Grichenko Natalie The Everglades today



Yüklə 37.97 Kb.
tarix30.08.2017
ölçüsü37.97 Kb.
Grichenko Natalie

The Everglades today

The Everglades is a unique treasure found in South Florida. It is one of the largest remaining subtropical wetlands in the world. Several hundred years ago, these wetlands were a major part of a 5,184,000 acre watershed that covered almost a third of the entire state of Florida. Marjory Stoneman Douglas, a famous Florida environmentalist in her book The Everglades: River of Grass calls the Everglades “the river of grass because throughout much of the shallow river grew an unusual plant called saw grass. In some areas, you could barely see the water because the saw grass was so dense.”1 Also the Everglades dominated by the wetlands consist of 1.5 million acres of mangrove forests and hardwood hammocks. And it is a home to endangered, rare, and exotic wildlife.

“To understand what the Everglades is today, we must first understand what it was like in the past - before humans changed it.”2 Historically, the Everglades covered over four million acres (1.6 million hectares). “The original Everglades extended south from Lake Okeechobee to the peninsular tip of Florida, east to the coastal ridge (with occasional connections to the sea through areas known as the transverse glades), and west to the Immokalee Ridge (roughly the border of the Big Cypress National Preserve).”3 This territory is often referred to as the "historic" Everglades. The shallow, slow-moving sheet of water of the Everglades created a mosaic of ponds, marshes, and forests. Over thousands of years this developed into a balanced ecosystem.

Wading birds such as great egrets, white ibis, herons, and wood storks were abundant. The Cape Sable seaside sparrow, Miami blackheaded snake, manatee, alligators, crocodiles and Florida panther made the Everglades their home.

When the Seminole and Miccosukee Indians settled in the Everglades, they did not interfere with the overall balance of the ecosystem. But when white settlers and land developers came to south Florida, they viewed the Everglades as a worthless swamp. “Because the land was so flat, water could flow from lake to lake, spill over natural river channels and spread into floodplains. There were no barriers or canals to direct or control the path of water.”4 The white settlers and land developers began to drain the land to create dry areas for farming and their homes. They drained the Everglades area in two main ways: by filling this area with soil (this was the most common cause of wetlands destruction). Another way in which white settlers and land developers drained the Everglades was by planting the melaleuca tree. The melaleuca takes up so much water that it is able to dry entire swamps. Today, people have stopped planting this tree, but the problem still exists because the melaleuca is an exotic species. "Exotic" means it did not originally live in the Everglades; therefore there are no diseases, pests, or consumers present to stop its growth. For this reason, the melaleuca tree prospers in southern Florida.

By the 1800s, developers started digging canals to drain the wetlands. “Between 1905 and 1910, large tracts of land were converted to agriculture. This “new” land stimulated the first of South Florida’s land booms. During this time, Henry Flagler constructed the first railroad down the Florida peninsula opening up this area to people.” 5

“By the 1920s, visitors and new residents flocked to towns like Fort Lauderdale, Miami, and Fort Myers.” 6 As they arrived, more canals were dug. The alteration of the wetlands—combined with increasing population—damaged the natural system.

Eventually, people began to recognize the various functions of wetlands ecosystems, including their importance as a habitat for many unique species of microorganisms, plants, and animals. For example, in 1948 Congress authorized the U.S. Army Corps of Engineers to construct a system of roads, canals, levees, and water-control structures stretching throughout South Florida. This was intended to provide water and flood protection and to help preserve the Everglades. Moreover, in an attempt to satisfy everyone and to protect the remaining Everglades, the government divided the land. Of the original 3,000,000 acre historic Everglades, the northern 1,000,000 acres was designated the Everglades Agricultural Area (E.A.A.). Today, most of this land is used to raise sugarcane. The southern 1,500,000 acres of the original Everglades was dedicated in 1947 as the Everglades National Park. The park consists of many types of wetlands that offer habitat to a wide variety of plants and animals. The remaining 500,000 acres, located in the middle of the historic Everglades, became a water conservation area with a system of canals, dams and dikes used to control the flooding in large Florida cities.

It is clear that during the century the Everglades was viewed as a wasteland waiting to be turned into a useful, productive purpose. Over the past 100 years, numerous government engineering projects have drained and dredged it, disrupting its natural water flow paths and cycles. As a result, less than half of the original Everglades remains today. The rest of this territory has been converted into dry land for urban development on which most of South Florida’s five million people now live and work.

Now, the main problem is to recreate conditions of the original Everglades.
Today, 50% of South Florida’s original wetland area that still exists “has less than two million acres (800,000 hectares) remain in a somewhat natural state, and half of that is locked into water conservation areas (WCAs). Deprived of natural sheet flow, WCAs function more like reservoirs than wetlands. Over 1,400 miles (2,258 kilometers) of canals, levees, spillways, and pumping stations criss-cross the region south of Lake Okeechobee. Built to drain coastal land for development, secure a steady supply of water for agriculture, and provide flood control and fresh water for urban areas, the canal system diverted much of the water that is vital for the Everglades.”7

“To appreciate the problems facing the Everglades today, it's important to understand what this ecosystem was once like.” 8 “The Everglades River, or wetland, was a few inches deep, but up to 50 miles (80 km) wide and 100 miles (160 km) long.”9 There, the shallow river mixed fresh water with salt water, which made it rich with marine life such as shrimp, lobster, crab, fish and home to millions of creatures.

“It was perhaps best known as the home to the American alligator and huge flocks of wading birds, by some accounts numbering up to two and one-half million at one time. Now, the numbers of wading birds have been reduced by 90%. Entire populations of animals are in danger of disappearing.”10 For example, 9 of the 14 species in the Everglades are endangered: Florida Panther, West Indian Manatee, Leatherback Turtle, Green Turtle, American Crocodile, Wood Stork, Snail Kite Red-Cockaded Woodpecker, Cape Sable Seaside Sparrow and Schaus Swallowtail Butterfly.

There are two main reasons that lead to the losses of wildlife.


The first reason for such losses is the fact that during the winter dry season human started to release too much water into the park making it hard for wildlife to find food, while too little can make it hard for them to find water. The second reason occurred because of the reduced flow patterns to Florida Bay. The watershed made a decrease in the amount of water reaching the bay at the very southern tip of Florida. “This resulted in less water flowing south to the Florida Bay. To make up for this difference, the bay takes in an increasing amount of marine water each year, raising the salinity of the natural water. This is extremely damaging to the fish and wildlife native to the bay, which are accustomed to only limited levels of saline water.”11 Mainly, these two reasons lead to a decrease in the numbers of wildlife in the Everglades today. Moreover, not only are the effects felt by the ecosystem, but they are also detrimental to the economy, as fishing in the Florida Bay is a major source of revenue for the region.

More recently, with an increase in the population of Florida scientists have realized that the Everglades water resources grow short .The passive diversion of water away from the Everglades has led to the removal of the wetlands. Several Florida cities, including Miami, Ft. Lauderdale, and West Palm Beach, rely on water drawn from the Everglades. The U.S. Department of the Interior reports predicts that the population of the 16 counties of southern Florida, already over 6 million people, will more than triple in the next 50 years. As Florida's population grows, the Everglades water resources become more important. An increase in population also means more people need to be protected from floods.

Also the scientists and rangers of the Everglades are concerned with the quality of water being let into the Everglades National Park. This is the only part of Florida that truly resembles the "original Everglades River". The water for the Everglades National Park is coming from water conservation areas. Water is let into the park by opening the dams, called "flood gates," along the Tamiami Trail. Scientists and other staff at Everglades National Park are trying to recreate conditions of the original Everglades River. But the problem is that these areas contain water that has flowed through large agricultural areas. “This water contains high amounts of fertilizer. Water, rich in fertilizer containing nitrogen and phosphorus, can change the types of plants living in the water and, ultimately, the food chains found there. There is serious concern that polluted water entering Everglades National Park could cause natural periphyton and sawgrass to be replaced by other plants, thus altering this last natural remnant of the original Everglades.”12

Another major problem that concerns scientists and rangers at Everglades National Park is the increasing demand being placed on a limited supply of fresh clean water. “Water conservation and better management of urban growth appear as two logical solutions to this problem.” 13 If the proposed solutions are not practiced, the area of the Everglades can lose the following:



  1. The Everglades can lose a natural recharge system for well fields. Salt water will pollute wells as it seeps into them from the ocean. Drinkable fresh water will become more difficult and more costly to find.

  2. Marine species may not survive well in Florida Bay. If the bay becomes too salty because of a lack of fresh water, shrimp, lobster, crab, and fish populations may decline dramatically throughout south Florida and the Florida Keys.

  3. Last, without water for the Everglades, many species would leave the area or die.

The next problem of the Everglades today is both vital for the economy and detrimental to the ecology of South Florida. “Agriculture in the South Florida region plays a dominant role in any water management decisions involving the Kissimmee - Okeechobee - Everglades watershed. The original draining of much of this region was the result of a desire to make the land more suitable for agricultural purposes. Under the Corps’ C&SF Project, the Everglades Agricultural Area (EAA) was created from the upper quarter of the original Everglades wetland. In its entirety, it covers approximately 750,000 acres. Along with this tremendous revenue, however, the EAA also consumes the majority of the region’s surface water supply, making its existence both vital for the economy and detrimental to the ecology.”14

One also very important problem that needs to be solved in the Everglades today is the loss of soil. “The soils covering the South Florida landscape were formed predominantly under wetland conditions. Submerged in water for a majority of the year, the organic material in the soil was slow to decompose because less oxygen was readily available. So, wetland soil contains a high amount of organic material. After drainage, however, the soil is exposed to air and an increased availability of oxygen. Decomposition of this organic material occurs at a much faster rate, and the soil surface elevation drops accordingly. Current estimates place this rate of soil loss at approximately 1 inch per year. Under these continuing conditions, some predict that the surface may reach the bedrock level in as little as 25 years.” 15


All of the above effects have led to significant changes in the natural environment. But still tremendous progress has been made in the past and continues to be made even now in terms of restoration of the South Florida Everglades.

One effort to restore the Everglades to its original state includes the purchase of land surrounding the Everglades National Park to create buffer zones that distance people and pollutants from the park. This land may increase the natural flow of water through the Everglades, increase habitat for plants and animals, and decrease agricultural pollution where the land purchased was farmland.

Another effort to restore the Everglades to its original state is through legislation. In 1989, the Everglades National Park (ENP) Protection and Expansion Act was established. The purpose of this Act is to increase park protection and assure better management of its resources. That same year the ENP Protection and Expansion Act authorized the Mod Waters Project. The goal of this project is to restore the natural flow of water to the ENP in order to restore its ecosystem. However, it was soon realized that merely pumping water into the Everglades with no regard for the quality, quantity, or the timing of the flow was not succeeding in restoring the wetlands ecosystem. 

In 1994, the Everglades Forever Act was passed. This Act provided for a comprehensive clean-up/restoration plan. It addressed the problems of quality, quantity, and timing of restored waterflow. This law also called for action to stop exotic (not native) species of plants from spreading further throughout the Everglades. The Everglades Forever Act of 1994 was followed by the Federal Water Resources Development Act of 1996 which provides for a "restudy" of water management in central and southern Florida. One goal of the federal "restudy" is to decide how surrounding land should be managed. Should it be purchased or left alone? Many of the changes in the Everglades are the result of canals and dams installed by the Army Corps of Engineers to control water flow and protect against floods. For this reason, the Federal Water Resources Development Act of 1996 required the Corps to recommend a plan by July 1, 1999 to restore the natural water flow of the Everglades. This plan was recommended and now it is functioning.

As we can see, the effort to restore and preserve the Everglades has been started a long time ago with all of this Everglades Restoration Projects listed above and many others in the planning stages, there are substantial steps being taken towards recreating the natural environment and ensuring that past mistakes in water management that are not still reinstated. However, this is a very slow process, because most of the problems of the Everglades today are inextricably linked, as one problem can cause new and sometimes unexpected complications.

In spite of the fact that the recreation of the natural environment is a very slow process, a lot of substantial steps are being taken because scientists of the Everglades have discovered that wetlands serve three very important functions in nature: they clean the environment, provide habitat for many organisms, and store energy. Wetlands microorganisms, as well as wetlands plants, serve as environmental filters by trapping impurities such as toxins and excessive nutrients as water flows through the wetlands system. Meanwhile, wetlands plants strain silt and larger debris from the water. The wetlands plants and sediment also serve to balance nutrient sources and sinks. In addition, wetlands serve as environmental sponges, absorbing and temporarily storing excess water caused by runoff, thus preventing flooding.

Wetlands also provide a home or habitat for many species of microorganisms, plants and animals. Wetlands serve as a resting place for migratory birds and a nursery for many young animals. The microorganisms, plants, and animals that find shelter in the wetlands serve as food for other microorganisms, plants, and animals.

Lastly, wetlands provide a sink in which energy is stored. Energy is the ability to do work. Having energy is very important because it is required by all organisms for life. Energy from the sun is acquired directly by plants. Through the process of photosynthesis, plants convert the sun's energy into carbon-containing compounds. The sun's energy is released from these carbon-containing compounds when they are broken down during combustion (burning) or during respiration by animals that have consumed the plants. Plants that are not burned or eaten eventually die and slowly decompose. The decomposing plant matter builds up to form carbon-rich deposits called peat. Over the course of millions of years, great temperatures and pressures transform the peat into coal and oil. These fuels are then burned by people in order to release the energy trapped inside the carbon-rich material.

Thus, we can see that the Everglades wetlands serve three very important functions in nature: they clean the environment, provide habitat for many organisms, and store energy.

Indeed, the Everglades is one of the largest remaining subtropical wetlands in the world. However, for most of this century the Everglades was viewed as a wasteland waiting to be turned into a useful, productive purpose. Over the past 100 years, numerous government engineering projects have drained and dredged it, disrupting its natural water flow paths and cycles. Today, the main goal for the scientists and other staff of South Florida is to recreate conditions of the original Everglades.




1http://www.saveoureverglades.org/education/education.html



2 http://www.saveoureverglades.org/education/education.html



3http://www.sfwmd.gov/site/index.php?id=515



4 http://www.sfwmd.gov/site/index.php?id=515


5 http://fcit.usf.edu/FLORIDA/lessons/everglades/everglades.html

6 http://fcit.usf.edu/FLORIDA/lessons/everglades/everglades.html

7 http://www.enviromentaleducationohio.org/Biosphere/Case Studies/everglades.html

8http://www.enviromentaleducationohio.org/Biosphere/Case Studies/everglades.html



9 http://www.saveoureverglades.org/education/education.html



10http://fcit.usf.edu/FLORIDA/lessons/everglades/everglades.html



11 http://www.ce.utexas.edu/prof/maidment/grad/dugger/GLADES/glades.html


12 http://www.saveoureverglades.org/education/education.html



13 http://www.saveoureverglades.org/education/education.html



14 http://www.ce.utexas.edu/prof/maidment/grad/dugger/GLADES/glades.html

15 http://www.ce.utexas.edu/prof/maidment/grad/dugger/GLADES/glades.html






Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur ©azkurs.org 2016
rəhbərliyinə müraciət

    Ana səhifə