Harvard Forest Research

Conservation While Under Invasion: Insights from a Rare Hemiparasitic Plant, Swamp Lousewort (Pedicularis lanceolata Michx.)

Principal Investigator: Aaron Ellison
Harvard Forest: Apr 01 2007 - May 01 2010:

Abstract:
It is commonly held that invasive, exotic species threaten rare, native plants, but we lack quantitative evidence of actual impacts. In Massachusetts, an Endangered hemiparasitic plant, Swamp Lousewort (Pedicularis lanceolata), grows with several invasive species. The degree of threat posed by invasive plants growing near P. lanceolata in Massachusetts is ambiguous because at least one known invasive host plant, Reed Canarygrass (Phalaris arundinacea), grows with this rare species. For my dissertation, I am examining the effects of invasive versus native species on P. lanceolata. The goal of this research is to understand how relationships with different host plants influence the persistence of populations of P. lanceolata. Greenhouse and field removal experiments will tease apart the effects of competitive versus facilitative interactions between P. lanceolata and different hosts. A demographic study of tagged P. lanceolata individuals will provide data for constructing a population viability analysis of the species that considers the influence of different management scenarios, as tested by the field removal experiment, on the possible fates of populations. This research will provide a better understanding of how interactions between rare hemiparasitic plants and native versus invasive hosts influence extinction risk. Further, this research will have direct conservation implications by answering some of the questions posed by the management plan written for this species in Massachusetts. :