for wide distribution of Pinus roxburghii across its native range.