Year of Award


Document Type


Degree Type

Master of Science (MS)

Degree Name


Department or School/College

Department of Geography

Committee Co-chair

Jeffrey Gritzner, Ragan Callaway

Commitee Members

Ulrich Kamp


Ageratina adenophora, allelopathy, China, India, invasive species, Mexico


University of Montana


Evans, Heather, Master of Science, May 2010 The Biogeography of Ageratina adenophora: A Mexican Trans-Global Invader Co-Chairman: Dr. Jeffrey Gritzner Co-Chairman: Dr. Ragan Callaway Invasive plants are a global problem often resulting in negative impacts upon populations of native plants and the environments in which they grow. Invasive plants inhibit native species and take over areas where they have been introduced. These invasive species create ecological problems for wildlife foraging, as they often transform the vegetation of native habitats resulting in conditions unsuitable for grazing. In addition, invasive plant species pose problems for humans in the areas of health, economics, and land management. Ageratina adenophora, a plant native to Mexico, has become a trans-global invader, particularly in China and India. In an effort to understand how the plant becomes a successful invader, a series of greenhouse experiments at The University of Montana were conducted to test for allelopathy and volatile chemical reactions. This study was designed to determine the effects of Ageratina adenophora regarding seed germination, mortality, and plant biomass on plants from the invaded environments of China and India. These tests compared seed germination and mortality from Mexican plants, where Ageratina adenophora is native. A second experiment tested the growth rates and biomass of plants in Ageratina adenophora’s native environment of Mexico, versus those plants from invaded China and India. This was done with the hypothesis that Mexican plants would grow successfully in the presence of Ageratina adenophora while Chinese and Indian plant’s growth would be inhibited. The findings suggest that indeed, there is a growth rate correlation between Mexican plants surviving in the presence of Ageratina adenophora and the Chinese and Indian plant’s growth rates were inhibited



© Copyright 2010 Heather Marie Evans