Nature forms interdependent networks in a landscape, which is key to the survival of species and maintenance of genetic diversity. Nature also provides crucial socio-economic benefits to people, but are typically undervalued in political decisions. This has led to the concept of Green Infrastructure (GI), which defines an interconnected network of (semi-)natural areas designed and managed to preserve a wide range of ecological, social, and economic benefits. GI is increasingly being recognized as a policy instrument to better integrate nature's values into landscape planning decisions, but there is no consensus in the scientific literature on how to map and implement GI, and its operationalization in spatial planning has never been done in Switzerland. Consequently, this thesis aims to examine how the concept of GI can be effectively implemented to support the integration of natural capital values into landscape planning decisions, with a focus on the canton of Geneva, Switzerland.