Habitat‐Specific Solute Retention in Two Small Streams: An Intersite Comparison

作者：Nancy L. Munn, Judy L. Meyer · 发表于：Ecology · 年份：1990 · DOI：10.2307/1938621 · 被引用次数：173 · 研究领域：Soil and Water Nutrient Dynamics、Fish Ecology and Management Studies、Freshwater macroinvertebrate diversity and ecology

We measured uptake rates of phosphorus, nitrate, calcium, and dissolved organic carbon within two headwater streams, one in the Appalachian mountains of North Carolina and the other in the Cascade range of Oregon. The major physical differences between these two streams are parent geology and local geomorphic structure. Uptake rates were measured following low—level nutrient releases during summer 1987 in 20—m reaches with different geomorphology. The relative importance of biotic vs. abiotic sorption of nitrogen and phosphorus by sediments from the two streams was assessed by laboratory experiments. Nitrate—N uptake rates were high for the western stream (11.9 mg°m—2°min—1) and low for the eastern stream (3.9 mg°m—2°min—1) during the summer. The debris dam reaches in Oregon were the most retentive of N (shortest uptake length of 17 m). Conversely, soluble reactive phosphorus (SRP) uptake rates were higher for the eastern stream (18.6 mg°m—2°min—1), primarily through biotic processes. SRP uptake lengths were short for the cobble (32 m), debris dam (35 m), and rock outcrop (40 m) reaches in the eastern stream. Uptake of SRP in either stream was not related to sediment size fraction but rather to a combination of sediment infiltration rates and quality of organic material. Calcium (Ca) uptake lengths were long in the Oregon stream (1278 m) but short in the Appalachian stream (106 m). Surprisingly, the eastern stream was more retentive of Ca than nitrate (shorter uptake lengths ...