Demographic compensation does not rescue populations at a trailing range edge

Species' geographic ranges and climatic niches are likely to be increasingly mismatched due to rapid climate change. If a species' range and niche are out of equilibrium, then population performance should decrease from high-latitude \"leading\" range edges, where populations are expanding into recently ameliorated habitats, to low-latitude \"trailing\" range edges, where populations are contracting from newly unsuitable areas. Demographic compensation is a phenomenon whereby declines in some vital rates are offset by increases in others across time or space. In theory, demographic compensation could increase the range of environments over which populations can succeed and forestall range contraction at trailing edges. An outstanding question is whether range limits and range contractions reflect inadequate demographic compensation across environmental gradients, causing population declines at range edges. We collected demographic data from 32 populations of the scarlet monkeyflower (Erythr...

受快速气候变化影响，物种的地理分布范围与气候生态位（climatic niche）的错配程度或将持续加剧。若某物种的分布范围与生态位未能维持平衡，则其种群表现将随纬度梯度呈现下降趋势：从高纬度的“前沿”分布边界（种群正扩张至新近适宜的生境），延伸至低纬度的“后缘”分布边界（种群正从不再适宜的栖息区域中退缩）。种群统计补偿（demographic compensation）是指在时间或空间维度上，部分关键生命参数的下降可被其他参数的上升所抵消的现象。理论上，种群统计补偿可扩大种群得以存续的环境范围，并延缓分布后缘的种群退缩进程。当前一个悬而未决的核心问题是：分布边界限制与种群退缩是否源于沿环境梯度的种群统计补偿不足，进而引发分布边界处的种群数量下降？本研究从红花猴面花（scarlet monkeyflower，学名Erythr...）的32个种群中采集了种群统计数据。