GRAM (Grup de Recerca Ambiental Mediterrània), Department of Geography, University of Barcelona, Montalegre, 6, 08001, Barcelona, Spain.
Environmental Management Centre, Mykolas Romeris University, Vilnius, Lithuania.
J Environ Manage. 2018 Jan 15;206:625-632. doi: 10.1016/j.jenvman.2017.11.011. Epub 2017 Nov 10.
Forest management practices in Mediterranean ecosystems are frequently employed to reduce both the risk and severity of wildfires. However, these pre-fire treatments may influence the effects of wildfire events on soil properties. The aim of this study is to examine the short-term effects of a wildfire that broke out in 2015 on the soil properties of three sites: two exposed to management practices in different years - 2005 (site M05B) and 2015 (site M15B) - and one that did not undergo any management (NMB) and to compare their properties with those recorded in a plot (Control) unaffected by the 2015 wildfire. We analyzed aggregate stability (AS), soil organic matter (SOM) content, total nitrogen (TN), carbon/nitrogen ratio (C/N), inorganic carbon (IC), pH, electrical conductivity (EC), extractable calcium (Ca), magnesium (Mg), sodium (Na), and potassium (K), microbial biomass carbon (C) and basal soil respiration (BSR). In the managed plots, a clear-cutting operation was conducted, whereby part of the vegetation was cut and left covering the soil surface. The AS values recorded at the Control site were significantly higher than those recorded at M05B, whereas the TN and SOM values at NMB were significantly higher than those recorded at M05B. IC was significantly higher at M05B than at the other plots. There were no significant differences in C/N ratio between the analyzed sites. Soil pH at M05B was significantly higher than the value recorded at the Control plot. Extractable Ca was significantly higher at NMB than at both M05B and the Control, while extractable Mg was significantly lower at M05B than at NMB. Extractable K was significantly lower at the Control than at the three fire-affected plots. C was significantly higher at NMB than at the Control. BSR, BSR/C and BSR/C values at the fire-affected sites were significantly lower than those recorded at the Control. No significant differences were identified in C/C. Overall, a comparison of the pre-fire treatments showed that NMB was the practice that had the least negative effects on the soil properties studied, followed by M15B, and that fire severity was highest at M05B due to the accumulation of dead plant fuel.
地中海生态系统中的森林管理措施常用于降低野火的风险和严重程度。然而，这些火灾前的处理措施可能会影响野火事件对土壤性质的影响。本研究的目的是检验 2015 年野火对三个地点土壤性质的短期影响，其中两个地点（M05B 和 M15B）经历了不同年份的管理措施，而另一个地点（NMB）没有进行任何管理措施。并将它们的性质与未受 2015 年野火影响的一个地块（对照）进行比较。我们分析了团聚体稳定性（AS）、土壤有机质（SOM）含量、总氮（TN）、碳氮比（C/N）、无机碳（IC）、pH 值、电导率（EC）、可提取钙（Ca）、镁（Mg）、钠（Na）和钾（K）、微生物生物量碳（C）和基础土壤呼吸（BSR）。在管理的地块中，进行了皆伐作业，部分植被被砍伐并留在土壤表面。对照点的 AS 值明显高于 M05B，而 NMB 的 TN 和 SOM 值明显高于 M05B。M05B 的 IC 值明显高于其他地块。分析地点之间的 C/N 比没有显著差异。M05B 的土壤 pH 值明显高于对照点。NMB 的可提取 Ca 明显高于 M05B 和对照，而 M05B 的可提取 Mg 明显低于 NMB。对照点的可提取 K 明显低于三个受火灾影响的地块。NMB 的 C 明显高于对照。NMB 的 BSR、BSR/C 和 BSR/C 值明显低于对照。C/C 没有显著差异。总体而言，对火灾前处理的比较表明，NMB 是对研究土壤性质负面影响最小的措施，其次是 M15B，而 M05B 的火灾严重程度最高，因为积累了死植物燃料。
