Services from ecosystems underpin water, food and energy security – whether abundance of fish, flows to turn turbines or water stored to mitigate scarcity and supply irrigation. Services provided by nature perform many of the functions of infrastructure, e.g. upland watersheds store water, wetlands store and clean water, floodplains buffer floods, rivers provide water transport and mangroves and coral reefs reduce disaster risk for coastal communities. These services are known as natural infrastructure. In fact, ecosystem services are at the centre of the water, energy and food security nexus (Figure 5).