Linda, here in the Pacific Northwest, invasive reed canarygrass reduces oviposition habitat for Oregon spotted frogs (Rana pretiosa), which require very open shallow marshes (see the paper by Kapust et al. (2012) among publications on my site. There is also research in the arena of growth and other effects on amphibians from invasive plant leachates, especially from purple loosestrife and select other species. See, for example, work my Maerz et al. (2005) Functional Ecology 19(6):970-975. A google scholar and other alterantive searches using several different search terms can bring up others.

I covered some of this issue in a recent book chapter.

Thank you Mark and David for your assistance and helping me complete my research. It seems that most of the amphibians in the US share the same problem with the same invasive non-native plant species of purple loosestrife, Japanese bayberry, and garlic mustard. There is still a need for more research on the environmental effects from these species.