Pilot
Study: Monitoring Impacts of Fraser Fir Seedling and Cone Harvests
David
White and Joan Walker
Concerns
about potential impacts of the harvest of Fraser fir seedlings and cones from
Roan Mountain spruce-fir forests led to the funding of a pilot study in
2000. The primary objective of this study is to develop and install a
sampling design that will a) effectively characterize the composition and
structure of spruce-fir stands on southeast to southwest facing slopes at Roan
Mountain, and b) be capable of detecting any changes in the future. These are
the necessary first steps to assess the status of the Fraser fir resource and
therefore to evaluate the consequences of seedling and cone harvests.
Our
efforts have involved: (1) analyzing and summarizing data previously collected
in permanent seedling plots by National Forest Botanists; (2) reviewing
literature pertinent to the spruce-fir ecosystem and acquiring data sets from
other sites in the Southern Appalachians; (3) interacting with forest managers
involved with seedling and cone harvests; and (4) developing a suitable
experimental design
followed by the installation of permanent plots.
Permanent Plot for
Tree canopy cover
vegetation assessment
assessment in plots
These data will provide an estimate of Fraser fir density by size class.
Size class distributions with known estimates of seedling abundance will
allow for an initial assessment of potential impacts of cone and seedling
harvests. Structure and composition of spruce-fir forests at Roan
Mountain will be compared to that of other spruce-fir forests in the Southern
Appalachians, in order to better understand the condition of the Roan Mountain
forests. Relationships between
seedling abundance, canopy composition and structure, canopy disturbance, and
understory composition, will also be examined.
In addition to this broad assessment of the current condition, permanent
plots in both harvest and non-harvest areas will allow for monitoring any
long-term changes.
Fraser
Fir mortality near Roan Mountain
After
examining the study area and stand maps and consulting with National Forest
personnel, we chose 3 areas to sample: (1) 70-80 year old fir dominated stands
that are off limits to future cone and seedling harvests, (2) 70-80 year old
fir-dominated stands open to future harvest, and (3) 35 year-old fir dominated
stands.
Plot
in 70-80 yr-old Fir Stand
Plot in 35-yr-old Fir Stand
With
these data we will assess the current condition of two distinct age classes of
fir-dominated forests. The younger
stands are of interest because they appear to be relatively healthy with minimal
Balsam Wooly Adelgid - induced mortality, and may represent a significant seed
source in the near future. The two
older stands are similar and both have been open to seedling and cone harvests
in the past. Sampling the older
stands not only will provide important information on the current condition, but
also will provide baseline date for monitoring change.
In the fall of 2000, sixteen 0.04 ha plots (20x20m) were installed across
the 3 areas. We believe this is a
minimum number of plots to provide an initial assessment of current conditions.
An analysis of this year’s data will help determine the number of
additional plots required to adequately assess change in the future.
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