Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, United Kingdom.
Spatial Foodweb Ecology Group, Department of Agricultural Sciences, University of Helsinki, PO Box 27, Latokartanonkaari 5, Helsinki, FI-00014, Finland.
Ecology. 2017 Oct;98(10):2626-2639. doi: 10.1002/ecy.1954.
Studies investigating how biodiversity affects ecosystem functioning increasingly focus on multiple functions measured simultaneously ("multifunctionality"). However, few such studies assess the role of species interactions, particularly under alternative environmental scenarios, despite interactions being key to ecosystem functioning. Here we address five questions of central importance to ecosystem multifunctionality using a terrestrial animal system. (1) Does the contribution of individual species differ for different ecosystem functions? (2) Do inter-species interactions affect the delivery of single functions and multiple functions? (3) Does the community composition that maximizes individual functions also maximize multifunctionality? (4) Is the functional role of individual species, and the effect of interspecific interactions, modified by changing environmental conditions? (5) How do these roles and interactions change under varying scenarios where ecosystem services are weighted to reflect different societal preferences? We manipulated species' relative abundance in dung beetle communities and measured 16 functions contributing to dung decomposition, plant productivity, nutrient recycling, reduction of greenhouse gases, and microbial activity. Using the multivariate diversity-interactions framework, we assessed how changes in species identity, composition, and interspecific interactions affected these functions in combination with an environmental driver (increased precipitation). This allowed us to identify key species and interactions across multiple functions. We then developed a desirability function approach to examine how individual species and species mixtures contribute to a desired state of overall ecosystem functioning. Species contributed unequally to individual functions, and to multifunctionality, and individual functions were maximized by different community compositions. Moreover, the species and interactions important for maintaining overall multifunctionality depended on the weight given to individual functions. Optimal multifunctionality was context-dependent, and sensitive to the valuation of services. This combination of methodological approaches allowed us to resolve the interactions and indirect effects among species that drive ecosystem functioning, revealing how multiple aspects of biodiversity can simultaneously drive ecosystem functioning. Our results highlight the importance of a multifunctionality perspective for a complete assessment of species' functional contributions.
研究生物多样性如何影响生态系统功能越来越多地集中在同时测量的多个功能上（“多功能性”）。然而，尽管物种相互作用是生态系统功能的关键，但很少有此类研究评估物种相互作用的作用，特别是在替代环境情景下，尽管物种相互作用是生态系统功能的关键。在这里，我们使用陆地动物系统来解决生态系统多功能性的五个重要问题。(1) 不同物种对不同生态系统功能的贡献是否不同？(2) 种间相互作用是否会影响单一功能和多种功能的实现？(3) 最大化单个功能的群落组成是否也能最大化多功能性？(4) 个体物种的功能作用以及种间相互作用的影响是否会随着环境条件的变化而改变？(5) 在反映不同社会偏好的不同生态系统服务权重下，这些角色和相互作用如何变化？我们操纵了蜣螂群落中物种的相对丰度，并测量了 16 种功能，这些功能有助于粪便分解、植物生产力、养分循环、减少温室气体和微生物活性。使用多元多样性-相互作用框架，我们评估了物种身份、组成和种间相互作用的变化如何与环境驱动因素（增加降水）共同影响这些功能。这使我们能够识别多个功能中的关键物种和相互作用。然后，我们开发了一个理想函数方法来检查单个物种和物种混合物如何有助于整体生态系统功能的理想状态。物种对单个功能和多功能性的贡献不均等，而且对多功能性的贡献由不同的群落组成。此外，对维持整体多功能性重要的物种和相互作用取决于对单个功能的重视程度。最佳多功能性是上下文相关的，并且对服务的估值敏感。这种方法的组合使我们能够解决驱动生态系统功能的物种之间的相互作用和间接影响，揭示了生物多样性的多个方面如何同时驱动生态系统功能。我们的结果强调了多功能性视角对于全面评估物种功能贡献的重要性。
