Chapter 13 Black and Pale Swallow-Wort (Vincetoxicum nigrum and V. rossicum): The Biology and Ecology of Two Perennial, Exotic and Invasive Vines C.H. Douglass, L.A. Weston, and A. DiTommaso Abstract Black and pale swallow-worts are invasive perennial vines that were introduced 100 years ago into North America. Their invasion has been centralized in New York State, with neighboring regions of southern Canada and New England also affected. The two species have typically been more problematic in natural areas, but are increasingly impacting agronomic systems such as horticultural nurs- eries, perennial field crops, and pasturelands. While much of the literature reviewed herein is focused on the biology and management of the swallow-worts, conclu- sions are also presented from research assessing the ecological interactions that occur within communities invaded by the swallow-wort species. In particular, we posit that the role of allelopathy and the relationship between genetic diversity lev- els and environmental characteristics could be significant in explaining the aggres- sive nature of swallow-wort invasion in New York. Findings from the literature suggest that the alteration of community-level interactions by invasive species, in this case the swallow-worts, could play a significant role in the invasion process. Keywords Allelopathy • Genetic diversity • Invasive plants • Swallow-wort spp. • Vincetoxicum spp. Abbreviations AMF: Arbuscular mycorrhizal fungi; BSW: Black swallow-wort; PSW: Pale swallow-wort C.H. Douglass () Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523, USA
[email protected] A. DiTommaso Department of Crop and Soil Sciences, Cornell University, Ithaca NY 14853, USA L.