The Carbon Sequestration Potential of Degraded Agricultural Land in the Amhara Region of Ethiopia

Abstract

Forests are a key player within the global carbon cycle and reforestation is an important climate change mitigation mechanism. In this study, we identify potentially suitable areas for reforestation to assess the carbon sequestration potential in the highly deforested and degraded Amhara region of Ethiopia. We apply biogeochemical mechanistic ecosystem modelling to predict the amount of carbon that can be potentially sequestered within different time horizons. Since human intervention plays a key role within the Amhara region, three different forest management scenarios and five different rotation periods following reforestation are tested: (i) unthinned; (ii) removal of 5% of the stem carbon every 20 years (thinning 1); and (iii) removal of 10% stem carbon every 20 years (thinning 2), as well as a rotation period of 10, 30, 50, 100, and 150 years. Sustainable management of reforested land is addressed by implementing the so called 'Normal-forest' system (equal representation of every age class). This ensures the long term sequestration effect of reforested areas. The study shows that 3.4 Mha (Mha = Million hectare) of land, including bare land (0.7 Mha), grass land (1.2 Mha), and shrub land (1.5 Mha) can be considered as ecologically potentially suitable for reforestation. Assuming a 100 year rotation period in a 'Normal-forest' system, this shows that a total net carbon sequestration potential of 177 Tg C (10.8 Tg C in the soil and 165.9 Tg C aboveground; Teragram = 10 12 g) is possible, if all 3.4 Mha are replanted. The highest total net carbon sequestration (soil and aboveground) was evident for the Highland-wet agro-ecological zone, whereas the lowest values are typically in the Midland-dry zone. The highest net aboveground carbon sequestration was predicted for reforestations on current grass land and shrub land versus bare land, whereas the highest net soil carbon sequestration was predicted on current bare land, followed by grass land and shrub land.

Carbon Stock Potential of Shilabo Shrubs Land among Soil Texture Somali Region, Eastern Ethiopia

“…In Ethiopia, population growth and investment are followed by deforestation and land use changes have resulted in a dramatic decrease in forest land over the last few decades (Berihu et al 2017). Burning of forests and heavy disturbances in the remaining natural forests, such as cattle grazing or logging, that result in severe soil degradation (Belay et al, 2018). Overgrazing is one of the major factors aggravated ecosystem degradation, which causes an increase in unpalatable species by destroying the most palatable species and reducing plant cover and biomass, thereby increasing erosion hazards and reducing the overall productivity of the land (Pulido et al, 2018).…”

Carbon Stock And Spatial Dynamics In Natural Forests Of Awi Zone, Amhara Region, Northwestern Ethiopia: Implication For Climate Change Mitigation And Adaptation

“…Aspect factor as it is a sunlight intensity and direction highly determine the vegetation growth performance and woody species diversity which related to woody biomass and carbon stock. In most studies [4], [33], [35], [39], [41], [42] north and east-facing having strong light intensity and perpendicular light direction speci cally in tropical countries have higher vegetation performance and carbon stock. However, the studies imply that this scenario depends on the anthropogenic disturbances and management intensity of the forest.…”

“…The other forest communities have faced a great challenge of anthropogenic disturbances. The study forest communities relatively have the highest carbon stock as an overall pool (254-ton ha − 1 to 1177-ton ha − 1 ) from [33] Furthermore, the carbon stock potential of the study forest communities were higher than tropical, subtropical, and temperate natural forests [5], [31], [36]- [39]. The study forest communities look intact on the outside that the aged large trees crown cover, however they are degraded and open.…”

Carbon Stock And Spatial Dynamics In Natural Forests Of Awi Zone, Amhara Region, Northwestern Ethiopia: Implication For Climate Change Mitigation And Adaptation

“…The other forest communities have faced a great challenge of anthropogenic disturbances. The study forest communities relatively have the highest carbon stock as an overall pool (254-ton ha − 1 to 1177-ton ha − 1 ) from[33] studies(Bazezew et al, 2015b;Belay et al, 2018;Feyissa et al, 2013;…”