论文标题
多物种计数转换模型
Multi-species count transformation models
论文作者
论文摘要
通过扩展单物种分布模型,多物种分布模型和联合物种分布模型能够描述环境变量与物种社区之间的关系。还可以在某些假设下对社区中每个物种(多物种模型)的边际分布(多物种模型)的边际分布进行建模,但是同时描述两个实体的模型尚未可用。我们提出了一个新型模型,允许描述多元转换模型框架内的多种物种的联合分布和边际单物种分布的模型。模型参数可以通过两个近似的最大样过程从丰度数据估算。 使用三只吃鱼类鸟类的模型群落,我们证明了一年中特定特定的食品竞争可以使用配备三个时间依赖性Spearman的等级相关参数的计数转换模型来建模。我们使用相同的数据集将模型的性能与有关物种分布建模的文献中的竞争对手模型的性能进行比较。多物种计数转换模型为多种物种分布模型提供了替代方案。除了捕获单物种分布的边际变换模型外,物种之间的相互作用还可以通过Spearman在总体模型公式中的等级相关性表示,该公式可以同时推断所有模型参数。在R系统的“ CotRAM”附加软件包中可用软件实现用于统计计算。
By extending single-species distribution models, multi-species distribution models and joint species distribution models are able to describe the relationship between environmental variables and a community of species. It is also possible to model either the marginal distribution of each species (multi-species models) in the community or their joint distribution (joint species models) under certain assumptions, but a model describing both entities simultaneously has not been available. We propose a novel model that allows description of both the joint distribution of multiple species and models for the marginal single-species distributions within the framework of multivariate transformation models. Model parameters can be estimated from abundance data by two approximate maximum-likelihood procedures. Using a model community of three fish-eating birds, we demonstrate that inter-specific food competition over the course of a year can be modeled using count transformation models equipped with three time-dependent Spearman's rank correlation parameters. We use the same data set to compare the performance of our model to that of a competitor model from the literature on species distribution modeling. Multi-species count transformation models provide an alternative to multi- and joint- species distribution models. In addition to marginal transformation models capturing single-species distributions, the interaction between species can be expressed by Spearman's rank correlations in an overarching model formulation that allows simultaneous inferences for all model parameters. A software implementation is available in the "cotram" add-on package to the R system for statistical computing.