Biodiversity in the city.
Biodiversity, the variety of life, is everywhere. There are as many types of microbe on your skin as there are bird species in the forest and, uncomfortable as it may sound, you are never more than a few feet away from a spider.
It should not be a surprise that researchers at University of California Santa Barbara National Centre for Ecological Analysis and Synthesis claim that even modern cities contain “surprisingly high numbers of plant and animal species persist and even flourish in urban environments — to the tune of hundreds of bird species and thousands of plant species in a single city”
The NCEAS researchers also established that the “mix of species in cities reflects the unique biotic heritage of their geographic location”.
In other words there were a few widespread species that were found in many cities but in most of the cities the biological compliment was drawn from the local species pool.
Before complacency sets in and we decry the many years of warnings and advice over biodiversity loss, we should note that this information is relative.
Cities are not rain forests.
The number of species lost when trees are felled for agriculture, a freeway or a new suburb is dramatic. And species loss continues after the initial shock of clearing as opportunities arise for invasive species that predate or outcompete many of the remaining native plants and animals.
Cities are not farms either.
The biodiversity on a farm will not be as prolific or varied as the forest it replaced but there are many more species of plant and animal than live in the city.
The point of noting biodiversity in the city is really as simple as realizing that it is there; to recognize that life persists even in our concrete jungles.
This happens because life is tenacious and will cling on even in extremes. That it does so in cities has been called the ‘Central Park Effect’ because of the surprisingly large number of species found in New York's Central Park, a relatively small island of green within a huge city.
The NCEAS researchers took their findings further to consider the benefits of cities on global biodiversity. So although there was biodiversity in the city and that this retained a regional flavor, there were far fewer species in cities than in similar areas of undeveloped land — 92% fewer birds and 75% fewer plants.
But the good news is that these numbers were not higher still. To retain one in four plants from those present in the forest is remarkable.
Plants and animals do hang on even amongst the traffic, pollution and buildings.
It also means that there is a pool of species that can be added to if we plan well. Green areas, mature gardens, green walls, water quality measures and a host of local actions can help to increase biodiversity in the city.
Biodiversity really is everywhere. The problem is that whatever biology remains is not what it was before, there is major depletion of both components [genes, species, ecosystems] and attributes [diversity, abundance, composition].
There is little chance of biodiversity performing the functions it once did in the forest or woodland that was cleared.
And yet we have to be realistic. Cities are where people live, not rain forests. That a city has some wildlife in it at all is worth a lot to the people living there. But it's not really about conservation it is about the ability to connect somehow to nature, even in the city.
Look out for some Alloporus tips on how to love nature when you live in the city.
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