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Research Summary:
Upland
hardwood forests of eastern North America are experiencing a period of
unprecedented change. Many of the
observed changes can be traced to anthropogenic influences. Modified disturbance regimes, fluctuating
wildlife populations, increased atmospheric pollution, introduction of alien
species, etc. have all had a pronounced effect on deciduous forest
ecosystems, both individually and collectively. Some of these changes are predictable and the result of natural
community succession. Differential
patterns of resource acquisition and utilization, biotic interactions,
response to the abiotic environment, and stochastic processes will all affect
the distribution and abundance of forest tree species.
One of the most dramatic examples of
forest change is the conversion of oak-hickory or mixed oak vegetation to
maple forest. Oak vegetation types
are some of the largest in eastern North America but do not appear to be
regenerating true to type anywhere in their range. Oak and hickory regeneration failure appears to be multi-causal
in nature and is likely the sum response of a variety of interacting factors. Studying the causes and consequences of
oak and hickory decline is one of the central focuses of my research program.
Because the root of forest change is
likely multi-causal in nature I am exploring a variety of approaches to test
different sorts of hypotheses.
Long-term demographic studies are being used to document changes in
forest composition, structure, and soil conditions. Experimental field,
garden, and greenhouse studies are being used to investigate the effects of
invasive plants (garlic mustard, honeysuckle, empress tree), wildlife
(weevils, squirrels, wild turkey), organic debris (leaf litter and logs), and
environmental components (light, water, fire) on oak and hickory
regeneration. Dendroecological
techniques are being used to understand past disturbance histories and stand conditions.
Selected References:
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Williams, A.C. and B.C. McCarthy (2001) A new index of interspecific competition for
replacement and additive designs. Ecol. Res. 16: 29-40.
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Meekins, J.F., H.E. Ballard Jr., and B.C. McCarthy (2001) Genetic variation in Garlic
Mustard (Alliaria petiolata, Brassicaceae) using inter-simple sequence repeats
(ISSRs). Int. J. Plant Sci. 162: 161-169.
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McCarthy, B.C., C.J. Small, and D.L. Rubino (2001) Composition, structure, and
dynamics of Dysart Woods, an old-growth mixed mesophytic forest of unglaciated Ohio.
For. Ecol. Manage. 140: 193-213.
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Rubino, D.L. and B.C. McCarthy (2000) Dendroclimatological analysis of white oak
(Quercus alba L. Fagaceae) from an old-growth forest in southeastern Ohio. J. Torrey
Bot. Soc. 127: 240-250.
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Meekins, J. Forrest and B.C. McCarthy (1999) Competitive ability of Alliaria
petiolata (Garlic Mustard, Brassicaceae), and invasive, nonindigenous
forest herb. Int. J. Plant Sci. 160: 743-752.
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Robison, S.A. and B.C. McCarthy (1999) Growth responses of Carya
ovata (Juglandaceae) seedlings to experimental sun patches. Am. Midl. Nat.
141: 69-84.
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Greer, G.K., R.M. Lloyd and B.C. McCarthy (1997) Factors influencing
the distribution of pteriodophytes in a southeastern Ohio hardwood forest.
J. of the Torrey Bot. Soc. 124:11-21.
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