Humans and nature are dependent on a healthy habitat, also in urban environments. A holistic discipline that brings both units together is urban ecology. This makes it predestined for research that is working on a more sustainable future, both ecologically and socially, and to form an integral part of sustainable urban planning. Sustainable urban planning works with measures for climate protection and adaptation and with concepts such as environmental justice to counter both gradual processes and extreme events leading to environmental degradation and socio-economic threats. Therefore, the urban nature urgently needs scientifically sound methods that draw on the vast resource of today’s environmental data.
Since the beginning of the 21st century, the majority of people live in cities. Improving the living conditions of urban populations is therefore one of the main interests of environmental science, politics and public debate. A central challenge in the urbanization process is the loss of important ecosystem services through soil sealing and vegetation loss, which lead to air and water pollution, increased impacts of extreme events such as heat waves and heavy rains, and to biodiversity loss. These far-reaching environmental problems have a direct impact on human health and may lead to further self-reinforcing effects.
The global changes caused by climate change urgently require an analysis of urban ecosystems. A more detailed understanding of how they function will enable us to both respond better to extreme events and counter gradual processes such as biodiversity loss or the urban heat island, as the recent summer heat waves around the globes have impressively shown. One way to curb these developments is to implement urban green infrastructure such as parks or small-scale measures such as green roofs. This is particularly advantageous because urban green can provide important ecosystem services directly in the human living environment.
To provide these ecosystem services, urban green infrastructure must be appropriately designed, distributed and managed. Therefore, the development of scientifically sound and regionally integrated management approaches to land use is necessary. This can be achieved through easy to use instruments that support spatial planning or governance actors to integrate ecological principles such as connectivity and complementarity as well as social-ecological systems thinking into policy and practice. Many urban ecosystem services are relevant to the immediate environment, where people live and work in constantly growing cities. While their scope is limited, the spatial arrangement, i.e. above all composition, configuration, permeability, density and location, of the green infrastructure is of central importance.
Despite considerable scientific progress, we still do not sufficiently understand the relationship between urban structures or management practices and different ecosystem functions and related ecosystem services. This is particularly true for the urban environment, as cities require a transdisciplinary, holistic approach that takes into account the complex urban web of human and natural relations. Ecosystem functioning affects many aspects of public health and human well-being, while human management affects ecosystem functioning. This mutual interaction not only generates risks, but also enables diverse biotopes with unique niches and high species richness to emerge.
The gain in scientific knowledge is faster today than ever. What is urgently needed are tools and frameworks that will allow us to better integrate and synthesize this wealth of knowledge – to engage science in planning and major policy debates.