Acadian Old-growth Forests
The Acadian Forest Region includes the three Maritime Provinces, parts of the Gaspe Bay Peninsula, and parts of the Northeastern United States. It is characterized by diverse types of vegetation assemblages, many of these vegetation types being diverse in both softwood and hardwood tree species. Old-growth Acadian forest ecosystems are usually dominated by trees that are of high economic value, and including Red Spruce, White Pine, Eastern Hemlock, Sugar (hard) Maple, Yellow Birc h, White Ash, Red Oak, and American Beech. These tree species are generally long-lived and are adapted to living amid small-scale ecosystem disturbances, referred to technically as the process of gap dynamics.
Gap dynamics denotes the series of events that begin when a tree or small group of trees are removed from the overstory (usually by wind or disease). The increased light and growing space created by each new gap means a new opportunity for seedlings and younger trees. It is this process that causes n a tural old growth forests to be dominated by tree species that can tolerant to shaded growing conditions during their youth. The more able to tolerate shade in the understory, the longer the young trees can "hold out" for their opportunity in life, as deli vered by the wind--or a logger! The trees that are notorious for this ecological strategy are referred to as shade tolerant, and can be referred to as old forest species. The degree to which a forest is dominated by these species is a good indication of the disturbance history of the forest. Typically, forests comprised of trees that thrive in open, full-light conditions indicate a higher level of large-scale human disturbances, such as repeated clearcutting. These species include White Spruce, Balsam Fir, White Birch, Wire Birch, Pin Cherry, Aspen (Poplar), and Red Maple.
We should remember that there is no one species composition that makes up an old growth Acadian Forest. Rather, there are many different vegetation types that occur, each reflecting the unique growing conditions and disturbance history of the forest. There are however characteristics that generally denote the level of human verses natural disturbance to the forest. Older more naturally-disturbed forests tend to exhibit larger, shade-tolerant tree species, a diverese tree age structure, and an abundance of dead and dying trees. Forests with these characteristics are increasingly less prevalent in the Acadian Forest Region today, owing mostly to an intensive history of forest use over the last 300 years. Practicing forest management that aims to restore these characteristics is essential to maintaining a balanced respect for the many stakeholders of the Acadian Forest Region, whether they are people seeking recreation or employment, or wildlife species that rely on these structures for part of their habitat.