Ecosystem services (ES) are the benefits that people receive from the environment, whether consciously or unconsciously, and directly or indirectly, for their well-being, survival, health, and economic growth (Acharya et al., 2019; Burkhard & Maes, 2017;Costanza et al., 1997; Costanza et al., 2017). These are categorized into provisioning services (food, feed, fiber, water supply), regulating services (water, climate, erosion control, and sediment retention), and cultural services (recreational, aesthetic, and spiritual) that directly benefit people, whereas supporting services (soil formation, photosynthesis, and nutrient cycling) are the core for the muster of all other services (Bera et al., 2022; Biratu et al., 2022; Costanza et al., 2017; Kindu et al., 2016; Rotich et al., 2022).
The Millennium Ecosystem Assessment (MEA) (2005), led by the United Nations, report that nearly 1,300 scientists had participated for five years and investigated that more than 60% of the ecosystem services are being degraded on account of both the direct (LULC, climate change, external inputs) and indirect (science and technology, demographic, economic) drivers of change. Among the drivers, LULC is one of the key indicators of the status of ES changes in targeted areas (Blamey et al., 2015; Costanza et al., 1997; Kindu et al., 2016; Tolessa et al., 2017).
Globally, regionally, and locally, most of the scholars quantified the ESVs based on the LULC change model (Akber et al., 2018; Anderson et al., 2017; Berihun et al., 2021; Cabral et al., 2016; Fei et al., 2018; Shiferaw et al., 2019; Tolessa, Senbeta, & Kidane, 2017). Consequently, total global ESVs were estimated US$ 145 trillion in 2007 and dropped to US$ 125 trillion in 2011 (Costanza et al., 2014). Similarly, in Sub-Saharan Africa, the total ESVs in 1992 were also US$ 9 trillion and declined to US$ 83.7 billion in 2015 (Fenta et al., 2020). (Gebreselassie, et al., 2016) estimated annual cost of land degradation to be about US$ 4.3 billion in Ethiopia. Thus, LULC dynamics and land degradation are the crucial and determinate factors contributed to altered structure and function of ESVs (Abera et al., 2020; Biratu et al., 2022; Gashaw et al., 2018; Mekuriaw et al., 2021).
Recently in Ethiopia, several studies have been carried out in different parts of the country to estimate changes of ESVs in response to LULC dynamics. For example, in Munessa- Shashemene landscape (Kindu et al., 2016), Rift Valley Basin (Biratu et al., 2022; Mekuria et al., 2021), Rib watershed of the Upper Blue Nile Basin (Anley, Minale, Haregeweyn, & Gashaw, 2022), Winike watershed of the Omo Gibe basin (Aneseyee, Soromessa, & Elias, 2020), Jibat forest landscape (Muleta et al., 2021), and in Peri-urban and urban and Bahir Dar City (Assefa et al., 2021). All these findings show that ecosystem services are more rapidly declining than in any comparable historical of time. Therefore, assessing and quantifying changes in ecosystem service values (ESVs) is an indispensable tool for awareness creation (Gashaw et al., 2018), focusing on the development of knowledge on natural resource capital (de Groot et al., 2012), formulating approaches and policies (Yin et al., 2021) and providing reassure to conserve the ecosystems that provide the services. As a result, underlined attention in ESVs has progressed rapidly in the scientific communities, international organization and policy decision-makers (Fang et al., 2022; Guo et al., 2021).
There are several alternative methods for valuing ecosystem services (Richardson et al., 2015), which may be nearly categorized into two groups: a) the primary valuation methods, which observe economic principles such as market prices, production approaches, travel costs, opportunity costs, conjoint analysis, and replacement costs; and b) the land use proxy-based method, which uses the Benefit Transfer Approach by using the existing ESV data from one location to another of similar setting (Anley et al., 2022; Biratu et al., 2022; de Groot et al., 2012; Kindu et al., 2016; Richardson et al., 2015; Rotich et al., 2022).
The Peripheral (areas away from the center region) Beles basin is branded by the Ethiopian government as one of the tremendous opportunities for a national economic growth corridor (World Bank, 2008). Thus, in this basin, giant mega projects have been running such as the Grand Ethiopian Renaissance Dam (GERD) (Teklemariam et al., 2017), Integrated Beles Sugar Development (Fantini et al., 2018), Tana-Beles Hydro Power (Annys et al., 2019), and Tana Beles Resettlement Program (Woldemeskel, 1989), and mechanized farms (Teklemariam et al., 2017). Subsequently, issues of socio-economics and ecological dynamics, deforestation, severe land degradation, and conflicts for land and water resource (Abebe et al., 2021; Annys et al., 2019; Nyssen et al., 2018) are become very critical.. In addition, as a result of 1984/85 drought (Woldemeskel, 1989), highly affected people from the northern and southern part of the country moved to the Tana-Beles Resettlement villages (Woldemeskel, 1989). To secure livelihoods for settlers and resttlers, there was massive mechanized deforestation, modern infrastructure establishment, mechanized agriculture practices, and use of synthetic agricultural chemicals, which depleted natural resources (“Anthropol. Approaches to Resettl.,” 2019) while no consideration was given to environmental sustainability mitigation measures.
While many activities have been made in the basin, no studies are addressed regarding to local LULC, ecosystem functions, and its ecosystem services associated with agricultural production (Nyssen et al., 2018). In addition, the basin is outlet parts and directly connected with GERD reservoir. On the other hand, the setting up of small, shifting and large scale agricultural investment and massive deforestation in the Beles basin which is directly contributed to rapid siltation and sedimentation on GERD reservoir (Nyssen et al., 2018; Teklemariam et al., 2017). These might be serious challenges that limit the economic lifespan of dams. As a result, establishing the scientific basis for actions needed to improve conservation planning and sustainable use of ecosystems, as well as estimating and evaluating the status of changes in ESV, is critical for policymakers and development practitioners (Abera et al., 2020; Biratu et al., 2021; Karimi et al., 2020; Nyssen et al., 2018). Therefore, the objectives of this study are: (1) to analyze the trend of ESV associated with land use and land cover change in the Beles Basin between 1986 and 2019; 2) to quantify the amount and rate of LULC changes undertaken during the past three decades; and (3) to estimate the loss of ESVs from 1986 to 2019 periods because of the LULC changes. Our research findings will provide a better understanding of the status and dynamics of ES in the Beles basin for future land management option and sustainable ecosystem management by the relevant stakeholders.