Spatial gradients in population growth, such as across latitudinal or elevational gradients, are often assumed to primarily be driven by variation in climate, and are frequently used to infer species’ responses to climate change. Here, we use a novel demographic, mixed‐model approach to dissect the contributions of climate variables vs. other latitudinal or local site effects on spatiotemporal variation in population performance in three perennial bunchgrasses. For all three species, we find that performance of local populations decreases with warmer and drier conditions, despite latitudinal trends of decreasing population growth toward the cooler and wetter northern portion of each species’ range. Thus, latitudinal gradients in performance are not predictive of either local or species‐wide responses to climate. This pattern could be common, as many environmental drivers, such as habitat quality or species’ interactions, are likely to vary with latitude or elevation, and thus influence or oppose climate responses.

中文翻译：

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人口增长的纬度梯度不反映人口对气候的反应

人口增长的空间梯度，例如跨纬度或海拔梯度，通常被认为主要是由气候变化驱动的，并且经常被用来推断物种对气候变化的反应。在这里，我们使用一种新的人口统计混合模型方法来剖析气候变量与其他纬度或当地地点对三种多年生草丛种群表现时空变化的影响。对于所有三个物种，我们发现当地种群的表现随着温暖和干燥的条件而下降，尽管人口增长向每个物种分布范围的较冷和潮湿的北部减少的纬度趋势。因此，性能的纬度梯度不能预测局部或物种范围对气候的反应。这种模式可能很常见，