Effect of impervious surface percentage within 500 m on the abundance and species richness of bees.

<p>A. Abundance of bees (filled circles = 2011, open circles = 2012); B. Species richness of bees (filled circles and full line = 2011, open circles and dashed line = 2012). Model for species richness  =  Impervious surface (Year) + Impervious surface<sup>2</sup> (Year).</p>