The article, by Matthew Sturm of the U.S. Army Cold Regions Research and Engineering Laboratory-Alaska and seven coauthors, notes that the evidence for increasing shrub abundance--including historical photographs-- is most comprehensive in northern Alaska. Information from other arctic regions supports the idea, however. Sturm's group argues that observations indicate that shrubs encourage deeper snowdrifts, which warm the soil below, preventing some subsurface water from freezing even during winter. This effect alters and boosts the winter activity of subsurface soil bacteria and fungi that provide accessible nutrients for shrubs, notably nitrogen. As a result, shrubs grow more rapidly, and so the spread continues.
Journalists may obtain a copy of the article by contacting Donna Royston, AIBS communications representative, at droyston@aibs.org . BioScience publishes commentary and peer-reviewed articles covering a wide range of biological fields. 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 89 member societies and organizations with a combined membership of about 240,000.
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