ABSTRACT
Nearly 20 years have passed since the first report of transgenic expression in plants (Meeusen and Warren 1989). It has been more than 10 years since development of transgenic Bt resistance in hybrid poplar against tent caterpillars and gypsy moths (McCown et al. 1991) and seven years since the first field trials (Kleiner et al. 1995). Yet we still have only a limited ability to assess the long-term implications of genetically modified organisms for forest ecosystems.
