1. The Biodiversity of the Southeastern United States

People are often surprised to learn that the southeastern United States is one of the most biodiverse temperate areas in the world.  In fact, it has been referred to as a "biodiversity hotspot" by some ecologists and conservationists.  We are aware that exotic, faraway places like the Amazon Rainforest and the Great Barrier Reef are rich in biodiversity, but most people are unaware that the southeastern United States is probably second only to southern China, and adjacent areas in Asia, in temperate biodiversity.  For example, there are a greater number of  native tree species just in the state of Georgia than there are in the entire continent of Europe!  If you want to experience an incredible natural wonderland of plant and animal species, not to mention natural beauty, all you have to do is to get outdoors in the natural areas of the southeast.

Providence Canyon, Georgia, a State Park with a large population of beautiful wild azaleas, Rhododendron prunifolium. 

The southeast has an unusually high number of species of plants, animals, and other organisms, some of which are found nowhere else in the world.  In fact, there is so much biodiversity in the southeast that new species are still being discovered and described every year.  There are also many different types of environments in the southeast, including some found nowhere else on earth. 

The southeast's biodiversity is due to several factors.  The first is its geological complexity.  Over the past billion years or so, the area that is now the southeast has been in the center of continental collisions that have created vast mountain ranges.  At other times much of it has been submerged under ancient seas.  Because of all of this geological activity the southeast is one of the most geologically complex areas in the world.  Metamorphic, igneous, and sedimentary rocks in many forms can all be found in different areas of the southeast, and all of these different rock types are found in Georgia.  These different types of geology give rise to many different types of soil, and the soil diversity helps to create ecological diversity.  Different plant communities exist on different soil types, and they provide the basis for different habitats.  If you are interested in learning more about the geology of Georgia the "New Georgia Encyclopedia" has some good information:

http://www.georgiaencyclopedia.org/nge/Categories.jsp?path=/ScienceMedicine/EarthSciences/GeologicalProvinces#/ScienceMedicine/EarthSciences/GeologicalProvince
 

Arabia Mountain, Georgia, a granite outcrop with many unusual species of plants.   

Along with diverse soil types, the southeastern U. S. has high annual rainfall, so plant communities get plenty of water.  Some areas of the southeast, such as along the Gulf Coast and in the mountains of northeast Georgia and South Carolina, get more rainfall than anywhere else in North America except the coast of the Pacific Northwest, which includes a temperate rainforest.  The southeast also has a long growing season, providing plenty of sunlight and warmth for plants.

Falls at The Pocket, Pigeon Mountain, Georgia, an area with many native wildflowers. 

The latitudinal range of the southeast also contributes to biodiversity.  It has areas which experience a wide range of seasonal temperature changes like the Carolinas and Kentucky in the northern part of the southeast, to areas that are much warmer throughout the year, like the Gulf Coast. 

There is also considerable altitudinal zoning in the mountains.  Every 1,000 foot increase in elevation in the mountains is equivalent to traveling 300 miles farther north in latitude.  Therefore, higher altitudes are cooler and may sustain plant communities normally found much farther north in places like New England.  Lower altitudes are warmer and may sustain mountain plant communities unique to the southeast.  Also, the northern sides of mountains are cooler and may sustain plant communities normally found farther north.

Rabun Bald, Georgia, an area with many native plants. 

The bottom line is that diversity in soils, plenty of rain, plenty of warmth and sunlight, longitudinal range, and altitudinal zoning are some of the important factors that create the unique richness of species and environments in the southeast.  Unfortunately, because many people are unaware of the rich natural heritage the southeast possesses, much of its biodiversity is under threat from urban and suburban development and other land use threats.  It is important to educate others and let them know about this great national treasure that we all possess- the natural history of the southeastern U. S. - and of our need to protect it through good stewardship so that we can continue to have this national treasure.

If you would like to know more about the ecological communities and systems of Georgia, this link at the "New Georgia Encyclopedia" will give you more information:

http://www.georgiaencyclopedia.org/nge/Categories.jsp?path=/LandResources/GeographyandEnvironment/EcologicalFunctionsofEnvironment/CommunitiesandSystems#/LandResources/GeographyandEnvironment/EcologicalFunctionsofEnvironment/CommunitiesandSystems

Wild Azaleas, Great Smoky Mountains National Park

 
-Wayne