The “Paradox of the plankton”
According to the “Paradox of the plankton”, more plankton species exist than allowed under the competitive exclusion principle of Gause. This principle states that the number of species cannot be greater than the number of niches utilized by these species, unless certain conditions are met. The Paradox of the plankton has played a crucial role in ecological theory. Hutchinson, who formulated the paradox, explained this discrepancy by nonequilibrium conditions, due to repeated weather - and climate - induced changes in environmental conditions. Recent work on marine and freshwater plankton has shown this to be correct, but it has also shown that the number of niches available for exploitation is far greater than earlier assumed (components of the white light spectrum, additional essential resources), and that chaotic fluctuations can increase diversity even when environmental conditions are constant.
You will find a detailed discussion of these studies on the Cambridge University Press website of my book Nonequilibrium Ecology (Resources and solutions. Appendix 2).