Losing Stream in Our Battle to Predict and Prevent Invasive Species

ScienceDaily (Aug. 22, 2012) — Invasive species -- plants, animals, and microbes introduced to regions beyond their native range -- carry a global price tag of $1.4 trillion dollars. They are responsible for the loss of natural resources and biodiversity, damages to infrastructure, and an uptick in infectious diseases.

Not all non-native species pose a threat. Scientists around the world have spent the last several decades teasing apart the conditions that set the stage for debilitating invaders, like giant hogweed, zebra mussels, or gray squirrels. A number of hypotheses have emerged to help predict how natural areas will respond to introduced plants, animals, and microbes.

An analysis of 371 invasion studies using six dominant invasion hypotheses has revealed their predictive power is weakening. The paper's authors -- Jonathan Jeschke, Lorena Gómez Aparicio, Sylvia Haider, Tina Heger, Christopher Lortie, Petr Pyšek, and David Strayer -- found empirical support for all six hypotheses declining, with recent studies showing the lowest levels of support. Hypotheses that were too broad or omitted ecosystem interactions fared among the worst, plants proved easier to predict than animals, and, contrary to popular belief, diverse ecosystems were not inherently resistant against invaders. The study was published in the open-access journal NeoBiota.

Continued: http://www.sciencedaily.com/releases/2012/08/120822101117.htm