Salix fragilis L.: Growth and survival of coppices in cold desert environment of the Lahaul Valley, North West Himalaya

Abstract

Willows (Salix fragilis L. And S. alba L.) are important cultivated trees in cold desert environment of the Lahaul valley for meeting fuel wood, fodder, small timber and other resource requirements of the people. Willows are cultivated on terraces of agricultural fields, wastelands, along with water channels (kuhls) and around settlements through traditional shoot-cutting plantation method. However, S. fragilis is more widely cultivated species as compared to S. alba in the Lahaul valley. At the end of Ist years growing season, length of coppices under CBH category of 1-30 cm was recorded maximum at Kuthar (1.25+0.01 m) and lowest at Khoksar (0.85+0.04 m). Similar trend was also recorded for coppice length under all the CBH categories at the end of IInd and IIIrd year’s growth seasons. Thus the longest coppices were at Kuthar village followed by Hinsa, Jahlma and smallest at Khoksar village. Diameter of coppice was also highest at Kuthar (11.34 + 0.53 mm) followed by Hinsa (9.76+0.32 mm), Jahlma (8.28+0.72 mm) and lowest value at Khoksar (7.04+0.13 mm). Emergence of coppices showed direct relationship with increase of the CBH categories of the trunks. The number of coppices during first year were lowest (28.00+2.00) under 1-30 cm CBH category of trunk followed by 30-60 cm (83.00+5.83), 60-90 cm (137.00+12.61) and highest (218.00+13.56) in >90 cm circumference category. Under all the CBH categories survivals of coppices were >80% at the end of IInd year and ~70% at the end of IIIrd year. Emergence of highest number of coppices resulted in lesser numbers of survival in the end of IIIrd year. Willow was found socially best accepted and ecologically suitable species as a source of renewable energy under cold desert environment of the Lahaul valley where a few other tree species survives due to prolong subzero temperature and xeric soil conditions.