The consideration of radiological protection of the environment during the licensing of nuclear facilities is a requirement formulated in the IAEA International Basic Safety Standards. Within this context the effect of ionizing radiation to flora and fauna is a key topic. This publication documents various important contributions to this area. A large number of dose effect studies were analysed statistically, and the database was used to elaborate dose response relationships to flora and fauna made in a unique ecosystem containing 238U-series radionuclides and other metals/metalloids in lakes that received uranium effluents for several decades. Substantial progress was made in considering radiation effects in the presence of other contaminants. Advances were also achieved in modelling effects to populations of wildlife by improving the models that link effects from individuals to populations.