Patterns of exotic plant invasions in Pennsylvania’s Allegheny National Forest using intensive Forest Inventory and Analysis plots

Biotic and Abiotic Conditions in Michigan Prairie Fen Invaded by Glossy Buckthorn (Frangula alnus)

“…In our study, we did not find significant differences in soil nitrogen, phosphorous, or potassium between invaded and uninvaded fen, although nitrate, ammonia, phosphorous, and potassium levels were all numerically higher in invaded areas. There is evidence that F. alnus alters nutrient properties in white-pine (Pinus strobus L.) dominated uplands (Fagan and Peart 2004) and has been associated with higher nitrogen levels in hardwood dominated uplands (Huebner et al 2009), but we found no published data on its effect on nutrients in wetlands. Increasing eutrophication of wetlands in North America may lead to decreased species richness within wetlands (Bedford et al 1999).…”

“…In addition, F. alnus may alter nitrogen cycling in invaded habitats. For example, F. alnus has been associated with elevated soil nitrogen in upland forest soils (Huebner et al 2009). In sum, a suite of characteristics may differ between areas with and without F. alnus invasion, and characterizing these differences is the first step to understanding its invasion.…”

The legacy of timber harvest: Do patterns of species dominance suggest recovery of lepidopteran communities in managed hardwood stands?

“…That is, the same species that appear dominant in the regional species pool should also be the most dominant taxa within each local species assemblage. Such patterns may appear most evident when local communities are dominated by an invasive species from the broader landscape (Huebner et al, 2009). In addition, however, disturbances such as timber harvest may homogenize herbivorous species dominance patterns at local and regional scales when plant communities regenerate as monotypic forest stands (Holl, 1996;Thomas, 2002).…”

Land use history alters the relationship between native and exotic plants: the rich don’t always get richer

“…Thus, we hypothesize that soil compaction arising from agricultural history disrupted the rich-get-richer effect by facilitating exotic but not native plant establishment (e.g., Burke and Grime 1996;Woitke and Dietz 2002;Kulmatiski et al 2006). Notably, in a study following the same plant survey methodology and measuring 26 variables at local scales, Huebner et al (2009) also found elevated numbers of exotic plant species in younger forests. Similarly, Mosher et al (2009) and Lilley and Vellend (2009) demonstrated that aspects of land use, including time since agricultural abandonment and proximity to human activities, respectively, can differentially alter the abundance of native and exotic species, in one case reversing the relationship between native and exotic plant richness (Lilley and Vellend 2009).…”