The percent of a site that was bare soil within circles increased with circle density as well as with mean circle area, but density and area changed independently of each other.

<p>Blue symbols were derived from the Google Earth selections in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0038056#pone-0038056-g011" target="_blank">Fig. 11</a> and are labeled with the same letters as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0038056#pone-0038056-g011" target="_blank">Fig. 11</a>. Bars are 95% confidence intervals. The red symbols are values for the selections from the 2008 satellite image used for calculating life span. Because of the large number of circles in these samples, confidence intervals were too small to show. Symbol size of both colors indicates the density of circles (see legend at upper left).