32 Planning land
2005). However, just as for historic building restoration and preservation, deter-
mining what the place looked like, the basic goal, and how attainable the goal
is remains problematic. Management might, for example, periodically burn an
area to reduce colonizing woody plants and produce a grassland with rare grass-
land species. But maybe the former grassland being mimicked was itself simply
aproduct of human economic activity, such as burning shrubs to stimulate
grass for sheep grazing (Foster and Aber2004). Or management might attempt
tominimize the presence of non-native invasive species. As suggested above, in
an urban region with a dense human population, manifold widespread activi-
ties, and outward urbanization spread, attempting to control non-native species
is reminiscent of Cervantes’ Don Quixote tilting with windmills. Still, maybe a
large nature reserve is one of the few places in the urban region where the goal
may be worthwhile. Keeping our eye on habitat loss and nature’s richness is far
more important.Wetlands
Wetland planning and conservation is particularly relevant and impor-
tant in an urban region, in part because wetlands tend to be scarce. Most were
drained and filled over history as human activities spread and intensified. Pro-
tecting the marshes, swamps, acid peatlands, and other wetlands that remain
in an urban region is a valuable societal priority. Wetlands provide ecosystem
services, including flood-hazard reduction and stormwater pollutant removal,
plus many other values from recreation to aesthetics and biodiversity protection
(Keddy2000,Mitschand Gosselink2000,Parsonset al.2002). However, mosquitoes
and public health problems may also be present (Robinson 1996).
Wetlandshave water atorabovegroundlevelforaprolongedperiod most
years. Three wetland characteristics are primary: hydrologic conditions, low-
oxygensoils, and so-called wetland vegetation. Planning and management of
awetland must focus on its surroundings, especially in the direction of incom-
ing water.
Wetland restoration may include mitigating degraded wetlands or creating
new ones. Establishing wetland vegetation and associated wildlife is the visible
part appreciated by society. However, wetland restoration mainly depends on
getting the hydrology right (Salvesen 1994, Mitsch and Gosselink2000,Keddy
2000,France2003). Three components are essential: establishing the right water
level to support wetland vegetation, maintaining the necessary entering flows
(and hence water source), and sustaining both inputs and water levels through
drought and flood periods over time. Tiny wetlands, particularly seasonal ones,
may be created at the ends of stormwater drainage pipes. Several types and sizes
of wetlands may be restored at the base of certain hills and mountains, and
particularly in floodplains with a high water table. Large wetland complexes may