Data from: Linking biological soil crust attributes to the multifunctionality of vegetated patches and interspaces in a semiarid shrubland

1.Understanding the importance of biotic community structure on ecosystem functioning, and whether communities inhabiting different microhabitats in highly heterogeneous areas provide different ecological functions is a challenge in ecological research in the face of biodiversity and habitat loss. Biological soil crusts (BSCs) have been largely treated as unique entities, and have been mostly examined in interspaces between perennial plants, limiting current understanding of their role as drivers of ecosystem functioning and their relative contribution in comparison to vascular plants.

2.We assessed the role of BSCs on ecosystem functioning in vegetated patches and interspaces, and how individual soil functions and ecosystem multifunctionality are related to changes in BSC species- and community-level attributes. We contemplated nine ecosystem functions associated with soil water dynamics, nutrient cycling and erosion potential.

3.We found that vegetated patches improve infiltration rates, soil stability and net potential nitrogen (N) mineralization compared to interspaces, and thus dominate multifunctionality. However, well-developed BSCs improve soil moisture and N pool in both microsites, and are multifunctional stabilizing soils and regulating soil moisture and infiltration in the interspaces. BSC surface microstructure, including changes in total cover, species richness, morphological functional groups and surface discontinuities, has significant effects on soil moisture. Differences in soil N and phosphorous are mostly related to the presence of BSC-lichens. The effect of BSCs on multifunctionality varies in dependence of the particular set of functions that are seek to simultaneously maximize.

4.Our results suggest that vascular plants and BSCs have idiosyncratic effects on different key ecosystem functions and multifunction, and BSCs substitute vascular plants in stabilizing soils and regulating water dynamics in the interspaces. BSCs greatly contribute to small scale heterogeneity in the functioning of vegetated patches and interspaces, hence consideration of BSCs in different microsites is essential for enhancing our understanding of their functional relevance at a regional scale. In addition, quantification of BSC microstructure is crucial, owing to the contrasting effects of BSC species- and community-level attributes on different functions and multifunction.

1. 探明生物群落结构对生态系统功能的重要性，以及高度异质性区域内不同微生境中的群落是否具备差异化的生态功能，是当前面临生物多样性丧失与生境破坏背景下，生态学研究面临的核心挑战。生物土壤结皮（Biological Soil Crusts, BSCs）长期以来被视为独立的独特实体，且绝大多数研究仅聚焦于多年生植物间的裸地间隙，这限制了学界对其作为生态系统功能驱动因子的角色，以及相较于维管植物的相对贡献的认知。
2. 本研究评估了生物土壤结皮在植被斑块与植物间隙中对生态系统功能的调控作用，并揭示了单一土壤功能与生态系统多功能性（ecosystem multifunctionality）如何随生物土壤结皮的物种及群落水平特征变化而改变。本研究共选取了9项与土壤水分动态、养分循环及侵蚀潜势相关的生态系统功能。
3. 研究结果显示，相较于植物间隙，植被斑块可提升土壤入渗率、土壤稳定性与净潜在氮（N）矿化作用，因此在生态系统多功能性中占据主导地位。然而，发育良好的生物土壤结皮可提升两类微生境中的土壤水分与氮库，且在植物间隙中可同时发挥稳定土壤、调控土壤水分与入渗的多功能作用。生物土壤结皮的表面微观结构——包括总盖度、物种丰富度、形态功能群及表面不连续性的变化——对土壤水分具有显著影响。土壤氮与磷含量的差异主要与生物土壤结皮属地衣的存在相关。此外，生物土壤结皮对生态系统多功能性的影响，会因需同时最大化的特定功能组合不同而存在差异。
4. 本研究结果表明，维管植物与生物土壤结皮对不同关键生态系统功能及多功能性具有特异性调控效应，且在植物间隙中，生物土壤结皮可替代维管植物发挥稳定土壤、调控水分动态的功能。生物土壤结皮极大地促成了植被斑块与植物间隙中功能的小尺度异质性，因此，在不同微生境中纳入生物土壤结皮的相关研究，对于深化我们对其在区域尺度上的功能相关性的认知至关重要。此外，由于生物土壤结皮的物种及群落水平特征对不同功能及多功能性存在差异化影响，对其表面微观结构进行量化分析亦极为关键。