BEF studies aim to understand how ecosystems respond to a gradient of species diversity. Diversity-Interactions (DI) models are suitable for analysing the BEF relationship. These models relate an ecosystem function response of a community to the identity of the species in the community, their evenness (proportions) and interactions. The number of species in the community (richness) is also implicitly modelled through this approach. It is common in BEF studies to model an ecosystem function as a function of richness; while this can uncover trends in the BEF relationship, by definition, species diversity is much broader than richness alone, and important patterns in the BEF relationship may remain hidden. In this paper, we introduce the DImodels R package for implementing DI models. We also compare DI models to traditional modelling approaches to highlight the advantages of using a multi-dimensional definition of species diversity. We show that using DI models can lead to considerably improved model fit over other methods; it does this by incorporating variation due to the multiple facets of species diversity. Predicting from a DI model is not limited to the study design points, the model can extrapolate to predict for any species composition and proportions (assuming there is sufficient coverage of this space in the study design). Expressing the BEF relationship as a function of richness alone can be useful to capture overall trends. However, collapsing the multiple dimensions of species diversity to a single dimension (such as richness) can result in valuable ecological information being lost. DI modelling provides a framework to test the multiple components of species diversity in the BEF relationship. It facilitates uncovering a deeper ecological understanding of the BEF relationship and can lead to enhanced inference.

翻译：BEF研究旨在理解生态系统如何响应物种多样性的梯度。多样性-相互作用（DI）模型适用于分析BEF关系。这些模型将群落生态系统功能响应与群落中物种的身份、其均匀度（比例）及相互作用相关联。群落中的物种数量（丰富度）也通过此方法隐含建模。在BEF研究中，通常将生态系统功能建模为丰富度的函数；虽然这能揭示BEF关系中的趋势，但物种多样性本身远不止丰富度，BEF关系中的重要模式可能被隐藏。本文介绍用于实现DI模型的DImodels R包。我们还将DI模型与传统建模方法进行比较，以突出使用物种多样性多维定义的优势。研究表明，DI模型可显著提升模型拟合度优于其他方法；其通过纳入物种多样性多维度引起的变异实现。DI模型的预测不受限于研究设计点，该模型可外推以预测任意物种组成和比例（假设研究设计中对该空间有充分覆盖）。将BEF关系仅表示为丰富度函数有助于捕捉总体趋势，但将物种多样性的多个维度压缩为单一维度（如丰富度）可能导致有价值的生态信息丢失。DI建模为检验BEF关系中物种多样性的多组分提供了框架，有助于深化对BEF关系的生态理解，并可增强推断能力。