9631740 Derry This proposal was submitted to the Environmental Geochemistry & Biogeochemistry solicitation NSF 96-2. The project described below is being jointly supported by the Division of Earth Sciences and Environmental Biology. The proposed research will address the sources, consequences, and fates of elements deposited to Hawaiian ecosystems. The project will focus on well-characterized long substrate age gradient (LSAG) sites. Objectives include: (1) determining the atmospheric input of elements at one site on the LSAG, measuring wetfall, dry deposition, and cloudwater interception - all components of the deposition will be analyzed for major elements, strontium and strontium isotopes; and (2) determining Sr isotopes in plants and soils on the LSAG, in lysimeters collecting water draining these sites and in streams. The results, especially the strontium isotope signatures, will be used to elucidate the source(s) of Sr and trace its fate along the ecosystem sequence.