A procedure is presented for developing environmental risk hypotheses associated with the
deployment of forest trees genetically modified to have altered wood properties and for
selecting non-target species to test these hypotheses. Altered-lignin Pinus
radiata trees intended for use in New Zealand are used as a hypothetical case
study to illustrate our approach. Firstly, environmental management goals (such as wood
production, flood control or preservation of biodiversity) were identified and linked to
the forest attributes they require. Necessary conditions for each attribute were listed
and appropriate assessment endpoints for them developed. For example, biological control
of pests may be one condition necessary for a forest to have healthy trees, and the
diversity and abundance of natural enemy species in the forest could be an appropriate
assessment endpoint for measuring this condition. A conceptual model describing the
relationships between an altered-lignin GM pine tree and potentially affected
invertebrates and micro-organisms in a plantation forest was used to develop a set of risk
hypotheses describing how the GM trees might affect each assessment endpoint. Because
purified lignin does not represent the properties it imparts to wood, maximum hazard dose
tests with non-target organisms, as are used to inform toxin risk assessment, cannot be
conducted. Alternative experiments, based on current knowledge of the responses of
organisms to lignin, must be designed. A screening method was adapted and applied to a
database of invertebrate species known to inhabit New Zealand pine forests to identify and
prioritize non-target invertebrate species that could be used as experimental subjects for
examining these hypotheses. The screening model and its application are presented, along
with a set of recommendations for pre-release tests with GM pines and potentially affected
invertebrates and micro-organisms.