Biodiversity, But Not Community Composition, Surprisingly Stable Over Time

A major turnover of species in habitats around the globe is underway, resulting in the creation of novel biological communities, but overall species diversity is much more stable than scientists had believed, according to a new report in the journal Science. In a survey of 100 long-term biodiversity monitoring projects in a variety of habitats around the world, the authors found that the majority of those studies (59 percent) documented increasing species richness. Biodiversity declined in 41 percent of the studies, but, in all cases the overall change in biodiversity was modest, the researchers said. When looking at changes in the species constituting those communities, however, the researchers found a surprisingly high rate of change — an average of about 10 percent change per decade. “A main policy application of this work is that we’re going to need to focus as much on the identity of species as on the number of species,” one of the study’s authors said. “The number of species in a place may not be our best scorecard for environmental change.”