Changes in ecosystem service values strongly influenced by human activities in contrasting agro-ecological environments

Abstract

Background Evaluating the impacts of land-use/land-cover (LULC) changes on ecosystem service values (ESVs) is essential for sustainable use and management of ecosystems. In this study, we evaluated the impact of human activity driven LULC changes on ESVs over the period 1982–2016/17 in contrasting agro-ecological environments: Guder (highland), Aba Gerima (midland), and Debatie (lowland) watersheds of the Upper Blue Nile basin, Ethiopia. Results During the study period, the continuous expansion of cultivated land at the expense of natural vegetation (bushland, forest, and grazing land) severely reduced the total ESV by about US$ 58 thousand (35%) in Aba Gerima and US$ 31 thousand (29%) in Debatie watersheds. In contrast, the unprecedented expansion of plantations, mainly through the planting of Acacia decurrens, led, from 2006, to a ESV rebound by about US$ 71 thousand (54%) in Guder watershed, after it had decreased by about US$ 61 thousand (32%) between 1982 and 2006. The reduction in natural forest area was the major contributor to the loss of total ESV in the study watersheds, ranging from US$ 31 thousand (63%) in Debatie to US$ 96.9 thousand (70%) in Guder between 1982 and 2016/17. On an area-specific basis, LULC changes reduced the average ESV from US$ 560 ha−1 year−1 (1982) in Guder to US$ 306 ha−1 year−1 (2017) in Debatie watersheds. Specific ESVs such as provisioning (mainly as food production) and regulating services (mainly as erosion control and climate regulation) accounted for most of the total ESVs estimated for the study watersheds. Conclusions In most cases, the total and specific ESVs of the watersheds were negatively associated with the population growth, which in turn was positively associated with the expansion of cultivated land over the study period. In Guder, however, ESVs were positively associated with population growth, especially after 2012. This is mainly due to the expansion of Acacia decurrens plantations. Our results suggest, therefore, that future policy measures and directions should focus on improving vegetation cover through planting multipurpose trees such as Acacia decurrens to prevent future loss of ESV in the midland and lowland regions of the Upper Blue Nile basin and beyond. However, caution must be taken during plantation of invasive species as they may have undesirable consequences.

Changes in Ecosystem Service Values in Response to the Planting of Eucalyptus and Acacia Species in the Gilgel Abay Watershed, Northwest Ethiopia

“…However, the value of food production followed by biological control and pollination service functions was increased as a result of the cultivated land expansion. The results agree with the findings of various studies (Aneseyee et al, 2020; Assefa et al,2021; Berihun et al, 2021; Gashaw et al,2018; Ketema et al,2021; Kindu et al, 2013; Shiferaw et al,2021; Sun et al, 2021; Woldeyohannes et al,2020). Land degradation mainly due to deforestation and agricultural expansion could severely contribute to a significant loss of ecosystem services (Shiferaw et al, 2021).…”

“…The results indicate that the expansion of cultivated land with the loss of natural vegetation and wetlands has led to a decrease in the total value of ecosystem services. The loss of natural vegetation and wetlands to cropland has significantly contributed to the total loss of ecosystem service value (Aneseyee et al, 2020; Berihun et al, 2021; Gashaw et al, 2018; Kindu et al, 2013; Shiferaw et al, 2019; Tolessa et al, 2016; Wang et al, 2017; Woldeyohannes et al, 2020). The decline in the value of natural shrublands ecosystem services of US$64.19 million, followed by a decline in the value of natural forest ecosystem services of US$26.54 million contributed significantly to the lowering the value of ecosystem services in 1998.…”

“…The decline in the value of natural shrublands ecosystem services of US$64.19 million, followed by a decline in the value of natural forest ecosystem services of US$26.54 million contributed significantly to the lowering the value of ecosystem services in 1998. The total and individual values of ecosystem services are negatively related to population growth and the loss of cropland expansion (Berihun et al, 2021). The clearing of natural forests and shrub ecosystems has reduced the quality and stability of water flows, carbon stocks, soil stabilization, and wild pollination services (Eguiguren et al, 2019; van Haaren et al, 2019).…”

“…Contrary to the findings of the first period of the study, an increase in forests, shrubs, grasslands, and wetlands contributed to an increase in the total value of ecosystem services by US$73.3 million in 2013 and US$ 95.74 million in 2021 compared to 1998 (Tables 5 and 6; Figures 3–5). The expansion of the Acacia decurrens planting area has contributed to an increase in the total value of ecosystem services (Berihun et al, 2021). The protection of forests and shrubs as well as the conservation of wetland ecosystems is essential as they represent a high value of ecosystem services per hectare and are essential to preventing the loss of further ecosystem service values (Ketema et al, 2021; Sharma et al, 2019; Temesgen et al, 2018).…”

Land use/land cover dynamics driven changes in woody species diversity and ecosystem services value in tropical rainforest frontier: A 20-year history

“…Land use/land cover (LULC) change is a critical challenge in tropical forests due to its detrimental effect on the environmental quality and the availability of resources [ 1 ]. Accelerated LULC change caused by rapid population growth, agricultural land, and settlement expansions [ [2] , [3] , [4] , [5] , [6] ] imposed environmental degradation, biodiversity loss, and changes in ecosystem service value [ 7 , 8 ]. The expansion of agricultural land at the expense of natural forest is the typical phenomenon of LULC change in the tropical forests of Ethiopia [ 9 ].…”