A systematic literature review of soil ecosystem services in the East and Southern African regions

Background Healthy soils provide foundational ecosystem services for human well-being, known as Soil Ecosystem Services (SESs). Ecosystem and landscape transformations in Sub-Sahara Africa have resulted in a significant decline in soil health and the services it provides. This deterioration is primarily driven by overexploitation of natural resources, climate change, unsustainable agricultural practices, uncontrolled human settlement, and infrastructural developments. Therefore, efforts have been directed towards understanding and generating knowledge to enhance soil health and ecosystem services. We reviewed the scope of soil ecosystem services studies in East and Southern African countries to provide an overview of existing knowledge gaps and needs. Methods We reviewed 330 studies on soil-related ecosystem services collected from Web of Science in September 2024 using bibliometric analysis and systematic quantitative content analysis (SQCA). We focus on categories of soil ecosystem services, geographic scales, data collection methods, and soil ecosystem services drivers of change. Results and discussion We show that the studies quantified different SESs, 55 studies included spatial mapping, 33 temporal analysis, and 8 stakeholder participation. Only six studies provided an economic valuation of SESs. A total of 480 soil ecosystem service assessments were identified across the reviewed studies. Of these, 192 studies evaluated soil-related ecosystem services, while 288 focused on soil management-related ecosystem services. The regulation of climate services was the primary focus, accounting for 236 assessments (49%). Soil nutrient cycling comprised 167 (35%). Erosion control was evaluated in 20 studies (4%), while 17 studies (3.5%) assessed food and nutrition crops, and 40 studies (8.5%) examined other soil ecosystem services. Only four (4) studies examined water provisioning services, and two (2) addressed cultural services such as nature-based education and training, and nature-based aesthetics. Most of the studies (89%) focused on local/specific landscapes, 6% on the national scale, and 5% on the transnational scale. Based on the multi-perspective analysis, 242 studies concentrated on a singular perspective: ecological, economic, or social. Only 12 studies analyzed all three perspectives together. In addition, studies rarely applied multi-data integration tools such as Artificial Intelligence for Environmental Sustainability, Integrated Valuation of Ecosystem Services and Trade-offs, or machine learning algorithms. Land management practices, climate change, and changes in land use were the main drivers of change studied, while other drivers, such as agricultural intensification and road development, remained understudied. Conclusions This review identifies underdeveloped research areas such as cultural, food, and water provisioning services and data analysis methods that future studies may focus on. Furthermore, the review provides an understanding of scientific collaborations and soil ecosystem services drivers of change in East and Southern African regions essential for policy development and implementation.