Diversity and complexity of vegetation in native sedge wetlands of southern Minnesota have become threatened by reed canarygrass (Phalaris arundinacea). The consequences for wildlife of widespread conversion of diverse sedge communities to reed canarygrass dominated communities are largely unknown. We conducted a study to determine the effects of reed canarygrass on the plant and wildlife (birds, mammals, and invertebrates) communities. We hypothesized that wildlife would be negatively affected by the invasion of reed canarygrass. To test our hypothesis, we selected 4 sites that had native vegetation (native) and paired those sites with sites invaded by reed canarygrass (invaded). We determined the characteristics of the plant and animal communities at all or a subset of the paired sites during 2006-2007. The plant community at invaded wetlands had lower richness and diversity of species than native wetlands. However, richness and diversity of the bird community was not different during 2007 and greater at invaded sites than at native sites during 2006. In contrast, diversity of mammals was lower at invaded sites during 2006, but no differences were detected during 2007. Similarly, richness and diversity of invertebrate families was lower at invaded sites than at native sites. Our results did not consistently support the hypothesis that there is a clear negative impact of reed canarygrass on wildlife.
