National Park Service

Appalachian Highlands Network (APHN)

Exploited Plant Monitoring

Galax urceolata is poached for its shiny evergreen leaves [photo by Gary Kauffman] Large-flowered trillium (Trillium grandiflorum) at GRSM Bloodroot in flower (Sanguinaria canadensis) Vasey's trillium (Trillium vaseyi) Bloodroot leaves (Sanguinaria canadensis) American ginsing (Panax quinquefolius) root

Exploited Plants Resource Briefs

There are currently no other documents or reports pertaining to this topic.

The monitoring protocol and procedures for this topic are currently under development.

For more information contact: Evan Raskin

Affected Parks

  • Blue Ridge Parkway (BLRI)

Importance / Issues

The illegal harvesting of plants for commercial sale in the herbal remedy and floral markets is a growing concern along the Blue Ridge Parkway, where individual poachers have been intercepted leaving the park with tens of thousands of plants. Numerous species of plants targeted by poachers are found in the Blue Ridge Mountains and there is evidence that illegal harvesting activity is increasing. Some of these species do not recover quickly (or at all) from intensive harvesting, and are being eliminated from habitats that are accessible to poachers. The close proximity of desirable species to the Parkway motor road makes them particularly vulnerable to illegal harvesting.

The National Park Service is working with NatureServe to develop monitoring plans for several plant species known to be significant poaching targets, including galax (Galax urceolata), black cohosh (Actaea racemosa), bloodroot (Sanguinaria canadensis), ginseng (Panax quinquefolius) and several species of trillium (Trillium spp.). With the exception of galax, these plants are often found in the same habitats, in concentrations large enough to make sampling feasible and to make the results statistically informative. If monitoring efforts indicate significant declines in populations of these plants, park managers will determine whether and where additional law enforcement should be deployed, or how best to target more public education efforts.

Monitoring Objectives

The goals of this long-term monitoring effort are to determine whether populations of commonly poached plant species are declining along the Blue Ridge Parkway and to detect any early warning signs that other potential poaching targets may be declining as well. Specific objectives are to:

  1. Be able to detect a 30 percent decrease in the overall abundance of galax, black cohosh, bloodroot, ginseng and trilliums (Trillium spp.) within the Blue Ridge Parkway study area.
  2. Detect a 30 percent decrease in the ratio of large (>3.5 inches) to small leaves in each monitored galax population.
  3. Periodically collect and qualitatively review presence and absence data of all species found in sample units for patterns indicative of potential large-scale change in species composition and abundance.

Preliminary Methods


Because galax grows in a wide variety of habitats and plant communities, predictive modeling was not feasible for locating monitoring plots. Instead, we mapped galax distribution along the entire 469-mile length of the Parkway, using 100-meter perpendicular trajectories run in opposite directions from the road edge, at half-mile intervals. On these 1,876 rapid assessment transects, data were collected on galax presence/absence, size of galax populations, percentage of large leaves within the populations, dominant tree and shrub species, aspect, slope, and elevation.

The qualities most desired by poachers (including leaves 3.5 inches or greater in diameter, populations at least 50 square meters in size, and "invisible accessibility" from the road where poachers can harvest plants without being seen) will be factored into final plot selection. Permanent monitoring plots were selected from these mapped populations, ensuring a representative geographic distribution of random plots on the Parkway.

Each plot consists of up to 10 line transects placed along a permanent central baseline covering the entire galax population. Total galax cover is measured using a laser point intercept device for a total of 500-1,000 data points at each monitoring site. The ratio of large to small leaves is calculated from the points. Abundance and leaf size ratios will be monitored annually and compared with previous years' data to assess population trends.

Black Cohosh, Bloodroot, Ginseng & Trilliums

A predictive GIS model was used to identify potential monitoring plot locations based upon a number of landform characteristics, geology and rainfall. Permanent plots are being randomly located in appropriate habitat in such a way as to achieve a representative geographic distribution of plots along the entire length of the Parkway.

Each plot consists of three 30 meter-long belt transects placed along a permanent baseline. To address Objective #1, within each plot, black cohosh, bloodroot, ginseng and trillium densities will be measured annually and compared with previous years' data to assess population trends. Transects will be wider for trilliums and bloodroot (4 m) than for black cohosh (2 m) to account for their greater rarity and patchiness.

A periodic inventory of all plant species within the belt transects will be carried out as often as funding allows, ideally at least once every five years. All species will be identified and recorded for each 10 meter long segment within the 2 meter wide belt transects used to count black cohosh.

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Last Updated: October 05, 2017 Contact Webmaster