Ecosystem carbon sequestration through restoration of degraded lands in Northeast India

This study evaluated the ecosystem carbon (C) stock and sequestration potential for predominant land uses converted from forest in Northeast India to advance the scientific knowledge and minimize the anthropogenic C emissions from land use change (LUC). Field assessments were conducted on 6 predominant land uses including (a) natural forest (NF), (b) degraded forest (DF), (c) rubber (Hevea brasiliensis) plantation (RP), (d) Areca (Areca catechu) plantation (ArP), (e) pan (Piper betle) jhum (slash and mulching) agroforestry (PB), and (f) Imperata grassland (IG) of Northeast India to assess changes in ecosystem C stock with progressive and retrogressive LUC. Ecosystem C stock was the highest for NF (300.5Mg ha(-1)) and the lowest under IG (110.4Mg ha(-1)). The ecosystem C stock under PB and IG was 11% and 63%, respectively, lower than that under NF. In comparison with DF, the gain in ecosystem C was in the order PB (125%)>RP (99%)>ArP (4%). The ratio of soil organic carbon to ecosystem C stock was similar to 50% for NF, PB, and RP and that shifted to similar to 80% for ArP/DF/IG. The LUC and management of DF through PB and RP indicated the ecosystem C sequestration rate of 5 and 4Mg ha(-1)year(-1), respectively. Similarly, the ecosystem C sequestration rate was 0.5 and 4Mg ha(-1)year(-1), respectively, when IG was converted into ArP and RP. Therefore, restoration of degraded lands (viz., DF and IG) through RP and PB enhanced ecosystem C sequestration rate and reduced CO2 emissions from LUC. Copyright (c) 2017 John Wiley & Sons, Ltd.