Janet A. Morrison research interests: invasive non-indigenous plants

Some plant species that have been introduced from other continents become invasive in their new territory. They occupy space that might otherwise be occupied by native species, and in some cases can decrease native biodiversity. I am interested in the ecological conditions that allow invasion, and in the genetic basis of characters in plants that allow them to be invasive. I have done research on three invasive plant species: 

1.  Alliaria petiolata (garlic mustard).

This is a biennial herb introduced in the 1800s from Europe, and now considered one of the most serious invaders of woodlands in the northeast. I am interested in the genetic basis for its high ecological amplitude for light conditions, since it thrives both in high-light forest edges and low-light forest interiors. I am also interested in the effects it has on native vegetation, and the role that herbivory by deer plays in its invasiveness. To that end, since 1996 I have been running a mid-sized factorial field experiment in three different forests in and near New York City, with Alliaria removals and deer exclosures.  

Morrison, J.A. and L. Brown. 2004. Effect of herbivore exclosure caging on the invasive plant Alliaria petiolata in three southeastern New York forests. Bartonia 62: 25-43.  Link to PDF

Morrison, J. A. and L. Brown. 1999. Herbivore exclosure effects on the forest herb layer and an invasive plant, Alliaria petiolata. Abstract.  Annual Meeting of the Ecological Society of America.  

Morrison, J.A. 1998. Ecological amplitude for light in the invasive forest plant Alliaria petiolata. Abstract. Annual Meeting of the Ecological Society of America.

(Manuscripts in prep)


2. Acer platanoides, Norway maple

I sponsored an Independent Study student on this project.


3. Lythrum salicaria, purple loosestrife


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