New Zealand Journal of Forestry (1977) 22(1): 53–63
©New Zealand Institute of Forestry
Impact of timber harvasting on nutrient losses in stream flow
Timber harvesting involves four operations which can seriously affect stream quality: (J) Road construction; (2) felling; (3) skidding and yarding; and (4) site preparation prior to re-establishment. The degree to which water quality is altered depends on the vegetation type, climate, soils, geology, topography, and (most importantly) the management of the harvesting operations. This paper reviews eight studies in the United States which have investigated the effects of timber harvesting on nutrient outputs in stream flow. These studies cover a considerable range of soils, topography, vegetation, and climate. They support the premise that well planned and managed logging operations produce only small increases of nutrient outputs in stream flow. Extreme nutrient losses, such as those reported in the Hubbard Brook study, should be viewed as the exception rather than the general rule. Planning and supervision of logging operations must be of a high standard if forest lands are to maintain the production of both wood and high quality water.