Logging intensity impact on small oak seedling survival and growth on the Cumberland Plateau in northeastern Alabama
Abstract
Ground disturbance caused by forest harvest operations can negatively impact oak regeneration. On the Cumberland Plateau, for successful regeneration, managers often must rely on very small (less than a ft in height) oak advance reproduction that is susceptible to disturbance by harvesting equipment. Furthermore, sites on the Plateau top are often harvested when conditions are too wet to permit operations elsewhere, increasing the risk to small seedlings that may be more easily pulled from the moist soil. This study was designed to assess the effect of unrestricted and restricted harvesting equipment traffic on small oak advance reproduction under a clearcutting prescription. A feller-buncher and grapple skidding were used to harvest sites under "free access," resulting in unrestricted traffic on the sites, or under "trail access," with restricted site traffic. Six hundred eighty-seven oak seedlings were permanently tagged (preharvest); species, height, and basal diameter were recorded and have been remeasured 1, 2, and 8 years postharvest. Fifty-two percent of the tagged seedlings survived after 8 years. The survival rate for seedlings exposed to restricted traffic did not differ from that for seedlings exposed to unrestricted traffic. No evidence of seedlings being pulled out of the ground was observed. After three growing seasons, there was no significant difference in visual site disturbance between the two treatments. After eight growing seasons, the status of the reproduction suggests that little damage was incurred under unrestricted equipment traffic.