Can Cities Ever Be “Natural”? An Ecologist’s View

When people think about nature, they often picture remote forests, unbroken grasslands, or mountain landscapes far removed from daily human activity. Cities, with their concrete surfaces, dense infrastructure, and constant disturbance, are usually imagined as the opposite of nature. From an ecological perspective, however, this division between the “natural” and the “urban” is far less clear than it appears.

I often hear people say that cities have no real ecology, only fragments of greenery placed for decoration. Yet the idea that nature only exists where humans are absent is a relatively recent cultural construct. For thousands of years, people have shaped ecosystems through agriculture, fire use, grazing, and settlement. Many landscapes now considered natural carry deep legacies of past human activity. Cities represent an extreme form of this influence, but they do not mark the end of ecological processes. Instead, they create new conditions under which life must persist, adapt, or disappear.

Urban environments dramatically alter temperature, water availability, soil structure, and light conditions. In my own fieldwork, I see this clearly in the ground itself; soils that feel almost cement-like underfoot, narrow tree pits that hold water only briefly after rain, and streets where heat lingers well into the evening. Pavements seal the soil surface, buildings reshape wind and shade, and repeated disturbance becomes part of everyday ecological life. Yet plants continue to grow, animals establish populations, and microbes drive nutrient cycling even in these constrained spaces.

Urban nature is often dismissed as artificial or inauthentic, but ecological function does not disappear simply because an environment is human-made. Photosynthesis, transpiration, decomposition, and species interactions still occur in cities, even if they are modified by urban conditions. Trees store carbon and cool the air, insects pollinate flowers, birds disperse seeds, and soils host complex microbial communities. These processes may be altered or fragmented, but they remain ecologically meaningful.

From an ecological standpoint, cities act as powerful environmental filters. Urban heat, drought, pollution, limited rooting space, and repeated disturbance select for species and traits that can tolerate stress. Some species fail quickly, others persist for decades, and a few thrive in unexpected ways. This filtering process makes cities valuable systems for studying resilience and adaptation. Urban ecosystems are not ecological voids; they are dynamic environments shaped by constraint, selection, and survival.

Urban ecosystems are often described as degraded, and in many ways they are. Species richness is typically lower, food webs are simplified, and non-native species are common. Yet degradation does not imply irrelevance. Urban ecosystems provide services that directly affect human health and quality of life, including temperature regulation, air purification, stormwater absorption, and the psychological benefits associated with everyday contact with green space. For many people, cities are where their relationship with nature begins and unfolds.

Whether cities can ever be considered natural depends on how the term is defined. If natural means untouched by humans, then cities will never qualify. If natural instead refers to living systems governed by ecological processes, then cities clearly belong within that definition. Urban environments can become more ecologically functional when design and management prioritize biological processes rather than appearance alone.

Urban ecology challenges us to rethink conservation in a world where most people live in cities. Rather than viewing cities as failures of nature, we can recognize them as places where ecological processes persist under pressure and where human decisions have immediate ecological consequences. The future of ecology will not be written only in protected wilderness, but also in streets, backyards, parks, and vacant lots.

Cities may never resemble untouched landscapes, but they can support living, functioning ecosystems. The more important question is not whether cities can be natural, but how thoughtfully we choose to coexist with nature where most of us live.