Keystone species and community effects of biological introductions / Daniel Simberloff -- Planned introductions in biological control / L.E. Ehler -- Surface transport of microorganisms by water / James A. Moore -- Soil and groundwater transport of microoganisms / Duane F. Berry and Charles Hagedorn -- Aerial dispersal of bacteria / Christen D. Upper and Susan S. Hirano -- Factors affecting the transfer of genetic information among microorganisms in soil / Guenther Stotzky, Lawrence R. Zeph, and Monica A. Devanas -- Genetic exchange and genetic stability in bacterial populations / Conrad A. Istock -- Models for the population dynamics of transposable elements in bacteria / Richard Condit. Quantifying fitness and gene stability in microorganisms / Richard E. Lenski -- Quantifying the risks of invasion by genetically engineered organisms / Junhyong Kim, Lev R. Ginzberg, and Daniel E. Dykhuizen -- Quantifying the spread of recombinant genes and organisms / Robin Manasse and Peter Kareiva -- Regulation of biotechnology by the Environmental Protection Agency / Marvin Rogul and Morris Levin --Ecological considerations in EPA's review for field tests of genetically engineered organisms / H. Resit Akcakaya and Lev R. Ginzburg --Regulation and oversight of biotechnological applications for agriculture and forestry / Maryln K. Cordle, John H. Payne, and Alvin L. Young. Ecological risk assessment and European community biotechnology regulation / Rogier A.H.G. Holla -- Ecological risk analysis of biotechnological waste decontamination / Anthony D. Thrall and Robert A. Goldstein -- On making nature safe for biotechnology / Mark Sagoff.