Am Nat. 2020 Feb;195(2):166-180. doi: 10.1086/706340. Epub 2019 Dec 13.
Plant community response to climate change ranges from synchronous tracking to strong mismatch. Explaining this variation in climate change response is critical for accurate global change modeling. Here we quantify how closely assemblages track changes in climate (match/mismatch) and how broadly climate niches are spread within assemblages (narrow/broad ecological tolerance, or "filtering") using data for the past 21,000 years for 531 eastern North American fossil pollen assemblages. Although climate matching has been strong over the last 21 millennia, mismatch increased in 30% of assemblages during the rapid climate shifts between 14.5 and 10 ka. Assemblage matching rebounded toward the present day in 10%-20% of assemblages. Climate-assemblage mismatch was greater in tree-dominated and high-latitude assemblages, consistent with persisting populations, slower dispersal rates, and glacial retreat. In contrast, climate matching was greater for assemblages comprising taxa with higher median seed mass. More than half of the assemblages were climatically filtered at any given time, with peak filtering occurring at 8.5 ka for nearly 80% of assemblages. Thus, vegetation assemblages have highly variable rates of climate mismatch and filtering over millennial scales. These climate responses can be partially predicted by species' traits and life histories. These findings help constrain predictions for plant community response to contemporary climate change.
植物群落对气候变化的响应范围从同步跟踪到强烈不匹配。解释气候变化响应的这种变化对于准确的全球变化建模至关重要。在这里，我们使用过去 21,000 年来 531 个北美东部化石花粉组合的数据，量化了组合与气候变化变化的紧密程度（匹配/不匹配）以及气候生态位在组合内的广泛程度（狭窄/广泛的生态耐受度，或“过滤”）。尽管在过去的 21000 年中，气候匹配一直很强，但在 14.5 和 10ka 之间的快速气候变化中，有 30%的组合的不匹配增加了。在 10%-20%的组合中，组合的匹配度反弹到了现在。在以树木为主导和高纬度的组合中，组合与气候的不匹配更大，这与持续存在的种群、较慢的扩散率和冰川退缩一致。相比之下，对于包含中值种子质量较高的分类群的组合，气候匹配度更高。在任何给定时间，超过一半的组合都受到气候的过滤，近 80%的组合在 8.5ka 时达到过滤的峰值。因此，植被组合在千年尺度上对气候变化的不匹配和过滤具有高度可变的速率。这些气候响应可以部分通过物种的特征和生活史来预测。这些发现有助于限制对植物群落对当代气候变化响应的预测。
