Invasive species in the watershed

BUSH HONEYSUCKLE


If you participate in a FLOW invasives cleanup, the great majority of what you will be removing will be exotic bush honeysuckle, generally L. maackii (Amur honeysuckle). This should not be confused with native honeysuckle which is a vine.

Bush honeysuckle was once planted by park departments to stem erosion and provide wildlife cover. Unfortunately it has grown to dominate great areas of open, upland habitats and riparian areas throughout the northeastern U.S. Because it is the first to leaf out in the spring, and the last to lose leaves in the fall, it crowds out native plants, depletes the soil and prevents the germination of trees. There is evidence it releases toxic chemicals that prevent other species from growing nearby. Its abundant berries are attractive to birds but lack the high fat and nutrients needed for migration or winter survival, leading to winter die-offs. There is some evidence that birds that depend on bright coloration to attract a mate (such as male cardinals) may gain an advantage by eating the berries that does not reflect actual high genetic quality.

To manage honeysuckle and restore woodlands, FLOW volunteers clear cut the shrubs and remove the brush from the location. Small seedlings can be pulled. Most areas will need an additional clearing the next season to remove new growth, since birds widely disseminate the seeds.

The flowers appear in early to late spring

Leaves are opposite along the stem, 1.5-2 inches long, and short-stalked.

The bark has distinctive ridges.

The bright red berries are widely spread by birds.

Older stems are usually hollow.

While hand tools can be used to remove younger honeysuckle, chain saws will really help with the older, larger ones.

Where permitted, herbicide is painted on the stumps to prevent regrowth.


OTHER INVASIVES COMMONLY FOUND IN THE WATERSHED

Ficaria verna, commonly known as lesser celandine or pilewort, is a low-growing, hairless perennial flowering plant in the buttercup family Ranunculaceae native to Europe and west Asia. It has fleshy dark green, heart-shaped leaves and distinctive flowers with bright yellow, glossy petals. (from Wikipedia)

Lesser celandine thrives along stream banks and in wet areas. It forms dense mats that crowd out spring ephemeral plants before it goes dormant in the summer.

Winter creeper - Euonymus fortunei - is an evergreen perennial vine, introduced as a ground cover. It covers the ground, crowds out all other plants, and climbs high into the tree canopy by clinging to the bark, weighing down the tree and damaging the bark. In the right conditions it produces bright orange berries.

Wintercreeper covering the ground near Bill Moose Run

Any introduced species can become invasive; while not on the official list of invasive species, this winter aconite (Eranthis hyemalis) which is in the buttercup family (along with lesser celendine) is problematic in Webster Park. Volunteers have been working on restraining it.