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The Effects of deer browsing and salvage operations in ice storm disturbed
forests of northern New York state
Katie Johnson
Introduction
In January of 1998, northern New York was struck by a severe ice storm
that affected 4.6 million acres and significantly disturbed 3 million
acres of forest communities. The counties of
Jefferson, Lewis, St. Lawrence, Franklin, Essex and Clinton were declared
disaster areas. The heaviest damage was sustained in a band through north-central
St. Lawrence, Franklin and Clinton counties. The ice storm resulted in
varying degrees of disturbance to the forest canopy. Disturbances noted
were the breaking and hanging of branches, split forks and snapped stems
and the uprooting of trees by the heavy glazing of ice. The storm resulted
in the opening of the canopy as well as the possible weakening of the
standing hardwoods. After the storm, many people speculated that the economic
value of standing timber may decrease over time, because injuries to trees
would leave them susceptible to disease, discoloration and decay. Additionally
many were concerned that regeneration of hardwoods could be threatened
by high deer populations, competing
vegetation and other environmental factors including acid rain.
Therefore, forest managers commonly initiated salvage or rehabilitation
operations to harvest disturbed stands before further economic loss, to
protect healthy standing timber and encourage regeneration. Any sign of
vulnerability to disease or further destruction resulted in the cutting
down of these specific trees.
Salvage operations removed much of the canopy, increasing the amount
of light reaching the forest floor. The sudden openness of the canopy
stimulated the growth of existing tree seedlings and herbaceous plants
and encouraged growth of healthy trees.
White-tailed deer can strongly alter the composition of understory communities
through selective browsing. Deer brow
sing
has been studied in the past and has been blamed for establishment failures.
New trees that appear after forest cutting are often severely browsed.
Deer browsing can favor less valuable hardwood and herbaceous species
over valuable hardwood. Deer selectively browse economically valuable
seedlings and small saplings of sugar maple, black cherry and white ash
and ignore the less desirable species such as American beech and hayscented
fern.
This research focused on 3 questions: (1) Is hardwood regeneration different
between salvaged and unsalvaged sites, (2) Are deer impacting regeneration
of the forest and (3) Are deer impacting plant communities differently
in salvaged areas vs. unsalvaged areas? 
Methods
This research took place in St. Lawrence County in northern New York State
in a northern hardwood forest which was severely impacted by the 1998
ice storm. The overstory composition was dominated by sugar maple, black
cherry, white ash and Am
erican
beech. In the early part of 2000 approximately 20 acres of the forest
was salvaged and an equal portion remained unsalvaged but disturbed. In
the summer of 2000 researchers constructed six exclosed plots paired with
unexclosed plots in each of the salvaged and unsalvaged areas, for a total
of twelve exclosures. Exclosures were 7x7m with an exclosed and unexclosed
sampling area of 25m2. Pairs of plots were systematically located approximately
100m apart depending on ground topography and other physical factors.
Paired exclosed and unexclosed plots were within 10 meters of each other
and were matched as closely as possible at the time of exclosure construction.
Within the plots woody species ranging in size from 0-1' in height, 1-3'
in height, 3-6' in height and 6' in height to 0.5" in diameter were measured
and identified to species. All herbaceous species present on the plot
were recorded by percent cover. Results reflected 1 growing season. The
data were analyzed using a 2-factor (Exclosure, Salvage) Analysis of Variance
(ANOVA).
Results
Overall, few significant differences (alpha = 0.05) were found for either
the deer exclosures or salvage treatments. Interaction between the 2 treatments
was also not significant. For woody stems there was no significant difference
in densities by species or for all stems between any of the salvage
d
and unsalvaged areas. More herbaceous vegetation was found in the salvaged
area than the unsalvaged area. Fern species of hayscented fern and New
York fern dominated both salvaged and unsalvaged areas (an average of
24% cover). There was no significant difference between the exclosed and
nonexclosed plots in terms of woody species. The herbaceous vegetation
in general was not significantly different between the exclosed and unexclosed
plots
Discussion
In general, not enough time has passed to see any significant impact of
deer browsing on vegetation composition. Only one growing season has passed
since exclosure construction. Possibly 5-10 years may be necessary for
browsing to make a substantial impact. There was no apparent shift in
composition of woody species. Species like sugar maple and black cherry
that dominated the canopy also dominated the understory as seedlings and
saplings.
The salvage operation did not substantially affect the woody species.
As would be expected more herbaceous vegetation was found in the salvaged
area probably due to the availability of light. In most plots, fern dominated.
Rhizomatous ferns, such as hayscented fern and New York fern, are effective
competitors with other herbaceous and woody species. In light-rich environments
these species can spread quickly, cast strong shade and can completely
exclude germinating seedlings and other herbs. Hardwood regeneration is
probably strongly dependent on the amount of competing fern cover. Although
overall results showed no difference in regeneration between exclosed
and unexclosed plots, in the few plots where ferns were not present, regeneration
within exclosures appeared to be more dense and greater in height. Future
monitoring is likely to demonstrate the long-term effects of deer browsing,
salvage operations and fern competition.
Contact Information
For more information contact Katie Johnson at kljohn02@syr.edu , Eugene
Nichols at Kingfisher06@hotmail.com or contact Karl Didier at kadidier@syr.edu
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