Constructing nature: Laboratory models as necessary tools for investigating complex ecological communities

Ecological systems are arguably among the most complex of all systems found in nature at any scale of observation. The origin of this complexity arises not only from the stunning diversity of entities that comprise such systems (i.e., species, individuals and highly variable nature of interactions among these entities), but also because such systems exhibit nonequilibrium, non-linear, historically contingent, self-organizing behavior replete with a host of emergent properties and attendant noise. There are few constants or laws past thermodynamic constraints and simple mechanics, and here process and mechanism operate across vast scales of existence in a fashion that is not precisely replicable. The basic approach of ecologists has been brute-force observation and experimentation in specific settings, with the tacit hope that answers will emerge from large data collection. Laboratory experiments, of course, suffer from many of the same difficulties that plague field studies. At the same time, the simplifying assumptions of laboratory community studies permit explorations of intact communities-something never accomplished in the field (Drake et al., 1996). But the lab is not enough. The general dynamic behaviors and phenomena observed in the lab provide fodder (in the form of potential and probable processes directing community structure) for field approaches.