A central lesson from theoretical ecology is that even simple ecological processes can cause complex, dramatic dynamics. An extreme example of this lesson is midges in Lake Mývatn, Iceland, where midge abundance fluctuates over five orders of magnitude, with crashes occurring irregularly every 4-10 years. The spatiotemporal dynamics of species depend on the strong interactions they have with species in a community, and in turn the dynamics of a single species can drive community-level changes. Understanding species and community dynamics, and how they are affected by environmental changes, requires a combination of long-term observations to document dynamics, targeted experiments to investigate underlying mechanisms, and theory to formulate and test hypotheses about why species and communities have the dynamics they do.
