Climate change mitigation through carbon dioxide (CO2) sequestration in community reserved forests of northwest Tanzania

Abstract

Forests play a key role in climate change mitigation through sequestering and storing carbon dioxide from the atmosphere. However, there is inadequate information about carbon accumulation and sequestered by community reserved forests in Tanzania. A study was carried to quantify the amount of carbon sequestered in two forests namely; Nyasamba and Bubinza of Kishapu district, northwestern Tanzania. A ground-based field survey design under a systematic sampling technique was adopted. A total of 45 circular plots (15 m radius) along transects were established. The distances between transect and plots were maintained at 550 and 300 m, respectively. Data on herbaceous C stocking potential was determined using destructive harvest method while tree carbon stocking was estimated by allometric equations. The collected data were organized on excel datasheet followed by descriptive analysis for quantitative information using Computer Microsoft Excel and SPSS software version 20, while soil samples were analyzed based on the standard laboratory procedures. Results revealed higher carbon sequestration of 102.49±39.87 and 117.52±10.27 for soil pools than plants both herbaceous (3.01±1.12 and 6.27±3.79 t CO2e/yr) and trees (5.70±3.15 and 6.60±2.88 t CO2e/yr) for Nyasamba and Bubinza respectively. The study recorded a potential variation of soil carbon sequestration, which varied across depths category (P < 0.05). However, there was no difference across sites (P >0.05) and species (P > 0.05) for herbaceous and trees. The findings of this study portrayed a significantly low value for carbon stocking and sequestration potential for enhanced climate change mitigation. Therefore, proper management of community reserved forest is required to accumulate more C for enhancing stocking potential hence climate change mitigation through CO2 sequestration offsets mechanism.