Environmental Engineering Reference
In-Depth Information
Box 6.5
Urban biodiversity
Urban biodiversity is the variety and richness of living organisms (including genetic
variation) and habitat diversity found in and on the edge of human settlements. This
biodiversity ranges from the rural fringe to the urban core. At the landscape and
habitat level it includes:
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Remnants of natural landscapes (e.g. leftovers of primeval forests).
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Traditional agricultural landscapes (e.g. meadows, areas of arable land).
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Urban-industrial landscapes (e.g. city centers, residential areas, industrial parks,
railway areas, formal parks and gardens, brownfields).
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Diversity of plants and animals in the urban landscape shows some interesting
patterns:
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The number of plant species in urban areas often correlates with human
population size - more so than it does with the size of the city area.
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The age of the city affects species richness; large, older cities have more
plant species than large, younger cities.
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Diversity may correlate with economic wealth. For example, in Phoenix, USA,
plant and bird diversity in urban neighborhoods and parks shows a significant
positive correlation with median family income.
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Twenty per cent of the world's bird species and 5 per cent of the vascular
plant species occur in cities.
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On average, 70 per cent of the plant species and 94 per cent of the bird
species found in urban areas are native to the surrounding region.
Source: Secretariat of the Convention on Biological Diversity (2012: 8).
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Increasing the biodiversity of urban food systems can enhance food and nutrition
security.
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Ecosystem services must be integrated in urban policy and planning.
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Successful management of biodiversity and ecosystem services must be based on
multi-scale, multi-sectoral, and multi-stakeholder involvement.
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Cities offer unique opportunities for learning and education about a resilient
and sustainable future.
•
Cities have a large potential to generate innovations and governance tools and
therefore can and must take the lead in sustainable development.
It is also important to keep in mind that just as cities influence biodiversity,
biodiversity influences cities and the quality of urban life. Water supply, recreation,
health, atmosphere and temperature are all influenced by the type and amount of
biodiversity existing within an urban environment. Consequently, the governance
of cities is an important, and in some cases, determining factor in sustaining or
creating biodiversity in urban environments.
