Blue oak stump sprouting evaluated after firewood harvest in northern Sacramento Valley

Abstract

Colifornia's hardwood rangelands, an oak-dominated woodland system, cover 10 million acres. More than 80% of these lands are privately owned, with two-thirds grazed by domestic livestock. Public concerns about long-term damage to habitat in areas harvested for firewood — particularly in the northern Sacramento Valley — led to this study of resprouting, to assess long-term trends in oak cover following harvesting and the potential of sprout (coppice) management to sustain woodlands. In field surveys on 103 sample plots at 19 ranches where oak firewood was harvested, we found that 54% of all oak stumps resprouted. Stump diameter, herbicide application, overstory crown cover percentage, and slope and aspect were significant variables in models developed to assess the probability of stump sprouting. Ten-year sprout height and crown growth models were developed, and livestock grazing, residual overstory canopy, herbicide treatment and stump diameter were found to be significant variables. These models can be used to predict stand development following firewood harvest and can be integrated with forage growth, wildlife habitat and residual tree growth models.