For every Kudzu, however, there are hundreds of less invasive and harmful non-native species. Just looking out my window I see scores of trees and plants that are decidedly non-native. I'd venture that virtually every suburb is largely populated by non-native plants. And with international shipping and travel, the introduction of non-native species of animals and plants in inevitable.
So, it is my opinion that we need to seperate the issues of harmful and not-so-harmful introductions of non-native species to the ecosystem. From what I can tell out west here, the introduction of kentucky bluegrass has not caused any sort of environmental ruin (except for the obscenely large watering requirements) while many areas are overrun with invasive, highly flamable, and messy eucolyptus forests.
Closer to the actual topic, can it be said that the introduction of S. purpurea poses an actual threat to any other species? Does it grow in sufficient density to crowd out D. californica? Would D. capensis really crowd out native D. rotundifolia? I suspect, but cannot back up in any way, that S. purpurea could safely grow alongside native species in California bogs.
Capslock