The researchers said that, since soil bacteria play a fundamental role in a vast array of ecological processes, their survey constitutes an initial step in a new research pathway to understanding that role.

Biologists Noah Fierer and Robert Jackson published their findings in the Early Online Edition of the Proceedings of the National Academy of Sciences. Their work was sponsored by the National Science Foundation and the Mellon Foundation.

Fierer, a former post-doctoral scientist at Duke University, is at the University of Colorado; and Jackson is in the Department of Biology and the Nicholas School of the Environment and Earth Sciences at Duke. In their survey, Fierer and Jackson collected 98 soil samples from across North and South America. The analyses revealed large differences among the samples in terms of diversity.

The scientists then correlated that diversity with environmental factors, including latitude, temperature and soil pH. ” The factor that correlated best with diversity was the pH of the soil they were growing in.

These findings also suggest that soils with similar levels of acidity, even if those soils are thousands of miles apart, have similar bacterial communities. Jackson emphasized that, “This is really just a first step to a better understanding of what controls microbial diversity around the world.?EUR??,,????'??