The Bamboo Fire Cycle Hypothesis: A Comment

The bamboo fire cycle hypothesis proposed by Keeley and Bond (1999) argues that lightning-ignited wildfire has synchronized flowering and recruitment of bamboos throughout Asia. They argue that mast flowering followed by mass mortality leads to fuel-load accumulation, encouraging ignition by lightning strikes that results in complete consumption of litter and dead stalks, which both enhances bamboo regeneration from seeds and seedlings and simultaneously suppresses neighboring vegetation. They further argue that such fires create the conditions for monocarpic (semelparous, or breeding only once) reproduction of clones at long intervals, a feature that distinguishes woody bamboos from other bamboos and from the vast majority of higher plants. We do not find the hypothesis compelling. Multiple causation is the rule in ecological and life-history explanation (Quinn and Dunham 1983), and it is always possible that fire has played a role in the evolution of some bamboo taxa somewhere. But we see no evidence that fire has played a central role in the evolution of mast flowering or monocarpy in general or in our area of direct experience in South Asia, where 70 of 72 woody bamboo species are monocarpic and mast flowering (eight species are strictly synchronous; see Gadgil and Prasad 1984; Kelly 1994). We do not see evidence that other plant taxa are fire adapted in habitats where mast-flowering, monocarpic bamboos thrive nor do we find the logic of the argument convincing on its merits. Aspects of bamboo biology remain puzzling, but we are forced to conclude that whatever resemblance