Box and whisker plots of nitrate uptake velocity (ʋ_f) in the buried and open reaches in Cincinnati, Ohio and Baltimore, Maryland, as reported in Beaulieu et al. [20] and Pennino et al. [21].

<p>Literature data were derived from a recent survey of 72 streams spanning several biomes and land-use conditions [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132256#pone.0132256.ref016" target="_blank">16</a>]. Plots display 10^th, 25^th, 50^th, 75^th, and 90^th percentiles and individual data points outside the 10^th and 90^th percentiles. Nitrate uptake velocity was 13 times greater in open than buried reaches (p<0.001, paired <i>t</i>-test).</p

Results of simulation scenarios involving an even distribution of burial across the watershed with incremental increases of 5%.

<p>The primary y-axis and solid line represent the average volumetric NO₃^- uptake rate among in the open reaches. The secondary y-axis and dashed line represent total NO₃^- uptake in the open reaches.</p

Percent change in nitrate export in response to stream burial simulation scenarios.

<p>The simulation scenarios involve an even distribution of burial across the watershed with incremental increases of 5% and include: 1) Allowing both uptake rate constants and water velocities to change in response to burial (Combined response); 2) Allowing water velocity to change following burial, but holding uptake rate constants at open reach values; and 3) Allowing uptake rate constants to change following burial, but holding water velocities at open reach values.</p

Stream burial is an extreme, but ubiquitous, consequence of urbanization in stream ecosystems.

<p>The buried stream channels in the cited studies were constructed from various materials including (a) a cement-lined corrugated metal pipe in Baltimore, Maryland (USA), (b) a concrete tunnel in Cincinnati, Ohio (USA), and (c) a corrugated metal pipe in Cincinnati.</p