Site and Environmental Characteristics Influencing Invasion of Ten Exotic Plant Species in Central and Southern New England

Marjorie Lundgren

Invasive exotic plants have been identified as one of the major threats to ecosystem function and biodiversity through competition with, suppression, and displacement of native plant species. Spreading and invading North American habitats at more than 283,000 hectares per year, invasive plant and animal species are considered second only to habitat destruction as the most serious threat to natural systems worldwide. This study examined extent to which common invasive plant species threaten natural and managed habitats in relatively rural areas of central and southern New England. Further, the distribution of invasive plant species was examined relative to varying land use intensity to better understand how these factors may promote or inhibit the spread of invasive plant species. Ultimately, this study sought to locate areas free of invasive plant species in the 13,760 hectare Quinebaug Highlands project area, located in Connecticut and adjacent Massachusetts, to provide recommendations to The Nature Conservancy for location priority to defend against encroaching invasive exotic plant populations. Using multiple regression analysis and Geographic Information Systems technology, this study was able to identify current areas of high infestation, and further, to determine areas that have the greatest potential for invasion in the future. Multiple regression analysis showed the factors most strongly influencing site invasion by our target species were past land use, level of human development, and soil texture. These results add to our current understanding of site and environmental characteristics correlated with invasive exotic plant species invasion. Because the control of exotic species in natural areas is a time- and resource- intensive task, this information may be used to direct conservation efforts by increasing efficiency in predicting and managing problems of biological invasions.