Forest Succession—Clues to the Past (Mid-Atlantic)

Successional forests can be ideal places to read some of nature’s stories, since this kind of forest can reveal clues to what kind or degree of disturbance the land underwent in the past.

Triple-trunked tuliptree (Liriodendron tulipifera), likely regrown from a stump.
Photographer: Erin Jones, courtesy of NatureServe
Where a forest was logged with minimal ground disturbance, a blend of various trees, including many of the original hardwood species, may quickly return from stump sprouts or from saplings that were left behind. Non-woody vegetation on the forest floor may recover as well. Trees within a formerly logged forest may vary somewhat in age, especially if the forest was only selectively logged.

Telltale signs of a logged forest include old stumps or multi-trunked trees (multiple sprouts regrown from a single stump). You may also find fairly deep holes in the ground left by rotted stumps, sometimes outlined at the surface by neighboring tree roots that once encircled the old trunk.

By contrast, where intensive fire, plowing, or earth moving has removed not only trees, but also stumps and seed banks (seeds in the soil ready to germinate), an entirely new forest is created.

The new forest is populated by pioneer species whose seeds germinate quickly when they reach bare mineral soil.** These tree seedlings quickly spread their large, juvenile leaves to the sun, casting shade that reduces the ability of some other plants to germinate or thrive on the forest floor.

A tree felled by natural or artificial means admits direct sunlight into the forest understory. Young oaks benefit.
Photographer: Tom Paradis, courtesy of CUE, NPS. Inset – Matt Jones.
In the Mid-Atlantic, these forests tend to regrow as even-aged stands of pine and/or tuliptree (or sweetgum in the Coastal Plain). Little by little, as mature trees die, an even-aged successional forest of this type may eventually give way to an uneven-aged suite of trees, shrubs, and herbaceous plants typical of a natural community found in the same environment. This process can take centuries.

Oaks can be clues when piecing together the past. White oak and many other species of oak are not typically found in the canopy of a young forest with a history of severely disturbed soil. Why? The acorns of many oak species are slow to grow, and oak saplings usually end up in the shade of pioneer species, lagging far behind until sunlight reaches them through a canopy gap, sometimes years or decades later.


**Examples of pioneer species in the Mid-Atlantic, quick to germinate on bare mineral soil: pine, tuliptree, sweetgum, black locust, red maple, or sassafras trees.