This is an author-produced version of a paper published in Nature. The paper has been peer-reviewed and proof-corrected but does not include journal pagination. The paper discusses the impact of biodiversity loss on ecosystems and human society. It reviews two decades of research on biodiversity and ecosystem functioning (BEF) and biodiversity and ecosystem services (BES). The paper highlights the importance of biodiversity for ecosystem functions, such as nutrient cycling, biomass production, and decomposition. It also discusses how biodiversity influences ecosystem services, such as water purification, flood regulation, and pollination. The paper concludes that biodiversity loss reduces the efficiency of ecosystem functions and can have significant impacts on human well-being. It also emphasizes the need for further research to better understand the relationship between biodiversity and ecosystem services, and to develop policies that can help mitigate the effects of biodiversity loss. The paper is part of a broader effort to understand the role of biodiversity in maintaining ecosystem services and to develop strategies for conserving biodiversity. The paper is published in the journal Nature, and the authors include researchers from various institutions around the world. The paper is part of a larger body of research on biodiversity and ecosystem functioning, and it builds on previous studies that have shown the importance of biodiversity for ecosystem functions and services. The paper also discusses the challenges of studying biodiversity and ecosystem functioning, including the need for more comprehensive data and the importance of integrating different disciplines to better understand the relationship between biodiversity and ecosystem services. The paper concludes that biodiversity loss is a major threat to ecosystem functions and services, and that conservation efforts are needed to protect biodiversity and maintain ecosystem services. The paper is part of a broader effort to understand the role of biodiversity in maintaining ecosystem services and to develop strategies for conserving biodiversity. The paper is published in the journal Nature, and the authors include researchers from various institutions around the world. The paper is part of a larger body of research on biodiversity and ecosystem functioning, and it builds on previous studies that have shown the importance of biodiversity for ecosystem functions and services. The paper also discusses the challenges of studying biodiversity and ecosystem functioning, including the need for more comprehensive data and the importance of integrating different disciplines to better understand the relationship between biodiversity and ecosystem services. The paper concludes that biodiversity loss is a major threat to ecosystem functions and services, and that conservation efforts are needed to protect biodiversity and maintain ecosystem services.This is an author-produced version of a paper published in Nature. The paper has been peer-reviewed and proof-corrected but does not include journal pagination. The paper discusses the impact of biodiversity loss on ecosystems and human society. It reviews two decades of research on biodiversity and ecosystem functioning (BEF) and biodiversity and ecosystem services (BES). The paper highlights the importance of biodiversity for ecosystem functions, such as nutrient cycling, biomass production, and decomposition. It also discusses how biodiversity influences ecosystem services, such as water purification, flood regulation, and pollination. The paper concludes that biodiversity loss reduces the efficiency of ecosystem functions and can have significant impacts on human well-being. It also emphasizes the need for further research to better understand the relationship between biodiversity and ecosystem services, and to develop policies that can help mitigate the effects of biodiversity loss. The paper is part of a broader effort to understand the role of biodiversity in maintaining ecosystem services and to develop strategies for conserving biodiversity. The paper is published in the journal Nature, and the authors include researchers from various institutions around the world. The paper is part of a larger body of research on biodiversity and ecosystem functioning, and it builds on previous studies that have shown the importance of biodiversity for ecosystem functions and services. The paper also discusses the challenges of studying biodiversity and ecosystem functioning, including the need for more comprehensive data and the importance of integrating different disciplines to better understand the relationship between biodiversity and ecosystem services. The paper concludes that biodiversity loss is a major threat to ecosystem functions and services, and that conservation efforts are needed to protect biodiversity and maintain ecosystem services. The paper is part of a broader effort to understand the role of biodiversity in maintaining ecosystem services and to develop strategies for conserving biodiversity. The paper is published in the journal Nature, and the authors include researchers from various institutions around the world. The paper is part of a larger body of research on biodiversity and ecosystem functioning, and it builds on previous studies that have shown the importance of biodiversity for ecosystem functions and services. The paper also discusses the challenges of studying biodiversity and ecosystem functioning, including the need for more comprehensive data and the importance of integrating different disciplines to better understand the relationship between biodiversity and ecosystem services. The paper concludes that biodiversity loss is a major threat to ecosystem functions and services, and that conservation efforts are needed to protect biodiversity and maintain ecosystem services.