Biogeochemical Budgets in a Mediterranean Catchment with High Rates of Atmospheric N Deposition – Importance of Scale and Temporal Asynchrony

摘要: In this study biogeochemical export in a set of catchments that vary from 6 ha to almost 1500 is investigated. Studying across large range scales enables us investigate the scale de- pendence and fundamental processes controlling catchment would not have been possible with more limited data set. The Devil Canyon catchment, San Bernardino Mountains, California, has some highest atmospheric N deposition rates world (40-90 kg � 1 year at crest catchment). These high translated into consistently levels NO 3 streams Mountains. However, widely varying dissolved inorganic nitrogen (DIN) concentrations export. differences are also, extent, present for organic carbon (DOC) but other species (Cl , SO 2� 4 ,C 2þ weathering products). As size increases DIN DOC first increase until area *150 then decrease as beyond size. dependence implies different spatial degrees saturation. reason effect appears be dominance flushing out soil small due temporal asynchrony between nutrient availability biological demand, ground- water exfiltration flushed intermediate removal streamflow through in-stream groundwater-surface interaction larger scales. While particular observed here may occur over same ecosystems, it likely ecosystems similar dependant DOC.