Date of Award

2016

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Natural Resources

First Advisor

Kimberly F. Wallin

Second Advisor

Deborah Neher

Abstract

Causes and patterns of invasive plant species establishment and success depend broadly upon their ecology, including habitat suitability and interactions with other plants and animals. Here I examine the traits and distribution of invasive plants in Vermont, using spatial analysis, laboratory and field studies. I used GIS to investigate environmental factors correlated with presence of 19 invasive plant species in Vermont campgrounds. My results support the assumption that human dispersal of invasive plant seed and stock may be more important than natural dispersal of these plant species to new sites. I also investigate in-depth the relationships of invasive herbaceous garlic mustard (Alliaria petiolata) with native tree seedlings and co-occurring herbaceous plants in the greenhouse and Vermont forests, respectively. Shade from > 1 m tall A. petiolata plants may effect root:shoot ratios of neighboring tree seedlings and interact with nutrition quality of sites to affect their growth patterns. Invasive plants' integration into novel environments is also mediated by their interactions with native invertebrate species. A. petiolata is associated with a unique assemblage of aboveground invertebrates compared with neighboring native plants. Observations indicate A. petiolata may also serve as an attractant for ants, bees, and wasps who feed from water and nectar at the base of the flower or silique during its flowering and seeding period. These results collectively inform our understanding of plant invasion patterns and management strategies of A. petiolata in Vermont. Community interactions are probably more important than allelopathy in determining the influence of Alliaria petiolata on native ecosystems.

Language

en

Number of Pages

170 p.

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