Critic’s Choice: Invasive Plants Versus Oklahoma’s Biodiversity

E. O. Wilson stated that invasive species are second only to habitat loss for reducing biodiversity, and that threat to biodiversity by invasive plants is the subject of this report. For that purpose, the standard definition of invasive species as one that causes harm to humans or other species when introduced to an ecosystem is too broad to be helpful. Under that definition, several native species are classified as invasive because they grow in cultivated fields, but biodiversity does not exist there. Even so, for this purpose, control of invasive plants in agriculture and less so at recreational sites, consumes an estimated $34.5 billion per year in the United States; whereas in natural systems only about $160 million is spent (Pimentel 2002). Herein, we are concerned with the displacement of the species in natural ecosystems.