Observations of Bifurcation and Chaos in Plant Physiological Responses to Light

Although some theoretical predictions have been made, no experimental evidence of chaotic behaviour in plant physiological responses has been reported. Here we present observations of period- doubling and tripling in higher plants. For leaf bioelectric and temperature responses of maize, tomato, and burweed plants to rhythmical light, two different routes to chaos were found experimentally. One was via successive period-doubling and the other via the formation of intermittently chaotic oscillations from a subharmonic synchronisation. Because these effects appeared in intact plants, under conditions close to those found in nature, they may have wide significance, including for plant phylogenesis.