Abstract Detail

Ecological Section

Morrison, Janet A. [1], Ball, Alison [1], Tomat-Kelly, Giovanna [2], Speigel, John [2].

Recruitment of invasive plant species in the herb layer of suburban forests.

Fragmented forests in the metropolitan landscape are subject to co-invasion by multiple non-native plant species. In the forests of eastern North America, two important herb layer invaders are garlic mustard (Alliaria petiolata) and Japanese stilt-grass (Microstegium vimineum). We have established a well-replicated, five-year field experiment that includes staged invasions of both species across six forests in a suburban/exurban region. We observed highly variable recruitment among forests and among the approximately twenty 16 m² plots per forest per species that had seeds added. We added equal numbers of seeds to each addition plot, but in the first year recruitment of garlic mustard ranged from 0-188 plants per plot, and for stilt-grass it was 13-605. Stilt-grass clearly dominated the initial stage of invasion. Recruitment success was highly significantly different among forests for both species. We hypothesized that differences in leaf litter quantity may explain the variation, since it also varied significantly among forests. Mean sample leaf litter mass explained 68% of the variation among forests in mean recruitment of garlic mustard, but did not explain stilt-grass recruitment. Within each forest, regression of the number of plants per plot on leaf litter mass explained a substantial part of the variation in only one of the six forests, and only for stilt-grass, which was negatively affected by greater leaf litter. The next steps are to understand how invasive recruitment is related to available understory light, how soil invertebrates correlate with leaf litter and recruitment from seed, and how competitive interactions between the invasive species may limit their recruitment.  

1 - The College Of New Jersey, Department Of Biology, P.O. Box 7718, Ewing, NJ, 08628, USA
2 - The College of New Jersey, Department of Biology, P.O. Box 7718, Ewing, NJ, 08628, United States

Keywords:
urban ecology
suburban
invasive plants
forest fragmentation
temperate deciduous forest
White-tailed Deer.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Eyrie/Boise Centre
Date: Monday, July 28th, 2014
Time: 5:30 PM
Number: PEC007
Abstract ID:782
Candidate for Awards:Ecological Section Best Undergraduate Presentation Award