Time and Space Scales
The range of processes and components in oceanic ecosystems is daunting, and new observing
techniques are constantly revealing new complexity. Even simple ideas of heterotrophs and autotrophs
cannot be distinguished unambiguously in many cases as species cross these boundaries. The
functional complexity of the ecosystem is further confounded by the broad range of temporal and
spatial scales associated with these processes (Denman and Powell, 1984; Mackas et al., 1985).
Because of the nonlinear interactions that dominate ecosystems, one cannot simply ignore processes at
scales smaller than the scales of interest (Denman and Powell, 1984). For example, the characteristic
scales of variability in the environment may drive the response scales of phytoplankton physiology
over evolutionary time scales (Harris, 1986; Abbott, 1993).
The observed richness and complexity of the natural world results in a tension between modelers who
try to retain only the critical elements of the system in order to develop a manageable and
understandable model and observationalists who insist that such sparse models are missing essential
processes. The tension between model robustness and model richness will never be resolved, and the
balance point between these two forces will depend on the goals of the model.