Weed Management and Invasive Species Control - Project Planning and Management for Ecological Restoration - page 198

Box 12-3. Lesson Learned: Temporary Nuisance Animal Control May Be Critical
to Project Success
In the late fall, an organization installed numerous pole cuttings on a recently re-
connected floodplain in an effort to create riparian habitat for native wildlife. That
winter, the site was inundated with several feet of standing water for a couple of weeks.
A site inspection that spring revealed that beaver had entered the site and girdled all
of the pole cuttings at the water level, thus killing the trees. The beaver were native
to the region and would be welcome inhabitants in the restored riparian forest. How-
ever, their early entry to the site resulted in replanting with added plant protection
and animal control to allow sufficient time for the habitat to mature.
The organization learned that during the plant establishment period and even into
the stewardship phase, it may be necessary to exclude or manage nuisance animals
even when they are native species.
nation site for weed seeds. Generally, a three- by three-foot square of landscape fabric is installed
at each planting location and stapled to the ground on all four corners. Paper fabrics can also be
used; however, they are generally good for only one year, whereas synthetic fabric lasts many years.
Manual labor is involved in installing weed mats and removing them at the end of the plant estab-
lishment period. Hand weeding may still be required at the base of each plant.
Control of Exotic Pest Animal Species
In some cases, introduced or escaped animals pose significant threats either to native species or to
the functioning of native plant communities. A common threat is the introduction of marine or-
ganisms from one region to another, either on the same continent or across oceans. Zebra mussels
and freshwater clams are common in many parts of the world because of the extensive shipping
now occurring (Cox 1999). During the early years of world exploration, goats, pigs, and other
animals were introduced to many of the Pacific islands to provide food for subsequent travelers.
These animals continue to seriously degrade many plant communities throughout the United
States and have subsequently caused population declines of numerous species of birds, mammals,
and reptiles.
Control of exotic animal species requires a pattern of approach similar to that for exotic plants;
however, with the mobility of some of the species, it may not be feasible to have a methodical
pattern of control. Several programs exist with the goal of trapping pest species, such as introduced
red fox, Norway rat, and domestic cat. It may not be feasible to attempt to completely eliminate
some exotic species; instead, the goal becomes to control the numbers to some reduced level so
that native species in the degraded community can regain a presence at a level that permits them
to reestablish ecological function (box 12-3). Consistency in a program is the key. This is especially
true if it is beyond your ability to eliminate the source of invasion.