The Scientific World Journal

The Scientific World Journal / 2001 / Article
Special Issue

Optimizing Nitrogen Management in Food and Energy Production and Environmental Protection: 2nd International Nitrogen Conference 2001

View this Special Issue

Research Article | Open Access

Volume 1 |Article ID 197057 | 8 pages |

Nitrate in Polluted Mountainous Catchments with Mediterranean Climates

Academic Editor: Joe Wisniewski


The mountains of southern California receive some of the highest rates of nitrogen (N) deposition in the world (~40 kg ha�1 year�1). These high rates of deposition have translated into consistently high levels of nitrate (NO3�) in some streams of the San Bernardino Mountains. However, not all streams are exhibiting these high levels of NO3�. Perennial streams have high NO3� concentrations (~200 [ ]moles l�1) while ephemeral streams do not (~20 [ ]moles l�1). This difference points to groundwater as the source of the NO3� observed in streams. Furthermore, the evidence indicates a differential impact of N deposition on terrestrial and aquatic systems in Mediterranean climates, with aquatic systems being impacted more quickly. The primary reason for this difference involves the asynchrony between the time that atmospheric deposition occurs (summer), the time period of maximum soil NO3� availability and leaching (winter), and the time of maximum plant N demand (spring). Our results indicate that semiarid Mediterranean climate systems behave differently from more humid systems in that, because of this asynchrony, aquatic systems may not be indicative of changes in terrestrial ecosystem response. These differences lead us to the conclusion that the extrapolation of impacts from humid to Mediterranean climates is problematic and the concept of N saturation may need to be revisited for semiarid and seasonally dry systems.

More related articles

51 Views | 210 Downloads | 8 Citations
 PDF  Download Citation  Citation
 Order printed copiesOrder

Related articles

We are committed to sharing findings related to COVID-19 as quickly and safely as possible. Any author submitting a COVID-19 paper should notify us at to ensure their research is fast-tracked and made available on a preprint server as soon as possible. We will be providing unlimited waivers of publication charges for accepted articles related to COVID-19. Sign up here as a reviewer to help fast-track new submissions.