Environmental Engineering Reference
In-Depth Information
wintering grounds of migratory waterfowl in the southern United States
and along northward migratory routes, improves the health and survival of
geese that spend the summer in Canadian arctic tidal flats.These geese have
reached enormous densities such that they now have a cascading and dev-
astating effect both on the production and abundance of vegetation and
on nutrient cycling within that arctic ecosystem (Jefferies et al. 2004). In
particular, they are beginning to cause the collapse of normal arctic ecosys-
tem function and there are hints that the damage may be irreversible be-
cause of wholesale changes in the physical attributes of the soil (moisture,
salinity, and temperature).
The most important lesson here is that it is no longer tenable to think
that the world is divided by sharp, impermeable boundaries, be it between
land and water, urban and rural, south and north, tame and wild. More im-
portantly, we need to contemplate the effects of our local actions in the
broader context. Returning to the goose example, reversing the trend of
ecosystem damage in the arctic is not simple. Developing policies to elim-
inate the agricultural practices in the southern United States to protect
comparatively uninhabited arctic ecosystems in another country would in
all likelihood not be given more than cursory consideration. But, what if
the opposite happened? What if some sort of management activity in the
arctic enhanced the goose populations such that geese heavily damaged
agricultural crops during their stay on the wintering grounds? This reason-
ing underscores that thinking globally
when acting locally can no longer
rest within the domain of environ-
mental activism. It must now be a
matter of course.This is further un-
derscored by recent understanding of
effects on ecosystems across global
scales.
What if the opposite happened?
What if some sort of management
activity in the arctic enhanced
the goose populations such that
geese heavily damaged agricultural
crops during their stay on the win-
tering grounds? This reasoning
underscores that thinking globally
when acting locally can no longer
rest within the domain of environ-
mental activism. It must now be a
matter of course. This is further
underscored by recent understand-
ing of effects on ecosystems across
global scales.
Humans and Geographic Transport of
Species
Globalization through expanding
transport and commerce over the past
five hundred years has also increased
the capacity of species within one ge-
ographic range to invade new geo-
