生物多样性与生态系统功能关系是生态学领域的前沿问题。全球变化背景下，生物多样性的丧失会显著削弱生态系统功能。然而，当前研究主要关注多样性与单个生态功能(如生产力、生态系统碳汇等)及生态系统多功能性(Ecosystem Multi-functionality, EMF)的关系，尚不清楚大尺度上多样性如何影响不同生态功能之间的互作程度(即生态功能耦合)，以及生态功能耦合与EMF的关联。本研究以青藏高原高寒草地为研究对象，基于对40个样地的标准化调查和采样，试图揭示EMF和生态功能耦合的大尺度格局及其与植物多样性的关系。结果显示，在环境梯度上EMF呈现显著的异质性，而生态功能耦合的变异程度较弱，且二者没有显著关联；EMF的空间格局受到气候、植物多样性和土壤因子的共同影响，而生态功能耦合对生物与非生物因素的变化均不敏感。上述结果表明EMF与生态功能耦合在大尺度上发生解耦，不支持基于单点控制实验得到的“生态功能耦合程度越强、生态系统多功能性越高”的传统认识，为深入理解“青藏高原生态屏障区”多样性与生态系统功能关系提供了新视角，也为实现基于生物多样性保护的“山水林田湖草沙一体化治理”国家战略奠定理论基础。

Aims The biodiversity-ecosystem function relationship is a prominent research topic within ecology. In the context of global environmental changes, biodiversity loss may constrain ecosystem functioning. Most existing studies focus on diversity effects on individual functions (e.g., productivity, carbon sequestration, etc.) or ecosystem multi-functionality (EMF), while overlooking the interactions among different ecological functions - a phenomenon quantified as ecosystem coupling. To date, it remains elusive how diversity changes impact ecosystem coupling and the relationships between EMF and ecosystem coupling. Methods Using standardized field surveys across 40 sampling sites across the Tibetan alpine grasslands, we explored the large-scale patterns of ecosystem multifunctionality and ecosystem coupling, and their relationships with plant diversity. Important findings The EMF exhibited highly spatial heterogeneity, while ecosystem coupling showed less variation at the regional scale. Meanwhile, no significant correlation was observed between EMF and ecosystem coupling. The EMF was significantly correlated with climatic factors, plant diversity, and soil properties, whereas ecosystem coupling remained insensitive to variations in both biotic and abiotic drivers. These results reveal a widespread decoupling between EMF and ecosystem coupling at the large scale, not supporting the notion that higher EMF associated with stronger ecosystem coupling based on controlled experiments. Our findings provide new insights into the relationship between biodiversity and ecosystem functions, and also lay a theoretical base for achieving the national strategy of "integrated management of mountains, waters, forests, farmlands, lakes, grasslands and deserts " via biodiversity conservation.