Common Needle, Shoot, Branch and Stem Diseases of Conifer Trees in Bhutan

Bhutan is a small, landlocked, densely forested country in the South-Eastern Himalayas (FAO 1999, 2001). Forests are of immense importance for the ecology, economy and social well-being of this country and for the livelihood of its people. In mountainous areas at elevations between about 2100 and 4200 m asl., temperate conifer forests form the natural vegetation in this part of the Himalayas. These forests occupy about 24% of the total area of Bhutan and they consist mainly of Eastern Himalayan fir (Abies densa), Eastern Himalayan spruce (Picea spinulosa), Himalayan hemlock (Tsuga dumosa) and Himalayan Blue pine (Pinus wallichiana) (Grierson – Long 1983, Rosset 1999). Other conifers and various broadleaved tree species (Rhododendron spp., Betula spp., Populus spp., Acer spp., Sorbus spp. and Salix spp.) are often admixed to the aforementioned major conifer species or sometimes dominate forest stands on specific sites (Grierson – Long 1983, Rosset 1999). Another important conifer in Bhutan is Chir pine (Pinus roxburghii), which occurs mainly in sub-tropical and warm temperate forests (Grierson – Long 1983). This pine does, however, not form part of cold temperate conifer forests.