A healthy forest will always be changing. We think of forests are static but they're not static
at all. They're continually changing. Forest succession is literally changes in the forest,
and it typically happens after an extreme disturbance or a stress event where an
entire vegetation or a forest dies. Whether it's a wildfire or a wind disturbance or an ice storm,
this whole restart of the vegetation happens from the grass stage to the mature forest stages.
There are grasses first which are followed by herb layer by shrubs and then by younger trees and then
finally by mature trees. So there is a gradual transition. And it's not only the plants that
are undergoing succession, it's actually also the animal communities that are undergoing succession
as well. The forest management practices that are used in any given forest and are really dependent
upon the landowners or forest managers objectives. If the objective is to have some sort of a natural
forest, then we allow the disturbance events to happen and we allow for natural succession
to happen. However, if the objectives are to manage the forest for economic purposes,
here in Georgia we have a lot of pine plantations for example, then there are tons and tons of
management practices that can be done starting from thinning to herbicide treatment to prescribe
burning. In many areas fertilization and so forth when it comes to healthy forests. Healthy really
means a community of fully functional trees and other plants but also animals and also
the physical environment. So there are two main points here. The first is that it's a community.
It's not a single tree. You can have sick trees. You can have a dying trees in a perfectly healthy
forest because it's the community that counts. And the other important term here is functional,
which means that the health of a forest is strictly linked to whatever is the function of
that forest. It could be a productive forest. It could be recreational. They will look different,
but they both can be healthy. Indicators of a healthy forest will be mainly vigorous canopies
and understory and the number of dying or that trees have to be adequate for the function of the
forest. If it's a productive forest, you want the minimum. If it's a recreational forest or
biodiversity conservation you can have more you want. To have a forest that is able to recover
after any type of disturbance you want to have as little as possible of erosion. You
want to have good quality of water. You want to have a good number of aquatic species,
and an adequate number of wildlife species which is not too little but also not too much.
If you have too many wildlife animals, that also is a sign of unhealthy balance in the forest.
Insect and diseases you want to have the right amount. A native species is native
to a geographical region and is adapted to the local conditions, and the environment itself is
adapted to that particular species. In terms of an invasive species, it has expanded its geographical
range and it can cause high impacts. Scientists make an important distinction in terms of invasive
species. We have native invasives and we have non-native invasives. Native invasives are already
present in the U.S. for example and perhaps have been moved from Arizona to California.
But the non-native invasives have actually come out of the country and they tend to be
a lot more damaging. The biggest environmental factors that influences the spread of invasive
species are actually humans because we are so much more connected globally and there's so much new so
many new trade routes that are emerging that the invasive species has become bigger of a problem.
And so a lot of regional economies are dependent upon these pine plantations, for example. And if
there is an invasive species that come in on pine plantations, it can be devastating to the economy.
We really want to protect Georgia forests from invasive species because Georgia
territory is mainly covered by forests. Almost 65 percent of our territory is covered by forest
and of this more than a half is covered by plantations. So southern pine plantations
we have to do our best to avoid any invasive species to come in. Whenever you see something
that you think it's not native look better into it and perhaps report it. A healthy
forest is important because forests provide us a numerous number of different functions.
And not only from the economical point of view. Of course the production of wood but
a healthy forest provides clean water clean air to the environment, it provides biodiversity,
provides habitats for insects for animals. So all of these factors are very important
and if you don't have a healthy forest you're not going to have those functions fulfilled.