In response to increasing fire, fuel‐reduction treatments are being used to minimize large fire risk. Although biocrusts are associated with reduced cover of fire‐promoting, invasive grasses, the impact of fuel‐reduction treatments on biocrusts is poorly understood. We use data from a long‐term experiment, the Sagebrush Steppe Treatment Evaluation Project, testing the following fuel‐reduction treatments: mowing, prescribed fire, and the use of two herbicides: one commonly used to reduce shrub cover, tebuthiuron, and one commonly used to combat cheatgrass, imazapic. Looking at sites with high cover of biocrusts prior to treatments, we demonstrate positive effects of the herbicide, tebuthiuron on lichens with an increase in cover of 10% and trending towards slightly negative effects on moss cover. Across plots, imazapic trended towards a decrease in lichen and moss cover without being statistically significant. Mowing and prescribed fire reduced cover of mosses, with the latter leading to greater declines across sites (declines of 18% vs. 32%). Reductions in moss cover mirrored gains in cover of bare soil, which is associated with increased risk of invasion by grasses responsible for increasing fire risk. We demonstrate that the use of herbicides simultaneously reduces fuels and maintains greater cover of lichens and mosses compared with other fuel‐reduction treatments, possibly reducing risk of invasion by annual grasses that are responsible for increasing fire risk.

中文翻译：

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并非所有的燃料减少处理都能降解生物结皮：除草剂对生物结皮的覆盖主要产生中性至积极影响

为了应对不断增加的火灾，正在使用减少燃料的处理措施以最大程度地降低大火的风险。尽管生物结皮与助火性入侵草的覆盖减少有关，但人们对燃料减少处理对生物结皮的影响知之甚少。我们使用来自长期实验，鼠尾草草原处理评估项目的数据，测试以下减少燃料的处理方法：割草，开除明火，以及使用两种除草剂：一种通常用于减少灌木覆盖率，替丁硫龙，另一种通常用于减少灌木丛。过去曾被用来对抗象草的象草。在处理之前观察生物结皮覆盖率高的部位，我们证明了除草剂替布丁龙对地衣具有积极作用，覆盖率增加了10％，并且对苔藓覆盖率有轻微的负面影响。跨地块，imazapic趋向于降低地衣和苔藓覆盖率，但无统计学意义。割草和开明的火减少了苔藓的覆盖，后者导致各个站点的下降幅度更大（下降幅度分别为18％和32％）。苔藓覆盖的减少反映了裸露土壤覆盖的增加，这与负责增加火灾风险的草类入侵的风险增加有关。我们证明，与其他减少燃料的处理相比，使用除草剂可同时减少燃料并保持更多的地衣和苔藓覆盖，从而可能减少一年生禾草入侵的风险，而一年生草可增加火灾的风险。后者导致各个站点的下降幅度更大（下降幅度分别为18％和32％）。苔藓覆盖的减少反映了裸露土壤覆盖的增加，这与负责增加火灾风险的草类入侵的风险增加有关。我们证明，与其他减少燃料的处理相比，使用除草剂可同时减少燃料并保持更多的地衣和苔藓覆盖，从而可能减少一年生禾草入侵的风险，而一年生草可增加火灾的风险。后者导致各个站点的下降幅度更大（下降幅度分别为18％和32％）。苔藓覆盖的减少反映了裸露土壤覆盖的增加，这与负责增加火灾风险的草类入侵的风险增加有关。我们证明，与其他减少燃料的处理相比，使用除草剂可同时减少燃料并保持更多的地衣和苔藓覆盖，从而可能减少一年生禾草入侵的风险，而一年生草可增加火灾的风险。