Hi, Danielle, One old-standby aquarium experiment is reproductive rate and competition among floating plants. You can use various species of duck weed (*Lemna, Wolfia*) liverwort (*Riccia*) and ferns (*Azolla, Salvinia*) and vary light levels, temperature, etc.
You could also test the affect of "predation" on the plants by aphids (Some aphids specialize on floating plants, but I can't give you the genera. * Salvinia,* which is fuzzy on top, is probably harder for aphids to deal with.) or goldfish. According to my observations, goldfishes' grazing on duckweed is related to fish size. Not surprisingly, perhaps, big goldfish eat A LOT more duckweed. Also of interest about these plants is that although they all occupy the niche of "tiny floating freshwater plants" they belong to wildly different taxonomic groups. If you want to work with a real predator/prey system, you could have aphids on the floating plants preyed on by water striders (*Gerris*). This would be a neat way to show how the presence of the predator could favor the growth of the plants by lessening the aphid burden. You could rig various baffles to make it harder for the striders to gobble up all the aphids on the first day. If you want to use striders, you may still be able to catch some if you go out to a pond or slow stream on a warm day and look from them at a sunny shallow spot. I hope this helps. Even if some of the experiments don't work out as you hope (algae takes over some of your tanks, say) there are still plenty of "teachable moments." E.g., ecology is tricky, and experimentation is fraught with pitfalls. Martin M. Meiss 2012/11/14 Danielle Garneau <danielle.garn...@gmail.com> > Hi all, > I was wondering if anyone has had luck doing some work using these systems > in a semester long class project setting? I wonder if some of the predation > risk expts similar to that of Oswald Schmitz (pred risk spiders, forbs, > grasshoppers) or that of Rick Relyea's (tadpoles--maybe guppies and their > predators assessing behavioral/morphological changes) might be feasible. > > I'd be setting this up over the winter break and attempting to get these > going in the spring semester population and community ecology course. > Currently we are doing mustard work in 2L bottles w/ student-designed > treatments. I was hoping to grow the scope of the project. Perhaps this is > too ambitious, but thought I'd seek advice from those who might have had > success earlier. > > thanks for sharing your ideas! > Danielle > > -- > Danielle Garneau, Ph.D. > Assistant Professor of Environmental Science > Center for Earth and Environmental Science > 227 Ward Hall > SUNY Plattsburgh > Plattsburgh, NY 12901 > office (518) 564-4073 > fax (518) 564-5267 > dgarn...@plattsburgh.edu > http://danielle.garneau.googlepages.com/ >
