TABLE OF CONTENTS PAGE NO. PREFACE 1 SOILS Plutonium in Surface Soils of Area 13: Report. Tswmeo Tamura. A Progress Nevada Applied Ecology Group Soils Element Activities for Period July 1, 1974, to May 1, 1975. FE. d. Essington and E. B. Fowler. 17 VEGETATION NAEG Plutonium Program Vegetation Studies Status Report, May 1975. &. M. Romney. 31 LARGE VERTEBRATES Seasonal Effects on the Solubility in In Vitro Bovine Gastrointestinal Fluids of Plutonium Ingested by Grazing Cattle. dJultus Barth. 35 Status Report on Grazing Studies on a Plutonium- Contaminated Range of the Nevada Test Site. Smith, D. D. Passage of Sand Particles Through the Gastrointestinal Tract of Dairy Cows. RFR. G. Patzer, G. D. Potter, and W. W. Sutton. Biological Transfer of Plutonium-238 Via In Vitro Labeled Milk. William W. Sutton. 41 47 51 SMALL VERTEBRATES Ecological Studies of Small Vertebrates in Pu- Contaginated Study Areas of Nevada Test Site and Tonopah Test Range. Moor. W. Glen Bradley and Kenneth S. 53 MICROORGANISMS Possible Influence of Desert Soil Microbial Changes. F. a. F. Au, V. D. Leavitt, and W. F. Beekert. 67