ARS | Publication request: Genetic evidence suggests a widespread distribution of native North American populations of reed canarygrass

Submitted to: Biological Invasions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 22, 2012
Publication Date: August 4, 2012
Citation: Jakubowski, A., Casler, M.D., Jackson, R. 2012. Genetic evidence suggests a widespread distribution of native North American populations of reed canarygrass. Biological Invasions. 15:261-268.

Interpretive Summary: Reed canarygrass is a valuable pasture and hay crop that was introduced into North America from Europe in the late 1800s. It rapidly spread across the continent as seed was sold to livestock farmers, and it was heavily used by the former Soil Conservation Service for soil stabilization. There is strong evidence that this species was native to North American wetlands prior to introduction from Europe. Ecologists have expressed strong opinions that European types have invaded wetlands and crowded out the native types. In this paper we document that reed canarygrass had a broad continental range prior to the introduction of European types. We found 40 herbarium specimens, ranging in age from 13 to 136 years old, to be completely unique in their DNA profile, unlike any of the European or Asian samples in our extensive database. These samples provide valuable evidence for ecologists and conservationists that native reed canarygrass may still be alive in some natural wetlands, which would be extremely valuable for conducting research on the genetics of invasiveness.

Technical Abstract: Reed canarygrass is an important agricultural crop thought to be native to Europe, Asia, and North America. However, it is one of the worst wetland invaders in North American wetlands. The native North American status has been supported by the circumstantial evidence of early botanical records and the dating and location of herbarium specimens. The lack of empirical evidence has left the North American native status of the species in doubt and prevented comparisons between native North American and Eurasian populations of the species. We utilized genetic markers to compare a wide range of European and Asian collections to DNA extracted from 40 early herbarium specimens collected in North America. The genetic data confirm the presence of a distinct population present throughout North America, but not present in Europe or Asia, ranging from Alaska, USA to New Brunswick, Canada. These native North American populations of reed canarygrass are likely present throughout Alaska today, as one specimen was collected as recently as 1996, and may still be present in parts of North America.