Genetically Engineered Trees: Promise and Concerns

Transgenic trees offer potential solutions to a number of forestry problems, yet the regulatory history for these trees in the United States is very short, explains RFF scholar Roger Sedjo in his new report, Genetically Engineered Trees: Promise and Concerns. The report focuses on the implementation of the Plant Protection Act and related regulations as the Act has been applied to transgenic trees.

Timber sources in the United States and throughout the world have evolved in recent decades, so that by the end of the 20th century, plantation forests accounted for about one-third of harvested industrial wood globally.

In addition to providing wood at a lower cost, these high-yield planted forests have the potential desirable environmental side effect of drawing timber harvests away from natural and old-growth forests.

While still in its infancy, forest biotechnology offers the opportunity to take plantation forests to the next level, giving great promise of providing for the expression of desired traits, and thereby increasing productivity and product quality, and expanding the range and types of land and climatic conditions under which production forests can thrive.

Yet, Sedjo comments, "just as in agriculture, biotechnology and transgenics are controversial topics in forestry."

In order to assess the safety of and environmental impacts of transgenics, including trees, the United States has a complex regulatory system in place under the Plant Protection Act. To date, only one tree- an orchard tree- has achieved deregulated status. No timber tree, where many of the benefits cited by Sedjo would derive, has passed through the system.

"Transgenic trees could increase the productivity of industrial wood, and benefit the environment by taking the pressure off of old-growth and natural forests," Sedjo notes. Potential benefits of transgenics in plantation forests include:

• Increased productivity, including changing wood fibers to either increase their volume or make them more amenable to processing necessary to convert wood fiber into wood pulp, used in paper production;
• Restoration of certain diseased or damaged tree species, for example, transferring a gene from the disease-resistant Chinese chestnut to the virtually decimated American chestnut;
• Toxic cleanup and bioremediation, by creating trees to remove heavy metals and other toxics from contaminated soils in places where other forms of cleanup are prohibitively expensive.

Despite these and other potential benefits, trees make up only a small portion of plants tested for deregulation, although the number has increased dramatically in recent years, along will total number of plants. The United States accounts for an estimated 61 percent of worldwide tree trials, yet the fruit tree papaya is the only transgenic tree of any kind to achieve deregulation to date. No other trees of any type appear ready for imminent deregulation in the United States. Worldwide, there are no documented transgenic timber trees that have been commercially released.

According to consistent health and environmental law principles in the United States, products introduced into commerce should either be safe or present no unreasonable risk to humans or the environment. Risks include the ability to harm other plants, potential to become a weed, and potential changes in cultivation that might accompany adoption of the transgenic.

Products of biotechnology do not always fit into the lines the law has drawn, which are based on the historical function and intended use of the products. Trees do not fit neatly into the common models of deregulation established by the Animal and Plant Health Inspection Service of the Department of Agriculture. Certain concerns are not relevant, as traditional health and safety issues related to food ingestion are largely absent with wood fiber; concerns about trees are mostly environmental. Trees also have a longer life span than other plant species, and therefore the timeline and guidelines for testing must be adjusted.

"In order to ensure that transgenic trees are being considered adequately and appropriately for deregulation under the Plant Protection Act, a greater understanding of the operation of the regulatory system as applied to trees is needed," Sedjo remarks.  

"As forestry undoubtedly continues its transition from harvesting natural forests to tree cropping, the potential of plant improvements to generate social and economic benefits increases. The United States must ensure that its standards for assessment and deregulation are effective and efficient in order to maximize the potential benefits of this technology."