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 CBD in the mid-storey (3–7 m) and a decrease in CBD in 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.

中文翻译：

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规定燃烧和野火对新泽西松林国家保护区激光雷达估计森林结构的影响

规定的燃烧是一种常见的土地管理工具，用于减少燃料、模拟野火的影响并增加易发生火灾的生态系统的异质性。然而，由规定燃烧产生的森林结构很可能与野火产生的森林结构不同。我们使用来自激光雷达数据的冠层容积密度 (CBD) 的三维估计来探索美国新泽西松林国家保护区的火灾类型、燃烧次数和燃料结构/森林结构之间的关系。我们发现，在先前规定的火灾地区，随着火灾数量的增加，下层（1-2 m）的CBD值略有下降，而上层冠层（15-23 m）的CBD值较高，≥4火灾，尽管这些差异在统计上并不显着。然而，越来越多的野火与中间层（3-7 m）的CBD在统计上显着增加和冠层（≥8 m）的CBD减少有关。这些结果对森林资源管理者具有重要意义，因为它们表明规定的燃烧减少了导致火炬和树冠火灾的阶梯燃料，但它并没有复制野火造成的结构。