9703908 Allen There is an emerging paradigm of ecosystem thermodynamics that recasts several of Odum's principles for ecosystem maturity as an increasing capacity for heat dissipation. More mature ecosystems have more elaborate structure and pathways, which dissipate the gradient from the warm planet surface to cold outer space. Data from whole biomes to small experimental plots suggest that more mature and structurally elaborate systems have a cooler upper surface. The theory of non-equilibrium systems suggests that the emergence of complex, dissipative systems is sudden and represents the emergence of higher hierarchical levels. Each higher level appears as the system avails itself of some new means of resisting being pushed up the temperature gradient. This Small Grant for Exploratory Research will experiment with Arabidopsis to investigate these phenomena under controlled conditions. The first phase will achieve replicable measurements of vegetation temperature that distinguish different vegetation treatments, such as plants grown in different air movement regimes. Arabidopsis allows such control as keeping all else equal but a single gene for stature in tests of increasing structural complexity of contrived Arabidopsis "vegetation." The goal is a protocol for distinguishing the temperate of contrived vegetation. Then the second phase will look for the emergence of the steps in cooling capacity earlier in the development of vegetation. Being able to predict in the ability to dissipate the temperature gradient will tell mechanists disjunctions were to look to explain emergent cooling phenomena. Such explanations will allow others to move up scale from physiological mechanism to phenomena of landscapes, ecosystems, and regions. It should also validate phenomena of emergent cooling that have been explained only post hoc heretofore.
