Forest landscape restoration through exclosure for revitalization of vegetation diversity and carbon stock accumulation

Understanding the role of forest landscape restoration (FLR) is vital to estimate its contribution for biodiversity conservation and climate change mitigation. The study was conducted to estimate vegetation diversity and carbon stock of restored forest landscape through Exclosure (Ex) versus open grazing forest (OGF). Diameter at the breast height and stump height (DBH, DSH), height (H) and herbaceous biomass were measured. Composite soil sample was taken from three soil depths of 0–10 cm, 10–20 cm and 20–30 cm. Vegetation diversity indices were estimated with various methodologies. Biomass carbon stock (BCS) was calculated with allometric equations. The soil organic carbon stock (SOC) was estimated following Walkley–Black method. An Ex has composed of greater number of individual than OGF. Species abundance (Ab), and Shannon diversity (H’) in the Ex were significantly higher than OGF. Croton macrostachyus Hochst.ex Dlile, Bridelia micrantha (Hochst.) Baill and Terminalia laxiflora Engl. & Diels were the domim = nat specie in the Ex whereas Croton macrostachyus Hochst.ex Dlile, Brucea antidysenterica J. F. Mill. And Vernonia abyssinica Sch.Bip.ex Hochst were the dominant speices in the OPG. Species Evenness (J) (0.47 ± 0.09) in the OGF was and significantly higher than Ex (0.10 ± 0.04 Mg C). The total carbon stock (TCS) in the Ex (43.33 ± 0.93) was significantly higher than the OGF (17.24 ± 1.10 Mg C). The species Ab, density (S) and H’ in the Ex were significantly higher at the upper elevation. The number of saplings in the Ex was greater than the number of seedlings and trees at all elevations. The BCS and SOC at the upper elevation of the Ex were significantly higher than the middle and lower elevations. Overall, FLR with the Ex can help to improve vegetation diversity, carbon accumulation of the study site. As a result, Ex could be implemented to degraded forest landscapes of the district. Further research is needed into the underground ecology of the studied Ex such as soil microbial communities, root dynamics, and nutrient cycling.