Typha angustifolia and Phragmites australis: Different affects on Rana clamitans and Rana catesbeiana and the implications for management

Lisa Regula Meyer

Invasive species can cause considerable change to ecosystems through multiple mechanisms and with varying affects. Invasive plants especially can change the community structurally by out-competing native species and limiting habitat diversity; exude novel compounds into the community which may directly harm other organisms; change the nutrient and chemical profiles of an ecosystem; change the microbial community; and change the amount and/or quality of detritus available for decomposition. These changes may be more pronounced in aquatic situations where chemicals move more freely than in soil. At the same time, one of our most at-risk ecosystems is wetlands. Wetlands are distinct in their flora and often fauna as well, when compared to surrounding habitats. Wetlands are also crucial for many taxa, including amphibians which are currently in decline in many areas. This study examines the effects of two invasive plants - Typha angustifolia and Phragmites austrlis - on the wetlands which they have invaded, and how those changes may affect amphibians especially Rana clamitans and Rana catesbeiana. While both plants are correlated with distinct changes in their environment, the changes are in very different directions. The changes correlated with each of the plants could be biologically relevant to amphibians and other organisms. The directions of these changes may also indicate differing degrees of risk to amphibians associated with the different plants. These are preliminary results and part of a larger dissertation project concerning these four species and their interactions.

Keywords: RANA, TYPHA, PHRAGMITES