DYNAMICS OF ADDED NITRATE AND PHOSPHATE COMPARED IN A NORTHERN CALIFORNIA WOODLAND STREAM1 |
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Authors: | Michael J. Sebetich Vance C. Kennedy S. Marc Zand Ronald J. Avanzino Gary W. Zellweger |
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Affiliation: | 1. Sebetich, Associate Professor, Dept. of Biology, William Paterson College, 300 Pompton Rd., Wayne, New Jersey 07470;2. Kennedy, Avanzino, and Zellweger, U.S. Geological Survey, Water Resources Division, 345 Mlddlefield Road, Menlo Park, California 94025;3. and Zand, Stanford Linear Acclerator, BIN 8A, P.O. Box 4349, Stanford, California 94305. |
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Abstract: | ABSTRACT: Injections of NO3 and PO4 were made during September 1975 into Little Lost Man Creek, a small pristine stream in Redwood National Park, California. Chloride, a conservative constituent, was added in a known ratio to the nutrients. Nutrient loss at a downstream point was calculated using concentration of added Cl as a reference. Nitrate nitrogen (NO3-N), added for 4 h, reached 920 μg/1 (above 5 μg/1 background) just below the injection point, but increased only to 405 μg/1 at 310 m downstream. The concentration decrease was attributed to dispersion and to uptake by stream biota. Percent of NO3-N lost decreased with increasing concentration of NO3-N. Phosphate phosphorus (PO4-P) was added a week after the NO3-N for 3 h, causing a concentration increase of 296 μg/1 (above 13 μg/1 background) just below the injection point, of 161 μg/1 at 90 m downstream, and of 98 μg/1 at 310 m. Percent loss of PO4-P at downstream sites increased with increasing PO4-P concentration and also for a short period after peak concentration occurred, but then decreased as PO4-P concentration continued decreasing. Differences in stream response to added NO3-N and PO4-P are attributed to differing rates of reaction with biota and differing degrees of interaction with abiotic stream solids. |
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Keywords: | KEY TERMS: small streams nitrate transport phosphate transport water sediment interactions water biota interactions nutrient cycling. |
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