Geoscience Reference
In-Depth Information
THE MOST COMPREHENSIVE
study of the changes wrought to the original New England/Acadian Forest in New
Brunswick was carried out in Kouchibouguac National Park and the surrounding area of southeastern New
Brunswick, bordering the Gulf of St. Lawrence. (This region is sometimes set apart from the New England/
Acadian Forest as the Gulf of St. Lawrence lowland forest, where the maritime climate encourages the growth
of hardwoods, which are mixed with red spruce, balsam fir, eastern hemlock, and white pine.) Researchers
used four lines of evidence to determine the makeup of the forest two hundred years ago: written documents of
the early travelers, explorers and settlers; records of “witness trees,” used to mark corners of original land
grants; timber petition records from 1820 to 1840, the peak time for harvesting of square timber for export to
Great Britain; and finally, ecosystem archaeology, which determines what trees had grown in areas cleared for
farming by fire, by examining charcoal and other identifiable macrofossils.
The last two hundred years have seen a dramatic shift from mostly late-successional, shade-tolerant species
such as hemlock, cedar, and yellow birch, to early successional species, including black spruce, jack pine, and
aspen. The forests are less diverse, with six tree species constituting 95 percent of the contemporary forest,
compared with nine species two centuries ago. White pine has declined, most of it having been removed from
riparian zones between 1820 and 1840. It has been replaced by jack pine, a product of the frequent fires in the
settled period. (The study showed that before European settlement the interval between major fires was 2,900
years.) Finally, the dominant, long-lived, eastern hemlock—the bearded one of Longfellow's poem—has been
replaced by short-lived species such as poplar and balsam fir. Poplar has increased by some 800 percent, while
beech has drastically declined. In short, the forest today is much younger and less diverse and, in composition,
more like the boreal forest to the north.
Forest Denizens, Old and New
Over the entire New England/Acadian Forest region, the forest has become simplified, with a loss of ecosys-
tem diversity. Inevitably, this has had a negative effect on a variety of species that were formerly adapted to
old-growth forest. Although few animal species are critically dependent on the old-growth forests of eastern
North America, a number of vertebrates exploit certain elements to complete their life cycle. The cavity
nesters, such as owls, bats, and woodpeckers, require large, partially decayed older trees to provide them with
nest sites. Pileated woodpeckers and barred owls are two species that require large hardwoods. But birds use
different components of trees, as pointed out by Richard H. Yahner in Eastern Deciduous Forest: Ecology and
Wildlife Conservation:
