Himalayan Balsam Impatiens glandulifera is evolving fast in Britain, with smaller leaves, fewer stomata, and larger flowers, in the 150 years it has been here: https://www.nature.com/articles/s41598-024-69710-y.pdf
Well, it's interesting. The Results section for Floral traits at the beginning says But then under Conclusions in that section, it says My streamkeeper friend was defending it in a conversation last night, saying that some of its blooming time here in the lower mainland of BC happens where there is little else available for pollinators to feed on.
I noticed that discrepancy in the article! Clearly, they're aware of it too, with their call for further research. Whether that will ever happen, is another thing . . .
Native pollinators don't need alien plants in order to exist as the pollinators have done for a long time before the arrival of nonnative species. With in addition to the adverse effects of the impatiens forming dense colonies in local streams where no similar plant has occurred in the past another thicket former butterfly bush (Buddleja davidii) is actually a butterfly killer. Any time that native butterflies lay eggs on it. Because their larvae are not able to eat butterfly bush - what similarly undesirable, perhaps yet to be recognized behavioral changes might the impatiens be causing with its presence? Historically the complexity of ecosystems results in system wide disruption when even a single species is added or removed.
My friend's response is that not all changes are all bad. She has sent a link to https://insideclimatenews.org/news/23082024/invasive-seagrass-species-halophila-stipulacea/, which describes an invasive seagrass in the Caribbean that may be increasing diversity in that area. But the article does mention that the native fish don't like the invasive seagrass, will seek out single blades of the native seagrass. Now there are "little nudibranchs and sea slugs" feeding on the new seagrass. About the Impatiens, she wrote that she was thinking about "little else available in shady woodlands and riparian zones with mostly spring-flowering native perennials and shrubs." And she has added this:
