Effect of Prescribed Burning on the Ectomycorrhizal Infectivity of a Forest Soil

Abstract

Ectomycorrhizae formation, seedling health index, and seedling survival were assessed for two-year-old nursery-grown seedlings of Pinus resinosa and Pinus strobus two months after planting in clear-cuts that had received prescribed burning under different fire intensities. Controls consisted of seedlings planted in unburned clear-cuts. Fire intensity positively correlated with percent ectomycorrhizal roots for P. strobus but not for P. resinosa. Seedling health index and survival were highest in burned-over sites as compared to control sites for both pine species. Fire intensity correlated with seedling health index for P. strobus but not for P. resinosa. Fire intensity correlated with seedling survival for both species. Colonization of seedlings by ectomycorrhizal fungi did not correlate with seedling health index or seedling survival. P. resinosa seedlings planted in burned-over sites had a smaller number of lateral roots per unit length primary/secondary roots compared to seedlings planted in control plots.