Pre-Visit Activities : Communities and Ecosystems : Background
Third - Fifth Grade Online Curriculum : Communities

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Despite being 40th in size among the states, South Carolina has one of the highest biodiversity levels of any state in the country. Regions ranging from Mountains to the Ocean, South Carolina supports a variety of populations, communities and ecosystems. Populations are a group of living things in a particular area that all belong to the same species. Humans, porkfish, river otters, mountain laurel trees and pitcher plants are all examples of different populations.

A community consists of all of the living things that inhabit a particular area. A community is an assemblage of populations that share an environment. The environment can be as small as a rotted log or as large as a continent. In the Mountain region, a community could consist of river otters, trout, mayflies, mountain laurel, cardinals and flowering dogwood.

An ecosystem includes all of the abiotic factors as well as the communities that exist in a certain area. Abiotic factors are those factors in an environment that are not living. Important examples of abiotic factors include water, temperature, light, soil and wind. In many ways, the abiotic factors of a particular area define the communities that live there.

South Carolina is divided into five major landform regions: the Mountains, Piedmont, the Sandhills, the Coastal Plain and the Coast. The vast Atlantic ocean is located off of the coast of South Carolina. Each of these regions is characterized by a unique set of physical factors, which in turn affects the animals and plants that are able to form communities there.

The smallest in area of the five regions, the Mountain region is located in the northwest corner of the state and found in only three counties. It is part of the Blue Ridge chain of the Appalachian Mountains. It is an area characterized by mountains and valleys, rocky outcrops, waterfalls and fast moving streams. Mountains in this region can be above 3,000 ft in elevation. The climate in this region tends to be cooler and less humid than the rest of the state but with a higher rainfall amount, ranging from 60 to 76 inches a year.

Mountain streams are a unique habitat in South Carolina. Found only in the mountains of the northwest corner of South Carolina, this habitat makes up only two percent of the state's freshwater habitats. The water in these streams is provided by abundant rainfall and groundwater springs. These streams erode away the soil in their beds leaving a rocky bottom. The water of mountain streams tends to be cool in temperature, clean and highly oxygenated. Streams tend to be shallow with areas of rapid moving water and slower- moving pools. Many plants and animals can be found along the banks of mountain streams.

The Piedmont region is in the northwest of the state and extends from the mountains to the fall line that crosses the state through Columbia. It is a generally flat area with gently sloping hills and wide river valleys. As most of the soil in the piedmont is composed of clay, a substance difficult for water to flow through, very little rainwater can soak into the soil. Much of the rainwater runs off to join the many streams and rivers that criss-cross the landscape. The Piedmont is a warm, humid area. Because of its distance from the ocean, it does not receive the temperature regulating effects the ocean provides and thus has wider temperature extremes than the coast has. It has a rainfall range of 45 to 60 inches a year.

The Coastal Plain is an area of flat land that comprises more than half of the state's area. Though hilly in certain places, most of the plain is flat and slowly lowers in elevation from the Sandhills to the coast. This flatness results in many wetlands as the slope is often too gradual to cause water to continuously flow. The climate of the region is warm and humid with an average yearly rainfall of 46 inches.

Blackwater swamps occur in the Coastal Plain. Because of the flatness of the plain, the blackwater rivers are slow-moving and follow a winding, meandering path. When rainfall amounts are high, the water in these rivers floods over the banks into the woods and creates the swamp habitat. Depending on rainfall amounts this swamp habitat can last a few days or a few months. The still, warm water of blackwater swamps is filled with organic material and provides habitat for a number of plants and animals.

The Coast is an area of land at the edge of the ocean that extends from the North Carolina to the Georgia border that is about ten miles wide. Of all the regions of South Carolina, the Coast is the most dynamic. The salinity of the rivers and wetlands in this region change throughout the day as tides rise and fall. Barrier islands, beaches and salt marshes will change in size and shape as waves and ocean currents erode and deposit sand. Because of sea breezes and proximity to the ocean, the Coast tends to be cooler than areas even just a few miles more inland from the coast. The Coast tends to be warm and humid with abundant rainfall.

The ocean is a body of water that has high salinity and generally stable conditions. Though hurricanes and other major storms can stir up the shallow waters above the continental shelf, ocean waters are generally not affected by the weather. The average temperature of the ocean remains fairly stable from year to year. Off the coast of South Carolina, the ocean seafloor is generally covered by a sandy or muddy bottom. In certain areas, however, rocky reefs jut upwards from the bottom of the ocean floor.

Rocky reefs occur in the waters off of South Carolina's coast. These rocky reefs, in large part, are formed from the remains of organisms, like corals and tube-building worms, which lived many, many years ago. These rocky reefs provide a hard substrate to which other organisms can attach. If sunlight can penetrate to the depths of a rocky reef location, seaweeds attach to the reef and thrive. Other small animals like barnacles, sponges, tunicates and soft corals also attach and grow upon the reef. The seaweeds and small animals that make their home on the reef attract larger predators, like sheepshead and porkfish. Rocky reefs are like an oasis of life surrounded by more desolate areas of sandy seafloor. Where rocky reefs occur, an abundance of life abounds.

Because these regions are so different in their abiotic characteristics, they support very different communities. By knowing the abiotic characteristics of an area, one can guess what kinds of animals might live in its community. In turn, knowing the habitat needs and adaptations of an organism can be used to determine what environment it might inhabit. This relationship between organisms and environments defines communities, and also shows how interconnected the natural world is.