One of the best places to see and learn about the diversity of plants in the piedmont of Georgia is the Southern Piedmont Mesic Forest, an ecological community unique to the piedmont of the southeastern U.S. It is a great place to go to with your tree and wildflower identification guides and learn about the natural plants of Georgia, especially in the Spring when wildflowers are in bloom.
The Piedmont
The piedmont is the
region of rolling hills in north-central Georgia that lays south of the
Appalachian Mountains and north of the flat Coastal Plain. The majority of the people who live in
Georgia live in the piedmont region since Atlanta and other piedmont cities
have large populations.
The Georgia Piedmont is represented by the
area in green. Photo Credit: Wikimedia Commons/Public
Domain.
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Piedmont Oak-Pine
Forests
Before talking
about the mesic forest of the piedmont, I want to mention the more typical
forest type of the piedmont, so that you'll understand why the mesic forest is
different. The natural plant community on
the upper slopes and tops of the hills in the Georgia Piedmont is the
Oak-Pine Forest, also known as the
Oak-Hickory-Pine Forest. These upper
slopes of the piedmont hills typically have drier soils, known as xeric (pronounced
zeer-ik) soils, since rainfall runs downhill away from these areas and they
subsequently dry out quickly. Due to the
geology of the piedmont, the soil also typically has an acidic pH. The dry, acidic soil conditions limit the
species of trees and other plants that can grow on these upland sites. This is because the acidic pH makes it harder
for plants to absorb nutrients from the soil, and many trees and other plants
need more moisture than is available in this type of environment.
Typical Piedmont Oak-Pine Forest in March. |
For more detailed information about this ecological
community, see the Natureserve Explorer
Ecological System Comprehensive Report.
Go to: http://www.natureserve.org/explorer/servlet/NatureServe?init=Ecol and enter "Southern Piedmont Dry Oak Pine Forest"
in the ecological unit field and press enter.
Piedmont Mesic Forests
There are some
areas on the northern and lower slopes of some piedmont hills where much richer
natural plant communities grow, some of the most species-diverse in the
piedmont. These areas are moister, or
more mesic (pronounced mez-ik), and are known as Mesic Forests. The higher moisture levels support more
species of trees and other plants than the xeric Oak-Pine Forest. The mesic conditions exist because these
areas are either at the bottom of slopes where rainwater drains into the soil,
or they are on the north-facing sides of hills.
The north sides of hills don't get any direct sunlight, even in
midsummer, since the sun is always a little to the south of our latitude even
at high noon. As a result the sun does
not dry out the soil as it does on the East, South, and West slopes of hills. These mesic soils are not water-logged or
wet; they are typically well-drained but have higher moisture levels. These plant communities should also not be
confused with alluvial floodplains (found along rivers) or riparian forests
(moist areas along streams and creeks).
The mesic forest is distinguishable because it is upslope from these
other natural communities.
You'll be able to
identify a Mesic Forest because beech trees (Fagus grandifolia), which
require mesic conditions, are either the dominant tree species or are very abundant. Other tree species that prefer or require
mesic conditions will also be present, including species like musclewood (Carpinus
caroliniana) and tuliptree (Liriodendron tulipifera), and will help you to confirm that you have found a mesic site. Most piedmont mesic
forests have an acidic pH level less than 7.0, but they still support a diverse
plant community.
To see images and descriptions of any of the trees in this post go to the Virginia Tech Forest Biology and Dendrology site and search for the tree species: http://dendro.cnre.vt.edu/dendrology/factsheets.cfm
For more in-depth information on each tree species in this post, go to the U.S. Forest Service's Sylvics of North America, Volume 2, Hardwoods:
http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/vol2_Table_of_contents.htm
To see images and descriptions of any of the trees in this post go to the Virginia Tech Forest Biology and Dendrology site and search for the tree species: http://dendro.cnre.vt.edu/dendrology/factsheets.cfm
For more in-depth information on each tree species in this post, go to the U.S. Forest Service's Sylvics of North America, Volume 2, Hardwoods:
http://www.na.fs.fed.us/pubs/silvics_manual/volume_2/vol2_Table_of_contents.htm
For more detailed information about this ecological
community, see the Natureserve Explorer
Ecological System Comprehensive Report.
Go to: http://www.natureserve.org/explorer/servlet/NatureServe?init=Ecol and enter "Southern Piedmont Mesic Forest" in the
ecological unit field and press enter.
Piedmont Basic Mesic
Forests
These mesic forests are rarer, but have conditions that support even more
plant diversity and are an exciting place to see and learn about plants. This is because they
have minerals in the underlying rocks, usually calcium or magnesium, that
buffer the soil pH and make it less acidic.
These forests are sometimes referred to as Basic Mesic Forests. Basic refers to a pH level greater than 7,
which is typically not found in these forests, but the name indicates that they
include minerals with a basic pH such as calcium and magnesium. Basic mesic forests typically have a
well-developed understory and many different species of herbaceous plants. Many of these plant species are not
found elsewhere on the piedmont but instead are normally found in the
mountains. Exploring a basic mesic
forest during Spring or Summer will provide you with a wonderful opportunity to
view a wide variety of trees, herbaceous plants, and wildflowers.
A Trip Through a Basic Mesic Forest in Mid-March, 2013
Mid-march in Georgia's northern piedmont is when the very first Spring wildflowers begin to emerge and bloom in mesic forests. Our first field trip into the forest after the winter was to a Basic Mesic Forest.
A Trip Through a Basic Mesic Forest in Mid-March, 2013
Mid-march in Georgia's northern piedmont is when the very first Spring wildflowers begin to emerge and bloom in mesic forests. Our first field trip into the forest after the winter was to a Basic Mesic Forest.
This is the same photo that was used above to show Beech trees. It is part of the Basic Mesic slope and shows the large Beech trees that are abundant on the slope. |
A closer look at the T. decipiens. This amazing display of these unusual woodland plants is one of the reasons we visited this site. It is an early reminder that Spring is almost here. |
Trillium decipiens in bud. The knife is 4 3/8 inches long. |