Report Yashwant S. Rawat, Santaram S. Oinam, Subhash C. R. Vishvakarma, Chandra P. Kuniyal and Jagdish C. Kuniyal Willow (Salix fragilis Linn.): A Multipurpose Tree Species under Pest Attack in the Cold Desert of Lahaul Valley, Northwestern Himalaya, India Salix fragilis is the most common willow species grown extensively under the indigenous agroforestry system in the cold desert of Lahaul valley located in the northwest- ern Himalayas, India. Presently, this tree is under severe pest attack, and other infections have made its survival in the area questionable. This deciduous multipurpose tree species provides vegetation cover to the barren land- scape of Lahaul and is a significant contributor of fuel and fodder to the region. This study is a detailed profile of the plant in three villages within this region: Khoksar, Jahlma, and Hinsa. The willow provided 69.5%, 29%, and 42% of the total fuelwood requirements of Jahlma, Khoksar, and Hinsa respectively. A striking observation was that only 30.0 6 20.1% trees were healthy: 55.2 6 16.1% of the willows have dried up and 14.8 6 6.1% were in drying condition due to a combination of pest infestation and infection. To sustain this cultivation of willow under the existing agroforestry system in the region, we recom- mend that locally available wild species and other established varieties of willow growing in similar regions of the Himalayas be introduced on a trial basis. INTRODUCTION About 350–500 species of willow (Salix spp.), mainly growing in the Northern Hemisphere, currently exist worldwide (1).Willow is very rarely found in the tropics and in the Southern Hemisphere; it is completely absent in Australia and the Pacific region (2). In the Indian Himalayan region, 24 species of Salix are found (3). Out of these, 10 shrubby, indigenous species are Salix acmophylla Boiss., Salix daphnoides Vill., Salix denticulata Anderss., Salix flagellaris Anderss., Salix karelinii Turcz., Salix lindleyana Wall., Salix oxycarpa Anderss., Salix pycnostachya Anderss., Salix tetrasperma Roxb., and Salix wallichiana Anderss. Most of these are found growing wild in the moist places of the cold desert of Lahaul valley (4). S. denticulata, being an exception, is found along dry slopes. Willow is the main source of fuelwood, fodder, and minor timber (agricul- tural implements, handles of tools, poles, and roofing material). It also provides raw material for basketry (S. denticulata Andress.) The dry leaves of the plant are used for cushioning the floor of cowsheds. Not too long ago, utensils made of willow were quite common in a Lahauli’s kitchen. In the typically xeric, cold desert conditions, with high fluctuations of temperature (high in short summers and subzero during winters), very scanty rainfall, and high snowfall, only two species each of willow (Salix alba Linn. and Salix fragilis Linn.) and poplar (Populus balsamifera Linn. and Populus nigra Linn.) have adapted well to the climate of Lahaul and thrive better than all other species. S. fragilis, in particular, is cultivated extensively under the indigenous agroforestry and forestry systems around settlements (5, 6). Traditionally, propagation is done through the shoot plantation method. The trees are pollarded during winter for fuelwood and fodder after an interval of 3–4 y. Bark of the branch cuttings is peeled off and given to cattle during winter as a substitute for green fodder. A large number of sprouts, called coppices, appear on the head of pollarded trunk during spring. Willow (S. fragilis), a deciduous, multipurpose plant, is most suitable for the dry temperate region because it grows gregariously along the riverbanks and the fields and also on steep slopes and erosion prone areas. This plant, as a source of renewable energy under cold desert climatic conditions, was supposed to be one of the best tree species for forestry programs, but the drying up of these trees, particularly above an altitude of 3000 m, has put a big question mark on its suitability. The present study examined the production of fodder and fuelwood from willow (S. fragilis) and the causes of its drying up in the cold desert of Lahaul valley. MATERIAL AND METHODS Study Area and Climate The cold desert of Lahaul and Spiti districts extends between 31844’34’’ N and 32859’57’’ N latitude and 76846’29’’ E and 78841’34’’ E longitude. The northern and southern boundaries of Lahaul valley are demarcated by the Great Himalayan range in the north and the Pir Panjal range of the Lesser Himalaya in the south. The total geographical area of the Lahaul valley is 6244 km 2 , and its population is 22,545. An average of 4 people km 2 inhabit the Lahaul valley (7). During winters, the Lahaul valley remains cut off from the rest of the country due to heavy deposits of snow on the Rohtang Pass (3978 m). The valley is accessible only during summers after the clearing of the snow from the pass. The Lahaul valley extends from Khoksar in the southeast to Tindi, near Udaipur town, in the northwest. Geographically, the Lahaul valley is made of three major subvalleys: Chandra, Bhaga, and Pattan. The width of the valley varies from 0.5 km to 2.0 km and the expansion of the rivers is 20 to 75 m. The Lahaul valley has a barren landscape (Fig. 1) with about 68.7% of the total geographical area falling under the nonreported category. That land category includes high hills, stony outcrops, and snowbound areas (8). The remaining 31.3% of the area comes under the reported category and includes the following subcategories of land use: forests (17.55%), land not available for agriculture (0.32%), permanent pastures (13.05%), area under tree plantations (0.01%), barren land (0.04%), currently fallow (0.01%), and net sown area (0.33%). Only 0.39% of the land is devoted to agriculture/ forestry use (i.e. forestry, barren land, current fallow, and net sown area). The valley has very few patches of relict pencil cedar (Juniperus macropoda Boiss) forests on the south-facing slopes. The north-facing slopes, on the other hand, have smaller Ambio Vol. 35, No. 1, February 2006 43 Ó Royal Swedish Academy of Sciences 2006 http://www.ambio.kva.se