Girona-García Antonio, Cretella Carola, Fernández Cristina, Robichaud Peter R, Vieira Diana C S, Keizer Jan Jacob
Biodiversity Research Institute (IMIB), CSIC-University of Oviedo-Principality of Asturias, Mieres, Spain.
School of Life Sciences and Environmental Technology (ALST), Avans University of Applied Sciences, Breda, the Netherlands.
J Environ Manage. 2023 May 15;334:117478. doi: 10.1016/j.jenvman.2023.117478. Epub 2023 Feb 14.
Wildfires usually increase the hydrological and erosive response of forest areas, carrying high environmental, human, cultural, and financial on- and off-site effects. Post-fire soil erosion control measures have been proven effective at mitigating such responses, especially at the slope scale, but there is a knowledge gap as to how cost-effective these treatments are. In this work, we review the effectiveness of post-fire soil erosion mitigation treatments at reducing erosion rates over the first post-fire year and provide their application costs. This allowed assessing the treatments' cost-effectiveness (CE), expressed as the cost of preventing 1 Mg of soil loss. This assessment involved a total of 63 field study cases, extracted from 26 publications from the USA, Spain, Portugal, and Canada, and focused on the role of treatment types and materials, and countries. Treatments providing a protective ground cover showed the best median CE (895 $ Mg), especially agricultural straw mulch (309 $ Mg), followed by wood-residue mulch (940 $ Mg) and hydromulch (2332 $ Mg). Barriers showed a relatively low CE (1386 $ Mg), due to their reduced effectiveness and elevated implementation costs. Seeding showed a good CE (260 $ Mg), but this reflected its low costs rather than its effectiveness to reduce soil erosion. The present results confirmed that post-fire soil erosion mitigation treatments are cost-effective as long as they are applied in areas where the post-fire erosion rates exceed the tolerable erosion rate thresholds (>1 Mg ha y) and are less costly than the loss of on- and off-site values that they are targeted to protect. For this reason, the proper assessment of post-fire soil erosion risk is vital to ensure that the available financial, human and material resources are applied appropriately.
野火通常会增强林区的水文和侵蚀响应，带来严重的环境、人类、文化和经济的场内和场外影响。火灾后土壤侵蚀控制措施已被证明在减轻此类响应方面有效，尤其是在坡面尺度上，但这些处理措施的成本效益如何，目前还存在知识空白。在这项研究中，我们回顾了火灾后土壤侵蚀缓解处理措施在火灾后的第一年降低侵蚀速率的有效性，并提供了它们的应用成本。这使得我们能够评估这些处理措施的成本效益（CE），即防止1吨土壤流失的成本。这项评估共涉及63个实地研究案例，这些案例取自美国、西班牙、葡萄牙和加拿大的26份出版物，重点关注处理类型、材料和国家的作用。提供保护性地面覆盖的处理措施显示出最佳的中位数成本效益（895美元/吨），尤其是农业秸秆覆盖（309美元/吨），其次是木材残渣覆盖（940美元/吨）和水力覆盖（2332美元/吨）。栅栏的成本效益相对较低（1386美元/吨），因为其有效性降低且实施成本较高。播种显示出良好的成本效益（260美元/吨），但这反映的是其低成本，而非其减少土壤侵蚀的有效性。目前的结果证实，只要将火灾后土壤侵蚀缓解处理措施应用于火灾后侵蚀速率超过可容忍侵蚀速率阈值（>1吨/公顷·年）且成本低于其旨在保护的场内和场外价值损失的地区，这些措施就是具有成本效益的。因此，正确评估火灾后土壤侵蚀风险对于确保合理应用可用的财政、人力和物力资源至关重要。
