Towards Agroforestry Dominated Land Use Systems Of The Southeastern Rift Escarpment,Ethiopia

Through the increased use of innovation,human population and subsequent economic development have been at rapid pace of growing its ability to derive resources from the environment.In Gedeo-Abaya study region,the predominant agroforestry system in the upstream is a semi-natural forest in which species composition has been adapted to human needs while retaining most of the structural characteristics and ecological processes of natural forests.Being settled by the highest population density,the miracle agroforestry system on steep terrain shows the wisdom of the fanners in natural resource management in the study area.The natural vegetation ecosystems in the downstream region particularly grassland and wetlands also have irreplaceable environmental and sociocultural values.However,the landscape has been recently under high anthropogenic and environmental pressure.The objective of the study were to contribute to the knowledge of agroforestry dominated Gedeo-Abaya landscape ecosystems-through analysis of their land use/cover(LUC)dynamics and underlining drivers,predicting spatial distribution of land uses and,developing estimation model for economic values of ecosystem services(ESs)as well as evaluate sociocultural and ecological importance of ESs on the basis of LUC dynamics.Based on RS-derived and GIS-computed LUC changes,and socioeconomic validations,LUC changes were explored from 1986 to 2015.To detect agroecological-based patterns of LUC change drivers,the recent change map and a cross-sectional survey design were employed.The actual LUC maps of 2000 and 2015 reference years together with natural and socioeconomic indicators were also utilized in a combined Markov-CA model with GIS technology to simulate 2015 validation map and forecast the LUC in 2025 and 2035.Afterward,Ecosystem Service Valuation(ESV)model was developed to estimate ESV changes of the study landscape between 1986 and 2015.Here,a combined approach of LUC area matrix and cross-sectional field investigations were used together with over 120 values sourced mainly from Ecosystem Service Valuation Database and allied sources to establish the value coefficients via benefit transfer method.To address farmers' values and perceptions of sociocultural and ecological ESV of selected five land use types,16 ESs were selected and evaluated for their service provision within two catchments using a multi-stage participatory approach.LUC change and the prevalence of drivers are appears to be highly diverse and vary throughout agroecological zones of the study landscape.Except for the population,most downstream top drivers are perceived as insignificant in the upstream region and vice versa.In the downstream,LUC change and the prevalence of drivers are appears to be highly diverse and vary throughout agroecological zones of the study landscape.Except for the population,most downstream top drivers are perceived as insignificant in the upstream region and vice versa.In the downstream,LUC classes are more dynamic,diverse,and challenged by nearly all anticipated drivers than are upstream ones.A rapid reduction occurred with woodland/shrubland(63%),while wetland/marshes increased threefold(158%),from 1986 to 2015 with annual change rates of-3.7%and+6%,respectively,in the downstream.Agroforestry has been increasing(by 25%of its initial cover)and is becoming the predominant cover type,although its rapid LUC modification also stated.This finding also highlighted,LUC change is prominently affecting land use system of the study landscape due to population pressure in the upstream region and drought/rainfall variability,agri-business investment,and charcoaling in the downstream.Based on the spatiotemporal LUC change trends,the change prediction was computed for 2025 and 2035.The predictive model,a combined Markov-CA with GIS technology,shows quit similar trends with the ongoing LUC changes except the slight difference with cultivation land which shows an expanding trend following the prominent natural variable(i.e.distance to the nearest road).Area based change generally shows significant increase in agroforestry,cultivation land,and wetland/marshes,while most natural vegetation classes,particularly woodland/shrubland,and grazing land would significantly decline in 2015 to 2035 prediction periods.The impact of LUC change to significantly alter ESs obtained particularly from agroforestry system is attempted using own developed valuation coefficient.Predominance of agroforestry cover and high value coefficient of wetland/marshes dominated the total ESV provided by the landscape and led to $18.3 million net increment-a comparative reflection of overall ecological resilience in our study landscape owing to continuity of government watershed restoration policy,and environmental friendly land management practices of the farmers.Yet,losses are observed with natural vegetation classes whose area andjor value coefficients are too small to offset the increased value.With regard to the accounts of farmers' values of ES concept,the majority of LUC types were perceived as multifunctional by most of the participants.Distinctly diverse opinions of and benefits in the services the land uses provides have been shown from rich and varied farmers experience.They also distinguished pristine ESs with spatial differences between up-and downstream regions,whereby shade and shelter values in the upstream and fodder sources in the downstream were among the top perceived services,followed by erosion control.Water treatment and tenure security paid insufficient worth.Identified threats to considered ESs were believed to be consequences of overpopulation coupled with climate change.Important to mention is that farmers' ESs value perception was apparently concurrent with the general natural capital valuation results,except for wetland/marshes land use type which was fairly perceived unlike its highest valuation coefficient.Thus,Gedeo-Abaya landscape ecosystems of southeastern Ethiopia were appears to be important for socioeconomic,cultural,biodiversity conservation and environmental services.However,these multiple ESs needs to be accredited and worked on how to benefit with the societal wellbeing.Young farmers and youths are forced to commercialize woodlots from agroforests(in the upstream)and woodlands(in the downstream)due to rapidly increasing human population with subsequent reduction in land holding size.On top of these,lack of off-farm jobs as well as rainfall variability that prolongs coffee seeding time and crop failure increased the pressure on and eventually deteriorate ecosystems in the region.Careful understanding and synthesis of scholarly outputs,including highlighted findings of this dissertation needs to be framed and used for policy formulations and as decision support tool.Forecasting the future LUC changes offers the possibility that the subsequent damage and unwanted changes are prevented with the involvement of local government officials through proper and timely policies.