Management impacts on nutrient fluxes in beech-podocarp-hardwood forests
- N.R.A.C. Post-Doctoral Research Fellow, Forest Research Institute, Rotorua, New Zealand
- Scientists, Forest Research Institute, P.O. Box 31-011, Christchurch, New Zealand
Clear felling and downhill skyline extraction of pulpwood and sawlogs in forest dominated by Nothofagus truncata/Dacrydium cupressinum/Weinmannia racemosa in the Maimai Catchment, N. Westland, New Zealand, followed by slash burning, produced greatly increased streamflow yields of N, P, Na, Mg, Ca and K. Streamflow nutrient concentrations were within drinking water quality limits, except for NH4-N which was over 0.5 mg/l in the first 12 hr (before dilution with water from other catchments). K loss was 5% of readily available K (but less than 0.1% of total K capital in forest and soil), which is higher than any reported in the literature; steep terrain, the concentration of crown material near the stream, a hot burn, and 2 small storms shortly after burning are possible reasons for the high loss. The risk of significant eutrophication downstream appears to be small.