Location: Emerging Pests and Pathogens ResearchTitle: Demographic Modelling in Weed Biocontrol
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 12/1/2015
Publication Date: 1/3/2016
Citation: Milbrath, L.R., Davis, A.S., Biazzo, J. 2016. Demographic Modelling in Weed Biocontrol. Meeting Proceedings. #13.
Technical Abstract: Demographic matrix modeling of plant populations can be a powerful tool to identify key life stage transitions that contribute the most to population growth of an invasive plant and hence should be targeted for disruption. Therefore, this approach has the potential to guide the pre-release selection of effective biological control agents. We have parameterized a five life-stage matrix model for the swallow-wort biological control program. Pale swallow-wort, Vincetoxicum rossicum, and black swallow-wort, Vincetoxicum nigrum (Apocynaceae: Asclepiadoideae), are herbaceous, perennial, milkweed vines introduced from Europe. Both species are invading a variety of natural and managed habitats in eastern North America. Demographic transitions were measured in field studies for both swallow-wort species in open field and, for pale swallow-wort, forest habitats in New York State (N = six populations). Vital rates that were estimated included germination, survival, maturation (growth to the next life stage), and fecundity (viable seeds produced per plant). Elasticity analyses have identified several potentially important transitions for one or both species of swallow-wort: survival of vegetative juvenile, small flowering and large flowering plants; growth of seedlings, juveniles and small flowering plants to the next life stage; and reproduction of small and large flowering plants. In general, a combination of moderate to substantial reductions in survival, fecundity, and/or growth is needed for most populations to decrease in size. Incorporation of available impact data of candidate biological control agents show that control may be promising for forest infestations of swallow-wort but not for most field infestations.