Late 21st Century Strasbourg

Cities in the twenty-first century are increasingly understood not as separate from nature, but as living socio-ecological systems in which human infrastructure and ecological processes must coexist. Urban wildlife refuges—ranging from parks and river corridors to overlooked brownfields and green roofs—are becoming embedded within the fabric of the city rather than pushed to its edges. This shift reflects a deeper recognition that biodiversity can persist in fragmented urban spaces if those spaces are connected and designed intentionally. Instead of treating nature as decorative or residual, cities are beginning to integrate it as a functional layer of infrastructure that supports both human and nonhuman life.

This integration is especially important because it enables cities to provide ecosystem services that would otherwise be extremely costly to replicate through engineering alone. Vegetation moderates urban temperatures, reducing the heat island effect and lowering energy demand for cooling. Trees and soils filter pollutants from the air and store carbon, while wetlands and permeable landscapes absorb stormwater and reduce flood risk. Even small habitats can sustain pollinators and support urban food systems, while access to green environments improves public health and wellbeing. These services are often invisible in economic terms, yet their absence would require expensive technological substitutes that are less adaptive and less resilient over time.

What is changing most significantly is not just the presence of green space, but the way it coexists with urban infrastructure. Roads are being reconceived as ecological corridors lined with trees and permeable surfaces. Buildings are designed to host vegetation and provide nesting habitats. Drainage systems are transformed into wetlands that manage water while supporting biodiversity. Former industrial sites are reimagined as ecological refuges rather than cleared for uniform development. This blending of grey and green systems allows cities to grow denser without losing ecological functionality, creating landscapes that are multifunctional rather than segregated.

These dynamics do not operate only at the scale of a single city. Ecosystem services depend on connections that extend across metropolitan regions and even between neighboring cities. Green infrastructure must link urban centers to surrounding forests, agricultural land, and river systems, forming continuous ecological networks. In this sense, cities are not isolated units but nodes within larger environmental systems, sharing resources such as water regulation, biodiversity, and climate stabilization. As urbanization accelerates, these interconnections will become essential for maintaining resilience at regional and continental scales.

The experience of Strasbourg illustrates how these ideas can be put into practice. The city has developed an extensive green-blue network that includes large parks, river landscapes, and protected alluvial forests along the Rhine. These natural areas are not separate from the city but integrated into its spatial and ecological structure, acting as carbon sinks, flood buffers, and biodiversity reservoirs. Strasbourg’s planning approach treats green space as a form of infrastructure and cultural heritage, embedding it into policy and long-term development strategies rather than considering it an optional amenity.

At the same time, Strasbourg functions as a kind of urban laboratory where biodiversity is supported across a wide range of environments, from formal parks to informal wastelands and even built structures. This diversity of habitats allows wildlife to adapt to urban conditions while maintaining ecological processes within the city. Importantly, the city has also begun to quantify the value of these systems, measuring benefits such as air pollution removal and carbon storage. By translating ecological functions into measurable outcomes, Strasbourg strengthens the case for investing in nature-based solutions as part of mainstream urban planning.

As cities continue to evolve throughout this century, the integration of wildlife refuges with infrastructure will become not just desirable but necessary. Increasing density, climate pressures, and resource constraints will make it impossible to rely solely on external ecosystems or engineered systems to provide essential services. Instead, cities will need to operate as ecosystems themselves, where built and natural elements are interwoven and mutually supportive. The example of Strasbourg suggests that this transformation is already underway, pointing toward a future in which urban environments are designed not only for human efficiency, but for ecological continuity and resilience as well.