East Africa heavily relies on agriculture and forests for food and to support informal livelihoods (Salami et al., 2010). The region’s fertile soils, diverse climates, and suitable growing conditions support a wide range of crops, including staple foods like maize, sorghum, millet, and beans (Tittonell et al., 2010; Kansiime et al., 2018). Agriculture is a significant contributor to the economy and employment in East Africa, with millions of people involved in farming and related activities. Assessing food production helps understand the availability, accessibility, and sustainability of the region’s food supply facing challenges like climate variability, market demands, policy restrictions etc (Midega et al., 2015). These challenges affect the wellbeing and livelihoods of the locals and exacerbates forest dependency, especially on provisioning ES. This comparative review revealed that all categories of provisioning ES were assessed in different studies, as shown in Table 1 , with varying contribution to forest fringe community’s livelihood and use.

In Kenya, 42% of the respondents in Mt Marsabit identified provisioning service like wood fuel and fodder for livestock as the most frequently used amongst other ES (Ouko et al., 2018). According to the respondents, anthropogenic activities like deforestation reduced supply of the provisioning ES to local forest communities. The research findings recommended long term engagement with the local community to initiate social learning processes that improve forest management practices. Similarly, in Uganda (Mawa et al., 2022) about 50% of the Budogo respondents identified wood fuel and raw materials like thatch material as the most frequently used for both subsistence and commercial purposes (Masiga et al., 2012). Mawa et al. (2022) revealed that participants in forest conservation groups had increased income derived from forest stands after two decades of management from USD 281 to USD 359. This was attributed to the allocation of agricultural use sections in forest plantation to participants who planted trees and gained income from the harvest. Another contributing factor was the involvement of participants in PES schemes in the region that promoted farm planting of trees with cash transactions for participating in the PES scheme (Aganyira et al., 2020). Further, the findings recommended that community involvement in forest management would significantly enhance the forest adjacent livelihoods and promote sustainable non-farm economic models with higher returns (Call et al., 2017).

In Rufiji (Tanzania) the respondents identified 67% of the provisional ES as the most important amongst other ES due to their direct market value and ease of accessibility (Nyangoko et al., 2022). Some of the prioritized provisioning ES include poles for building, wood fuel for cooking, and honey used as additive in tea. According to Nyangoko et al. (2022) some other provisioning services were identified but ranked lowly like traditional medicines, which were used in the past before the presence of health care centres offering modern medicines. In contrast to the findings in Mt Marsabit (Kenya), respondents in Rufiji identified fodder as an important provisional ES, but lowly ranked due to inland grazing (i.e., grasses and shrubs). In Ethiopia’s Munessa-Shashemene forest (Furo et al., 2022), the provisioning ES identified as important included wood fuel, honey, construction poles and non-timber forest products that support household income. This overdependence on the forest resulted in forest degradation and deforestation (Duguma et al., 2019). Further, Girma et al. (2022) indicated that wood fuel contributed more to household income compared to other provisioning ES identified by the respondents, mainly attributed to the use of wood fuel in alcohol production within the study area. The policy recommendations of the study were to incentivize and subsidize strategies that increase agricultural income for the studied local communities (Abebaw et al., 2012).

Regulating services occurred as either final or intermediate benefit, and often supporting the delivery of other service categories (Kumar et al., 2010). In most of the economic valuation of ES, high consideration was given to services with a consumptive or productive function (Kieslich and Salles, 2021). Our findings revealed that water regulation, carbon storage and climate regulation had the highest percentage share in terms of assessments amongst the other regulating services ( Table 1 ). These results reflect the general interest to assess deforestation rates and establish sustainable forest management within tropical forest ecosystems in developing countries (Rahman et al., 2017), because of their ability to sequester and store carbon, improve water quality and quantity, regulate floods and climate (Logsdon and Chaubey, 2013; Gould et al., 2024). Interest for regulating ES varies according to the spatial scale. For instance, in Kenya the implementation of a PES mechanism with the aim of equitable payment for watershed in reference to water quality as ES ensured up stream farmers managed their lands to control soil erosion, conservation of riparian lands by reforestation, reduce use of ago- chemicals, and use of grass strips to retain soil (Nyongesa et al., 2016). This improved the water quality downstream, and participants of the PES mechanism reported an improvement in soil fertility and increased crop productivity (Haile et al., 2019).

East Africa is the preferred destination for most of the carbon sequestration PES in Africa (Jindal et al., 2008; Lee et al., 2016). For instance, in Kibale (Uganda) (Cavanagh and Benjaminsen, 2014) the carbon sequestration PES has led to 1.2 million tons of carbon sequestered since inception (Omeja et al., 2011). The project totals about 6,500 ha of restored natural forest and has directly created 140 permanent jobs. Some of the PES schemes indirectly promoted regulation ES which was not the focus of the PES schemes. For instance, the PES scheme in Kenya (Khalifa et al., 2021) with the aim of incentivizing local communities to be involved in forest management by using commercial insects, led to increased abundance of pollinating bees which benefited the horticultural famers.

In Tanzania, Nyangoko et al. (2022) assessed ES in Rufiji Delta and established that 53% of the respondents identified three regulating ES that improved their well-being i.e., sediment trappings, coastal protection, and climate regulation. Further, Ntibona et al. (2022), revealed that respondent’s insight on the value of mangrove forest protecting their villages coincided with coastal flooding due to overflow of River Rufiji. The respondents also identified rain formation as a contribution of mangrove forest, which provided suitable conditions for agricultural activities (Njana, 2020). Sediment trappings had the lowest score from rankings of the regulating ES, and this was attributed to its intangible value, which made it difficult to identify and rank. In Ethiopia, Mekuria et al. (2018) determined that changes in regulating ES occurred in communal grazing lands after the establishment of enclosures. The study revealed that all the enclosures displayed a higher ES than communal lands. Over a 30-year period, 246 Mg ha -1 of carbon was sequestered while the total soil nitrogen increased by 7.9 Mg ha -1. The net ES value of the enclosures was 28% more than alternative wheat production. This highlighted how enclosures were a better competitive alternative land use than communal lands (Mekuria et al., 2018; Kleinschroth et al., 2021).

The valuation of supporting ES was limited due to a lack of consensus in the definition of terms when the intermediate benefits were assessed (Khan, 2020). In this review, supporting services were the least assessed category at 6.42%. Moreover, only three services resulted from this meta-analysis of ES valuation i.e., habitat at 62%, nutrient cycling at 21% and soil formation at 17% ( Table 1 ). Similarly, a study on the global perspective of ecosystem classification by Notte et al. (2017) established that some studies opted to exclude the economic valuation of support services because of the difficulty in finding a valuation technique which distinguishes between intermediate services and final benefits (Boerema et al., 2017). Further, some services such as soil formation often require a much longer time frame for proper assessment, while others, like nutrient cycling, must be evaluated while considering underlying ecological systems which pose a potential for duplicity in evaluation (Khan, 2020; Kadykalo et al., 2021; Ingram et al., 2023).

Provision of ES is dependent on the state and maintenance of habitats which form the grounds for most biological interactions between organisms (Rajpar, 2018). For instance, the ecosystem accounting study in Uganda by UNEP revealed that protected wildlife habitats prevented loss of natural ecosystem benefits and had a higher diversity index compared to degraded habitats (King and Obst, 2017). Similarly, the mangrove ecosystems along the coast of Kenya and Tanzania have also been credited for harbouring different species of crabs, which recycle nutrients by feeding on detritus that provide a food source for other marine species (Theuerkauff et al., 2018; Kimeli et al., 2021; Naidoo, 2023). In Ethiopia (Fashing et al., 2022), the isolated Afromontane regions exhibited higher levels of biodiversity and ecosystem services compared to the explored sections in the lowlands which consequently exhibited lower quality of ecosystem services (Mengist et al., 2022). Therefore, the quality of support ES which often stems from high species diversity relies on habitat status (Durán et al., 2020).

East Africa is one of the leading tourist destinations in the African continent, with a diverse portfolio ranging from clear sandy beaches, wildlife safaris and cultural tourism (Okello and Novelli, 2014; Gogo and Masaki, 2022). This review established that ecotourism ranked highest at 44% amongst all the other cultural services i.e., recreational at 23%, cultural practices at 20% and spiritual services at 13%. Results in Table 1 shows that nearly half of the ecotourism assessments were done in Kenya. Reports by the Kenya Tourism Board indicate that the country had over 2 million visitors pre-COVID-19 and 1.5 million of them were non-resident who primarily visited for holiday and ecotourism purposes, which directly contributed over USD 5 billion to the country’s GDP (Tourism Research Institute (TRI), 2023). Moreover, the tourism performance increased by 70.45% post -COVID-19 which registered a growth of 83% according to the annual report by Tourism Research Institute (Ministry of Tourism, 2022; Tourism Research Institute (TRI), 2023).

In terms of cultural tourism, both Kenya and Tanzania have the Maasai tribe who live in the border-region and are nomadic between the Maasai-Mara National Reserve and Serengeti National Park (Snyder and Sulle, 2011; Brinks, 2016). The unique cultural niche offered by the Maasai is their preservation of indigenous way of life i.e., beliefs system, arts, food, and customs (Ngaruiya, 2015; Oduor, 2020). Uganda has remnants of the Baganda Kingdom and Kabaka palaces, which offer a perspective on the indigenous cultural practices of the Baganda people (Kasfir, 2020). However, there is still heavy reliance on wildlife-based tourism since Uganda is landlocked and prioritizes marketing its national parks since touristic earnings from them account for approximately 9% of the national GDP (Ayorekire et al., 2019). Similarly, Tanzania’s tourism sector contributes about 10.7% to the national GDP (Kweka et al., 2003).

Ethiopia exhibited a diverse portfolio of cultural services: studies frequently assessed the spiritual and recreational sites such as the churches of Lalibela, the site of true Holy Cross of Christ, Ethiopian Tewahedo Orthodox churches (Gessese et al., 2021) and Tiya stones (Karbo, 2013). Moreover, the county has a religious history as amongst the oldest to accept Christianity and Islam (Aerts et al., 2016). However, the country’s tourism sector underperforms (Ali, 2016) when compared to countries like Tanzania and Kenya, resulting from touristic preference towards game drives and beaches as well as low marketing campaign to attract tourist from the relevant authorities (Norton, 1996; O’Halloran, 2016).

The production function approach under revealed preference category was used to assess supporting ES primarily associated with agricultural production i.e., soil fertility, nutrient cycling, and soil organic matter (Bekunda et al., 2005). Regionally, the African Development Bank (Salami et al., 2010) reported agriculture as one of the main economic activities in the East African region, primarily done by small holder farmers who occupied farmlands adjacent to forest ecosystems (Gelgo et al., 2023; Birkhofer et al., 2024). Further, the International Food Policy Research Institute affirms that agriculture contributes an average of 30% to the GDP of Kenya, Tanzania, Uganda, and Madagascar (Waithaka et al., 2013; Tambo et al., 2023). In Kenya, the land degradation surveillance network established indicators of productivity in Sasumua catchment and its capacity to deliver ES to the local farmers (Kyei, 2017). Similarly, sample plots in Usambara Mountains (Tanzania) determined the productivity of farms using soil organic carbon as an indicator. The studies enabled the improvement of crop productivity to small holder farmers (Winowiecki et al., 2016).

The rural communities in this review demonstrated overwhelming dependence on provisioning ES products such as wood fuel and raw materials (Miller et al., 2021). In Uganda, assessment on forest stock and household fuel choice established that the likelihood using biofuel significantly increased for households in rural areas near large forest stocks (Gebru and Elofsson, 2023). For wood and raw products, market price approaches determined demand and supply of wood fuels and the priority areas of wood energy use in Eastern Africa i.e., Rwanda, Kenya, Tanzania, Uganda, Egypt, Burundi, and DR Congo (Sulaiman et al., 2017). The study established a nexus between the use of wood fuels under the prevailing socioeconomic conditions within the region and suggested effective points of intervention (Drigo, 2005). Similarly, market price approaches were used to assess regulatory ES of two different catchment areas in Kenya (Elgeyo and Nyambane), and their estimated value was over USD 480 million (Eregae et al., 2022).

For cultural ES, the ecotourism and recreational value of Maasai Mara National Park in Kenya was estimated to be over US$ 70 million (Mulwa et al., 2018) per year, using the individual travel cost methods derived from modelling the visitor data logs and entrance fees (Márquez et al., 2023). Abdeta (2022) used a contingent valuation method (CVM) to assess household willingness to pay (WTP) for the conservation of spiritual and recreational values of forest sites in Ethiopia (Ramdas and Mohamed, 2014). The findings indicated that demographic and socio-economic factors influenced perceived ES benefits and highlighted the need for public participation to improve management of forest resources. Similarly, stated preference methods such as CVM were used estimate the WTP for the cultural ES in Wof-Washa Forest in Ethiopia (Getachew, 2018).

The global demand for accurate, verifiable, and cost-efficient forest inventory data, especially for the vast and unexplored tropical ecosystems in Africa, South America and Southeast Asia led to the adoption of the recent advancements in forest management i.e., use of satellites, drones, LiDAR, and GIS (Mitchell and Schaab, 2008; Tang and Shao, 2015; Li et al., 2019). This assisted to bridge conventional ecosystem management methods with remote sensing and GIS applications (Baban and Niţă, 2022; Diallo et al., 2024) in forest ecosystem valuation. Different studies (Breugel et al., 2011; Rodríguez-Veiga et al., 2017; Vorster et al., 2020) indicate a demand for accurate forest biomass data because of its significance in the estimation of carbon (Araujo Barbosa et al., 2015). Remote sensing techniques and GIS application were primarily used for the valuation of provisioning ES (Araujo Barbosa et al., 2015; Negese, 2024). In Eastern Africa, regulatory ES i.e., climate and weather variability too, were assessed to determine effect on agricultural output using remote sensed data from the period 1961 to 2016 (Luc et al., 2021).

The valuation of the provisioning ES in Central Ethiopia, Biratu et al. (2022) highly relied on spatial data derived from remote sensing techniques to get an estimate of the total ecosystem valuation for the timeframe 1986–2021. Similarly, remote- sensing and GIS approaches provided crucial data on water supply, which was used in the quantification of livelihood dependency of communities along the Omo River in Turkana Basin at the boarder of Kenya and Ethiopia (Kleinschroth et al., 2021). The data were crucial for the assessment of changes in ES benefits along River Omo Basin (Yigezu et al., 2018; Anose et al., 2021) and its implications on the culture of nomadic people in that region. The rise of interest in biomass and carbon storage estimates were incentivized by mechanisms such as REDD+ and carbon credit systems for developing countries (Scharlemann et al., 2010; Parrotta et al., 2012; Thangata and Hildebrand, 2012). For instance, USD 100 billion was pledged in the Africa Climate Summit towards climate adaptation on the continent (African Union (AU), 2023). In contrast, the priorities of the European countries towards quantification carbon are to reduce GHG emissions and reduce dependence on fossil fuels (Siddi, 2020; Allam et al., 2022). Further, the European Green Deal (Vela Almeida et al., 2023; Popielak et al., 2024) centres on assisting EU countries to become carbon neutral (European Union (EU), 2021).

The participatory approaches identified in this review (Langan et al., 2018; Ketema et al., 2021; Daw et al., 2023) i.e., interviews, focus groups discussions, and household surveys gave an overall perspective on the value attributed to the regulating ES. In the context of ES valuation, it was particularly important when assessing WTP for non-market ES i.e., temperature and coastal protection (Comte et al., 2016). In Kenya, interviews with open-ended questionnaires were the preferred method to assess and quantify the full value of ES benefits to livelihood of forest adjacent communities in Maasai Mau (Koech et al., 2009). Similarly, a series of household surveys and interviews in Uganda (Bush et al., 2005) were used to estimate the value of tropical high forest in protected areas to the livelihoods of communities surrounding them and determine contribution of the non-market ecosystem services to the GDP. This approach recognised the values communities hold, their priority towards ecosystem services and offered a more informed perspective for decision makers (Mawa et al., 2023).

For cultural ES, participatory approaches such as interviews, focus group discussions and household surveys (Waruingi et al., 2021; Masselus and Fiala, 2024) highlight the effectiveness of non- monetary approaches in evaluating perception of non-market values of ES such as culture and recreational benefits (Zeppel, 2007; Márquez et al., 2023). In Kenya, Wangai et al. (2017) used household surveys to determine cultural ES indicators of well-being within the peri-urban areas of Nairobi and to develop suitable ES response models. Similarly, Mwakaje et al. (2013) used data from key informants and focus group discussions to assess the perceived cultural ES benefits from respondents living in Northern Tanzania on the value associated with living near the Serengeti National Park (Zeng et al., 2023).