| Impact ID | 4596 |
| Impact Type | Competition |
| Study Type | Observational |
| Study Location | Field |
| Impact Description | Species richness was lower in beaver dam habitats when the introduced Phalaris arundinacea was present in Alsea drainage area of the Oregon Coast Range, with one species lost for every 7% increase in Phalaris arundinacea cover. |
| Reference | 36918 |
| Cost | |
| Location | Alsea Drainage, Oregon, USA |