Removal of logging waste, thinning debris, and litter from a Pinus radiata pumice soil site

After felling of the first crop of Pinus radiata D. Don on rhyolitic pumice soil, an area was cleared of all logging debris. During the ensuing 16 years of the second P. radiata crop all litter material, including that of a pre-commercial thinning, was raked off this area regularly. Just prior to a late second-thinning at age 16 (from c. 1000 to 250 stems/ha) the impact of this treatment on stand productivity, foliar nutrient, and soil properties was examined. It was estimated, using stem analysis procedures, that the raked area contained 471 m3 total stem wood/ha compared to 535 m3/ha in a control area-a reduction in productivity of some 12%. This was considered a real difference as basal areas were identical in the two areas at age 6 years. Analysis of the current year's foliage prior to thinning showed that the only nutrient significantly lower in the raked area was boron- 7.2 ppm compared to 10.6 ppm for the control area. In addition to boron, potassium and manganes