The influence of prescribed burning and wildfire on lidar-estimated forest structure of the New Jersey Pinelands National Reserve

Abstract

Prescribed burning is a common land management tool used to reduce fuels, emulate the effects of wildfire and increase heterogeneity in fire-prone ecosystems. However, the forest structure created by prescribed burning is likely to be dissimilar to that produced by wildfire. We used three-dimensional estimates of canopy bulk density (CBD) from lidar data to explore the relationship between fire type, number of burns and fuel structure/forest structure in the New Jersey Pinelands National Preserve, USA. We found that in areas of previous prescribed fires, as the number of fires increased, the understorey (1–2 m) exhibited a slight decrease in CBD, while the upper canopy (15–23 m) had higher values of CBD for ≥4 fires, though these differences were not statistically significant. However, an increasing number of wildfires was associated with a statistically significant increase in CBDin the mid-storey (3–7 m) and a decrease inCBDin the canopy (≥8 m). These results have important implications for forest resource managers because they indicate that prescribed burning reduces ladder fuels that lead to torching and crown fires, but it does not replicate the structure created by wildfire.

Citation

Warner, Timothy A.; Skowronski, Nicholas S.; La Puma, Inga. 2020. The influence of prescribed burning and wildfire on lidar-estimated forest structure of the New Jersey Pinelands National Reserve. International Journal of Wildland Fire. 29(12): 1100-1108. https://doi.org/10.1071/WF20037.