Transition forests

In Frederick County we have areas where the plant life found in the Southern forests and Northern forests intermingles, creating a transition forest community. This normally occurs in the mountainous areas on cooler sites such as northfacing slopes or where stream corridors or ravines have formed.

The cool moist areas often contain fairly common trees like tulip poplar, red and white oak, red maple, black birch, black gum, and ash mingling with trees that are more common in the Northern states. The Northern varieties found here are beech, shagbark hickory, sugar maple, yellow birch, basswood, white pine and hemlock.

Yellow birch near Wolfsville

Credit: - Mike Kay

The rather uncommon cucumber magnolia tree found in elevated sections of the Appalachian Mountains can also be found here as well. Similarly, the cool moist conditions found in these forests also invite a variety of native shrubby species such as ironwood, muscle wood, bladdernut, rhododendron, holly, hazelnut, alder, witch hazel, spicebush, silky dogwood, and viburnums. Some uncommon herbaceous plants can be found here as well such as trillium, wood anemone, wild ginger, leeks and skunk cabbage. The cool moist conditions are also ideal for a number of salamanders, frogs and other amphibians.

The hemlocks that were once a common component of these forests have been declining mainly due to hemlock woolly adelgid, an insect that positions itself on the underside of the needle sucking out the juices. This feeding activity causes needle drop, which in the case of the evergreen hemlock will eventually result in the death of the tree.

Hemlock woolly adelgid looks like white fluffy wax on the underside of the needles.

In recent years some parasitic beetles have been released in spots to help control the adelgid; adelgid numbers decline in response to cold temperatures and cool moist spring conditions, so in some places the hemlocks are staging a comeback of sorts.

Frederick County is a large diverse land area with many interesting features including many of its forest communities.

Article by FCFCDB member

Nature Note for 4/6/2014