Carbon Stock and Regeneration Status of Community Managed Sal (Shorea Robusta Gaertn.) Forests in Dadeldhura District, Western Nepal

Abstract

Community forests of developing countries are among the best examples of mitigating global climate change by carbon sequestration. This research compares the carbon stock and assess the regeneration status of community managed Shorea robusta (Sal) forests managed for 10-21 yrs in Dadeldhura district of Far Western Nepal. These forests were categorized into two groups according to management duration (≤ 11 yrs and ≥ 20 yrs). The above-ground carbon stock of trees and shrubs were estimated using allometric equations. Regeneration status of forest was estimated by calculating the density of each species in each developmental phases (seedling, sapling and tree). The mean carbon stock of living biomass of the studied forests was 175 Mg ha -1 (148-202 Mg ha -1 ). The carbon stock in living biomass of the forest managed for ≥ 20 yrs (199 Mg ha -1 ) was significantly higher than the forests managed for ≤ 11 yrs (151 Mg ha -1 ) (P < 0.05). The carbon stock increased with the increment of soil available potassium but it decreased with increased soil total nitrogen (P < 0.05). However, it did not vary significantly with soil organic carbon, soil available phosphorus and soil pH (P > 0.05). Similarly, there was no any predictable relationship of carbon stock with litter cover, canopy cover, ground vegetation cover, relative radiation index and species richness. Sal was the highest contributor of tree layer carbon in both categories of forests whereas it was replaced by Phoenix humilis (Thakal) in shrub layer in ≤ 11 yrs managed forests. The studied forests had good regeneration status with 9764 seedlings/ha, 1850 saplings/ha and 1263 trees/ha and sal was the dominant species in terms of regeneration. Forests managed for ≥ 20 yrs had greater number of seedling, sapling and tree than the forest managed for ≤ 11 yrs. Thus, the community management has increased the carbon stock of forests and also it had promoted the productivity of forests.