From the online journal Urban Habitats comes an intriguing study of the flora of the New York Metropolitan area. Using a century of herbarium records, Steven E. Clemants and Gerry Moore discovered a trend of expanding ranges of non-native plants and shrinking ranges of native species. In one of the sobering examples they discuss, native honeysuckles (Lonicera spp. and Diervilla lonicera) all have a negative change index, while their non-native congeners have all increased their range dramatically.
A quick sort of their data, and the species list with the top ten highest change indices reads like a who's who of invasive plants in the Northeast U.S....
- Celastrus orbiculata (Asiatic bittersweet)
- Rosa multiflora (multiflora rose)
- Lonicera morrowii (Morrow's honeysuckle)
- Morus alba (white mulberry)
- Elaeagnus umbellata (autumn olive)
- Aralia spinosa (devil's walking-stick)
- Ampelopsis brevipedunculata (porcelainberry)
- Ailanthus altissima (tree of heaven)
- Acer negundo (boxelder)
- Robinia pseudo-acacia (black false-locust)
Thanks to a member of the Yahoo! group ma-eppc for posting a link to the article.