Research Highlights

Summary

In response to southern pine beetle recently invading pine-dominated forests in New Jersey and Long Island, New York, Forest Service scientists and their partners at Dartmouth College are studying changes in forest structure and fuel loading associated with the three major treatment alternatives used for southern pine beetle control. The scientists found that across all three treatment types basal area of live pine trees was reduced 90 percent by the southern pine beetle, while oaks and mesic hardwoods were nearly unaffected. In addition, southern pine beetle infestation rapidly reduced crown fuels in pines and shortened the amount of time that dead needles, which form hazardous fuels, were retained in the canopy. As pine trees begin to die from southern pine beetle infestation, fuel loading on the forest floor is high, but over time, understory composition becomes less flammable and hardwood fuels become dominant. Ultimately, most pine-dominated stands impacted by southern pine beetle will become dominated by hardwoods reducing future wildfire risk. Results of this research demonstrate how successional changes are accelerated in insect-impacted forests and enable researchers to update wildfire risk maps for the benefit of wildland fire managers in the region.