Biological Resources
A. Wildlife
1. Terrestrial
Central Pennsylvania is blessed with abundant wildlife, and the Juniata watershed is no exception. The abundance of forestland interspersed with plentiful farmland and water sources creates a diversity of habitat types that favors many species, including most Pennsylvania game species. White-tailed deer and wild turkey are the most significant game species in the region, but other important game species include black bear, gray squirrel, Eastern cottontail rabbit, and woodchuck. Fur-bearing species that can be trapped and/or hunted include beaver, muskrat, red fox, gray fox, raccoon, opossum, skunk, various species of weasel, and coyote (PA Game Commission, 1999a). Approximately 50 species of mammals live in the watershed, including non-game species such as the bobcat, porcupine and small mammals such as bats (nine spp.), mice, rats, voles (12 spp.), and shrews (eight spp.) (USACOE, 1995a).
For various reasons, white-tailed deer have become extremely populous over the past decade. The high population of deer exerts a severe impact on regeneration of forest stands as deer clean out the understory of tree seedlings. Deer can also frustrate farmers by eating a significant amount of crops. In addition, the overpopulation of deer, in some areas of the state including the Juniata watershed, leads to a high number of automobile-deer collisions. The Pennsylvania Game Commission, led by Gary Alt, is presently developing a plan to address the problem of deer overpopulation.
Large numbers of birds live in the Juniata watershed, including songbirds, waterfowl, and raptors. One hundred seventy-two species of birds live and breed in the watershed, out of 211 breeding species in Pennsylvania. Perhaps the most notable breeding pair is the family of Bald Eagles who nested at the northern end of Raystown Lake recently. Game birds include waterfowl such as the Wood Duck, American Black Duck, Mallard, Redhead, Hooded Merganser, Red-breasted Merganser, American Coot, Sora, Virginia Rail, Common Moorhen, and Canada Goose, and forest/meadow birds such as Wild Turkey, Ruffed Grouse, Ring-necked Pheasant, Northern Bobwhite, American Woodcock, Common Snipe, American Crow, Mourning Dove, and Rock Dove (PA Game Commission, 1999b). Non-game birds include 29 species of warblers, 18 species of sparrows, finches, and grosbeaks, nine species of hawks and eagles, eight species of flycatchers, seven species of woodpeckers, six species of swallows, five species of owls, and assorted wrens, vireos, thrushes, nuthatches, chickadees and more (Brauning and Gill, 1983-1989).
Reptiles and amphibians are the less glamorous and sometimes feared members of the Juniata watershed faunal community. Approximately 10 species of snakes live in the watershed, including two poisonous species: the northern copperhead and the timber rattlesnake. Eight species of turtles and lizards and 20 species of amphibians fill out the cold-blooded contingent, including bullfrogs, wood frogs, and the American toad (USACOE, 1995a).
2. Aquatic
Aquatic habitat in the Juniata River watershed has historically been quite good. Habitat types range from the renowned warm-water bass fisheries of the Juniata River mainstem, Raystown Lake, and Shawnee Lake, to the pristine cold-water trout fisheries of the smaller headwaters. Spruce Creek, which feeds the Little Juniata River, is notorious for its excellent trout fishing, which lures such notable fishers as former President Jimmy Carter. Important game fish include brown and brook trout, smallmouth bass, muskellunge, walleye, pike, rock bass, and white sucker (USACOE, 1995a).
Sixty-three species of fish (not counting Threatened and Endangered species) have been identified in the Juniata watershed through sampling undertaken from 1975 to 1995 by the PA Fish and Boat Commission (PAFBC) (Argent, 1998). This includes 22 species of carps and minnows, eight species of sunfishes and bass, six species of perches, four species of catfishes, and four species of trout.
American shad, which used to be the largest fishery in the Chesapeake Bay, is a migratory (anadromous) fish that once traveled from the Juniata River to the Bay and back. The shad’s route is presently hindered by four large hydroelectric dams on the lower Susquehanna River: York Haven, Safe Harbor, Holtwood, and Conowingo. A “trap and transport” program was instituted in 1972 at the most downstream dam, Conowingo, to catch adults and take them by truck to upstream spawning beds. This program made the first real progress in a region-wide shad restoration effort. In the meantime, fish lifts have been built at the three lower dams, and a fish ladder was opened at York Haven in the spring of 2000. These lifts have worked well enough that the “trap and transport” program was recently discontinued. In fact, the summer 2000 return of shad was the highest ever. The Van Dyke shad hatchery along the Juniata River in Thompsontown bolsters these efforts by maintaining viable populations of shad in the lower Juniata and Susquehanna rivers (Hendricks, n.d.; Carney, 1999).
Although trout fishing is vital to the region’s recreational appeal, most trout communities in the watershed are not native or reproducing. Rather, they have been stocked by the PAFBC. Table C-7 in Appendix C lists the 98 trout stocking sites in the watershed. A number of pristine headwater streams are not stocked, however. These are classified as Class A Wild Trout Streams, which represent the “best of Pennsylvania’s naturally reproducing trout fisheries,” according to the PAFBC (PAFBC, 1999b). In these streams, naturally reproducing populations are allowed to flourish. Table C-8 in Appendix C lists the 22 stream segments in the watershed identified as Wild Trout streams.
In addition to fish, aquatic macroinvertebrates make up an important part of the aquatic ecosystems in the watershed. Indeed, without healthy populations of macroinvertebrates, fish communities would suffer from lack of food and overall aquatic biological communities would be diminished. Approximately 119 different macroinvertebrate taxa live in the watershed, including larva of mayflies, caddisflies, stoneflies, dobsonflies, damselflies, horseflies, black flies, and mosquitoes, as well as water beetles, crayfish, and worms (USACOE, 1995a).
Approximately two-thirds of the Juniata watershed is forested, although this was not always the case. Prior to European settlement, the amount of forestland was considerably greater, as only a few scattered areas were cleared for agriculture. By the beginning of the 20th century, much of the forestland was completely cleared, either for farmland or for the timber. Trees were used primarily for making charcoal to fire the iron furnaces of the region, such as the one at Greenwood Furnace State Park. But wood was also in high demand for building and heating homes, making furniture and mine supports, and cooking food. So few forests existed in the early part of the 20th century that the deer populations plummeted. Presently, the amount of forestland in the watershed is considerably greater than a century ago.
The predominant natural forest zone in the watershed is Appalachian Oak Forest, with small areas of Northern Hardwoods interspersed throughout the dominant zone of oaks (Merritt, 1987). Major forest associations in the watershed include oak-hickory, maple-beech-birch, and elm-ash-red maple. Deciduous trees are predominant, although stands of hemlock and pine are scattered throughout the landscape. Other common trees and shrubs include flowering dogwood, tulip poplar, wild cherries, shadbush, witch hazel, and mountain laurel.
Agriculture makes a significant mark on the Juniata watershed landscape. Row crops such as corn, soybeans, and some small grains (wheat, oats, barley) fill the fields. Pastures of alfalfa and grass provide good cover for meadow birds, such as quail. Fencerows are increasingly rare, but where they remain they provide good shrubby habitat for sparrows and other birds. Unfortunately, intensive agriculture can sometimes remove all vegetation along streams. The lack of riparian buffers can exacerbate stream bank erosion, sedimentation, and nutrient pollution in streams.
Purple loosestrife and multiflora rose are two exotic, invasive species that vex farmers and foresters alike. When they enter a pasture or cleared patch of forest, they can multiply quickly and take over an area. These plants can exclude other plants that may be vital to the diversity and health of the local ecosystem.
Arguably worse than the vegetative invasive species is the insect bane of Pennsylvania’s deciduous trees: the gypsy moth. In its larval (caterpillar) stage, this insect eats all the leaves it can get its mouth on. Gypsy moth infestations can easily defoliate whole hillsides. Insecticide spraying and an introduced fungus keep the moth in check in some places, but summer 2000 is proving to be a particularly bad year for the gypsy moth in some areas of the watershed.
C. Rare and Endangered Species
The Pennsylvania Natural Diversity Inventory (PNDI) is a site-specific information system that tracks species of special concern as well as unusual or unique habitats. PNDI is a cooperative effort of the PA Department of Conservation and Natural Resources (DCNR), the Nature Conservancy, and the Western Pennsylvania Conservancy. One hundred eighteen species of special concern and 12 important features are identified in the Juniata watershed (DCNR, 1999e). Most of the species of concern are terrestrial plants, although a few animals are on the list as well. Table C-9 in Appendix C lists all of the PNDI information.
Natural Heritage Inventories (NHI) identify and map the most significant natural areas in counties that choose to undertake these projects. Western Pennsylvania Conservancy, a non-profit conservation organization, offers their services to carry out these inventories. Thus far, Bedford, Centre, and Perry counties have each completed an NHI. Contact these counties to see a copy of their NHI.
Natural Heritage Areas are ranked by the importance of each area to the biological diversity and ecological integrity of the region being studied. Areas are classified into three distinct types: Biological Diversity Areas, which contain state or federal species of special concern or natural communities supporting exceptional native diversity; Dedicated Areas, which are identified by the owners as being managed primarily for the protection of ecological integrity; and Landscape Conservation Areas, which are important because of the size and variety of habitats and biological diversity areas within them. Identification of these areas does not provide any regulatory control over management in these areas, but simply enables local people to plan for the future of biodiversity conservation, if they so choose.
Although not a designated Natural Heritage Area (as an NHI has not been completed for Blair County), Canoe Creek State Park is the home of the largest nursery colony of little brown bats in Pennsylvania (DCNR, 1999a).