Coates T Adam, Chow Alex T, Hagan Donald L, Waldrop Thomas A, Wang G Geoff, Bridges William C, Rogers Mary-Frances, Dozier James H
J Environ Qual. 2018 Jan;47(1):170-176. doi: 10.2134/jeq2017.02.0055.
Understanding the relationship between fire intensity and fuel mass is essential information for scientists and forest managers seeking to manage forests using prescribed fires. Peak burning temperature, duration of heating, and area under the temperature profile are fire behavior metrics obtained from thermocouple-datalogger assemblies used to characterize prescribed burns. Despite their recurrent usage in prescribed burn studies, there is no simple protocol established to guide the orientation of thermocouple installation. Our results from dormant and growing season burns in coastal longleaf pine ( Mill.) forests in South Carolina suggest that thermocouples located horizontally at the litter-soil interface record significantly higher estimates of peak burning temperature, duration of heating, and area under the temperature profile than thermocouples extending 28 cm vertically above the litter-soil interface ( < 0.01). Surprisingly, vertical and horizontal estimates of these measures did not show strong correlation with one another ( ≤ 0.14). The horizontal duration of heating values were greater in growing season burns than in dormant season burns ( < 0.01), but the vertical values did not indicate this difference ( = 0.52). Field measures of fuel mass and depth before and after fire showed promise as significant predictive variables ( ≤ 0.05) for the fire behavior metrics. However, all correlation coefficients were less than or equal to = 0.41. Given these findings, we encourage scientists, researchers, and managers to carefully consider thermocouple orientation when investigating fire behavior metrics, as orientation may affect estimates of fire intensity and the distinction of fire treatment effects, particularly in forests with litter-dominated surface fuels.
对于试图通过计划性火烧来管理森林的科学家和森林管理者而言，了解火灾强度与燃料质量之间的关系是至关重要的信息。峰值燃烧温度、加热持续时间以及温度曲线下的面积是通过用于描述计划性火烧特征的热电偶 - 数据记录器组件获得的火灾行为指标。尽管它们在计划性火烧研究中经常被使用，但尚未建立简单的协议来指导热电偶安装的方向。我们在南卡罗来纳州沿海长叶松（Mill.）森林的休眠季节和生长季节火烧实验结果表明，水平放置在枯枝落叶 - 土壤界面的热电偶所记录的峰值燃烧温度、加热持续时间以及温度曲线下面积的估计值，显著高于在枯枝落叶 - 土壤界面上方垂直延伸28厘米的热电偶（<0.01）。令人惊讶的是，这些测量值的垂直和水平估计值之间并未显示出强烈的相关性（≤0.14）。生长季节火烧的水平加热持续时间值大于休眠季节火烧（<0.01），但垂直值并未显示出这种差异（=0.52）。火灾前后燃料质量和深度的实地测量结果有望作为火灾行为指标的重要预测变量（≤0.05）。然而，所有相关系数均小于或等于=0.41。鉴于这些发现，我们鼓励科学家、研究人员和管理者在研究火灾行为指标时仔细考虑热电偶的方向，因为方向可能会影响火灾强度的估计以及火灾处理效果的区分，特别是在以枯枝落叶为主导地表燃料的森林中。
