Significance Dry deposition is an important removal mechanism for oxidized atmospheric compounds. This process remains, however, poorly understood due to the scarcity of direct flux observations for all but small, inorganic molecules in the atmosphere. The chemically speciated fluxes presented here comprise a unique and novel dataset that quantifies the dry deposition velocities for a variety of trace gases in a typical forested ecosystem. The data illustrate the key role of molecular diffusion in the atmosphere−biosphere exchange of water-soluble species. Furthermore, this work enabled evaluation of the dry deposition parameterization in a global chemical transport model. The results aid in resolving key discrepancies within the global model, resulting in more-accurate predictions of trace gas lifetimes and surface concentrations.