4.1. Perceptions and Their Motivations
This study was aimed at uncovering the ES which are being supplied by the three land use types that are threatened by urban expansion, and to integrate them in the land use policy and decision making and management. Our assessment indicates that the stakeholders were shown to have the ability to distinguish ES in terms of their use, and ecosystems in terms of their potential to deliver services. Our result shows that most of the ES that are found in the provisioning services category (67%) have received high or very high perceived use value at least in one of the land use types. These include food, fodder, timber, firewood, fresh water, wild fruit, biomass, and compost. As compared to others, in aggregate terms, the highest perceived use value of ES were given to the provisioning services which is similar to the results of previous studies conducted on the participatory assessment of agricultural ES [48
] and other studies [67
]. Our results also show that there are some ES within regulating services category such as climate regulation, water regulation, erosion prevention and water purification and treatment that received high or very high perceived use values. This shows that the use of regulating services were also noticed, even though there are studies which indicated that the respondents do not often notice regulating services [69
], and they are unfamiliar to the general public [71
]. Nevertheless, there are studies which documented that regulating services were likely to be perceived by the participants [72
]. Supporting services has been given the least perceived in all ecosystem categories, while cultural services are given moderate perceived use values in all ES categories. We believe that our explanation during the interview might have helped the participants to understand the services, but it would not be easy to understand all the ES bundles within the limited interview period and also the lack of previous knowledge.
The results of the study revealed that the perceived use value of ES has been found different among land use types. In the study area, from the three land use types, the perceived use value of ES (i.e., the aggregate mean points) from agroforestry is the highest in all ES categories, followed by cropland. This may be because agroforestry is an ecosystem that makes possible to have trees and crops together which can help to diversify and increase revenue and production while protecting ES. This result is consistent with a study by Temesgen and Wu [48
]. Considering individual ES, agroforestry has been recognized for very high usage of timber production, firewood production and climate regulations, while cropland has received very high usage of food (including crops, vegetables, livestock products) and fodder. Erosion prevention, water purification and treatment, and nutrient recycling are perceived as very high usage in grassland. It has also been shown that the perceived use value of ES is different at kebele level. In this regard, Zenzelima kebele is perceived as the one which has ES with the highest perceived use values in all ES categories. According to information from Bahir Dar Zuria Wereda Agriculture Office (2019), this is because it has some characteristics such as the most productive and less stony soils, and highest water storage that ease plantations in the area as compared to other kebeles.
Regarding the potential of the land use types to deliver ES, the results are consistent with the outcomes of the assessments of ES’s use. This shows that frequent use aligns with an acknowledgment of a more capacity to supply what has been used [36
]. It is observed that the farmers’ perception on the potential of the land use in supplying ES are different at land use level. Accordingly, in the study area, agroforestry is the dominant land use, which has been perceived to have the highest potential to provide ES in all ES categories. This result is consistent with a study by Temesgen and Wu [48
]. When we see the potential of the land use to provide individual ES, agroforestry has very high potential in providing climate regulation and erosion prevention, while grassland has very high potential in supplying water regulation, erosion prevention, water purification and treatment and nutrient recycling. In view of the local people, cropland has very high potential in supplying food and fodder. This result is in line with the findings of other studies [36
]. We also found that the potential of the land use to supply ES is different at kebele level. Land use types in Zenzelima kebele have been perceived to have the highest potential to supply ES for all ES categories, with the same reason mentioned above about the characteristics of this particular kebele. We also found the differences in ranking of the selected ES by experts and the local communities, which gave more value to benefits such as food, fodder, fresh water, timber, firewood, and erosion prevention, whereas climate regulation and water purification and treatment were relatively better ranked by the experts. This shows the local communities are better in recognizing the direct uses of ES than the indirect uses, which matches the results of other studies [48
Cultural services are ranked low by the local communities. This result is consistent with the results of other studies [48
]. This may be due to the fact that cultural services that represents the non-material benefits from the land uses that arise from human–ecosystems relationships [73
], are less directly related to the well-being of the society than provisioning and regulating services [4
]. In addition, the characterizations of most cultural services categories are imprecise which makes difficulties in establishing the relationship between ecosystem structures and functions and the satisfaction of societal needs [74
]. However, it should be noted that their possibility for conciliation is low [4
], i.e., it is not possible to replace the loses of cultural ecosystem services while it is possible to substitute the locally degraded provisioning and regulating services by other means. Thus, the implication for the peri-urbanization processes is higher in cultural services case than in other ecosystem service categories. As the peri-urban areas develop more, the people’s dependency on the provisioning and regulating services may decrease while their dependency on cultural services raises [75
Respondents’ assessments were highly related with their interaction with the land use. The respondents’ perception of maximum use value in food and fodder may be due to their livelihood depending on crop and livestock production (97% of them). Timber and firewood production are also in the group of the highest perception, since the farmers’ source of energy is wood, and timber is used for housing construction and some house equipment. These result are in line with various assessments that found interaction with the land use [76
], their farming activities [66
] and livelihood dependency as factors which highly drive the favorable assessments of ES by stakeholders [77
]. Moreover, the interviewees assigned highest mean values to climate regulation and erosion prevention. During the interview, for some of the respondents’ climate regulation coincided with the timing of rain. They are really concerned about the timing of rain as they practice rain-fed agriculture and are good at recognizing the role of ecosystems in providing climate regulations (they are also getting awareness training by the kebele
’s natural resource experts). Regarding the importance of erosion prevention, stakeholders are more aware as the government has a 2-month campaign (January and February each year) on awareness creation and making terraces by the farmers on the land use.
According to our findings, generally there is a decreasing trend of supply of ES in the study areas over time, similar to previous studies at larger scales, which indicate a global tendency of decreasing ES supply [1
]. In the study area, the process of urban expansion has been taken as one factor for the degradation of the supply of ES in the peri-urban area through the replacement of cropland, agroforestry, and grasslands by urban land use such as housing construction, industries and manufacturing, infrastructure developments, etc. This result is consistent with the results of other studies which assessed the impacts of urban expansion on agri-ecosystem services that reveals the fact that the urbanization process results in losses of ES [15
]. The losses of ES of the peri-urban land due to urban expansion is irreversible. In the study area the rapid urbanization is projected to increase in the future [54
], which is believed to cause further losses of identified ES and the potential of the land use.
4.2. Implications of the Research Process and Findings
The Bahir Dar city administration is incorporating significant amounts of land each year from the study kebeles
. According to our earlier findings [23
], the city administration has expropriated, on average, 150 hectares of land in each year between 2007 and 2017. This implies that the city has been expanding on average by 150 hectares of land each year; on the other hand, the sizes of the four rural kebeles
(Addis Alem, Weramit, Wereb and Zenzelima) have been decreased by the same proportion. Our results confirmed that it is not only the provisioning services that are being lost in case of land expropriation for urban expansion, but also other ES categories. However, according to our earlier findings [23
], at the time of land expropriations for urban expansion, the land use decision makers are not taking in to account the total values of ES.
Therefore, we believe that the research process and the findings of this study may have the following implications: First
, the assessments of the use of ES and potential of the land use are thought to be vital for the planning and implementation of sustainable land use systems [3
]. In this regard, the results of this study can provide a valuable input for land use policy and decision makers to make environmentally friendly land use decisions. That is: (i) to consider the importance of all ES categories in the process of land expropriation for urban expansion, (ii) to integrate it into urban land use planning to achieve sustainable development [80
]. More specifically, to sustainably manage the lands using the information where a particular ES is very useful and which kebele
and land use has more potential. For instance, part of the expropriated land can be used for urban green space which can provide ES that can moderate climate change and make the city sustainable [81
, the research process itself has its own implications in awareness creation among the stakeholders about the benefits that nature is providing to the society. Many of the farmers (74%), who participated in this study are illiterate and might not have been aware of some of the ES benefits. Therefore, the data collection processes can potentially be taken as an awareness creation movement among the stakeholders [82
]. There is a consensus that a well - informed community will be more willing to accept environmental protection measures [36
, it can be taken as an additional case study to the literature on the use of long-time experiences of the community, and the knowledge and skill of experts to assess the values of ES in data poor regions. Our research investigated stakeholders’ perceptions about the use, potential and changes of an entire range of ES in the three land use types, which makes even more interesting since there are only a few ecosystem research assessments covering all the ES of a given area [37
]. Lastly, the methods used, and the findings of this study, can serve as an incentive to conduct similar studies and help to initiate an additional environmental policy in Ethiopia related to land expropriations due to urban expansions.