The important role of biological soil crusts (biocrusts) in determining the soil carbon balance in dryland ecosystems under future climate change has been widely explored. However, when assessing the effects of biocrusts on soil respiration, few studies have considered biocrusts in bare soil patches and shrub soil patches. A field experiment was performed with five simulated rainfall addition events (0, 5, 15, 25, and 40 mm) in shrub and bare soil patches in June (early growing season, EGS), July (middle growing season, MGS) and September (late growing season, LGS) in 2016 and 2017. Our objective was to examine whether biocrusts at shrub and bare soil patches have the same effect on soil respiration under altered rainfall regimes. The results showed that the removal of biocrusts from bare patches reduced soil respiration by 15 % after rainfall amounts of 5–40 mm and increased the subsurface soil temperature and decreased the soil moisture after various rainfall treatments. However, in shrub patches, the removal of biocrusts led to a significant increase in soil respiration of 57 % and subsequent increases in subsurface soil temperature and moisutre. The discrepancy in the soil respiration response between the two types of patches might be attributable to the increase in soil infiltration after biocrust removal, with a greater stimulating increase in soil carbon emissions stimulated in the shrub patches than in the bare patches due to more the greater amounts of roots distributed under the former shrub patches. Our results indicate that the destruction of biocrusts in shrub patches may reduce the ability of biocrust ecosystems to become a net carbon sinks, with potentially negative consequences for ecosystem function and sustainability in water-limited regions.

生物土壤结皮（生物结皮）在未来气候变化下决定旱地生态系统土壤碳平衡的重要作用已被广泛探索。然而，在评估生物结皮对土壤呼吸的影响时，很少有研究考虑裸露土壤斑块和灌木土壤斑块中的生物结皮。6 月（生长早期，EGS）、7 月（生长中期，MGS）和 9 月在灌木和裸土斑块中进行了五个模拟降雨增加事件（0、5、15、25 和 40 毫米）的田间试验（生长季后期，LGS) 在 2016 年和 2017 年。我们的目标是检查灌木和裸土斑块上的生物结皮是否对改变降雨情况下的土壤呼吸具有相同的影响。结果表明，在降雨量达到 5-40 毫米后，从裸露的斑块上去除生物结皮使土壤呼吸减少 15%，并在各种降雨处理后增加了地下土壤温度并降低了土壤水分。然而，在灌木丛中，生物结皮的去除导致土壤呼吸显着增加 57%，随后地下土壤温度和水分增加。两种类型斑块之间土壤呼吸反应的差异可能是由于去除生物结皮后土壤入渗增加，与裸露的斑块相比，灌木斑块中刺激的土壤碳排放量的增加更大，因为更多的根分布在前灌木斑块下。我们的研究结果表明，灌木丛中生物结皮的破坏可能会降低生物结皮生态系统成为净碳汇的能力，对缺水地区的生态系统功能和可持续性产生潜在的负面影响。