Environmental Engineering Reference
In-Depth Information
natural economies cannot be about deciding which species in the portfo-
lio should be let go. Rather, it is about recognizing the need to keep all
species as part of the portfolio.That is, conservation should be about man-
aging for sustainable function of ecosystems, not about protecting selected
species.The goal of management, then, is deciding what abundance of the
different species should make up the portfolio in order to achieve some de-
sired end.This reasoning is predicated on the idea that species play comple-
mentary rather than strictly redundant roles in determining ecological
functions, for which there is some evidence (chapter 8).
Second, natural economies oper-
ate on longer timescales than most
market economic systems.There isn't
a measure of daily performance such
as a Dow-Jones or NASDAQ index
for natural economies because they
do not respond to changes that
quickly.As illustrated in chapter 7,the
effects of tinkering with an ecologi-
cal portfolio (e.g., predator species re-
movals to enhance game species
populations) can require decades to
half centuries to fully manifest them-
selves in ways that are detectable by
scientific measurement. Thus, the
consequences of our ecological in-
vestment choices often will only be fully realized by our children and grand-
children. This cautions against a strategy of species triage because that
inevitably dooms some species to extinction.That is, new companies and
stocks can be freely created; new species cannot.Thus, the potential for ir-
reversibility in investment choices created by triage strategies paints our
children and grandchildren into a proverbial environmental corner.
I have, nonetheless, offered examples of investment reversibility in a nat-
ural economy by highlighting in chapter 7 the case of wolf reintroductions
into Yellowstone Park. Restoring the top carnivore led to changes in the
distribution and abundance of the wolves' major prey species, elk, and in-
creases in the abundance of tree species that are both food resources for elk
and habitats for other animal species. Devising ways to restore ecosystems,
to correct what in hindsight may have been imprudent choices, is an im-
Intelligent tinkering with an ecolog-
ical portfolio requires that we
appreciate some important differ-
ences between market and natural
economies. First, and foremost,
natural economies obey classical
laws of thermodynamics, which
means that we cannot “grow”
them indefinitely. Furthermore, the
consequences of our ecological
investment choices often will only
be fully realized by our children
and grandchildren.
