RE: Serpentine Barrens Conservation Park - Land Acquisition Recommendation - LOS - November 19, 2015
Dear Commissioner Anderson and members of the Planning Commission,
The Maryland Native Plant Society strongly urges the Planning Commission to not consider adding multi-use trails into the globally rare, old-age Serpentine Barrens Conservation Park (Travilah Serpentine Barrens; Hunting Hill Serpentine Barrens) in Montgomery County, Maryland, as well as similar highly sensitive natural areas. Moreover, we feel that proposals for such are not in accordance with Best Management Practices and sustainable planning principles for quality natural area sites. The preservation and future sustainability of natural area sites and the overarching principle of “Do No Harm” should guide all efforts in this regard.
The Travilah Serpentine Barrens (Serpentine Barrens Conservation Park) is the mid-Atlantic region's stellar example of a globally-rare, forested serpentinite community. This vegetation type once comprised many thousands of acres in the area of Montgomery County west of Potomac and Rockville, with about 1,000 acres of this rare local landscape preserved today. Serpentinite is an ultramafic rock derived from magnesium-rich silicate materials that typically weathers to a soil that is high in magnesium and iron.
As you know, the Travilah Serpentine Barrens hosts numerous R,T,&E species, almost all of which are scattered throughout the woodlands. Additionally, a mosaic of several state and globally rare natural community types comprise much of the site, including:
Piedmont Ultramafic Woodland:Pinus virginiana - Quercus stellata - Quercus marilandica / Schizachyrium scoparium Woodland [Provisional] (USNVC: no equivalent). Global/State Ranks: -/SU
(This type is certainly globally rare, but stemming from its rarity worldwide, more studies are needed to better define its classification.)
Eastern Red-cedar - Virginia Pine / Roundleaf Greenbrier Serpentine Forest: Juniperus virginiana - Pinus virginiana / Smilax rotundifolia Serpentine Forest (USNVC: CEGL006440). Global/State Ranks: G1G2, SNR.
Piedmont Acidic Oak - Hickory Forest: Quercus alba - Quercus rubra - Carya tomentosa / Cornus florida / Vaccinium stamineum / Hylodesmum nudiflorum Forest (USNVC: CEGL008475).
Piedmont Upland Depression Swamp (Pin Oak - Swamp White Oak Type): Quercus palustris - Quercus bicolor / Viburnum prunifolium / Leersia virginica - Impatiens capensis Forest (USNVC: CEGL004643).
Global/State Ranks: G2.
(Quantitative compositional and environmental data were collected from four 400 m² sample plots. Plots were sampled using the relevé method (sensu Peet et al. 1998). All natural community data were analyzed using a combination of cluster analysis, statistical analyses, and ordination by the Maryland Wildlike and Heritage Program and Virginia Department of Conservation and Recreation, Division of Natural Heritage (DCR-DNH) as part of the United States National Vegetation Classification (USNVC)-National Park Service, National Capital Region (NCR) project.)
In addition to numerous R,T,&E species and natural communities in harm’s way of proposed multi-use trails at the site, several additional factors have increasingly been found to be highly damaging to exceptionally-rare and sensitive natural resources throughout the greater region.
It is now widely recognized that invasive exotic species are perhaps the greatest threat to natural areas and global biodiversity (Vitousek et al. 1996, Knight et al. 2009), second only to habitat loss resulting from development and urbanization. Unfortunately, this trend is expected to increase.
Chinese Silvergrass (Miscanthus sinensis) is slowly seeding into the large, formerly pristine open grassy area under the powerline along with Ravenna-grass (Tripidium ravennae), from ornamental grass plantings of nearby residences along Palatine Street. A large clone of Common Reed (Phragmites australis ssp. australis) has become established in a damp swale under the power line. Japanese Stiltgrass (Microstegium vimineum) and other non-native invasive plants of disturbed soil areas are also increasing their presence at the site.
Careful stewardship management is urgently needed to eradicate these grasses and other invasive plants on site before they become established. Best Management Practices for the area under the power line also need to be discussed with PEPCO (or owner of utility) to minimize activities that cause soil disturbance and nutrient-loading via dumped organic material that alters soils structure and chemistry and causes the spread of non-native invasive plants.
Fortunately, most of the non-native invasive plants on site are confined to the edges of the gravel road that traverses the property under the power line. The forested interiors of the site are still largely pristine and free of invasive plants. However, that will undoubtedly change if multi-use trails are allowed and constructed.
The spread of invasive species correlates directly with soil disturbance, especially when activities creating disturbance are located near a source of invasive species producing seed material. Moreover, seed material from a source near or far can be transported into relatively pristine or undisturbed natural areas, such as interior forest, where it can persist dormant in the seed bank indefinitely until a disturbance mechanism, natural or otherwise, allows it to emerge (Honu et al. 2009).
Unprecedented numbers of White-tailed Deer (Odocoileus virginianus), whose population increases directly correspond with human actions, are also causing severe disturbance to herbaceous and understory vegetation throughout forest communities in the eastern U.S. (Knight et al. 2009). Moreover, an overpopulation of deer results in new infestations of invasive exotic plants, especially Japanese Stiltgrass and Garlic Mustard, into hitherto undisturbed forest, as well as increasing the spread and abundance of invasive species (Knight 2009).
In conclusion, creating trails of any kind at the Serpentine Barrens Conservation Park would be highly damaging to fragile soils, geologic features, vegetation, and wildlife, as well as create an active disturbance mechanism for the spread of invasive exotic species. Additionally, constructing trails and artificial landscape features are not in any way congruent with Best Management Practices and ecological stewardship of rare and sensitive natural areas. Moreover, there is little need for trails, as the gravel road under the power line is more than sufficient for folks to traverse the site easily and safely.
Rod Simmons, Plant Ecologist, Natural Resource Manager, and MNPS Board member
Marney Bruce, President, Maryland Native Plant Society
Jason Harrison, Maryland State Vegetation Ecologist
Chris Frye, Maryland State Botanist
Jonathan A. McKnight, DNR Associate Director for Habitat Conservation
Harrison, J.W. 2004. Classification of vegetation communities of Maryland: First iteration. NatureServe and Maryland Natural Heritage Program, Wildlife and Heritage Service, Maryland Department of Natural Resources. Annapolis, Maryland.
Honu, Y.A., S. Chandy, and D.J. Gibson. Occurrence of non-native species deep in natural areas of the Shawnee National Forest, southern Illinois, U.S.A. Natural Areas Journal 29: 177-87.
Knight, T.M., J.L. Dunn, L.A. Smith, J.D. Davis, and S. Kalisz. Deer facilitate invasive plant success in a Pennsylvania forest understory. Natural Areas Journal 29: 110-116.
Peet, R.K., T.R. Wentworth, and P.S. White. 1998. A flexible, multipurpose method for recording vegetation composition and structure. Castanea 63: 262-274.
Vitousek, P.M., C.M. D’Antonio, L.L. Loope, and R. Westbrooks. 1996. Biological invasions as global environmental change. American Scientist 84: 218-228.