Nature\u27s Computers: Patchiness, Collective Dynamics, and Emergent Computation in Stomtata

Plants have evolved incredible tools to respond to changing environmental conditions in order to maximize their efficiency. In particular, the stomata on plant leaves are capable of maximizing photosynthesis while minimizing water loss for the whole leaf. In fact, the leaves develop patches of open and closed stomata that oscillate and shift in response to external (and internal) stimuli. These tiny cells seem to behave in ways reminiscent of cellular neural (nonlinear) networks, which are largely studied in computational science. The research then focuses on constructing a model of plant stomata based on temperature, humidity, carbon dioxide, and light intensity experiments using high-resolution thermal imaging. For the last year experiments have been run in the laboratory on several species of plants that involve placing a plant into a test chamber, then changing variables such as humidity, temperature, and light intensity. The thermal image files of the plant are converted into stomatal conductance values and graphed versus time. In addition, a series of differential equations describing macroscopic conductance based on microscopic parameters of the plant and cell pressures are derived, analyzed, and run in simulations that are then compared to the real experiments. Values for the microscopic parameters are then inferred from the fitting of the theoretical to the experimental data. Further research focuses on developing a dynamical model of a leaf’s interactions with its environment, involving differential equations to model the rates of change of carbon dioxide and photosynthetic product. The model works towards deriving a complete system of equations and parameters to describe the patches of uniform conductance on a leaf\u27s surface and the way in which they interact