The thin line between native and invasive in aquatic plants: Implications for surveillance, outreach, and management

Dr. Dan Larkin

Associate Professor, UMN Department of Fisheries, Wildlife and Conservation Biology

Abstract

Evolutionary history and speciation shape biological invasions. For example, non-native plants often perform better where they have close relatives among the native flora. And hybridization between native and introduced lineages is associated with increased invasiveness in plants. These phenomena may be magnified in aquatic environments, where low oxygen and light availability impose strong environmental constraints: taxa able to overcome these physiological challenges are equipped to spread widely and, on reaching a new area, are likely to encounter similarly adapted relatives that got there first. Thus we might expect aquatic invasions to be characterized by “thinner lines” separating native and invasive taxa. An analysis of evolutionary relationships between native and invasive species in terrestrial vs. aquatic plants of the upper Midwest supports this prediction. These basic biological patterns pose applied challenges, requiring careful approaches to outreach, surveillance, management, and other elements of invasive species response.