Geoscience Reference
In-Depth Information
sweet smell. When the land blows out of the northwest, and the smoke is driven to the sea, it happens that
the land is smelt before it is seen.
Two decades earlier, Henry Hudson also observed a “great fire” on the south Jersey coast, which he attrib-
uted to natives. The fires not only served to drive the deer, improve visibility, and aid travel by foot but also
encouraged the growth of plants in the forest that attracted game.
Lumbering began in the early 18th century and first concentrated on Atlantic white cedar, which grew in
dense stands in lowland “cedar swamps.” Its light, straight-grained, and rot-resistant wood was deemed ideal
for shingles. By the end of the 19th century, this resource had been exhausted by recurring fires and the cutting
of immature stands. During the 1800s the pine forests furnished fuel wood for Philadelphia and New York,
which had depleted their surrounding woodlands, and supplied coastal steam vessels with their source of
power.
The greatest impact on the native forests was wrought by the production of charcoal, used in the nearby cit-
ies as domestic cooking fuel but more significantly as a substitute for coal in smelting iron, produced from li-
monite or bog iron precipitated from the tannin-rich, tea-colored local rivers. At the same time, a glass industry
grew up that depended upon the high heats produced by burning pitch pine.
The history of the region, in short, is one of fire, both deliberate and accidental, but in either case the result
of human activity.
The dominant tree in the Pine Barrens forest, the pitch pine, is well adapted to repeated fires. The thick bark
protects and insulates the trunk from fire damage, and even if the fire reaches into the canopy and destroys the
needles, the tree can recover, since its trunk and branches are supplied with dormant buds, which can quickly
replace its seed-producing capacity. Trees that are repeatedly subjected to fire sometimes produce what are
known as serotinous cones, which are tightly sealed by a resin, allowing the seeds inside to remain viable for
years. If a catastrophic fire kills the tree, the heat will be great enough to open the cone and sow the seeds,
which can take root and grow even in soil with no humus. Some pitch pines carry both serotinous and non-
serotinous cones. The latter open mainly in winter and are scattered by the wind.
PINE BARRENS TREE FROG
Fire also serves the pitch pine by killing competing hardwoods such as maples and oaks. Pitch pines and oak
species usually occur together, however; pitch pines form the canopy on the drier sites, and oak is more domin-
ant on the upland sites. The Pine Barrens ecosystem can be seen as a function of both moisture in the soil and
soil texture, from fine to coarse, both of which influence the frequency and intensity of fires. Oak forests oc-
cupy the more nutrient-rich upland sites, which have finer soils that retain moisture. On coarser soils, which
are drier because they allow rainwater to filter through them, fire is more frequent, and the pines and a differ-
ent set of oaks become more dominant. Dwarf pitch pine and scrub oak form a pygmy forest under the driest,
most fire prone conditions. And in the case of extreme disturbance, the pitch pine gives way to an oak-heath
community.
