40 Planning land
amajor source of outward-moving foxes. Some animals reach the small patches.
That relatively continuous influx helps prevent a small subpopulation from drop-
ping to very small. It also brings new genes to the small patch, reducing the
detrimental effects of inbreeding. In effect, the presence of a large natural patch
provides a brighter future for foxes in the landscape, and also for foxes in the
small fragments of nature surrounded by human land uses. In this way land
protection of large patches helps sustain biodiversity as a whole.
Spatial land planning for protection and management can provide additional
benefits that improve the persistence of species on small patches. Local species
extinction or disappearance from patches followed by recolonization of the
patches isreferred to asmetapopulation dynamics.Attributes of the patch pri-
marily affect local extinction rate, whereas attributes between patches mainly
affect recolonization. Large patch size and high-quality habitat on the patch
reduce the chance of a subpopulation size dropping to zero, i.e., local extinc-
tion. Increasing recolonization rate, in turn, benefits from patches being near
rather than far apart, from the presence of a connecting natural corridor or row
of stepping stones, and from higher-quality habitat conditions between patches.
Protecting and managing land to reduce local extinction and increase recolo-
nization provides a brighter future for species, including foxes, on the numerous
small natural-habitat fragments in the urban region.Planned cities
Since planning and urban regions are key themes in this book, we now
turn to the ambitious projects of whole cities that have been planned and built,
in order to gain insights into urban regions. City and urban planning and its
rich intellectual history, theory, diverse approaches, and examples, provide the
framework (Sutcliffe1980,Ravetz2000,Williset al.2001,Hall2002,LeGates
and Stout2003,Campbell and Fainstein2003,Berkeet al. 2006). Case studies
and giants in the field predominate, though guidelines and theories somewhat
emergent from history and persona exist. Still, it would be hard to articulate, for
example, US urban planning today without mentioning Frederick Law Olmsted,
David Burnham, Jane Jacobs, Robert Moses, Benton MacKaye, Rexford Tugwell,
Lewis Mumford, Ian McHarg, and even, perhaps, Britain’s Patrick Geddes.
Today’s theories to guide planning partly rest on earlier ‘‘basic” prin-
ciples, such as settlement, location, concentric-ring, industry, central-place,
neighborhood-unit, and circulation theories (Hall2002). Olmsted used proto-
ecology principles in his work, and Geddes frequently cited biological models,
ranging from nature to the human body, for his planning.