An Evaluation of Some Effects of Bole and Branch Pulpwood Harvesting on Site Macronutrients

Macronutrient removals by conventional and bole and branch harvesting systems were evaluated on a mixed hardwoods site in north central Wisconsin. Samples indicate that minimum soil reserves of nitrogen, phosphorous, and magnesium are 5–15 times greater than the amounts removed by a harvest cut at the end of a 45-year rotation. Currently available reserves of potassium and calcium are 1–3 times greater than harvest removals. Estimates indicate that natural inputs will supplement these reserves over such rotations, but may not balance drains over substantially shorter rotations. Nutrient cycling and possible replenishment of elements are discussed along with silvicultural implications.