Date of Award

Spring 2010

Project Type


Program or Major

Environmental Conservation

Degree Name

Master of Science

First Advisor

Thomas D Lee


My objective was to determine whether purple loosestrife (Lythrum salicaria L.) individuals could be aged using the pattern of ramet production. Assuming current year loosestrife ramets produce new basal ramets only in the following year, plant age could be estimated by counting ranks of sequentially produced ramets. I found that in four New Hampshire wetlands the assumptions of the method were generally met, although some ramets were not produced sequentially. Using ramet counts I was able to estimate minimum age for individuals in each of the four populations. All populations were dominated by individuals > 1 year old. I tested whether mechanical damage to ramets releases lateral buds, inducing production of more than one rank of new ramets in one growing season and thus affecting age estimates. Clipped ramets produced lateral ramets (from leaf axils) that were morphologically distinct from basal ramets that characterize normal annual growth.