Dear Jeff,
That is not exactly my area of expertise, but when I was an undergraduate
student (while ago) I got involved in an experiment evaluating germination
of an invasive species. We used gerbox with seeds to compare germination at
different forest locations (open cannopy, litter, etc). We used dark
covered gerbox as controls in any stations and we also had controls within
controlled temperature and light in the lab. We used shade clothes of
different intensity covering some gerbox in the lab only, as a treatment. I
remembered that our conclusions were that light quality probably played a
big role than the amount of light. But I did not follow subsequent
experiments controling light quality. And in the project I took part we had
the focus only on germination (not on the establishment of seedlings). I
believe other people did that later. But by that time i was getting more
involved with animal ecology.
But anyway, my suggestions would be for you to try to match field
experiments with controlled lab experiments. If you manage to do that you
could perhaps enhance the certainty of your conclusions. But again, that is
not my area of expertise. So I am sorry if I am not bringing any news. But
I thought a small comment sometimes could help.
Good luck!!! All the best!!!
Alan
2014-06-17 14:31 GMT-03:00 Corbin, Jeffrey <[email protected]>:
> Hello Ecologgers - I am planning to conduct an experiment in which I
> simulate several restoration strategies to control garlic mustard (Alliaria
> petiolata) populations. I am leaning toward establishing new populations in
> a meadow near my college's campus where I could more carefully control seed
> input, etc. between plots. (The meadow is currently mowed, but mowing would
> cease). I would erect a shading canopy with shade cloth over the plots to
> more closely mimic the light environment that garlic mustard tends to
> favor, and to also tamp down somewhat the meadow plants that would
> ordinarily dominate such full-sun conditions. My hypotheses have to do with
> comparing treatments that would all experience similar light levels, rather
> than comparisons between light levels.
>
> My question: Does anyone have strong opinions about the artifacts of such a
> shade cloth canopy?
>
> My thought is that the downsides of using shade cloth are offset by the
> benefits of being able to create more of a "controlled laboratory" setup
> than would be possible in a forested environment. I would be able to
> control more variables (e.g. seed input, light levels) and therefore
> isolate the particular variables (namely, my treatments) I am most
> interested in.
>
> Obviously, though, if the artifacts of shade cloth are too great, then I
> would not be able to apply my findings to the forested sites where such
> questions would be meaningful.
>
> Thanks in advance for your thoughts.
>
> -Jeff
>
> --
>
> ************************************
>
> Jeffrey D. Corbin
>
> Associate Professor
>
> Department of Biological Sciences
>
> Union College
>
> Schenectady, NY 12308
>
> (518) 388-6097
>
> http://jeffcorbin.org
>
> ************************************
>
