Survey and Analysis of Shisham (Dalbergia Sissoo Roxb) Mortality in Doon Valley, Uttarakhand

Shisham (Dalbergia sissoo Roxb) is facing large-scale mortality, both in natural forest as well as in plantations. Survey was carried out in six sites in Pathri, Lalpani and Thano forests in Doon valley of Uttrakhand (India). Quadrat size of 50 x 50 mt. was randomly laid in triplicates at each site. In all the sites in the natural zone of shisham, mortality varies from 20–70%. In general, in site I, mortality ranges between 20–62% as compared to 14–25% in the site II of Pathri. In site III of Lalpani 25–63% mortality was observed as compared to the 9–25% in the site IV. Site V shows 28–63% mortality much higher than 11–25% site VI of Thano. Site II of Pathri, VI of Thano and IV in Lalpani suffer very less mortality as compared to the above said sites. Intensity of mortality in different diameter classes was observed to find out the most susceptible diameter class of tree mortality. In the site I, the dead tree category experience 61.1% mortality in total, individually being 16.66% in the diameter class of 20–25 cm, 13.88% mortality in the 25–30 cm followed by 11.11% mortality in the 30–35 cm diameter class. Most affected diameter class in the dead tree category was 20–25 cm and in the partially dead tree category was 25-30cm. similarly in site II of Pathri, most affected diameter class in the partially dead tree was 20-25cm. and in the dead tree was 20–35 cm. Young and mature trees are resistant to mortality as compared to the middle-aged trees. The study suggests that continuous water logging in Pathri site leads poor aeration (asphyxiation) of root and boulder areas long water stress in Thano site superficial root system of shisham leads mortality.