Carbon stocks and sequestration potential of dry forests under community management in Tigray, Ethiopia

Abstract

Introduction: Forests form a major component of the carbon (C) reserves in the world's ecosystems. However, little is known on how management influences C stocks of woody vegetation, particularly in dry areas. We developed regression models for two dominant tree species to predict C stocks and quantified the potential of community managed forests as C sinks. Methods: Plots were randomly selected from community-managed natural forest, herbivore exclosures, and from communal grazing land. Tree and shrub biomass were estimated using a regression model on the most dominant woody species while herbaceous biomass was determined using destructive sampling.Results: The simplest model, based on only one single predictor variable, showed a good fit to the data for both species (Juniperus procera and Acacia abyssinica). Diameter at breast height (r 2 > 0.95) was a more reliable predictor than height (r 2 > 0.54), crown diameter (r 2 > 0.68) (p < 0.001). The C content of the total biomass for the managed natural forest and the exclosure were estimated as, 58.11 and 22.29 Mg ha −1 , respectively, while that for the grazing land was 7.76 Mg ha −1 , and the mean carbon content between the three land uses were significantly different (p < 0.05). Conclusions: We conclude that forests managed by the community have a high potential for C sequestration and storage and their conservation should be promoted.

Assessment of above- and belowground carbon pools in a semi-arid forest ecosystem of Delhi, India

“…The C stored in different pools was estimated as aboveground (29.28 Mg C ha −1 ), roots or belowground (12.59 Mg C ha −1 ), litter (0.26 Mg C ha −1 ), and SOC (21.36 Mg C ha −1 ). The estimated average forest standing biomass C (sum of AGB and BGB), i.e., 41.87 Mg C ha −1 , was lower than the values reported for tropical dry forests of Asia (Gibbs et al 2007;IPCC 2006) and forests from Mexico (Dai et al 2014) and Ethiopia (Solomon et al 2017(Solomon et al , 2018, but higher than forests from Africa (Gibbs et al 2007;IPCC 2006) and Brazil (Júnior et al 2016). Carbon in AGB was also lower than that of a semi-arid (Picea crassifolia) forest in the North Eastern Tibet (Wagner et al 2015).…”

“…The mean standing biomass C for the present forests is within the range reported for tropical dry deciduous (12.79-62.48 Mg C ha −1 ) and evergreen forests (18.85-48.58 Mg C ha −1 ) but higher than tropical thorn forests (4.91-13.3 Mg C ha −1 ) from India (FSI 2017) ( Table 6). Tree species composition also affects the total biomass and C stock of forest (Yang et al 2005;Borah et al 2015;Solomon et al 2017). In the present study, P. juliflora was found to be the most dominant tree species in both forest sites, having the highest TD, BA (Meena et al 2016), biomass, and C stock.…”

Carbon sequestration and soil restoration potential of grazing lands under exclosure management in a semi‐arid environment of northern Ethiopia

“…Vegetation response to different grazing land management practices has been investigated in several studies (Bikila, Tessema, & Abule, ; Gebregerges, Tessema, & Birhane, ; Mekuria et al, ; Tessema et al, ; Yayneshet, Eik, & Moe, ) in which the results indicated that overgrazing of communal grazing lands causes a change in vegetation structure through decreasing the vegetation density and biomass. Continuous heavy grazing can also affect the carbon sequestration potentials of grazing lands through reduction of carbon accumulation in the soil systems (Alemu, ; Dlamini, Chivenge, & Chaplot, ; Mekuria, ; Solomon, Birhane, Tadesse, Treydte, & Meles, ). According to Mekuria et al () soils in areas excluded from gazing had a higher soil organic matter (SOM) contents compared to open grazed areas.…”

Carbon Sequestration and Soil Restoration Potential of Grazing Lands under Exclosure Management in a Semi-Arid Environment of Northern Ethiopia

“…Vegetation response to different grazing land 48 management practices has been investigated in several studies [5,9,[12][13][14] in which the results 49 indicated that overgrazing of communal grazing lands causes a change in vegetation structure 50 through decreasing the vegetation density and biomass. However, continuous heavy grazing can 51 also affect the carbon sequestration potentials of grazing lands through reduction of carbon 52 accumulation in the soil systems [15][16][17]. According to Mekuria,et al [18] soils in areas excluded 53 from gazing had a higher soil organic matter (SOM) contents compared to open grazed areas.…”