Exploiter-mediated coexistence and frequency-dependent selection in a numerical model of biodiversity

The key feature of the Daisyworld approach is to explicitly model feedbacks between the competitive dynamics of a planetary biota (daisies with different albedos) and the planet's climate, namely its surface temperature. Self-regulation of surface temperature and stable population dynamics are striking emergent properties of this system, despite increasing energy output from the model's sun. In this paper we attempt to perturb Daisyworld by introducing herbivores endowed with one of four strategies for feeding on daisies in a system rich in daisy diversity, and find that the herbivores only moderately diminish the temperature regulating abilities of the system. Furthermore, we find that the precise trajectory of the system's temperature regulation depends critically on which daisy species the herbivore allows to co-exist, thereby revealing that climate and patterns of biodiversity are highly interrelated in this model, and, possibly, in the real world. (C) 1996 Academic Press Limited