[en] The earth's climate is a nonlinear dynamical system, which functions through complex feedbacks, as a self-regulating system, involving physical, chemical, biological and human aspects. Gaia theory has proposed the existence of a feedback between climate and biota on earth. A global zero-dimensional model of planetary climate involving Gaia theory is presents. Our model is based on the well-known daisyworld model with a significant modification represented by a simplified hydrological cycle. This model allows one to explore feedbacks between different elements of the climatic system including water and energy balances of the surface and the atmosphere, the dynamics of biota, the greenhouse effect and the role of cloudiness via the global Albedo. We obtain solutions of the temporal evolution of climate (represented by average temperature), as well as biological populations and variables representing the hydrological cycle. Our results confirm the existence of couplings and suggest the relevance of taking into account for the hydrological cycle into the daisyworld