Fuel composition influences fire characteristics and understorey hardwoods in pine savanna
Fuel composition influences fire characteristics and understorey hardwoods in pine savanna
复制标题
燃料成分影响松树稀树草原的火灾特性和林下硬木
DOI：
10.1111/1365-2745.12008
复制
发表时间：
2013
影响因子：
5.5
通讯作者：
W. Platt
中科院分区：
文献类型：
--
作者：
Darin P. Ellair;W. Platt
在频繁燃烧的东南部松树稀树草原的地被中的燃料包括落叶。长叶松（Pinus palustris）的易燃针叶可能会增加最高火灾温度和加热持续时间，对地被内的其他树木产生负面影响。在秋天，聚集在硬木树（如山核桃）的下层茎基部周围的易燃性较低的叶子可能会降低最高火灾温度和加热时间，从而提高火灾后的恢复能力。我们实验操纵量的松树和山核桃叶下层山核桃茎在松树稀树草原，在规定的火灾和评估燃烧的燃料和生存和再生的山核桃茎测量温度。松针增加火灾的温度和持续时间的加热相对于草本燃料和增加燃烧的山核桃叶。山核桃叶，但是，既不增加也不减少火特性相对于草本燃料。所有的山胡桃树都是通过重新发芽而幸免于难的。当没有松针时，大多数山核桃从位于地上的芽重新发芽，沿着茎在高度与温度升高呈负相关。与此相反，重新发芽只发生在地下根冠时，松针。在生长季节结束时，这种重新发芽的位置差异影响茎的大小。合成.地被燃料含有热带稀树草原树木的致热物种脱落的易燃树叶，影响当地的火灾特征和非致热下层树木的重新发芽。因此，当地的变化，在可燃燃料产生的热解物种可以工程师景观动态的其他树木在热带稀树草原。
Fuels in the groundcover of frequently burned south‐eastern pine savannas include shed leaves of trees. Flammable needles of longleaf pine (Pinus palustris) potentially increase maximum fire temperatures and durations of heating, negatively affecting other trees within the groundcover. Less flammable leaves that accumulate around the bases of understorey stems of hardwood trees such as mockernut hickories (Carya alba) in the fall potentially depress maximum fire temperatures and durations of heating, enhancing post‐fire recovery. We experimentally manipulated amounts of pine and hickory leaves beneath understorey hickory stems in a pine savanna, measured temperatures during prescribed fires and assessed combustion of fuels and survival and regrowth of hickory stems. Pine needles increased fire temperatures and durations of heating relative to herbaceous fuels and increased combustion of hickory leaves. Hickory leaves, however, neither increased nor decreased fire characteristics relative to herbaceous fuels. All hickories survived fire by resprouting. When pine needles were absent, most hickories resprouted from buds located above‐ground along the stem at heights inversely related to temperature increase. In contrast, resprouting occurred only from underground root crowns when pine needles were present. Such differences in locations of resprouts influenced sizes of stems at the end of the growing season. Synthesis. Groundcover fuels containing flammable leaves shed by pyrogenic species of savanna trees affect local fire characteristics and resprouting of non‐pyrogenic understorey trees. Thus, local variation in flammable fuels produced by pyrogenic species can engineer landscape dynamics of other trees in savannas.