Distribution and Abundance of Ramps (Allium tricoccum and
A. burdickii) in the Upper Nantahala River Watershed
David White and Joan
Walker
In
response to concerns about impacts of ramp harvesting in the Nantahala and
Pisgah National Forests, we initiated a pilot study on ramp monitoring in the
Wine Spring Creek Watershed in 1998, and followed up with a study plan and study
implementation in the winter and spring of 1999.
The objectives of that study are to (1) characterize the distribution and
size of ramp populations within two areas of the Upper Nantahala River
Watershed, (2) quantify abundance (cover and density) and change through time in
ramp populations representing a range of environmental and disturbance
conditions, and (3) evaluate the effectiveness of the sampling design for
detecting year-to-year change at designated statistical power and significance
levels.
Ramp
patches within each study area (approximately 2600 ha each) have been identified
and mapped. Results from the initial
mapping of ramp populations in our study area, indicated that the distribution
of ramp populations is affected by accessibility
and evidence of digging disturbance. After classifying ramp patches based on
accessibility and disturbance criteria, 21 permanent plots were installed for
monitoring change in ramp density and cover. Woody and herbaceous vegetation
have also been measured within each permanent plot in order to examine the
relationship between ramps and other species. Permanent photo points were also
installed in the permanent plots. Permanent plots established in 1999 were
resampled in 2000 and 2001. Sampling intensity within some permanent plots was
increased after the first year of data collection in response to the results of
the power and sample size analyses. We are presently analyzing 3 years of
monitoring data as well as vegetation data and have produced a distribution map
of all ramp patches within the 2 study areas.
Measuring
cover and density of ramps along 10 m
transects
Permanent
photo point
- Permanent photo
point -
no recent disturbance
recent disturbance.
In
2000, we initiated a collaborative project with other SRS research scientists (RWU
4157, 4101 and 4702 and Biometrics unit) to assemble the broad spectrum of
information that Southern Appalachian National Forests need to develop policy
for sustainable management of this relatively widespread and economically
valuable edible forest product. Cooperating units are addressing four areas of
research that will support harvest policy development: 1) socio-economic aspects
of ramp harvesting; 2) ramp distribution, abundance and habitat modeling; 3)
monitoring design, and 4) population processes.
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