Effects of Crown Scorch on Longleaf Pine Fine Roots

Photosynthate production is reduced by foliage loss. Thus, scorch-induced decreases in the leaf area of longleaf pine (Pinus palustris Mill.) may reduce photosynthate allocation to roots. In this investigation the root carbohydrate concentrations and dynamics of longleaf pine after two intensities of prescribed burning were monitored. In September 1996, 65-year-old longleaf pine were burned. Plots of 10 trees were established in two patches each of nonscorched and scorched trees. Root carbohydrate concentrations and dynamics were monitored May 1997 through December 1998. Root sucrose and starch concentrations were lower on the scorched plots than on the nonscorched plots. One year after burning, fine root mass density and secondary root development were reduced in response to orown scorch. These results indicate that prescribed fires that cause crown scorch may reduce photosynthate allocation to roots. Further research is needed to determine the impact of fire intensity on root system growth and function.