prevention of wind erosion and acts as an intermediary trap for blowing particulate material. Discussion of desert environment problems and associated recommendations are presented by Wallace and Romney for measures to be considered in the proposed cleanup and restoration of areas at the Tonopah Test Range and Area 13, NTS. Through examination of past decontamination and soil disturbance experiences in the Great Basin Desert, Wallace and Romney found indications of tendencies toward slow natural recovery in disturbed areas. Revegetation considerations of disturbed areas are addressed in detail, with excellent bibliographic material included. The inventory of plutonium, americium, and uranium in/on vegetation samples from Plutonium Valley (Area 11) intensive study sites was deter- mined from analyses of samples at McClellan Central Laboratory. (Mount's excellent report of analyses of 238pyu, 24 1am, and 235y in vegetative material is included in this document.) The soils under desert plants in mounds were investigated by Tamura, ORNL, to determine whether the character and behavior of the plutonium in the mounds were similar to that in desert pavement soils. Analysis of samples reflected some of the problems of sampling mounds. The distribution of radioactivity observed demonstrated the importance of sampling techniques. Preliminary data on the activity in particle size fractions, in terms of activity per unit mass, indicates that the coarse silt (50-20 um) contains the highest activity in the desert pavement samples. The medium silt (20-5 um) contains the highest activity in the desert mound samples. As considerable mechanical mixing had occurred in the mound sampled, it was difficult to interpret measurements of depth distribution. In making particle density measurements, Tamura found an indication that the desert mound particles in the 20-5 and 5-2 um size classes are lower in density than the corresponding size classes in the desert pavement. In the smaller Size classes in both types of samples, the data suggest that plutonium is distributed in the lighter fractions as well as the heaviest fraction. Study of the implications for uptake by man and grazing animals through ingestion or inhalation of particles from desert mound samples character- ized by Tamura awaits more definitive data. NAEG plans include investigation of various natural mechanisms (organic and inorganic soil complexing) by which biological uptake may be enhanced. Fowler and Essington emphasized the fact that current soil profile data from samples taken down to 25 cm indicate that the maximum depth of penetration of plutonium in soils at NTS is still unknown. (Greater in-depth sampling, of course, depends of availability of funds.) Another problem indicated is the disparity in the plutonium-americium ratios among study sites. Difficult analysis of americium is suggested as a possible cause of the disparities. Also, other factors impinge on the data available, e.g., mechanical disturbance at some sites, differences in times and types of plutonium release, variance in climatic environments at NTS, etc. 318