Impact of prescribed burning on blanket peat hydrology
Impact of prescribed burning on blanket peat hydrology
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DOI：
10.1002/2014wr016782
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发表时间：
2015-08
影响因子：
5.4
通讯作者：
J. Holden;S. Palmer;K. Johnston;C. Wearing;B. Irvine;L. Brown
中科院分区：
文献类型：
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作者：
J. Holden;S. Palmer;K. Johnston;C. Wearing;B. Irvine;L. Brown
众所周知，火会影响土壤性质和水文流动路径。然而，人们对规定的植被燃烧对毛毯泥炭地水文的影响知之甚少。我们研究了10个毛毯泥炭源头集水区。其中5人接受规定的焚烧，5人为未焚烧的对照组。在烧毁的集水区内，我们研究了在测量开始之前最后一次烧伤发生在∼2(B2)、4(B4)、7(B7)或大于10年(B10+)的地块。将这些数据与对照流域中相似地形湿度指数位置的样地进行了比较。经过规定植被焚烧的地块比未焚烧的地块的地下水位明显更深(平均差异为5.3厘米)，地下水位的变异性更大。不同烧伤年龄组(B2>；B4>；B7>；B10+)的地下水位差异有统计学意义，而B10+地下水位与非烧伤对照组无显著差异。在烧焦泥炭上的陆流比在未烧焦泥炭上要少，分别占所有径流捕集器访问的9%和17%。在燃烧的集水区，风暴滞后时间和过程线退缩肢体周期显著较长(分别为∼1和13h)，但对于最大的20%的风暴样本，燃烧的和未燃烧的集水区之间的风暴滞后时间没有显著差异。对于最大的20%的风暴，烧毁的集水区的过程线强度显著大于未烧毁的集水区(平均值分别为4.2×10−5和3.4×10−5 S−1)，表明对规定的燃烧具有非线性的径流响应。总而言之，从样地到整个河流流域的这些结果表明，规定的植被焚烧在一定的空间尺度上对沼泽泥炭地水文有重要影响。
Fire is known to impact soil properties and hydrological flow paths. However, the impact of prescribed vegetation burning on blanket peatland hydrology is poorly understood. We studied 10 blanket peat headwater catchments. Five were subject to prescribed burning, while five were unburnt controls. Within the burnt catchments, we studied plots where the last burn occurred ∼2 (B2), 4 (B4), 7 (B7), or greater than 10 years (B10+) prior to the start of measurements. These were compared with plots at similar topographic wetness index locations in the control catchments. Plots subject to prescribed vegetation burning had significantly deeper water tables (difference in means = 5.3 cm) and greater water table variability than unburnt plots. Water table depths were significantly different between burn age classes (B2 > B4 > B7 > B10+) while B10+ water tables were not significantly different to the unburnt controls. Overland flow was less common on burnt peat than on unburnt peat, recorded in 9% and 17% of all runoff trap visits, respectively. Storm lag times and hydrograph recession limb periods were significantly greater (by ∼1 and 13 h on average, respectively) in the burnt catchments overall, but for the largest 20% of storms sampled, there was no significant difference in storm lag times between burnt and unburnt catchments. For the largest 20% of storms, the hydrograph intensity of burnt catchments was significantly greater than those of unburnt catchments (means of 4.2 × 10−5 and 3.4 × 10−5 s−1, respectively), thereby indicating a nonlinear streamflow response to prescribed burning. Together, these results from plots to whole river catchments indicate that prescribed vegetation burning has important effects on blanket peatland hydrology at a range of spatial scales.