Allegheny River Headwaters Watershed Conservation Plan

Allegheny River Headwaters Conservation Plan
Chapter 4. Biological Resources
Small, isolated populations should be contained to control spreading. Once established, invasive
pests may be controlled by manual (physically pulling, cutting, or mowing weeds), chemical application
of herbicides and pesticides, or biologically (utilizing another living species to control the invasive target)
methods. Often, for well-established invasive species, a combination of control methods is necessary to
effectively and efficiently control the invasives. When chemical means are necessary to control an
infestation, the person(s) applying the pesticide must be certified by the Commonwealth of Pennsylvania.
Landowners, and land managers should contact their county cooperative extension office or a private,
certified applicator to seek assistance.
Education is a critical component in the management of invasive species. Volunteers, land managers,
and citizens in general should be taught the correct identification of invasive species that threaten the
watershed, so they can be detected and reported to the proper agency at the first sign of encroachment.
Addressing the problem early also helps to minimize the negative impacts on native species and natural
resources. Once well established, many of these species are difficult and costly to control
Plants
Invasive plant species post the most significant threat in areas that have been altered by disturbances,
such as impoundments, development, oil and gas extraction, poor forestry and agricultural management
practices, or those that border invasive plants in the landscape. In disturbed areas, invasive species can
displace native plants intolerant to the changing conditions; and native wildlife that prefer native plant
species will tend to avoid feeding on invasive plants, which allow the invasives to proliferate.
Invasive plants that pose a threat to
health and human safety are categorized
as noxious weeds. This federal
designation, set forth by USDA Animal
and Plant Health Inspection Service
(APHIS), adds additional penalties and
controls on those species. According to
the Pennsylvania Department of
Agriculture (PDA), it is illegal in
Pennsylvania to propagate, sell, or
transfer any of the state designated
noxious weeds (PDA, 2007c). Noxious
weeds within the project area are
identified in Table 4-2.
The sections below identify current
invasive plant species, which have been
identified within the project area.
Table 4-2. Noxious Weeds of Pennsylvania
Noxious Weed
bull or spear thistle (Cirsium vulgare)
Canada thistle (Cirsium arvense)
giant hogweed (Heracleum mantegazzianum)
goatsrue (Galega officinalis)
jimsonweed (Datura stramonium)
Johnson grass (Sorghum halepenses)
kudzu (Pueraria Montana v. lobata)
marijuana (Cannabis sativa)
mile-a-minute (Polygonum perfoliatium)
multiflora rose (Rosa Multiflora)
musk or nodding thistle (Carduus nutans)
purple loosestrife (Lythrum salicaria)
shattercane (Sorghum bicolor)
Located in
Project Area
Autumn and Russian Olives
Autumn olive and Russian olive species are deciduous shrubs or small trees that can grow up to 20
feet tall. The woody stems contain silvery scales that are predominant in younger plants. Each plant is
capable of producing up to 80 pounds of fruit per growing season
Native to Asia, autumn olive can thrive in poor soils. It was introduced in the U.S. in 1830 as an
ornamental plant. Autumn olive was cultivated for use in wildlife habitat and erosion control because of
its fast growth rate and ability to grow into deep thickets. It is widely dispersed by birds.
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