Publication Date:
1985-08-01
Description:
Measurements were made of the transfer of N,P,K, Ca, Mg, Mn, and B to the atmosphere during low-intensity (350–600 kWm−1) prescribed burns in three Australian subalpine eucalypt forests dominated by overstoreys of either Eucalyptuspauciflora (Sieb. ex Spreng), Eucalyptusdives (Schau.), or Eucalyptusdelegatensis (R. T. Baker). Elemental transfer was calculated as the difference between the quantity of an element in the fuel (litter plus understorey) before burning and that present in the postfire residues which were recovered quantitatively using small aluminium trays. Complete recovery of fine ash is essential for accurate budgeting for elements other than N. The mass ranges of elements transferred to the atmosphere (kilograms per hectare) were as follows: N, 74–109; P, 1.96–3.04; K, 12.1–21.0; Ca, 18.7–29.7; Mg, 4.5–9.7; Mn, 1.6–4.3; B, 0.08–0.12. These transfers represented, as a percentage of the element initially present in the fuel, the following: N, 54–75; P, 37–50, K, 43–66; Ca, 31–34; Mg, 25–49; Mn, 25–43; B, 35–54. The percentage loss of elements was positively linearly correlated with the percentage loss in fuel weight. High concentrations of P and cations occur in fine ash, especially grey (mineral) ash. In comparison with unburnt litter, concentrations of Ca, Mg, and P were increased by 10- to 50-fold, 10- to 35-fold, and 10-fold in fine (
Print ISSN:
0045-5067
Electronic ISSN:
1208-6037
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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