Genetically modified poplars in context

Poplars (genus Populus) have emerged as a model organism for forest biotech nology, and genetic modification (GM: asexual gene transfer) is more advanc ed for this genus than for any other tree. The goal of this paper is to con sider the benefits expected from the use of GM poplar trees, and the most s ignificant claims made for environmental harm, by comparing them to impacts and uncertainties that are generally accepted as part of intensive tree cu lture. We focus on the four traits with greatest commercialization potentia l in the near term: wood modification, herbicide tolerance, insect resistan ce, and flowering control. After field trials and selection of the top perf orming trees, similar to that during conventional poplar breeding, GM popla rs appear vigorous and express their new traits reliably. The ecological is sues expected from use of GM poplars appear similar in scope to those manag ed routinely during conventional plantation culture, which includes the use of exotic and hybrid genotypes, short rotations, intensive weed control, f ertilization, and density control. The single-gene traits under considerati on for commercial use are unlikely to cause a significant expansion in ecol ogical niche, and thus to substantially alter poplar's ability to "invade" wild populations. We conclude that the ecological risks posed by GM poplars are similar in magnitude, though not in detail, to those of routine poplar culture. We also argue that the tangible economic and environmental benefi ts of GM poplars for some uses warrant their near-term adoption-if coupled with adaptive research and monitoring-so that their economic and ecological benefits, and safety, can be studied on commercially and ecologically rele vant scales. We believe that the growing demand for both wood products and ecological services of forests justifies vigorous efforts to increase wood production on land socially zoned for tree agriculture, plantations, or hor ticulture. This is the key reason for poplar biotechnology: the combination of economic efficiency with reduction of farm and forestry impact on the l andscape.