How Was Silviculture Modeled?
Silvicultural activities can degrade water and habitat quality if sufficient care is not taken to prevent adverse effects. Sediment from erosion due to the presence of access roads and harvesting activities, temperature increases due to riparian shade removal, and pesticides and fertilizers used during timber operations are some of the major pollutants exported from timber-harvesting sites to receiving waters. The methodology used to estimate the costs of controlling NPS pollution from silvicultural activities employed the following components: • Develop estimates of annual forestland area harvested per State. The area of forestland harvested annually was computed by using the U.S. Forest Service’s Forestry Resources of the United States, 1992. The distribution of the timberland area in relation to the type of terrain, however, was developed by considering the geographical characteristics of each State. Only privately owned forestlands were considered (Federal lands are ineligible for
