introduction - Pennsylvania Natural Heritage Program

Less saturated areas have vegetation more typical of floodplain forest, with goldenrods (Solidagospp.), and spicebush (Lindera benzoin) prevalent. Towards the southern end, the elevation is lowerand the ground is saturated, resulting in a wet shrubland dominated by steeplebush (Spiraeatomentosa), jewelweed (Impatiens sp.) and rough alder (Alnus incana).The Supporting Natural Landscape is the immediate watershed above the wetlands. The condition ofthis area impacts the water quality in the wetlands. The terrain is steeply sloped and mainly forested,with oak species (Quercus rubra, Quercus alba, Quercus montana) and red maple (Acer rubrum)prominent in the canopy. The forested condition of this area also contributes to the long-termviability of the wetland areas, as wetlands embedded in forest have been documented to haveenhanced integrity over wetlands surrounded by cultural land use types (Mensing et al. 1998, Findlayand Bourdages 2000, Spackman and Hughes 1995, Barclay 1980, Karr and Schlosser 1978).Threats and StressesFloodplain core habitat area —Invasive exotic species have not spread extensively at this site todate; however, two species which can dominate floodplain communities, Japanese knotweed(Polygonum cuspidatum) and Japanese stiltgrass (Microstegium vimineum) were present.Seepage wetland core habitat area —This wetland area is receiving pollution from road runoff (theheavily trafficked SR 36 forms its western boundary). The primary contaminants borne in roadrunoff are heavy metals, aromatic hydrocarbons (petroleum compounds), sediments, and salts. Heavymetals and aromatic hydrocarbons arise from wear of automotive parts and compounds, and theamounts released increase with traffic volume. Although they are released at low concentrations,these compounds are toxic to aquatic life, very slow to degrade, and accumulate over time.Sediments arise from erosion of non-paved, exposed soil; release of sediments into water bodies isharmful to aquatic plants and animals. Salt release results from applications of salt for road de-icing;chloride-based salts (sodium chloride, magnesium chloride, potassium chloride, etc.) can havedetrimental impacts on vegetation, soil chemistry, and aquatic life (Environment Canada 2001).Supporting Natural Landscape—Any herbicides, pesticides, or other toxic materials released in thisarea will drain into the wetland, where they may be toxic to its inhabitants. The area is highlyvulnerable to soil erosion if forest cover is removed, due to the steeply sloping terrain. Erosion willresult in sediment pollution in the wetlands, which degrades the habitat for many plant and animalspecies. Greatly decreased forest cover in this area may also diminish the long-term viability of thewetland community.RecommendationsFloodplain core habitat area — these communities are adapted to natural disturbance, and can likelytolerate foot traffic without lasting damage. However, motorized vehicle traffic should be avoided, asit generates more intensive disturbance than is natural. Monitoring the distribution and abundance ofinvasive species at this site, to determine if they are spreading further, would provide a basis forevaluating whether removal strategies are warranted.Seepage wetland core habitat area —If not already in place, best management practices for roadrunoff drainage along SR 36 may help to minimize the amount of contaminants entering the wetland.Runoff should be slowed and filtered in close proximity to the road, to minimize contaminantsreaching the wetlands and the stream. The Arkansas Forestry Commission provides a good referenceoutlining BMP options, available at: http://www.forestry.state.ar.us/bmp/roads.html.Chloride salts should not be applied in this area; calcium magnesium acetate is an alternative de-icingcompound which is less environmentally damaging.44