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Vegetation management
As discussed in section 4.1.2, the high percentage of invasive non-native plant species in the vegetation compromises the quality of the site as a natural area. While it will be impossible to eliminate these species, ecological restoration should be carried out to improve the habitat value and ensure that a diverse compliment of native species will become established as vegetation succeeds into a greater dominance of woodland.
Common Buckthorn is undoubtedly the most overwhelming of the invasive plants that presently occur on site. It dominates well established stands and the high proliferation of seedlings in the ground layer indicates a heavy seedbank that appears to perpetuate itself. Consequently restoration should concentrate on areas of riparian or upland meadow where buckthorn is younger or not yet dominant.
Using volunteers, as well as hiring Steve Smith of Urban Forest Associates (who is experienced in control of exotic species), the recommended approach involves cutting shrubs at ground level and applying Roundup or other non-persistent herbicide to stem to kill roots and prevent sprouting. Shortly thereafter, seedlings or saplings of native trees and shrubs should be interplanted to ensure that the community will develop into one dominated by native species.
In very mature Buckthorn stands, whips or saplings of shade tolerant trees (e.g. Sugar Maple, American Beech, Eastern Hemlock and White Ash) can be planted to eventually create a native canopy. In addition a basal herbicide can be applied to the lower bark of some standing large Buckthorns to create openings in the canopy, which would also allow use of some less shade tolerant species such as White Pine, Red Oak or Paper Birch.
Black Alder is common on the floodplain but not yet abundant. It may still be possible to carry out a 'search and destroy' mission before the species is firmly established. Shrubs can be either cut or applied with basal herbicide. This species is also prone to suckering. Since most of these trees grow immediately along the creek, special care will need to be taken to ensure that herbicide does not get into the water.
Similarly, Autumn Olive is not yet well established so a concerted effort should be conducted to keep it under control. Smaller plants can be pulled out or it should be applied with non-persistent herbicide. Basket Willow is also becoming increasingly common on the floodplain and would be another good candidate for control. A few small patches of Common Reed occur along the sanitary sewer alignment and these would be best eliminated by careful application of Roundup during dry weather early in the growing season.
Restoration plantings should imitate natural vegetation communities within the appropriate site (i.e. soil type, slope and moisture regime) that are indigenous to the general area. If possible, plants should be obtained from a local gene pool. Suitable plantings for
| Riparian Habitat | Upland Habitat |
|---|---|
| White Cedar | White Cedar |
| Eastern Hemlock | White Pine |
| Red Maple | Sugar Maple |
| Mountain Maple | American Basswood |
| Red Ash | White Ash |
| Black Ash | Black Cherry |
| Bur Oak | Red Oak |
| Yellow Birch | Paper Birch |
| Balsam Poplar | Trembling Aspen |
| Nannyberry | Staghorn Sumac |
| Red-osier Dogwood | Hawthorn |
In the long term, we can expect that all field areas will succeed into thicket and eventually forest communities. Field habitats are a desired feature as they contribute to diversity, heterogeneity and aesthetics of the site. Many plants, birds and most butterflies require open sunny habitats to persist. Management is required to maintain field habitat either through periodic mowing (once every two or three years is sufficient) or use of fire. Some areas should be identified where both upland and riparian meadow should persist, and the appropriate maintenance taken.
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