Baer Kathryn C, Maron John L
Anchorage Forestry Sciences Laboratory USDA Forest Service Pacific Northwest Research Station Anchorage AK USA.
Department of Biological Sciences University of Montana Missoula MT USA.
Ecol Evol. 2020 Jul 8;10(15):8251-8264. doi: 10.1002/ece3.6532. eCollection 2020 Aug.
The potential for ecological niche models (ENMs) to accurately predict species' abundance and demographic performance throughout their geographic distributions remains a topic of substantial debate in ecology and biogeography. Few studies simultaneously examine the relationship between ENM predictions of environmental suitability and both a species' abundance and its demographic performance, particularly across its entire geographic distribution. Yet, studies of this type are essential for understanding the extent to which ENMs are a viable tool for identifying areas that may promote high abundance or performance of a species or how species might respond to future climate conditions. In this study, we used an ensemble ecological niche model to predict climatic suitability for the perennial forb across its geographic distribution. We then examined relationships between projected climatic suitability and field-based measures of abundance, demographic performance, and forecasted stochastic population growth (λ). Predicted climatic suitability showed a J-shaped relationship with abundance, where low-abundance populations were associated with low-to-intermediate suitability scores and abundance increased sharply in areas of high predicted climatic suitability. A similar relationship existed between climatic suitability and λ from the center to the northern edge of the latitudinal distribution. Patterns such as these, where density or demographic performance only increases appreciably beyond some threshold of climatic suitability, support the contention that ENM-predicted climatic suitability does not necessarily represent a reliable predictor of abundance or performance across large geographic regions.
生态位模型（ENMs）在整个地理分布范围内准确预测物种丰度和种群统计学表现的潜力，在生态学和生物地理学领域仍是一个备受争议的话题。很少有研究同时考察环境适宜性的ENM预测与物种丰度及其种群统计学表现之间的关系，尤其是在其整个地理分布范围内。然而，这类研究对于理解ENMs在何种程度上是识别可能促进物种高丰度或良好表现区域的可行工具，或者物种如何应对未来气候条件至关重要。在本研究中，我们使用了一个综合生态位模型来预测多年生草本植物在其地理分布范围内的气候适宜性。然后，我们考察了预测的气候适宜性与基于实地的丰度、种群统计学表现以及预测的随机种群增长（λ）指标之间的关系。预测的气候适宜性与丰度呈现出J形关系，低丰度种群与低到中等适宜性得分相关，而在预测气候适宜性高的区域丰度急剧增加。从纬度分布的中心到北缘，气候适宜性与λ之间也存在类似关系。像这样的模式，即密度或种群统计学表现仅在气候适宜性超过某个阈值时才显著增加，支持了这样一种观点，即ENM预测的气候适宜性不一定代表大地理区域内丰度或表现的可靠预测指标。
