invasive plant adventures

Garlic Mustard (Alliaria petiolata) is just a super-nasty invasive plant, with some very profound negative impacts on forest ecology. Our entire campus is full of it. I have one study plot where I've managed to keep it under some semblance of control.  Next year, I plan to do some invertebrate trapping to see if there is any difference in the types of soil-surface creatures in Garlic Mustard plots versus the plots where I have prevented it from taking hold. I'd like to know what types of prey items are available to ground-foraging migrant birds in invaded areas.

Last week while doing a bird survey, I encountered this interesting individual plant, in which most of the leaves were variegated.  Of the literally thousands of Garlic Mustard plants I have seen, this is the first I've encountered like this, and yet a day or so after, another blogger posted a similar finding in Canada. A quick search revealed someone on a native plant forum finding a variegated plant last year in PA.
 

Leaf variegation is the result of a lack of chlorophyll-producing cells. Sometimes this may be caused by viral infections. In any case, this variegation may weaken the plant, as the pale tissues are not manufacturing food via photosynthesis. Viruses can have other negative side effects. Maybe these instances of Garlic Mustard chimeras are a good sign!

The same day, I took a leaf sample from the handiest patch of Japanese Knotweed (Polygonum cuspidatum) on campus. This is another bad actor, but not as widespread around here. I put the sample in a tube of dessicant for DNA analysis. Apparently, not a lot is known about genetic diversity of this invader in the U.S., and University of Massachusetts-Boston grad student Jonna Grimsby is embarking on a study.  You, too, can contribute to her project.  Read all about how to get a sample kit over at the Invasive Species Weblog and do a little pruning for science.

Comments

[Jenn]

Garlic mustard is not the only invasive plant to have that beautiful marbling - I've seen it in Asiatic bittersweet in the wild, and the nursery industry sells a variegated Japanese knotweed cultivar as well.

Thanks for the linkback!

[Roger B.]

Here in the UK, where garlic mustard is an indigenous species, I don't recall ever coming across a plant with variegated leaves.

[Nuthatch]

That's pretty interesting. Maybe there is some sort of genetic bottleneck here, or a susceptibility to a North American virus? We can hope...