Hayden, B. P. in press. Ecosystem feedbacks on climate at the landscape scale. Philosophical Transactiions, Series B Keywords:Hydrocarbons, dewpoint, ice nuclei, climate, Feedbacks:: Abstract:Vegetation controls aspects climate at all scales. These controls operate through fluxes of mass (water vapor, particulates, trace gases, condensation nuclei, and ice nuclei) and energy (latent and sensible heat, radiative exchanges, and momentum dissipation) between the biosphere and the atmosphere. The role these fluxes play in controlling minimum and maximum temperature, temperature range, rainfall, and precipitation processes are detailed. On the hemispheric scale, the importance of evapotranspiration, vegetation surface roughness, and vegetation albedo in the current generation of atmospheric General Circulation Models (GCMs) is reviewed. Finally, at the planetary scale, the global climate effects of biogenic emissions that are well mixed throughout the troposphere are assessed. It is shown that daily maximum and minimum temperatures are, in part, controlled by the emission of non methane hydrocarbons and transpired water vapor. In many regions, a substantial fraction of the rainfall arises from upstream evapotranspiration rather than from oceanic evaporation. Biosphere evapotranspiration, surface roughness, and albedo are key controls in the general circulation of the atmosphere\; climate models without adequate specifications of these biosphere attributes fail. The biosphere modulates climate at all scales. :: Notes: submitted by bhayden, Fri May 30 15:14:14 EDT 1997 ::