ISSN:
1435-0661
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Pseudotsuga menziesii (Mirb.) Franco] plantation growing with volunteer red alder (Alnus rubra Bong.). Ten years earlier, the preceding mature conifer stand was clearcut and nearly all logging slash and forest floor were consumed by slash fire. Forest floor mass in the 9-yr-old plantation averaged 9.86 Mg ha-1, with 3.71 Mg C, 98.0 kg N, 10.6 kg P, and 8.4 kg S ha-1. Mineral soils to 1-m depth averaged 176 Mg C, 8330 kg N, 3340 kg P, and 605 kg S ha-1 in the 〈2-mm fraction. The 2- to 〈6-mm soils fraction averaged an additional 100 Mg C, 4480 kg N, and 1700 kg P ha-1. Net mineralizable N as NH4 (anaerobic N mineralization index) totaled 99 kg N ha-1 in the top 45 cm of the mineral soil and 62 kg N ha-1 in the 45- to 100-cm depth. Density fractionation showed that the light fraction (〈1.65 Mg m-3 ) was only 13.4% of the fine soil mass of the 0- to 15- cm depth, yet contained about 40% of the total C and N capital in the 〈2-mm size fraction. The substantial amounts of C and nutrients in this low-bulk density soil (〈2-mm fraction, 0.30 Mg m-3) indicate a fertile soil despite large previous losses of organic matter and N from the site.
Type of Medium:
Electronic Resource
