SGHdata.zip

This study demonstrates the occurrence of SGH in biocrust succession, elucidating the underlying mechanisms across phylogenetic, functional, and taxonomic facets. We highlight the pivotal role of functional redundancy in driving community organization, but niche overlap is the linchpin for the framework of SGH that determines stress-competition correlations in biocrusts. Crucially, we highlighted the pivotal role of functional redundancy in driving crust community organization and species competition. However, given that cyanobacteria serve as primary facilitators under high-stress conditions, future research must address the relative cost of being a facilitator and how this cost changes with environmental stress. Further refining cyanobacterial crust classification could separate the effects of interactions between the facilitators and beneficiary on stress gradients, which contribute to enhance the understanding of the SGH through integration with biocrust photo-respiratory characteristics.

本研究证实了胁迫梯度假说（SGH）在生物土壤结皮（biocrust）演替过程中的存在，并从系统发育、功能及分类学三个维度阐明了其背后的作用机制。研究强调了功能冗余在驱动群落构建中的核心作用，而生态位重叠则是构建胁迫梯度假说（SGH）框架的关键，该框架决定了生物土壤结皮中的胁迫-竞争相关性。尤为重要的是，本研究进一步明确了功能冗余在驱动结皮群落构建与物种竞争中的核心作用。然而，鉴于蓝细菌（cyanobacteria）在高胁迫环境中作为主要促进者发挥功能，未来研究需阐明作为促进者的相对成本，以及该成本如何随环境胁迫程度发生变化。进一步细化蓝细菌结皮的分类标准，可区分促进者与受益类群间的相互作用对胁迫梯度的影响，结合生物土壤结皮的光呼吸特性，将有助于深化对胁迫梯度假说（SGH）的认知。