Figure 1.18 Experimental venues. The choice of experimental venue often represents a trade-off between the complexity of natural conditions and the more highly controlled conditions of a laboratory experiment. (a) Manipulative experiments of entire lakes, such as this lake in Wisconsin, include natural conditions, but such experiments are difficult to replicate. (b) Microcosm experiments, such as this experiment at the University of Pittsburgh’s Pymatuning Lab of Ecology, include many features of a lake by containing communities of aquatic organisms. Using microcosms allows the manipulations to be replicated many times. (c) Laboratory experiments, such as this pesticide experiment conducted in Petri dishes, allow researchers to conduct highly controlled experiments, but they are conducted under very unnatural conditions.
Photos (a) courtesy of Carl Watras; (b) and (c) courtesy of Rick Relyea.