Some visitors to Rewild Earth have commented that the before pictures
often look "nicer" (i.e., greener) than the after pictures. They find this confusing. Allow us to explain.
A number of invasives, including Chinese privet, autumn olive, thorny olive and multiflora rose, are
understory ("An underlying layer of vegetation, especially the plants that grow beneath a forest's canopy.")
shrubs or small trees.
In a healthy forest, there will be understory trees, grasses, shrubs, herbs and more. There will also
be saplings (young trees) of the same species as the canopy trees (the big ones). But there will also
be lots of open space - precisely because the canopy shields the ground from most of the sun.
When a big tree falls, light suddenly reaches the forest floor and then a new phase of growth begins. The
saplings begin to grow, eventually in many cases filling the gap left by the tree fall. But everything
else will also take off for the sky
When the understory has been invaded by aggressive, non-native species, however, something very
different happens. As invasives, when given enough time, they will fill up the understory.
They often thrive in low light and out-compete everything else.
When this happens, you end up with lots and lots of green, but only one kind of green. Many native
plants are driven out of these areas of the forest. Insects that depended on those plants also
disappear. Fauna like deer are unable to move through the forest as they normally would. Their
passages are blocked.
The bottom line is that the health of an ecosystem cannot be measured solely by the amount of greenery in
it. And the result of many of our tree rescues is that the understory is much clearer (less green) and
ready to be populated by native species again!