The use of virtual species to test species distribution models is important for understanding how aspects of the model development process influence model performance. Typically, virtual species are simulated by defining their niche as a function of environmental variables and simulating occurrence probabilistically via Bernoulli trials. This approach ignores endogenous processes known to drive species distribution such as dispersal and population dynamics. To understand whether these processes are important for simulating virtual species we compared the probabilistic simulation approach to those incorporating endogenous processes. This comparison was done by evaluating changes in the relationship between species occurrence and habitat suitability over a number of landscapes with varying spatial structure. We found that the combined effects of population dynamics and dispersal meant the probability of occurrence of a single cell was not only dependent on habitat suitability, but also the number of occupied cells nearby. This resulted in a dependence on the size of clusters of high suitability cells (analogous to patch size) to maintain populations, increased residual spatial autocorrelation and non‐stationarity of the species response between landscapes. These data characteristics are attributes of real species distribution data and are not present in probabilistic simulations. Researchers using virtual species should consider the importance of these characteristics to their study objectives to decide whether the inclusion of endogenous processes is necessary.

中文翻译：

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创建虚拟物种以测试物种分布模型：景观结构，扩散和种群过程的重要性

使用虚拟物种测试物种分布模型对于理解模型开发过程的各个方面如何影响模型性能非常重要。通常，通过将虚拟物种的生态位定义为环境变量的函数来模拟虚拟物种，并通过伯努利试验概率地模拟虚拟物种的出现。这种方法忽略了已知的驱动物种分布的内在过程，例如分散和种群动态。为了了解这些过程对于模拟虚拟物种是否重要，我们将概率模拟方法与那些结合了内生过程的方法进行了比较。通过评估空间结构变化的许多景观中物种发生与栖息地适宜性之间关系的变化来完成此比较。我们发现，种群动态和扩散的综合影响意味着单个细胞出现的可能性不仅取决于栖息地的适宜性，而且还取决于附近所占据细胞的数量。这导致依赖高适应性细胞簇的大小（类似于斑块大小）来维持种群，增加了剩余空间自相关性以及景观之间物种响应的不平稳性。这些数据特征是真实物种分布数据的属性，在概率模拟中不存在。使用虚拟物种的研究人员应考虑这些特征对其研究目标的重要性，以决定是否有必要包括内生过程。