| Impact ID | 7998 |
| Impact Type | Competition |
| Study Type | Observational |
| Study Location | Field |
| Impact Description | Glyceria maxima (reed manna grass) can form monospecific stands and reduce plant diversity along the shore to a depth of about 15 cm. |
| Reference | 25461 |
| Cost | |
| Location | Vanern, Vattern, Hjalmaren, and Malaren Lakes, Sweden |