26 Regions and land mosaics
level. Having a similar woody clump adjacent on the neighbor’s lot, or even four
adjacent areas of woody vegetation where four lots intersect, can produce quite
asignificant habitat for woodland species in a housing development.
Twoother design options that have big effects on biodiversity should be
mentioned. First, edges or boundaries between land uses or habitats may be
hard or soft (Forman1995).Hard boundariesare relatively straight and abrupt
and attract a limited number of species.Soft boundaries, which normally attract
many more species, may be gradual (i.e., wider edges), curvy with lobes and
coves, or simply irregular and patchy.
The second broad design option is to artificially enhance or inflate biodiversity
byadding human-created resources. The options stretch the imagination: bird
feeders, brush piles, limestone walls, east--west soil berms, bat boxes, gradual fish-
pool borders, still or splashing water, deer salt-licks, red foliage to attract autumn
bird-migrants, and on and on. Concentrating such approaches can artificially
raise biodiversity enormously.
In short, city parks, road networks, stream corridors, and house lots are small
objects that are typically numerous and widespread across an urban region.
Each has a range of spatial attributes suggested above which represent useful
handles for planning and design options. More importantly, wise solutions, when
multiplied by the hundreds or thousands, are likely to have a major cumulative
beneficial effect on the urban region as a whole.