Pinus patula Schl. and Cham.-its Problems and Prospects in West Bengal

Acclaimed as a reliable species for high production Pinus patula has been widely planted in its native country, Mexico and also, in Soulh Afriqa, Rhodesia, Tansania, Kemfa, Malawi, Uganda, Malagasy etc. In India too, the species has of late, come into prominence and several states have adopted it for large scale plantation. Pinus patula is a native of Mexico where it grows on a wide range of sites in the southern region. In this region, three thermal zones can be clearly defined, viz. (a) temperate colder, (b) temperate warmer and subtropical-determined by altitude within the limits 19°21° north latitudes. Good growth of the species is however restricted to certain typical moist tracts. It is abundant in the warmer and colder temperate zone where dense and pure stand naturally occur at elevations ranging from about 1500 to 3000 with an annual rainfall of 700 to 2000 mm and frequent mists. The crop is superior in quality in the valleys and on the flats with deep, moist, well drained loamy solis. It is diluted with several associates of Pines in the marginal areas and on the poor, gravely and shallow solis with a lower rainfall and on the edge of escarpment it is usually replaced mainiy by P. teocote and Oak scrubs. Pinus patula often grows into a denseiy packed crop-about 1500 to 2500 stems can occur on a he ctare of land at the middle ages i.e. 30-40 years. On good sites, the trees show rapid growth in the early stages and in certain areas the species can attain a diameter of 25 cm at about 10 years. This extraordinary growth rate accounted for extensive trial plantations of P. patul in different parts of the world. The Silvicultural characteristic of P. patula should not vary fundamentally from those growing in its native habitat, and it should not be difficult to select suitable sites in this country.