Nitrogen Accretion in Developing Ceanothus Velutinus Stands
1976
Youngberg, C. T. | Wollum, A. G.
Nodulation, N accretion, and above-ground biomass production were investigated in Ceanothus velutinus (snowbrush) stands developing following wildfire and salvage logging in second growth ponderosa pine (Pinus ponderosa Laws) and logging and slash burning in old growth Douglas-fir stands [Pseudotsuga menziesii (Mirb.) Franco]. In the pine site 82% of the Ceanothus plants were nodulated the first year, whereas in the fir site only 42% were nodulated. Above-ground snow-brush biomass production at the end of 10 years was 48,000 and 54,000 kg/ha, respectively, for the pine and fir sites. Nitrogen accretion in biomass, litter, and soil for the 10-year period was 715 and 1,080 kg/ha, respectively, for the pine and fir sites. The higher accretion in the fir site despite slower nodulation is due to more favorable temperature and moisture conditions at the fir site than at the pine site.
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