“The Everglades is a land of paradoxes. Fire is a major influence in country much of which is submerged for half the year. Elevation is a critical factor in a region flatter than most pancakes.”
~ William B. Robertson, Jr. (1959: 16)
When European settlers explored southern Florida, they thought of it as a magical location. Ponce de Leon searched for his infamous fountain of youth here, and it is no surprise that this area was and is thought of a wondrous location to many people. Mangrove trees and alligators give an indication of the unique flora and fauna found here; today’s Everglades National Park has some of the most diverse wildlife found in the United States. The climate, unique position and natural history have created a true gem of a home for many animals, including an incredible number of bird species. The Everglades is an important enclave for the study of biology, ecology, botany, and many other sciences. Truly, it is a place worth getting to know.
The Role of Glaciers in Florida
Glaciers have, of course, never been in Florida. But glaciers exert a global impact. It is difficult to understand the Everglades without first understanding the effect the most recent glacial period had on southern Florida. According to McCally (1999: 1), the Everglades part of Florida did not exist as we know it previous to five thousand years ago.
Glaciers cause the ocean levels to rise and fall; the large series of glaciations during the Pleistocene Epoch (2 million-10,000 years ago) caused sediments to be deposited and eroded quite rapidly, resulting in a varied organization for the current Everglades bedrock (McCally 1999: 6). The topography is also quite flat. In fact, today very small changes in elevation can mean very sharp changes in vegetation type. Sandy formations created by the windy conditions that accompany glaciers in the Florida region also aided in the development of the Everglades – they restrict the Everglades to the middle band of land that it currently occupies.
Landforms of the Everglades
Florida is very flat. Most of its flatness is a result of the ocean. Most of Florida and the Everglades has been covered by the ocean for millions of years and formed layer upon layer of limestone, which are fairly flat, although they collectively tip a bit towards the west (McCally 1999: 4).
As a result of the overall smoothness of southern Florida, it is difficult to realize that the Everglades is one part of a huge freshwater river system (Tebeau 1968: 19). The Kissimmee River feeds into Lake Okeechobee, the largest lake in Florida. When Lake Okeechobee is full of water, it, in turn, feeds streams to its south that broaden into one large expanse of water that creeps toward the Gulf of Mexico at a rate of 600 meters per day (Barcher 1997). This expanse is, at its deepest, around three feet deep due to the very slight slope of the land beneath the water. The fact that it is so shallow and wide makes many think at first that it is nothing more than a large inland swamp.
In fact, the Everglades, despite being a river, does incorporate other landforms. The mouth of the Everglades is composed of estuarine swamps (Larson 1995: 1). Here, the fresh water and salt water mix and create an incredibly rich habitat for animals, including shrimp, birds and crocodiles.
Another landform around the Everglades is the barrier islands at the mouth. They are formed by the deposition of sand eroded from the coast. Barrier islands help prevent strong wave action and protect the beach and inland areas from storm surges during thunderstorms and hurricanes. Without barrier islands, the lower section of the Everglades would be more vulnerable to erosion and devastation from waves and storm surges.
Soils of the Everglades
Most of the Everglades is underlain by histosols, a type of soil that is typically associated with waterlogged land. Histosols are the accumulation of large amounts of organic material; the dominant suborder in Florida is the Saprist suborder (Christopherson 2003: 581). Little decomposition occurs because most of the soil is under water, which tends to retard the breakdown of this material. Surface areas may appear boggy due to paludification, the formation of peat through the accretion of moss and plant material. Histosols are fairly fertile.
Another type of soil, marl, tends to help weed out trees after storms (Tebeau 1968: 29). Marl is actually a mud-like calcium deposit that washes up and possibly poisons damaged trees, thereby helping wildfires and hurricanes rid the river of trees while keeping grasses.
Climate of the Everglades
The Everglades straddles the line between the tropical and humid subtropical climates; it is the only location in the continental United States to do so (Christopherson 2003: 284). Temperatures range from lows in the fifties in the winter to average highs near ninety in the summer. The area receives more precipitation in the summer, averaging about 130-135 cm of rain per year. The impact of high temperatures on all that water is that a lot of the water is lost due to evaporation and transpiration. Scientists estimate that only about twenty percent of all precipitation that falls in the region actually makes it into the Everglades.
The pleasantness of tropical temperatures belies the fact that this region has endured despite the fact that it is a high-stress area for plants and animals (Levin 1998: 21). Hurricanes are frequent threats to the entire southern United States, but are especially dangerous in places that are as close to sea level as the Everglades is.
Hurricanes form solely within the moist tropical air above the Atlantic just off the west coast of Africa. They then move towards the Caribbean and North America. They can wreak havoc with just about everything; torrential rains and winds help increase erosion and knock down trees. Storm surges, waves that accompany a strong storm, create flood conditions. Vegetation is destroyed, animals die, and the flow of water out to the Gulf of Mexico may be impeded. It may also cause increased salinity in areas that are used to mostly fresh water, causing problems with the reëstablishment of plants. Barrier islands can protect the inland area to a certain extent.
Vegetation of the Everglades
One nickname of the Everglades is the “River of Grass,” and it is an apt moniker. The large majority of the Everglades flows through reeds and grasses. These areas are called freshwater marl prairies and freshwater sloughs; they contain the sawgrass that is so indicative of southern Florida. Sawgrass is about ten feet tall and is very sharp; it is also found almost exclusively in the Everglades (Larson 1995: 88).
Variation in the main type of plant often depends on a slight change in elevation above sea level. Mangroves live near the sea, partially under the water; pines live in the highest parts of the Everglades. Wherever there are trees, there are epiphytes – plants that live on trees and use water and nutrients available above-ground to survive.
Wildfires are an important part of the cycle of plant life in the Everglades. Burning plants removes dying debris, returns nutrients to the soil, and provides new opportunities for species. Most importantly, fire maintains the grasslands at the expense of forests and savanna. Grasslands are an important part of the habitat of many animals. Some plants rely on fire to undertake reproduction, as well.
The Human Impact
Humans have had the tendency to drain the Everglades in order to obtain land for roads, farms, buildings, and drinking water, as well as other uses. The result is that the land is devastated; with a shallow river, diverting water causes serious problems. Frequently, humans force the river to go dry, causing plants to die and animals to lose habitat.
As a solution to the degradation, the national government plans to institute a plan to reclaim most of the water that flows to the Gulf of Mexico and returning it to the Everglades system (DeSena 1999: 22). This will be very expensive to set up and execute, and probably will cause unforeseen problems with the ecosystem. The only solution that will not cause problems is for people to stop using the water that is already there.
Another problem that humans have caused is the introduction of alien species. For example, farmers in the 1950s started rock-plowing, the crushing of bedrock in order to add it to the soil (Li 2001: 400). The limestone bedrock increased the fertility of the soil appreciably, but also made the Everglades much more susceptible to Brazilian pepper (Schinus terebinthifolius), an aggressive plant that has taken over areas that used to be populated with sawgrass and pine trees (Li 2001: 400). The only solution that is known to actually keep Brazilian peppers out is to remove everything down to the bedrock and to let the topsoil come back on its own.
Many people are concerned with the fate of the Everglades. Such a place of amazing biodiversity and incredible uniqueness deserves saving. Many scientists are working on ways to reduce water use, decrease the likelihood of alien species invading, and maintain the natural workings of the region. If we can preserve the Everglades from human misuse now, we can continue to enjoy a place that is unique in so many ways: it is the only place where crocodiles and alligators live side-by-side; it is one of the largest bird sanctuaries in the world; and it is a location of beauty and wonder.
The Everglades is a unique national park. One of the widest rivers in the world that also straddles the line between temperate and subtropical vegetation; the area’s importance to the quality of water and wildlife in Florida cannot be overemphasized. Now that restoration is occurring, it is important for ecotourists to come and visit the Everglades National Park to see what we are protecting. It is land like this that Florida is famous for. But we all have the responsibility of shielding it from human encroachment and keeping it as it has been – an efficient and capable ecosystem that supports incredible amounts of life.
Bacher, K. L. 1997. Hydrology of Everglades National Park. Retrieved March 22, 2003, from http://www.nps.gov/ever/ed/edhydro.htm.
–. 2002. Can the Everglades Survive? Retrieved March 22, 2003, from http://www.nps.gov/ever/home.htm.
Christopherson, R. W. 2003. Geosystems: An Introduction to Physical Geography (Fifth Edition). Upper Saddle River, NJ: Pearson Education, Inc.
DeSena, M. 1999. Everglades plan last best chance to restore irreplaceable ecosystem. Water Environment & Technology 11 (September): 21-4.
–. 1997. Everglades National Park: An Introduction to the Ecosystem. Retrieved March 22, 2003, from http://www.nps.gov/ever/eco/ever101.htm.
–. 2002. Everglades National Park Fire Management. Retrieved March 22, 2003, from http://www.nps.gov/ever/fire/index.htm.
–. 1999. Everglades National Park Habitats. Retrieved March 22, 2003, from http://www.nps.gov/ever/eco/habitats.htm.
–. 1997. Geology of Everglades National Park. Retrieved March 22, 2003, from http://www.nps.gov/ever/eco/ecology.htm.
–. 2000. Histosols. Retrieved April 16, 2003, from http://www.geo.msu.edu/geo333/histosols.html.
Larson, R. 1995. Swamp Song: A Natural History Of Florida’s Swamps. Gainesville, FL: University Press of Florida.
Levin, T. 1998. Listening to wildlife in the Everglades. National Wildlife 36 (June/July): 20-31.
Li, Y. and Norland, M. 2001. The role of soil fertility in invasion of Brazilian pepper (Schinus terebinthifolius) in Everglades National Park, Florida. Soil Science 166: 400-405.
McCally, D. 1999. The Everglades: An Environmental History. Gainesville, FL: University Press of Florida.
–. 2003. Monthly Climatology for Travel Section. Retrieved April 16, 2003, from http://www.weather.com/weather/climatology/monthly/USFL0329.
Robertson, W. B. 1959. Everglades: The Park Story. Coral Gables, FL: University of Miami Press.
Tebeau, C. W. 1968. Man in the Everglades: 2000 Years of Human History in the Everglades National Park (Second Edition). Coral Gables, FL: University of Miami Press.