Bear Run Watershed

Bear Run Nature Reserve is managed by the Western Pennsylvania Conservancy and includes most of the watershed of Bear Run and parts of two other watersheds: Laurel Run and Lick Run. Being a large property of over 5,000 acres, Bear Run is classified as Exceptional Value stream by the Department of Environmental Protection and as such, receives an additional level of protection. The initial Bear Run property was acquired in 1964 from Edgar Kaufmann, Jr. as part of the Fallingwater property. A large portion of the Bear Run Watershed now belongs to Western Pennsylvania Conservancy.

Most of the Bear Run watershed is dominated by hardwood forest. Common species in the canopy include tuliptree (Liriodendron tulipifera), red oak (Quercus rubra), chestnut oak (Q. prinus), sugar maple (Acer saccharum), red maple (A. rubrum) and yellow birch (Betula allegheniensis). Beech (Fagus grandifolia) is a dominant species in the floodplain of the upper sections of Bear Run, but is uncommon in the rest of the reserve. Hemlock grows along major drainages such as Bear Run or Laurel Run. Understory species include spicebush (Lindera benzoin), cucumber tree (Magnolia acuminata), rosebay rhododendron (Rhododendron maximum), smooth azalea (Rhododendron arborescens), witch-hazel (Hamamelis virginiana), black gum (Nyssa sylvatica) and mountain laurel (Kalmia latifolia). The herbaceous cover in the watershed reflects the diversity of topography, aspect and soils. Common herbs include white wood aster (Aster divaricatus), painted trillium (Trillium undulatum), New York fern (Thelypteris noveboracensis), intermediate shield fern (Dryopteris intermedia), woodland goldenrod (Solidago caesia), wild yam (Dioscorea villosa), nodding mandarin (Disporum lanuginosum) and Indian cucumber root (Medeola virginica).

Two plant species of concern occur here, mountain saxifrage (Saxifraga micranthidifolia) and solitary pussytoe (Antennaria solitaria). Mountain saxifrage is found in seepage areas where there is a perennial source of groundwater. Solitary pussytoes are found in a section of forest containing an old road and stream crossing. This plant generally grows in somewhat open areas as would be found on rocky slopes or dry woodland. Open abandoned roads or trails serves as appropriate habitat.

Threats and Stresses Loss of canopy, direct disturbances to the soils or other changes in microhabitat could adversely affect the plant populations. The mountain saxifrage grows in the seepage areas and needs a perennial source of discharging groundwater in order to exist. Activities that change the hydrology by affecting the recharge zones or lower the groundwater can impact these plants. For the solitary pussytoe, direct disturbance and loss of habitat due to succession stands as the main threat to this species.

Recommendations Activities that alter the hydrology by affecting groundwater flows and recharge zones in the aquifer should be avoided. Any direct disturbance to the plant species of concern that affects the microhabitat and results in a loss of water quality by increased sediment or nutrient load can be detrimental. Use of the logging road where the solitary pussytoe grows should be avoided so as not to impact the species population. Both species should have a management regime that allows for periodic cutting of the trail and adjacent openings.