Spatial assessment of urban forest ecosystem services to explore opportunities for nature-based solutions: A study from Kumasi, Ghana

Project description

More than half of the world’s population already lives in cities. According to estimates, this share will rise to more than 70% by 2050. The fastest urbanization is taking place in developing countries. Due to the enormous population growth and urbanization, cities are facing numerous challenges. These include increasing air pollution, heat waves, droughts and floods, as well as poverty and socioeconomic inequalities. This increases the vulnerability of the population to extreme weather events.

In this context, nature-based solutions (NbS) are becoming increasingly important in urban planning. NbS are measures to protect, sustainably manage, and restore ecosystems that can address societal challenges. They simultaneously benefit human well-being and biodiversity. The urban forest is a very important ecosystem as it provides numerous benefits to the population. It promotes a good urban climate, reduces air pollution, regulates the water cycle, and mitigates the effects of climate change. In addition, urban forests promote social cohesion as they can serve as gathering places and contribute to the well-being and stress reduction of the urban residents.

However, growing populations and rapid urbanization exceed the planning and implementation capacity of many municipal authorities in West Africa and other parts of the world. The urban forest and its ecosystem services are under severe threat in Ghana, for example, due to the continuous conversion of urban green spaces to other land uses. This can also be observed in Kumasi. The metropolitan region in south-central Ghana, which serves as the case study for this project, is one of the largest agglomerations in the country with more than three million inhabitants and, like many cities in West Africa, is characterized by rapid growth and high population density. The city was built on the garden city model and was considered the “Garden City of West Africa” as recently as the 1960s. However, especially since 2009, much of the green space in the city has been lost, and the remaining fragments of urban forest have come under pressure from increasing urbanization.

To ensure sustainable development, urban forest management strategies that take into account biodiversity as well as human, social, and cultural factors must be implemented. However, this is only possible if the various services provided by the urban forest are recognized and properly valued and appreciated.

This project will therefore spatially analyze and quantify both biophysical and cultural ecosystem services as well as access, use, and valuation of the urban forest by the population. Explicitly, inhabitants of informal settlements will also be included in the analyses. Finally, trade-offs between the different services of the urban forest will be analyzed, which could be mitigated by management strategies. Together with representatives of different stakeholders, it will be determined how an improved understanding of the ecosystem services of the urban forest can improve management and governance strategies toward nature-based solutions. The overall goal of the project is thus to identify opportunities for NbS to tackle various climate and societal challenges in Kumasi, Ghana, and other cities in West Africa.

The project’s interdisciplinary methodological approach includes field campaigns with measurements of urban trees, geographic information system (GIS)-based analysis, participatory mapping with urban populations, and qualitative interviews with stakeholders.

Administrative data

Supervisor: Dr. Somidh Saha
Advisor: Prof. Dr. Sebastian Schmidtlein (IfGG-KIT), Prof. Dr. Fabian Fassnacht (Freie Universität Berlin), Prof. Dr. Armin Grunwald (ITAS)
Doctoral students at ITAS: See Doctoral studies at ITAS


Angela Beckmann-Wübbelt, M.Sc.
Karlsruhe Institute of Technology (KIT)
Institute for Technology Assessment and Systems Analysis (ITAS)
P.O. Box 3640
76021 Karlsruhe

Tel.: +49 721 608-28177