Data from: Less favorable climates constrain demographic strategies in plants

Correlative species distribution models are based on the observed relationship between species’ occurrence and macroclimate or other environmental variables. In climates predicted less favourable populations are expected to decline, and in favourable climates they are expected to persist. However, little comparative empirical support exists for a relationship between predicted climate suitability and population performance. We found that the performance of 93 populations of 34 plant species worldwide – as measured by in situ population growth rate, its temporal variation and extinction risk – was not correlated with climate suitability. However, correlations of demographic processes underpinning population performance with climate suitability indicated both resistance and vulnerability pathways of population responses to climate: in less suitable climates, plants experienced greater retrogression (resistance pathway) and greater variability in some demographic rates (vulnerability pathway). While a range of demographic strategies occur within species’ climatic niches, demographic strategies are more constrained in climates predicted to be less suitable.

关联物种分布模型（Correlative Species Distribution Models）基于物种出现记录与大气候或其他环境变量之间的观测关联。该模型假设，在预测为较不适宜的气候条件下，物种种群将出现衰退；而在适宜气候条件下，种群则得以存续。然而，目前鲜有对比性实证证据支持预测气候适宜性与种群表现之间存在关联。本研究发现，全球34种植物的93个种群，其表现以原位（in situ）种群增长率、增长率的时间变异及灭绝风险为衡量指标，与气候适宜性并无关联。但支撑种群表现的种群统计过程与气候适宜性之间的关联，却揭示了种群对气候响应的两条路径：抗性路径与脆弱性路径——在不适宜程度更高的气候中，植物种群出现了更显著的退化（抗性路径），且部分种群统计率的波动幅度更大（脆弱性路径）。尽管物种种群的气候生态位内存在多种种群统计策略，但在预测为不适宜的气候条件下，种群统计策略会受到更强的约束。