摘要：Application of herbicide to reduce competing brush and hardwood species is a common silvicultural activity in young loblolly pine (Pinus taeda) stands. A reduction in competition generally increases the amount of available resources to the loblolly pine crop trees thereby increasing foliage biomass, fascicle dimensions, and foliar nutrient concentrations. To what extent herbicide application and competition control alters these foliar characteristics in mid-rotation stands has rarely been reported. The purpose of this paper is to evaluate whether the application of herbicide alters the morphology, mass, and/or nitrogen concentration of mid-rotation loblolly pine foliage. We aerially applied an imazapyr herbicide to 6 study plots within each of four mid-rotation stands in Louisiana and Arkansas. Another 6 plots in each stand were untreated and served as a control Average fascicle length, fascicle mass, and foliage nitrogen concentrations in the herbicided-treated plots did not significantly differ from that in the control plots. However, foliage concentrations and fascicle size one year after herbicide application were greatest in plots with the greatest competing vegetation mortality.
