| Impact ID | 4580 |
| Impact Type | Competition |
| Study Type | Observational |
| Study Location | Field |
| Impact Description | Phalaris arundinacea outcompeted the endangered Howellia aquatilis
(Water howellia), replacing it as the dominate canopy cover and prevent seedling growth in the Swan River Oxbow Preserve. |
| Reference | 27597 |
| Great Lakes Region | No |
| Cost | |
| Location | Swan River, Lake County, Montatna, USA |
