Southern New England Habitats IV: Bog

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Transcript Southern New England Habitats IV: Bog

Southern New England
Habitats IV: Bog
• Definition: Bogs are habitats that initially develop over the
surface of a pond and, as they mature, ultimately replace the
pond.
• Physical environment: Bogs typically (but not always) develop
in highly acidic, low nutrient, low oxygen wetlands. In these
environments, plants grow on the partly decayed remains of
other plants that accumulate into a peat layer. Hence, bog
organisms may be said to create the environment they inhabit.
• Diversity: Plants inhabiting bogs are capable of tolerating the
difficult environmental conditions present. Many species
present are found only in bogs.
Bog Types
• In southern New England, bogs
include those with northern and
those with southern geographical
affinities.
• Northern bogs (upper right) are
characterized by species of the
boreal zone, and are found
principally in the Berkshire
plateau of western
Massachusetts and Connecticut.
• Southern bogs (lower right) are
characterized by species of the
southeastern coastal plain, and
are found principally in eastern
Massachusetts, eastern
Connecticut and Rhode Island.
Development: Young Bogs
• Bogs begin their development at the edge of a pond. Old bogs
often developed in glacial kettlehole ponds that formed after a
buried block of glacial ice melted.
• Plants that can extend their roots and stems over the surface of
water, such as grasses and sedges, are often among the first to
colonize.
• As a bog mat develops over the surface of the water, dead plant
remains accumulate on it and rain down to the pond floor.
• In the acidic, low oxygen environment of the pond, this detritus
accumulates into a partly decomposed peat layer.
Mature Bogs
• As the peat layer accumulates and the
floating (quaking) bog mat thickens, woody
shrubs, particularly acid-loving members of
the blueberry family, become more common
on the bog surface (above).
• As the mat thickens further over time, tree
species colonize (left).
• Individual bogs may, however, develop very
differently in response to local conditions.
Even very old bogs may have herbaceous and
shrubby mats.
Plant Diversity
• Northern and southern bogs share
many species like the shrub leatherleaf
in common.
• Characteristic trees of southern bogs
are the evergreen Atlantic white cedar
and rhododendron (above).
• Characteristic trees of northern bogs
are the black spruce (left) and
tamarack- a deciduous conifer.
Profile of a New England Bog
Adaptations
• Plant species like the Calopogon orchid (left)
derive nutrients from this low nutrient
environment by parasitizing other plants.
• Carnivorous plants like the pitcher plant
(above) derive nutrients by capturing and
digesting insects.
• Many species are evergreen, which helps
reduce the loss of nutrients stored in leaves.