Deforestation In The Everglades Essay

How has deforestation impacted the Everglades and the surrounding ecosystem?

The Everglades is a subtropical wetland ecosystem spanning two million acres across central and south Florida. Originally the Greater Everglades ecosystem had a large diversity of habitats connected by wetlands and water bodies. Since the 1800s, humans have been altering the Everglades landscape. Water diversions and flood control structures restrict the flow of water across the sensitive landscape. Combined with agricultural and urban development, the size of the Everglades has decreased dramatically, affecting the quality of habitats in the area. "In the past hundred years, people have been digging canals and building dams in the Everglades so they could take water

out of it, develop agriculture and build homes,” says Dr. Tom Van Lent, senior scientist at the Everglades Foundation. “We’ve built so many canals and drained so much water that the natural flow is interrupted.” As a result, the Everglades is now less than half its original size. 1,800 miles of canals and dams break it up, with water control points and pump stations diverting the natural flow of water to coastal towns and cities. Water must be released to estuaries to prevent flooding and Florida finds itself in a situation where there is often too much water in the wet years, and not enough in the dry. What little water that does enter the Everglades system is often polluted and full of nutrients from runoff. Fertilizers from agriculture and pollutants from ever expanding urban centers contribute heavily to the low quality of the water entering the system. These pollutants lead to changes in vegetation and community composition and are detrimental to native plant and animal species.
Other threats to the Everglades ecosystem include urban encroachment from all sides, invasive exotic species, and loss of natural processes such as fire. South Florida is one of the fastest growing regions of the country. All of these new residents need places to live and water to drink, and the suburbs are continuing to encroach into the Everglades system. Exotic species have also slowly been invading the region and are threatening native populations. Many of these exotics are successful because they take advantage of unnatural alterations to the Everglades environment. An example is the control and reduction of wildfires that normally would benefit the native species that are dependent on a regular fire regime for seed dispersal or the removal of competitors. These are simple examples of a very intricate and complicated system that is being pressured from all sides.

The Everglades are being threatened by numerous plants and animals that were introduced both on purpose and by accident.

Some introduced species become a small part of the landscape, while others thrive at the expense of native plants and wildlife. When an introduced species puts additional stresses on native wildlife and threatens habitats, it's called an invasive species. Invasive exotic (nonnative) species are seriously threatening the integrity of south Florida's native communities. With exotic fishes devouring native fish species and melaleuca trees shading out indigenous plants, the Florida Everglades is suffering from a barrage of pressures brought on by nonnative species. Far from their native homelands, these invaders have a competitive advantage over native species. Because nonnative species typically lack natural predators, they can outcompete native species. They can multiply unchecked, using up valuable resources such as sunlight, water, and nutrients. Native species suffer from this intense competition. In addition to the environmental havoc they wreak, invasive exotic species have major economic impacts. This economic effect is magnified in Florida where the climate and landscape are favorable to the establishment of invasives. Despite best efforts, many of these alien invaders are here to stay. Their spread, however, may be controlled by putting a stop to the release of non-native plants and animals into the wild and by aggressively managing species that are

encroaching on natural areas.
The change taking place in the Everglades also effects surrounding areas.

The weather in the Everglades is warm year-round, with distinct wet and dry seasons. However, even the dry seasons have some rainfall. All this precipitation enters a watershed that flows through Everglades National Park. The watershed starts with the Kissimmee River, then drains into Lake Okeechobee. When Lake Okeechobee is full, water flows south into the Everglades. This usually happens in the wet season between May and October. The Everglades receive 100–165 centimeters (40–65 inches) per year of precipitation. Almost 70% of this falls as rain during the wet season, which begins with thunderstorms in May and ends in October. The Everglades ecosystem consists of several interspersed and interdependent plant communities. Small changes in elevation, water depth, or salinity cause great differences in plant communities. The three most prominent communities in the Everglades are saw-grass prairies, freshwater ponds and sloughs, and swamps and marshes. There are also mangrove swamps, pine forests, and coastal prairie plant communities. The Everglades also provides critical, and often undervalued, benefits to people, called ecosystem services. For example, the Everglades ecosystem provides drinking water for one-third of Floridians and irrigation for much of the state's agriculture. The wetlands improve water quality by filtering out pollutants and absorbing excess nutrients, replenish aquifers, and

reduce flooding.
Most of the Everglades is covered by saw-grass prairie. Saw grass, the most abundant plant in this ecosystem, is not actually a grass, but a sedge. This sedge gets its name from sharp, serrated edges that look like a saw blade. Few grazing animals eat saw grass because of the sharp edges. The water flows slowly through the saw grass. A saw-grass prairie hides the water, and from a distance it looks like solid ground. Channels, or sloughs, that form in the saw grass are a little deeper and allow the water to flow faster.

The grass in the Everglades was very important to the evolution of the land and the water. It rooted itself in the soft limestone that arose from the ocean bottom from an accumulating deposition of seashells. The saw grass prospered and went through the seasonal death and rebirth, covering the limestone with its decaying leaves. A spongy mass of peat then arose from the decay soaking up the rains in the wet season and slowly distributing the water into the porous limestone and the underlying aquifers. The Biscayne Bay aquifer, the area's main source of fresh water, was continually being recharged by the action of water slowly seeping through the peat. Without this system of peat and limestone the water would have run off creating floods never allowing the water table to be adequately refilled. Solution holes in the limestone were created through these processes. They served to provide shelter for fish, insect larva and small mollusks in both the wet and dry seasons. A myriad of wading birds feasted on these fish and animals in the river, relying on the seasonal changes for nesting and survival. While the Everglades is mostly known for its once massive river, it is actually home to many different ecosystems with 61% of the vegetation being tropical (Levin, 1998).
Urban development, industry, and agriculture pressures have destroyed more than half of the original Everglades. Ever-increasing population growth along with industry in south Florida has resulted in large metropolitan areas and rising pressures on the surrounding natural environments. Agriculture, such as sugar cane, rice, and dairy farms, exists on drained land within the Everglades. experts are labeling the fight to save the Florida Everglades as a “losing battle,". Conversion of everglades into residential land and agricultural land is still an ongoing problem as the population of Florida is rapidly growing. Increase in residential and agricultural land destroyed wildlife habitat. In addition, as the number of residents increase, more freshwater is needed. To fulfill the needs, the ground water and surface water are diverted, consequently draining out Everglade ecosystem. The water flowing from agricultural land and urban areas into the Everglades has been polluted with pesticides and fertilizers- mostly nitrogen and phosphorus.
It is important that we consider restoration efforts for the Everglades. Many observers have identified the Everglades as one of the most endangered of North American ecoregions as a result of clearing for agriculture, diversion of water flow, and other developments. Recovery efforts are now underway, supported by a broad association of environmentalists active in the region. For years ecologists have argued that something must be done to save the Everglades but it was never as obvious as it is today. Recently the government, ecologists and citizens of Florida have agreed that something needs to be done about the state of the Everglades. But restoration will not be easy. Restoring a clean flow means taking thousands of acres out of sugar, clearing immense fields of cattails and other invading species. Controversy arose when fingers were pointed at Florida's booming sugar industry in November 1996. Attempts were made to hold this major contributor of the pollution primarily responsible for the cleanup. This effort is being achieved largely under the direction of the Army Corps of Engineers who will revamp the drainage system that they created fifty years ago. This plan that intends to restore the natural flow of the Everglades is being called the Restudy. Complete with its own WebPages, the Restudy is calling for a 7.8 billion-dollar overhaul that will take approximately 20 years to complete (Enserink, 1997). Setting a precedent for the amount of money to be spent, the state of Florida and the Federal government plan to split the cost.