Forest pests accumulating despite regulations

Nonindigenous insects and pathogens continue to become established in US forests with regularity despite regulations intended to prevent this, according to a study published in the December 2010 issue of BioScience.

The study, by a team led by Juliann E. Aukema of the National Center for Ecological Analysis and Synthesis in Santa Barbara, California, found that nonindigenous insects are being newly detected in US forests at a rate of about 2.5 per year, and high-impact insects and pathogens that cause significant effects in forests, including tree death, are being newly detected every 2 to 2.5 years. The rate of detection of harmful forest invaders seems to have increased in the past two decades.

Nonindigenous insects and pathogens have profound effects on US forests and inflict high costs on society, including direct market losses to the nursery and timber industries, the costs of control and eradication, and the loss of nonmarket benefits, including wildlife habitat and carbon sequestration. In the case of one notorious example, the emerald ash borer, the cost to municipalities over the next 10 years is estimated to be close to $10 billion for landscape tree treatment or removal. This pest threatens native ash species across North America.

The researchers analyzed 455 insect species, of which 62 were considered high-impact, to arrive at their conclusions. Sap-feeding insects dominated the list of non-indigenous insects, especially aphids, adelgids, and scale insects. New nonindigenous sap feeders and foliage feeders have historically been detected more frequently than insects that bore into phloem or wood, the researchers found, although wood- and phloem-borers have increased markedly in recent decades.

Increased trade and travel probably explain why invaders keep arriving despite regulatory efforts, Aukema and her coauthors believe. They advocate strengthening broad-based efforts to prevent arrivals of nonindigenous organisms, because such efforts are much more effective than attempts to eradicate arrivals that have become established. But enhanced efforts to detect newly arrived forest insects could also help, the researchers maintain.

By noon EST on 6 December 2010 and until early January, the full text of the article will be available for free download through the copy of this press release available at www.aibs.org/bioscience-press-releases/.

BioScience, published 11 times per year, is the journal of the American Institute of Biological Sciences (AIBS). BioScience publishes commentary and peer-reviewed articles covering a wide range of biological fields, with a focus on “Organisms from Molecules to the Environment.” The journal has been published since 1964. AIBS is an umbrella organization for professional scientific societies and organizations that are involved with biology. It represents some 200 member societies and organizations with a combined membership of about 250,000.

The complete list of peer-reviewed articles in the December 2010 issue of BioScience is as follows:

Self-organization, Natural Selection, and Evolution: Cellular Hardware and Genetic Software.

Brian R. Johnson and Sheung Kwan Lam

Historical Accumulation of Nonindigenous Forest Pests in the Continental United States.

Juliann E. Aukema, Deborah G. McCullough, Betsy Von Holle, Andrew M. Liebhold, Kerry Britton, and Susan J. Frankel

Ecohydrology of Terrestrial Ecosystems.
Paolo D'Odorico, Francesco Laio, Amilcare Porporato, Luca Ridolfi, Andrea Rinaldo, and Ignacio Rodriguez-Iturbe
The River Discontinuum: Applying Beaver (Castor canadensis) Modifications to Baseline Conditions for Restoration of Forested Headwaters.

Denise Burchsted, Melinda Daniels, Robert Thorson, and Jason Vokoun

Empowering 21st Century Biology.
Gene A. Robinson and colleagues
Evolution of Collaboration within the US Long Term Ecological Research Network.
Jeffrey C. Johnson, Robert R. Christian, James W. Brunt, Caleb R. Hickman, and Robert B. Waide
Are Gray Wolves Endangered in the Northern Rocky Mountains? A Role for Social Science in Listing Determinations.

Jeremy T. Bruskotter, Eric Toman, Sherry A. Enzler, and Robert H. Schmidt