Straw mulching is one of the most common treatments applied immediately post fire to reduce soil erosion potential and mitigate post-fire effects on water quality, downstream property, and infrastructure, but little is known about the long-term effects on vegetation response. We sampled six fires that were mulched between 9 and 13 years ago in western US dry conifer forests. We compared understory plant species diversity and abundance, tree seedling density and height by species, and fractional ground cover on mulched and unmulched paired plots. Mulch did not influence understory plant diversity, species richness, or fractional ground cover. However, on mulched plots, tree seedlings grew taller faster, especially on north-facing aspects, and there was slightly more graminoid cover. Mulch did not affect overall tree seedling density, but there were fewer ponderosa pine (Pinus ponderosa Lawson & C. Lawson) and more Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) in mulched areas, especially on south-facing slopes. Managers will be able to weigh the long-term implications of mulching against the short-term reductions in soil erosion potential. While there are many concerns about vegetation suppression and exotic species introduction from using straw mulch, our study suggests that the long-term effects are subtle 9 to 13 years after post-fire mulching.

中文翻译：

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火后秸秆覆盖后的长期植被响应

秸秆覆盖是火灾后立即采取的最常见的处理方法之一，可减少土壤侵蚀的可能性，并减轻火灾后对水质，下游财产和基础设施的影响，但对植被响应的长期影响知之甚少。我们采样了9到13年前在美国西部干旱针叶林中覆盖的六场大火。我们比较了林下植物物种的多样性和丰度，树木幼苗的密度和树高，以及覆盖和未覆盖的成对地块的地表覆盖率。地膜未影响林下植物多样性，物种丰富度或部分地被植物。但是，在覆盖的地块上，树木的幼苗长得更快，尤其是在朝北的地方，并且有更多的类人动物覆盖。地膜未影响整体树苗密度，但是在被覆盖的地区，特别是在朝南的斜坡上，黄松树的松树（Pinus tankerosa Lawson和C. Lawson）较少，而花旗松（Pseudotsuga menziesii [Mirb。] Franco）则更多。管理人员将能够权衡覆盖的长期影响与土壤侵蚀潜力的短期减少。尽管人们对使用秸秆覆盖物抑制植被和引入外来物种有许多担忧，但我们的研究表明，长期的影响在后火覆盖后9至13年是微妙的。