| 2018 | 2013 | |||
|---|---|---|---|---|
| Species | Observances | Percentage of plots | Observances | Percentage of plots |
| Multiflora rose | 101 | 85.6 | 239 | 74.5 |
| Nonnative bush honeysuckles | 45 | 38.1 | 120 | 37.4 |
| Japanese honeysuckle | 43 | 36.4 | 103 | 32.1 |
| Garlic mustard | 41 | 34.7 | 63 | 19.6 |
| Japanese stiltgrass, Nepalese browntop | 40 | 33.9 | 95 | 29.6 |
| Autumn olive | 21 | 17.8 | 55 | 17.1 |
| Oriental bittersweet | 15 | 12.7 | 20 | 6.2 |
| Creeping jenny | 14 | 11.9 | 20 | 6.2 |
| Reed canarygrass | 11 | 9.3 | 32 | 10 |
| Black locust | 10 | 8.5 | 38 | 11.8 |
| European privet | 10 | 8.5 | 22 | 6.9 |
| Common buckthorn | 7 | 5.9 | 3 | 0.9 |
| Tree of heaven | 7 | 5.9 | 7 | 2.2 |
| Japanese barberry | 6 | 5.1 | 6 | 1.9 |
| Canada thistle | 5 | 4.2 | 12 | 3.7 |
| Bull thistle | 3 | 2.5 | 10 | 3.1 |
| Common barberry | 1 | 0.8 | 5 | 1.6 |
| Dames rocket | 1 | 0.8 | 12 | 3.7 |
| English ivy | 1 | 0.8 | 1 | 0.3 |
| Silktree | 1 | 0.8 | -- | -- |
| Glossy buckthorn | -- | -- | 3 | 0.9 |
| Japanese meadowsweet | -- | -- | 2 | 0.6 |
| European cranberrybush | -- | -- | 2 | 0.6 |
| Siberian elm | -- | -- | 1 | 0.3 |
| Japanese knotweed | -- | -- | 1 | 0.3 |
| Russion olive | -- | -- | 1 | 0.3 |