AN ECOLOGICALLY BASED APPROACH TO OAK SILVICULTURE: A SYNTHESIS OF 50 YEARS OF OAK ECOSYSTEM RESEARCH IN NORTH AMERICA

oak (quercus l.) is an abundant and widely distributed genus in eastern north america. a history of periodic fire, grazing, canopy disturbance and timber harvesting has favored oak’s dominance. but, changes in this regime toward much less fire or complete fire suppression, and selective cutting are causing the successional replacement of oak. high populations of forest herbivores such as white- tailed deer (odocoileus virginianus), invasive species such as gypsy moth (lymantria dispar), or dominance of native flora such as mountain laurel (kalmia latifolia) can also inhibit oak regeneration and add to its loss within a region. successful oak regeneration is dependent on having an adequate number of large oak advance reproduction before stand regeneration. however, this prerequisite is often lacking in eastern oak for ests. many oak stands have either few or no oak advance reproduction, and when present, it is small and noncompetitive. these common situations can be addressed through silviculture. the lack of oak seedlings in older, mature stands is addressed with a three-stage shelterwood method that promotes acorn production and site preparatory burning that increases acorn germination success. in younger, i.e., sapling and pole stands, crop tree thinning to release co-dominant oaks promotes crown development and future acorn production. the lack of competitive-sized oak reproduction is addressed with a two – or three – stage shelterwood sequence because this method is very useful for providing adequate light to foster root development of the shade intolerant oak seedlings. application of the shelterwood method often includes herbicides or prescribed fire to control competing vegetation either before or after the final overstory removal. when adequate oak advance reproduction is present, then clearcutting is a viable option, but measures may be needed after harvesting to control competing vegetation. prescribed fire applied several times after final removal of the