Habitat
restoration is one of the most important challenges facing
conservationists today. Without adequate habitat, endangered species
can’t be recovered. Many human activities require restoration as
well. Fully functioning wetland systems can provide flood control and
clean drinking water. How does the process of habitat restoration
work?
Restored coastal marsh, where dikes were removed to allow the sea to once again access the land |
The
first step, as in medicine, is “First, do no harm.” A site
evaluation will determine exactly what needs to be done to restore
what once was. Noting current conditions establishes a baseline for
measuring success of the project. It might involve stabilizing a
feature immediately, such as an eroding stream bank. After figuring
out what needs to be done, the next step is figuring out how to do
it.
In
many cases, conservationists will use a reference site similar to
what is being restored to determine plants and other features. Plants
will influence what kind of animals will begin using the site, but
the land and water on the site will determine what plants can live
there.
Live willow stake planted to reforest a former pastureland |
A
lot of times, restoration work is more than simply replacing plants
and animals that lived on a site before people came in and messed it
up. A site I monitored in Washington had once been a thriving salmon
stream with a wide flood plain. 19th
century farmers drained the area by straitening the stream to allow
water to flow in and out faster. They also cleared the trees. Fast
forward to the 21st
century, and we’ve figured out that the stream needs to be slowed
and shaded. Over a period of several years, the curves were put back
in the stream and thousands of new trees and shrubs were planted.
Fixing the stream required building temporary dams, removing fish by
hand, and using heavy equipment to excavate a new stream bed at just
the right depth and slope.
Ohop Creek after being restored to its twisted ways |
After
work has been completed, the site must be monitored for success.
There should be some kind of measurable goal, and even if the
restoration fails it can be a lesson for future attempts. The site I
mentioned was restored for salmon habitat, and while it will take a
few years for trees to begin cooling the water temperature, it has
been under constant observation since work began. Several times a
year, conservation groups involved in the restoration work check
water levels, tree survival, how many salmon are spawning, and what
kinds of animals are using the habitat. All of this is checked
against initial observations from before the project began.
This prairie, currently a restoration work in progress, was a field of weeds a few years ago |
My work with habitat restoration has been monitoring (documenting wildlife and animal signs, as well as plant survival rates), site maintenance, and invasive species removal. The work is hard and sometimes conditions are brutal, but I find it to be very rewarding.
In
many cases, restored habitat is second rate compared to what it once
was and what nature has provided. It’s not for a lack of trying,
but nature is a much better architect of natural features than what
man could ever hope to be. But it’s better than nothing.
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