| "The urban
revolution has obliterated the natural environment, its wildlife, and its
wilderness. Amoeba-like, the city spreads out from its core. Following
roads into the countryside, industrial sites, housing developments, and
shopping malls engulf woods, fields, and croplands. As life in the inner
city becomes less tolerable, many of us, still retaining some vestiges of
our million years’ attachment to the natural environment, move to a
special twentieth-century semi-country institution, the suburbs. The
movement aggravates rather than improves the problem. Suburban lots - the
suburbanites’ little peasant plots - eat up land at an enormous rate.
Suburban development demands more highways and air-polluting automobiles
to carry suburbanites back to the city and to work. Highways and beltways
proliferate, burying more and more of the countryside beneath concrete and
asphalt. The city moves outward to swallow up suburbs, creating large
areas that are neither city nor countryside. These areas then become new
core areas that, once firmly established, initiate a further spread of
metropolitan areas. An extreme example is the large belt of coastal cities
that extends from Boston, Massachusetts, to Miami, Florida. Trapped within
this growth are pockets of natural vegetation and wildlife that may never
survive. "The urbanized environment with its parks and suburbs is a different world
ecologically than the one it displaced. The inner core is impoverished in
species of both plants and animals, mostly exotic and able to endure urban
conditions. Surrounding the core is an irregular ring of gradual change in
vegetation and animal life. In a zone of transition or deterioration the
plants are remnants of species such as maple, planted when the area was
largely residential. On the edges of the city, plant life is dominated by
small lawns with ornamental foundation plantings, largely conifers and
scattered shade trees. In the residential zone or the semi-suburbs, lawns,
flower gardens, ornamental shrubs, scattered, often large, old shade
trees, and some native species and some exotics dominate the plant life.
In the outer suburbs, the commuter zone, remain some vestiges of
predevelopment vegetation, including forest and scrubland. These forests,
subject to landowner modifications, are a mix of native and exotic
landscape species, and their overall structure has been simplified.
Further, the region is permanently altered. Waterways are often
channelized, soils have been disturbed and altered, plant life is subject
to such stresses as air pollution and soil compaction, and native fauna is
subject to competition and predation from domestic and exotic animals.
From inner city to outer suburbs, urban plant communities are human
creations, reflecting life-styles, values, and goals of the human
inhabitants, not nature.
"Adding to the physical disturbance is large-scale diversion of water from
rivers and lakes for irrigation, seriously effecting the health and
stability of the aquatic ecosystems exploited. Drainage from agricultural
fields carries fertilizers and pesticides to groundwater, streams, and
lakes, reducing water quality and impairing the health and reproduction of
wildlife." |
