HAWKINS, TRACY S. School of Biological Sciences, University of Kentucky, Lexington, KY 40506 and Hazard Community College, Jackson, KY 41339. - A vegetation transect of the south slope of Pine Mountain, Kentucky: changes since E. Lucy Braun and chestnut blight.
Forest composition and structure were determined on a 68-ha tract on
the south slope of Pine Mountain, Kentucky, in 1997. Data collected
from 28 0.04-ha plots were summarized as importance values. Canopy
compositions were compared with those described by E. Lucy Braun
(The American Midland Naturalist 16: 517-565, 1935) prior to
the peak of chestnut blight (Cryphonectria parasitica). No
significant change has occurred in canopy composition on the xeric SSE
dip slope. Pinus echinata and P. rigida have persisted
as co-dominants, and Quercus prinus has remained an important
component in the canopy. In mesic sites, canopy composition has
remained stable; however, near the crest of the mountain Acer
rubrum has replaced Castanea dentata and assumed secondary
importance to Liriodendron tulipifera. On the ESE aspect of
the dip slope, where C. dentata made up one third of the
pre-blight canopy, forest gaps were filled by Q. coccinea and
Q. velutina, which now have a higher importance value than that
of the pre-blight oak dominants (Q. alba, Q. prinus).
Except for the absence of C. dentata, canopy components of the
forest communities have remained relatively unchanged during the past
65 years; however, the loss of C. dentata initiated changes in
the relative importance of these species in the forest community.
Further, in all sampling sites the contribution of existing canopy
species to importance values for the sapling/small tree and
shrub/woody seedling strata is less than that of fire-sensitive
species (A. rubrum, Nyssa sylvatica, Sassafras
albidum), suggesting future changes in these post-blight forest
communities.
Key words: Braun, Castanea dentata, chestnut blight, forest community