General Impact
Mehrhoff et al. 2003 states that, "R. cathartica tends to form dense, even-aged thickets, crowding and shading out native shrubs and herbs, often completely obliterating them. Dense buckthorn seedlings prevent native tree and shrub regeneration. In fire-adapted ecosystems such as savannas and prairies, the lack of vegetation under buckthorn prohibits fires. Buckthorn control is also of interest to small grain producers; the shrub is an alternate host of the crown rust of oats, which affects oat yield and quality." Schmidt and Whelan (1999) conducted a study on the effects of exotic shrubs on songbird nests and concluded that the, "Data show that exotic R. cathartica affected songbird nest success in two ways. First, exotic shrubs directly enhanced nest predation (primarily by large mammals) in American Robins, perhaps through a combination of lower nest height, the absence of sharp thorns, and a branch architecture that may facilitate predator movement." Gale (2000) reports that, "An extended growing season likely gives R. cathartica a competitive advantage over native plant species as well. Harrington et al. (1989, in Gale 2000) showed that R. cathartica leaves remain on the tree an average of 58 days longer than its native counterparts, Cornus racemosa and Prunus serotina. Its leaves emerge earlier and senesce later. In both cases, upper canopy foliage is largely absent. Consequently, photosynthesis under high light availability conditions is significantly greater for R. cathartica than for native shrub species." R. cathartica is a host for soybean crop pest Aphis glycines, the Soybean aphid (Ragsdale et al. 2003). Converse (1984) states that, "R. cathartica rapidly forms dense, even-aged thickets. In an open site, R. cathartica establishment is followed by lateral crown spread. This extension continues until branches touch adjacent shrubs. The large leaves and continuous canopy create dense shade. Even-aged thickets are common in both wetlands and in woodland under stories."The litter of R. cathartica decomposed rapidly, and promotes the rapid decomposition of litter in the forest floor adjacent to where it grown (Heneghan et al. 2002). Soils under R. cathartica have been shown to have modified nutrient cycling – with a higher percent N and C, and impact that may persists after the plant has been physically removed (Heneghan et al. 2004).
Location Specific Impacts:Nova Scotia (Canada) 
Agricultural: Mehrhoff et al (2001) states that, "Buckthorn control is also of interest to small grain producers; the shrub is an alternate host of the crown rust of oats, which affects oat yield and quality."
Modification of fire regime: Mehrhoff et al (2001) states that, "In fire-adapted ecosystems such as savannas and prairies, the lack of vegetation under buckthorn prohibits fires."
Reduction in native biodiversity: Mehrhoff et al (2001) states that, "R. cathartica tends to form dense, even-aged thickets, crowding and shading out native shrubs and herbs, often completely obliterating them." Saskatchewan (Canada)
Agricultural: Mehrhoff et al (2001) states that, "Buckthorn control is also of interest to small grain producers; the shrub is an alternate host of the crown rust of oats, which affects oat yield and quality."
Modification of fire regime: Mehrhoff et al (2001) states that, "In fire-adapted ecosystems such as savannas and prairies, the lack of vegetation under buckthorn prohibits fires."
Reduction in native biodiversity: Mehrhoff et al (2001) states that, "R. cathartica tends to form dense, even-aged thickets, crowding and shading out native shrubs and herbs, often completely obliterating them." Chicago (United States (USA))
Competition: Schmidt and Whelan (1999) conducted a study on the effects of exotic shrubs on songbird nests and concluded that the, "Data show that exotic R. cathartica affected songbird nest success in two ways. First, exotic shrubs directly enhanced nest predation (primarily by large mammals) in American Robins, perhaps through a combination of lower nest height, the absence of sharp thorns, and a branch architecture that may facilitate predator movement." Connecticut (United States (USA))
Agricultural: Mehrhoff et al (2001) states that, "Buckthorn control is also of interest to small grain producers; the shrub is an alternate host of the crown rust of oats, which affects oat yield and quality."
Modification of fire regime: Mehrhoff et al (2001) states that, "In fire-adapted ecosystems such as savannas and prairies, the lack of vegetation under buckthorn prohibits fires."
Reduction in native biodiversity: Mehrhoff et al (2001) states that, "R. cathartica tends to form dense, even-aged thickets, crowding and shading out native shrubs and herbs, often completely obliterating them." Maine (United States (USA))
Agricultural: Mehrhoff et al (2001) states that, "Buckthorn control is also of interest to small grain producers; the shrub is an alternate host of the crown rust of oats, which affects oat yield and quality."
Modification of fire regime: Mehrhoff et al (2001) states that, "In fire-adapted ecosystems such as savannas and prairies, the lack of vegetation under buckthorn prohibits fires."
Reduction in native biodiversity: Mehrhoff et al (2001) states that, "R. cathartica tends to form dense, even-aged thickets, crowding and shading out native shrubs and herbs, often completely obliterating them." Massachusetts (United States (USA))
Agricultural: Mehrhoff et al (2001) states that, "Buckthorn control is also of interest to small grain producers; the shrub is an alternate host of the crown rust of oats, which affects oat yield and quality."
Modification of fire regime: Mehrhoff et al (2001) states that, "In fire-adapted ecosystems such as savannas and prairies, the lack of vegetation under buckthorn prohibits fires."
Reduction in native biodiversity: Mehrhoff et al (2001) states that, "R. cathartica tends to form dense, even-aged thickets, crowding and shading out native shrubs and herbs, often completely obliterating them." New Hampshire (United States (USA))
Agricultural: Mehrhoff et al (2001) states that, "Buckthorn control is also of interest to small grain producers; the shrub is an alternate host of the crown rust of oats, which affects oat yield and quality."
Modification of fire regime: Mehrhoff et al (2001) states that, "In fire-adapted ecosystems such as savannas and prairies, the lack of vegetation under buckthorn prohibits fires."
Reduction in native biodiversity: Mehrhoff et al (2001) states that, "R. cathartica tends to form dense, even-aged thickets, crowding and shading out native shrubs and herbs, often completely obliterating them." Rhode Island (United States (USA))
Agricultural: Mehrhoff et al (2001) states that, "Buckthorn control is also of interest to small grain producers; the shrub is an alternate host of the crown rust of oats, which affects oat yield and quality."
Modification of fire regime: Mehrhoff et al (2001) states that, "In fire-adapted ecosystems such as savannas and prairies, the lack of vegetation under buckthorn prohibits fires."
Reduction in native biodiversity: Mehrhoff et al (2001) states that, "R. cathartica tends to form dense, even-aged thickets, crowding and shading out native shrubs and herbs, often completely obliterating them." Vermont (United States (USA))
Agricultural: Mehrhoff et al (2001) states that, "Buckthorn control is also of interest to small grain producers; the shrub is an alternate host of the crown rust of oats, which affects oat yield and quality."
Modification of fire regime: Mehrhoff et al (2001) states that, "In fire-adapted ecosystems such as savannas and prairies, the lack of vegetation under buckthorn prohibits fires."
Reduction in native biodiversity: Mehrhoff et al (2001) states that, "R. cathartica tends to form dense, even-aged thickets, crowding and shading out native shrubs and herbs, often completely obliterating them."
|
