Biological soil crusts (BSCs), composed of lichens, cyanobacteria, mosses, liverworts and microorganisms, are key biotic components of arid and semi-arid ecosystems worldwide. Despite they are widespread in Spain, these organisms have been historically understudied in this country. This trend is beginning to change as a recent wave of research has been identifying BSCs as a model ecological system. Many studies and research projects carried out in Spain have explored the role of BSCs on water, carbon and nitrogen fluxes, the interactions between BSCs and vascular plants, their dynamics after disturbances, and their response to global change, among other topics. In this article we review the growing body of research on BSCs available from semi-arid areas of Spain, highlighting its importance for increasing our knowledge on this group of organisms. We also discuss how it is breaking new ground in emerging research areas on the ecology of BSCs, and how it can be use to guide management and restoration efforts. Finally, we provide directions for future research on the ecology of BSCs in Spain and abroad.

中文翻译：

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西班牙半干旱生态系统中生物土壤结皮的生态学和功能作用

生物土壤结皮 (BSCs) 由地衣、蓝藻、苔藓、地钱和微生物组成，是全球干旱和半干旱生态系统的关键生物成分。尽管它们在西班牙很普遍，但这些生物在这个国家历史上一直未被充分研究。随着最近一波研究将 BSC 确定为模型生态系统，这一趋势开始发生变化。在西班牙开展的许多研究和研究项目探讨了 BSCs 对水、碳和氮通量的作用、BSCs 和维管植物之间的相互作用、它们在扰动后的动态以及它们对全球变化的响应等主题。在本文中，我们回顾了西班牙半干旱地区越来越多的 BSC 研究，强调了它对于增加我们对这组生物的了解的重要性。我们还讨论了它如何在 BSC 生态的新兴研究领域开辟新天地，以及它如何用于指导管理和恢复工作。最后，我们为西班牙和国外BSCs生态学的未来研究提供了方向。