These photographs were sent along to me by one of the frequent contributors to Botany Photo of the Day. I believe they are from coastal Connecticut. I think a Rubus, but with so many in the eastern USA, anyone have suggestions as to species?
Reminds me of Rubus laciniatus. http://en.wikipedia.org/wiki/Rubus_laciniatus http://luirig.altervista.org/cpm/albums/bot-units13/rubus-laciniatus11911.jpg
If there is only a couple of small ones like this on the site so for they should be removed in order to prevent a larger infestation.
"The fruits of this plant are eagerly consumed by a number of animal species, including many birds and mammals. The thickets provide valuable cover for animals." http://en.wikipedia.org/wiki/Rubus_laciniatus
Woody weeds bearing attractive fruits (including this species) get spread around here because birds etc. are dispersing them. But it isn't always locally native wildlife that is doing the dispersing, and the cover provided isn't necessarily a bonanza for native animals - the loss of native vegetation being excluded by heavy growths of dominating exotics like blackberry and ivy is probably much more significant. In one study of native bird foraging at the Seattle arboretum it was seen that exotic planted species including those in the same genera were largely passed over in favor of the native ones.
Treating the symptoms not the causes will lead us nowhere. The problem is, that for many people it is too difficult to understand.
Not seeing how a thorny thicket made up of a plant of foreign origin covering part of a beach is an improvement. It is not the case that in every instance exotic woody weeds are dominating acreage because the general environment has become unsuitable for native plants due to human activities. Often a foreign invader merely has to be present on a site for the natural vegetation to become adversely impacted to a significant extent, the weed itself being the agent of destruction - with no bulldozing, farming or polluting required beforehand.
Unfortunately, there is much more to it than "bulldozing, farming or polluting" in any given locality. For example, a sharp decline in populations of birds and pollinators has a very negative impact on the native plants species ability to survive. Destroying plants that are food and shelter sources for birds and insects, regardless if those plants are native or 'invasive', can only speed up their decline and make the problem even worse. It looks like the occasionally thriving 'invasive' species, supplying food and shelter to other species necessary and interrelated in the Nature's great scheme of sustaining life, may be the Nature's desperate attempt to repair the damage caused by human simplistic thinking and activities.
Ecological impacts of invasive alien plants: a meta-analysis of their effects on species, communities and ecosystems Abstract: The question then becomes: what is the primary goal for managing the area (assuming the first question is "should it be managed")? For increased primary productivity or ecosystem services? For maintaining resident populations of plants and animals? From the study:
I would like to draw your attention to the sentence in your first quote (from the abstract): "On average, abundance and diversity of the resident species decreased in invaded sites, whereas primary production and several ecosystem processes were enhanced." Your second quote (from the study) supports only the first part of that sentence. In the paper, however, just after the text quoted by you, there is the following: "With regard to ecosystem impacts, alien plants enhanced microbial activity by 32.3%, available N (53.7%), N, P and C pools (22.1, 19.7 and 11.6%, respectively)" Also, from your second quote, "total community production increased by 56.8% following invasion" So, long term impacts are still to be seen. To pull or not to pull, to manage or not to manage, that is the question. Those who really care for the environment, native species included, will agree with me that the best solution would be to start paying more attention to our own destructive impact on the environment and our own treatment of native species. No person who lives in an oversized home, built and maintained at the huge expense of the environment, who uses herbicides to prevent even one little native flower to bloom in his or her lawn, who kills with pesticides all the insects who could otherwise pollinate native species or feed the birds, who in turn could help native species to propagate, who uses fertilizers to help his monoculture lawn thrive, all this, again, at the huge expense of environment, who goes to the grocery store and buys fruit and other products grown or manufactured on the other side of the globe, all in rigid plastic containers that he or she puts in plastic bags to carry home, who doesn't even care that little as to buy local, no person like that has any credibility with me, regardless how many alien plants he or she has pulled up.
I wasn't intending to make a statement one way or the other. My intent was to post some of the more recent analyses on the topic. Regarding: This is what I was directly referring to when I asked this: Similarly, I was aware that the second quote also contained analysis that was not wholly in support of one approach over another.
