Dr. William Russell found that the negative effects of timber harvesting in riparian coast redwood forests lessen with respect to two conditions; (1) longevity of the forest and (2) wider no-cut buffer zones. Longer-lived forests and forests with wider buffer zones surrounding rivers show less harm from logging. Riparian buffers are strips of forest left on either side of rivers after logging that control the amount of sediment and nutrients filtering into the water. In recently harvested forests and ones with thin or no buffers, young tree crowns crowd the canopies, letting through less sunlight, deciduous hardwoods thrive, extra dead wood litters the forest floors, and exotic and disturbance-prone understory species invade. These alterations, in addition to affecting the physical structure of rivers, down the line cause higher levels of organic material to filter into them. Learn more about this research.