An urban wild is a remnant of a natural

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...

found in the midst of an otherwise highly developed

urban area An urban area, built-up area or urban agglomeration is a human settlement with a high population density and infrastructure of built environment. Urban areas are created through urbanization and are categorized by urban morphology as cities ...

Utility

Urban wilds, particularly those of several acres or more, are often intact ecological systems that can provide essential ecosystem functions such as the filtering of urban run-off, the storing and slowing the flow of

stormwater Stormwater, also spelled storm water, is water that originates from precipitation ( storm), including heavy rain and meltwater from hail and snow. Stormwater can soak into the soil ( infiltrate) and become groundwater, be stored on depressed l ...

, amelioration of the warming effect of

urban development Urban means "related to a city". In that sense, the term may refer to: * Urban area, geographical area distinct from rural areas * Urban culture, the culture of towns and cities Urban may also refer to: General * Urban (name), a list of peop ...

, and generally benefiting local

air quality Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are many different types ...

. Typically, urban wilds are home to native

vegetation Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic charac ...

and

animal Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage ...

life as well as some

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...

. Urban wilds are vital to

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

migratory bird Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. Many species of bird migrate. Migration carries high costs in predation and mortality, including from hunting b ...

s that have

nest A nest is a structure built for certain animals to hold eggs or young. Although nests are most closely associated with birds, members of all classes of vertebrates and some invertebrates construct nests. They may be composed of organic materi ...

ed in a given area since prior to its

urbanization Urbanization (or urbanisation) refers to the population shift from rural to urban areas, the corresponding decrease in the proportion of people living in rural areas, and the ways in which societies adapt to this change. It is predominantly th ...

Preservation

Without formal protection, urban wilds are vulnerable to development. However, achieving formal protection of a large urban wild can be difficult.

Land tenure In common law systems, land tenure, from the French verb "tenir" means "to hold", is the legal regime in which land owned by an individual is possessed by someone else who is said to "hold" the land, based on an agreement between both individual ...

of a single ecological area can be complex, with multiple public and private entities owning adjacent properties. Key strategies used in the preservation of urban wilds have included conservation restrictions that keep complex land tenure systems in place while protecting the entire

landscape A landscape is the visible features of an area of land, its landforms, and how they integrate with natural or man-made features, often considered in terms of their aesthetic appeal.''New Oxford American Dictionary''. A landscape includes the ...

. Public/private partnerships have also been successful in protecting urban wilds. The urban wilds prioritized by municipalities tend to be partial

wetlands A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The p ...

that perform a range of ecological services while contributing to the

biological diversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic ('' genetic variability''), species ('' species diversity''), and ecosystem ('' ecosystem diversity'') ...

of the region.

Passive parks

There is some discussion about whether natural areas that are not at an appropriate scale to perform significant

ecosystem services Ecosystem services are the many and varied benefits to humans provided by the natural environment and healthy ecosystems. Such ecosystems include, for example, agroecosystems, forest ecosystem, grassland ecosystems, and aquatic ecosystems. ...

should instead be categorized as passive parks as opposed to urban wilds. Smaller urban wilds are used for passive recreation and have less value to the city in terms of enhancing ecosystem function.

References

{{Reflist Urban planning Parks Ecology