MaxEnt versus MaxLike: empirical comparisons with ant species distributions
MaxEnt versus MaxLike: empirical comparisons with ant species distributions
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DOI：
10.1890/es13-00066.1
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发表时间：
2013-05-01
期刊：
影响因子：
2.7
通讯作者：
Ellison, Aaron M.
中科院分区：
文献类型：
--
作者：
Fitzpatrick, Matthew C.;Gotelli, Nicholas J.;Ellison, Aaron M.
MaxEnt是生态学、生物地理学和进化中使用最广泛的工具之一，用于使用仅存在的发生记录和相关的环境协变量来建模和绘制物种分布。尽管它很受欢迎，但MaxEnt实现的指数模型并不能直接估计发生概率，这是建模物种分布时感兴趣的自然量。相反，MaxEnt生成了一个相对栖息地适宜性指数。MaxLike是一种新引入的最大似然技术，已被证明可以克服使用仅存在数据直接估计发生概率的问题。然而，MaxEnt和MaxLike的性能和相对优点在很大程度上还没有经过测试，特别是在对物种进行建模时，数据相对较少，只包含该物种地理范围的一部分。利用新英格兰地区6种蚂蚁的地理参考发生记录，对MaxEnt和MaxLike进行了比较。我们表明，通过大多数定量指标，MaxLike的性能超过了MaxEnt，无论MaxEnt模型是否考虑采样偏差，以及是否包含比MaxLike实现的更大的模型复杂性。更重要的是，对于大多数物种，MaxEnt估算的相对适宜性指数与MaxLike估算的发生概率往往相关性较差，这表明两种方法估算的数量不同。对于物种分布建模，MaxLike和基于显式采样过程并直接估计发生概率的类似模型应被视为广泛使用的MaxEnt框架的重要替代方案。
MaxEnt is one of the most widely used tools in ecology, biogeography, and evolution for modeling and mapping species distributions using presence-only occurrence records and associated environmental covariates. Despite its popularity, the exponential model implemented by MaxEnt does not directly estimate occurrence probability, the natural quantity of interest when modeling species distributions. Instead, MaxEnt generates an index of relative habitat suitability. MaxLike, a newly introduced maximum-likelihood technique, has been shown to overcome the problem of directly estimating the probability of occurrence using presence-only data. However, the performance and relative merits of MaxEnt and MaxLike remain largely untested, especially when modeling species with relatively few occurrence data that encompass only a portion of the geographic range of the species. Using geo-referenced occurrence records for six species of ants in New England, we provide comparisons of MaxEnt and MaxLike. We show that by most quantitative metrics, the performance of MaxLike exceeds that of MaxEnt, regardless of whether MaxEnt models account for sampling bias and include greater model complexity than implemented in MaxLike. More importantly, for most species, the relative suitability index estimated by MaxEnt often was poorly correlated with the probability of occurrence estimated by MaxLike, suggesting that the two methods are estimating different quantities. For species distribution modeling, MaxLike, and similar models that are based on an explicit sampling process and that directly estimate probability of occurrence, should be considered as important alternatives to the widely-used MaxEnt framework.