Changes in Nitrogen Cycling at an Old-Growth Douglas-fir Site After Disturbance
1981
Sollins, P. | Cromack, K. | Mc Corison, F. M. | Waring, R. H. | Harr, R. D.
Effects of disturbance on the N cycle in a 450-year-old Douglas-fir stand (Pseudotsuga menziesii) were studied in an experiment in which herbicides were used to kill all vegetation while minimally disturbing the litter layer and soil. Nitrogen concentration in falling foliage was greater on the treated area than on a control area, as was soil moisture. Nitrate and Kjeldahl N concentrations in the soil solution were greater on the treated than on the untreated area, but only at or below the bottom of the rooting zone (≥1-m depth). On the untreated area, nitrate was present in solution in significant amounts only at the 2-m depth.
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