Biodiversity in western North
Carolina
The southern Appalachians offer a plethora of fascinating flora
and fauna, with each season offering something for the nature
enthusiast - wildflowers, birds, autumn color, and much more.
This region is the most biologically diverse area in North America.
But what does that mean? And how did it happen?
Simply put, there are more species of plants in this area than
in any other area of similar size in North America. Botanical
studies have indicated that there are over 4,000 species of plants,
2,000 plus species of fungi, and more than 500 species of mosses
and lichens. The state of North Carolina has more species of
salamanders than the rest of the world combined, more species
of Oak trees than all of the United Kingdom, is home to a breeding
population of Monarch butterflies, and is on the Atlantic flyway
for migratory songbirds.
But what accounts for this biodiversity? First, and perhaps most
important, is the age of these mountains. The original Appalachian
chain was formed 250 million years ago and the current elevations
are 50 - 60 million years old. (By contrast, the Rocky Mountains
are a mere ten million years old.) Over the course of these millions
of years, this region has had time for soil to accumulate and
for plants to evolve to fit the many niches found here.
Second, we have elevational changes. Using Asheville as a starting
point you can be in a typical southern Loblolly Pine forest in
an hour. By traveling an hour in the opposite direction you can
be in a Spruce-Fir forest similar to those found in southern
Canada. In between are a wide variety of forest communities.
Each of these communities has its own wildlife populations, each
with their own unique adaptations to the environment. As I mentioned
earlier, this area is known for the various salamanders. Why?
Many salamanders do not possess lungs, breathing instead through
their skin. Temperature is a key factor in their ability to do
this, each ten degree increase in the ambient temperature equates
to doubling the effort required just to breathe. Our cold, highly
oxygenated mountain streams are ideal for them.
The third major factor is the orientation of the mountains in
eastern North America. While the major mountain ranges in Europe
run east to west, our Appalachian mountains run north to south.
During the last glaciation, ten thousand years ago, this orientation
provided escape routes for species retreating in front of the
advancing ice. Plants which relied on small mammals, amphibians,
and insects to disperse their seeds were able to move south,
and many of those refugees adapted to their new environments.
The opposite applied to many European plants and animals which
were trapped at the base of the European mountain ranges and
destroyed by the glaciers.
So be sure to get out and enjoy the beauty for which the region
is noted. Let me stress that this has been a very basic explanation
of how this area developed, so whenever you're out in the woods
be sure to take a moment to consider the many factors which prepared
the area for you.
This article was written for Travel Host of
Western North Carolina, May/June 2003.
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