干旱区生态环境知识资源中心

In barren land escape of cold desert environment of the Lahaul valley 10 bushy/under tree species of willow are found in wild under moist areas, except, Salix denticulala, which is found on south facing dry hill slopes. Two imported willow tree species (S. fragilis and S. alba) are extensively cultivated in the Lahaul valley through traditional shoot-cuttings plantation method in indigenous agroforestry and forestry systems for fuel wood, fodder and minor timber; both the willows are well established in the cold desert environment. The density of S. fragilis was highest at Jahlma (365 individuals ha(-1)) followed by Hinsa (244 individuals ha(-1)) under agroforestry systems in south facing hill slopes; I these are middle altitude sites in the Lahaul valley. Highest density of willow was at Hinsa (453' individuals ha(-1)) followed by Jahlma (305 individuals ha(-1)) on north facing hill slopes. S. fragilis was not found in natural condition in forest of the Lahaul valley, relatively lesser density of 20 individuals ha-1 at south facing hill slopes of Jahlma and 6 individuals ha-1 at Hinsa in north facing hill slopes, basically planted by the villagers. The average biomass production were 37.3 t ha(-1) and 20.3 t-ha(-1) under idle circumference categories of 60-96 and 30-60 cm girth classes, respectively. Willow provides 18.5% to 69.5% of total fuel,wood requirement of the farmers in the Lahaul valley. The average number of willow trees per household ranged from 5.8 to 127.5 individuals at village level, which was not sufficient to fulfill the present wood based requirement of farmers for survival in cold desert environment. To sustain unique cold desert ecosystem and environment, plantation of wild and cultivated willow, varieties of other established indigenous and exotic plant species (trees, shrubs, bushes, grasses, herbs, climbers), that survive under -40 degrees C to -20 degrees C temperature in general and fulfill primary requirement of farmers along with potential of alleviate xeric cold desert environment is needed.