Conservation Biology 387Restoring Damaged or
Destroyed Habitats
When preserving habitats is not
possible, scientists can reclaim
disturbed lands and convert
them into areas with high bio-
logical diversity. In restoration
ecology, an important part of
in situ conservation, ecological
principles are used to help return a degraded environ-
ment to a more functional and sustainable one.
Restoration of disturbed lands creates biological hab-
itats and provides additional benefits, such as the regen-
eration of soil damaged by agriculture or mining. The
disadvantages of restoration include the expense and the
time required to restore an area. Even so, restoration is
a vital aspect of in situ conservation, as restoration may
reduce extinction.deserts, the tropical grasslands and savannas of Brazil and
Australia, many islands and temperate river basins, and dry
forests all over the world.
Wildlife Refuges The National Wildlife Refuge
System, established in 1903 by President Theodore
Roosevelt, is the most extensive network of lands and
waters committed to wildlife habitat in the world. The
National Wildlife Refuge System contains more than
545 refuges, with at least 1 in each of the 50 states, and
encompasses 38 million hectares (95 million acres) of
land (see Figure 13.1). The refuges represent all major
U.S. ecosystems, from tundra to temperate rain forest to
desert, and are home to some of North America’s most
endangered species, such as the whooping crane. The
mission of the National Wildlife Refuge System, which
the U.S. Fish and Wildlife Service (FWS) administers,
is to preserve lands and waters for the conservation of
fishes, wildlife, and plants of the United States.
restoration
ecology The study
of the historical
condition of a human-
damaged ecosystem,
with the goal of
returning it as closely
as possible to its
former state.Human knowledge of ecosystems is limited,
and more scientific data are needed to make
good management decisions.Conservation
management must be
adaptive (flexible to
meet new problems)
rather than adhere to
old procedures
because “that’s what
has always been
done.”Human-affected environments
often surround protected
areas, threatening them with
invasive species, pollution,
and other problems.Human development
threatens some
protected areas—for
example, the harvest
of natural resources
for human use.Protected areas are often so fragmented
that, when a local population declines in
number, natural migration to rebuild the
population can’t occur.Protected areas
are often too small to
support certain populations
and ecological processes in
the long term.Humans are an
important part of
nature. Human values,
needs, and desires
must be considered
when making
management
decisions.Challenges in
conservation management-iÊV >i}iÃÊÊVÃiÀÛ>ÌÊÊ>>}iiÌÊUÊ}ÕÀiÊ£x°£äÊ
What are some specific human activities that have
likely harmed wildlife habitats around the world? in
environments near you?GLOBALLOCAL