Submitted to: Ecological Society of America Abstracts
Publication Type: Abstract only
Publication Acceptance Date: 7/1/2006
Publication Date: 8/6/2006
Citation: Averill, K.M., Ditommaso, A., Mohler, C.L., Morris, S.H., Milbrath, L.R. 2006. Vegetative expansion and seedling fate of swallow-worts (vincetoxicum spp.), introduced invasive vines in the northeastern united states [abstract]. Ecological Society of America Abstracts. 91:16. Interpretive Summary:
Technical Abstract: The exotic invasive vines pale and black swallow-wort [Vincetoxicum rossicum (Kleopow) Barbar. and Vincetoxicum nigrum (L.) Moench, respectively (Asclepiadaceae)] are becoming increasingly problematic in many northeastern states and in the Canadian Provinces of Ontario and Quebec. These herbaceous perennials invade a range of habitats and have the capacity to smother and out compete native vegetation. The effective management of the swallow-worts using the classical biological control approach may provide economically and environmentally feasible long-term suppression. The eventual success of a biological control program is dependent on the availability of essential biological and ecological data about which life stage(s) of the swallow-worts are important for population growth and are most susceptible or sensitive to control efforts. The objectives of this study are to determine (1) the rate of vegetative expansion of isolated swallow-wort plants and (2) seedling density and fate at six infested sites in New York State. Assessments of V. rossicum were made in two habitats that are typically invaded by this species, old fields and forest under stories, but only in old field habitats for V. nigrum. Vegetative expansion data were collected from 30 V. rossicum target plants in 2005 and at the start of the 2006 growing season. From 2005 to 2006, the number of tillers per plant increased by 45% plus or minus 5.4 in old field plants and by 19% plus or minus 3.0 in forest understory plants. Seedling density data were collected for both swallow-wort species in May 2006. The distribution of seedlings was variable across species, location, and habitat. Differences in land-use history, light availability, and soil organic matter levels between the sites explain some of the variability observed, particularly in forest under stories. Established seedlings (at least one year old) were more prevalent (79% plus or minus 3.0) than newly germinated seedlings (20% plus or minus 3.0). Habitat did not affect this relationship. More newly germinated V. rossicum seedlings were recorded (23% plus or minus 3.5) than V. nigrum seedlings (9% plus or minus 2.8). Of the newly germinated V. rossicum seedlings, 38% plus or minus 6.0 were polyembryonic (having 2 or 3 seedlings per seed) whereas 24% plus or minus 9.8 of newly germinated V. nigrum seedlings were polyembryonic. Of established V. rossicum seedlings, 10% plus or minus 2.9 had 2-3 stems per root crown while 4% plus or minus 2.1 of established V. nigrum seedlings had 2-3 stems per root crown. The population dynamics of these two species will continue to be monitored during the 2006 and 2007 growing seasons.