[en] Measurements of natural beryllium-7 (⁷Be) were made in field vegetation and rainwater at the Department of Energy's Oak Ridge Reservation throughout the months of July 1982 to June 1983. Laboratory experiments were also conducted on the adsorption and desorption of ⁷Be, cesium-137 (¹³⁷Cs), lead-210 (²¹⁰Pb), and iodine-131 (¹³¹I) to the foliage of fescue, 3 varieties of beans, and loblolly pine. The field loss of artificially applied ⁷Be to field fescue was also measured. The weathering half-life (T/sub W/) was found to be 36.5 days during November-January 1982-1983; no difference was found in the loss of ⁷Be during the months March-May 1983, T/sub W/ = 38.5 days. The loss of sulfur-35 (³⁵S) was studied concurrently with the spring loss of ⁷Be; the T/sub W/ for ³⁵S was much smaller, equal to 18.4 days. The interception fraction, r, was determined experimentally in the field using the flux of ⁷Be in rainwater incident upon clover; the mean value was 0.172. Total deposition velocities were estimated using monthly ⁷Be rainwater concentrations and quarterly air concentrations; the yearly average was 1.66 cm/sec. An equation for predicting vegetation concentrations was derived for ⁷Be from the US Nuclear Regulatory Commission's Guide 1.109. Generic and site-specific values for deposition rate, interception fraction, effective half-life, exposure time, and biomass density were summarized separately and the derived equation was employed to make predictions of monthly ⁷Be vegetation concentrations. These predictions were compared to actual field observations. With the exception of the month of May, both generic and site-specific predictions were found to underestimate the actual ⁷Be vegetation concentrations. 44 refs., 9 figs., 15 tabs