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.
