Centre for Ocean Life, Technical University of Denmark, Lyngby, Denmark.
School of Mathematical Science, Yangzhou University, Yangzhou, China.
J Anim Ecol. 2020 Jun;89(6):1497-1510. doi: 10.1111/1365-2656.13207. Epub 2020 Apr 2.
The concept of biodiversity-ecosystem functioning (BEF) has been studied over the last three decades using experiments, theoretical models and more recently observational data. While theoretical models revealed that species richness is the best metric summarizing ecosystem functioning, it is clear that ecosystem function is explained by other variables besides species richness. Additionally, theoretical models rarely focus on more than one ecosystem function, limiting ecosystem functioning to biomass or production. There is a lack of theoretical background to verify how other components of biodiversity and species interactions support ecosystem functioning. Here, using simulations from a food web model based on a community assembly process and a trait-based approach, we test how species biodiversity, food web structure and predator-prey interactions determine several ecosystem functions (biomass, metabolism, production and productivity). Our results demonstrate that the relationship between species richness and ecosystem functioning depends on the type of ecosystem function considered and the importance of diversity and food web structure differs across functions. Particularly, we show that dominance plays a major role in determining the level of biomass, and it is at least as important as the number of species. We find that dominance occurs in the food web when species do not experience strong predation. By manipulating the structure of the food web, we show that species using a wider trait space (generalist communities) result in more connected food webs and generally reach the same level of functioning with less species. The model shows the importance of generalist versus specialist communities on BEF relationships, and as such, empirical studies should focus on quantifying the importance of diet/habitat use on ecosystem functioning. Our study provides a better understanding of BEF underlying mechanisms and generates research hypotheses that can be considered and tested in observational studies. We recommend that studies investigating links between biodiversity and ecosystem functions should include metrics of dominance, species composition, trophic structure and possibly environmental trait space. We also advise that more effort should be made into calculating several ecosystem functions and properties with data from natural multitrophic systems.
生物多样性-生态系统功能（BEF）的概念在过去三十年中通过实验、理论模型和最近的观测数据进行了研究。虽然理论模型表明物种丰富度是概括生态系统功能的最佳指标，但显然除了物种丰富度之外，还有其他变量可以解释生态系统功能。此外，理论模型很少关注一种以上的生态系统功能，将生态系统功能限制为生物量或产量。缺乏理论背景来验证生物多样性的其他组成部分和物种相互作用如何支持生态系统功能。在这里，我们使用基于群落组装过程和基于特征的方法的食物网模型的模拟，测试了物种生物多样性、食物网结构和捕食者-猎物相互作用如何决定几种生态系统功能（生物量、新陈代谢、生产和生产力）。我们的结果表明，物种丰富度与生态系统功能之间的关系取决于所考虑的生态系统功能的类型，并且多样性和食物网结构的重要性在不同的功能中有所不同。特别是，我们表明，优势在决定生物量水平方面起着主要作用，其重要性至少与物种数量一样。我们发现，当物种不受强烈捕食时，优势会在食物网中出现。通过操纵食物网的结构，我们表明，使用更广泛特征空间的物种（一般社区）会导致更具连接性的食物网，并且通常使用较少的物种达到相同的功能水平。该模型表明了一般主义与专家社区在 BEF 关系中的重要性，因此，实证研究应侧重于量化饮食/栖息地利用对生态系统功能的重要性。我们的研究提供了对 BEF 潜在机制的更好理解，并产生了可以在观察研究中考虑和测试的研究假设。我们建议，研究生物多样性与生态系统功能之间联系的研究应包括优势、物种组成、营养结构和可能的环境特征空间的指标。我们还建议，应该通过从自然多营养系统中获取数据，更加努力地计算几种生态系统功能和特性。
