Above – Ground Standing Biomass and Carbon Stock Dynamics under a Varied Degree of Anthropogenic Pressure in Tropical Rain Forests of Uttara Kannada District, Western Ghats, India

Above-ground standing biomass and carbon-stock dynamics were monitored for 25 years (from 1984 to 2009) in six 1- ha permanent forest sites subjected to different levels of anthropogenic pressure in tropical rain forests of Uttara Kannada district,Western Ghats, south India. Over the years, total loss of trees ranged from 97 to 761 (23.95- 60 .7%) trees/ha, removal of trees by people ranged from 42 to 559 (5.5-55.17%) trees/ha and number of trees dead ranged from 55-370 (5.52-38.38%) trees/ha, leading to reduction in basal area in two sites (-1.81 m2/ha, and -1.73 m2/ha). In four sites, basal area increased from 0.98 to 22.19 m2/ha, because of compensatory growth of surviving trees and added above-ground standing biomass ranging from 6.40 to 144.67 t/ha. Tree recruitment ranged from 214 to 1,840 trees/ha and it was more than the number of trees lost in four sites, indicating faster recovery of tree density. In the 25th year, recruits formed 28.34 - 85.06% of the stand tree density and shared 1.20-18.47% of the stand basal area and accounted for 1.0 -14.67% of the above- ground standing biomass and carbon stock, making all six sites as C-sinks. In general, the rate of carbon accumulation in forests of Uttara Kannada district was 1.13 t C /ha /yr , of which, 0.58 ± 1.18 t C /ha/year was contributed by surviving trees and 0.55 ± 0.33 t C/ha/year was added by recruits. With proper management strategies, the C-sequestration potential in the forests can be elevated and by reforesting degraded area, the carbon sink can be enhanced in the Western Ghats region. Role of recruits in forest dynamics must be considered while planning and management of forests to enhance carbon stocks