Everglades
part two
The modern
canal systems have introduced an over abundance of nutrients into a system that
developed with very low levels (of nutrients), impacting the everglades “in
several trophic levels, including microbial, macrophyte, and vertebrate
communities” (FDEP, 2011). Species dependent on shallow marshlands are disappearing.
An example of a species directly affected by this is the snail kite (Rostrhamus
sociabilis), which feeds exclusively on the apple snail (Ampullariidae); the
snails have depleted populations as a result of the changing marshlands.
Large
highway systems and roads make up much of the landscape of south Florida. All
of these anthropogenic changes to the Florida Everglades have presented
problems for maintaining biodiversity in south Florida. The highway systems
throughout south Florida “serve as barriers, confining many species of wildlife
within restricted areas” (Rocus & Mazotti, 2006, p. 1). This leads to
inbreeding, genetic depression and reduced adaptability to an environment that
is constantly changing (Rocus & Mazotti, 2006).
The Florida panther (Puma
concolor coryi), a flagship species of the Everglades (Ake, 2008), exhibits
signs of inbreeding (e.g. thoracic cowlicks and kinked tails) and severe
population declines (Johnson, et al., 2010). For larger species, such as the
Florida panther (Puma concolor coryi), Florida black bear (Ursus americanus
floridanus), Key deer (Odocoileus virginianus clavium) and the American
alligator (Alligator mississippiensis), the road barriers cause more
difficulties. The natural range of these larger, far ranging animals is
extensive, forcing them to cross road boundaries. Vehicle collisions are a
major threat to these species (Rocus & Mazotti, 2006).
“Above all,
the fragmentation of habitat from human activities across American landscapes
is considered to be the leading cause of species decline and the loss of
ecosystem integrity” (Peck, 1998, cited by Brody, 2011, p. 819). The fragmented
habitats in the Everglades (due to the canal systems and roadways) are also
vulnerable to the edge effect. Areas that used to be surrounded by water are
now surrounded by urban construction or farm lands, allowing the edge species
(e.g. raccoons [Procyon lotor ]) to invade further inward, displacing or
depleting those interior species (Beringer, 2004). The white crowned pigeon (Patagioenas
leucocephala) is experiencing depleted populations due to predation by edge
species (Beringer, 2011).
Only the
southernmost part of the Florida Everglades is protected by federal land,
(Everglades National Park and Big Cypress National Preserve) “together they
encompass over 2.2 million acres of more or less contiguous habitat” (Rocus
& Mazzotti, 1996, p. 2). Even with this amount of land, the Everglades are
struggling to survive. The urban systems expanding outside the park are now
directly affecting “the ability to protect the areas within the park
boundaries” (Beringer, 2011).
A
multi-agency ecological approach is necessary for restoring the Florida
Everglades. The future of the Everglades will be in the hands of county
commissioners and zoning boards. According to Brody, land use decisions occur
at the local level, not the federal level. The efforts to save the Everglades
have been reactionary approaches to a crisis that already exists. The
development has already taken place. The conservation strategy should change
from damage control to anticipation and prevention (Brody, 2011).
Redirecting
some of the water to restore the natural flow would be beneficial to the
southern portions of the Everglades. There is a plan to remove 240 miles of
levees and canals along the Tamiami Trial from Tampa to Miami. According to
Scully, this approach to restoring flow to function as it did prior to all of
the drainage is staggering. Scientists must consider roles of individual
species, soil, salinity, natural weather patterns and growing human populations
(Scully, 2001).
“Because
species diversity is perceived as a fundamental component to maintaining viable
ecosystems over the long term, the identification and protection of
biodiversity lies at the core of planning for ecosystem integrity” (Vogt, et
al., 1997, cited by Brody, 2011, p. 819). However, since we have destroyed a
large portion of the Everglades, it may be impossible to restore it into the
whole system it once was (Scully, 2001). Passing legislation, changing zoning
laws to end further development (in areas that could help restore the
Everglades) and purchasing contiguous tracks of habitat (that would bring back
populations of large predators to the area) may be additional steps toward
restoration.
References:
Ake, Anne, 2008. Everglades an ecosystem facing choices and challenges. Sarasota, Florida: Pineapple Press.
Arrrieta, Diane, 2012. Exerpt from unpublished class paper. University of Edinburgh, Scotland.
Beringer, Joe, 2004. Conserving biodiversity in South Florida. [online]: Miami University. Available at: http://jrscience.wcp.muohio.edu/filedcourse04/PapersMarineEcologyArticles/Whathav ew edoneWhattodonow.html. [18 November, 2011].
Brody, Samuel D., 2003. Examining the effects of biodiversity on the ability of local plans to manage ecological systems. Journal of Environmental Planning and Management, [online] 46:6, pp. 817-837. Available through: Taylor & Francis Social Science and Humanities Library [8 November, 2011].
Florida Department of Environmental Protection (FDEP), 2011. Learn About your Watershed. [online] Available at: http://www.protectingourwater.org/watersheds/map/ev erglades/ [9 November, 2011].
Rocus, Denise &
Mazolli, Frank J.,1996. Threats to Florida’s Biodiversity, [online]:
University of Florida IFAS Extension. Available at:
http://edis.ifas.edu/uw107. [8 November, 2011].
Scully, Malcolm G., 2001. Restoring the Fragile Everglades, Evermore. Chronicle of Higher Education [online] 47:18, p. B14. Available through: Academic Search Primer (Ebscohost) [22 November, 2011].
image: http://en.wikipedia.org/wiki/File:Everglades_Sawgrass_Prairie_Moni3.JPG
