Allegheny River Headwaters Watershed Conservation Plan

Allegheny River Headwaters Conservation Plan
Chapter 4. Biological Resources
CHAPTER 4. BIOLOGICAL RESOURCES
Natural Setting
Ecosystem and Biodiversity
A group of plants and animals—including humans—living and interacting together within a specific
physical environment is an ecosystem. An ecosystem that is biologically diverse incorporates a wide
variety of species and community interactions. The more biologically diverse a community is, the greater
the likelihood of a healthier and high functioning ecosystem.
Each native species and wildlife community helps to maintain the ecosystem’s integrity. Each
species has a specific role to perform; whether a plant or animal provides food for wildlife or humans,
pollinates, cleans water, decomposes, cycles nutrients, cleans air, or improves soils; they are fulfilling
their individual role in maintaining the ecosystem’s health and functionality. Losing just one species can
have a profound effect on the entire ecosystem.
Ecoregion Characteristics
An ecoregion is a geographic locality containing a compilation of distinct natural communities that
interact and thrive in a particular area in ways that sustain their collective existence over a period of time
(World Wildlife Fund, 2010). As mentioned in the Land Resources chapter, the project area is located
within two EPA designated subregions—Glaciated Allegheny High Plateau and the Unglaciated
Allegheny High Plateau within the North Central Appalachians ecoregion. The majority of the project
area is located within the Unglaciated Allegheny High Plateau, but both subregions are deeply dissected
highlands composed of plateau remnants, rounded hills, low mountains, and narrow valleys. These
ecoregions are discussed in more detail within the Land Resources chapter.
In addition to EPA-designated ecoregions, U.S. Forest Service (USFS) has delineated domains,
divisions, provinces, and ecoregions. Through this classification, the Allegheny River Headwaters
watershed is located within the Northern Unglaciated Allegheny Plateau and Northern Glaciated
Allegheny Plateau ecoregions within the Laurentian Mixed Forest Province of the Warm Continental
Division in the Humid Temperate Domain.
Natural Habitats
A habitat is a specific area where particular species of plants and animals naturally live or thrive. A
variety of natural habitats occur within the headwaters of the Allegheny River, ranging from unique
wetland plant to animal species, some of which cannot live elsewhere.
Wetlands
Wetlands are defined as areas having anaerobic or hydric soils, wetland vegetation, and evidence of
the area being either permanently or seasonally inundated with water. They are functional, ecological
components of a watershed. Many feeder streams originate from wetlands in headwater areas, which aid
in groundwater recharge. Wetlands in riparian areas and on the margins of farmlands are vital in filtering
excess nutrients, chemical pollutants, and sediment from water before it enters streams. Also wetlands
harbor a multitude of plants and animals, making them biodiversity hot spots of the watershed. Several
plant species grow exclusively in wetlands. Wetland vegetation plays an important role in filtering water,
slowing its flow to allow sediments to drop out, and allowing groundwater to recharge. Wetland
vegetation also provides a variety of food sources, cover, and nesting material for insects, birds,
mammals, and other wildlife.
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