Forecasts of future forest change are governed by ecosystem sensitivity to climate change, but ecosystem model projections are under‐constrained by data at multidecadal and longer timescales. Here, we quantify ecosystem sensitivity to centennial‐scale hydroclimate variability, by comparing dendroclimatic and pollen‐inferred reconstructions of drought, forest composition and biomass for the last millennium with five ecosystem model simulations. In both observations and models, spatial patterns in ecosystem responses to hydroclimate variability are strongly governed by ecosystem sensitivity rather than climate exposure. Ecosystem sensitivity was higher in models than observations and highest in simpler models. Model‐data comparisons suggest that interactions among biodiversity, demography and ecophysiology processes dampen the sensitivity of forest composition and biomass to climate variability and change. Integrating ecosystem models with observations from timescales extending beyond the instrumental record can better understand and forecast the mechanisms regulating forest sensitivity to climate variability in a complex and changing world.

中文翻译：

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森林对上千年水气候变化的响应取决于生态系统敏感性的空间变化

未来森林变化的预测取决于生态系统对气候变化的敏感性，但生态系统模型的预测却受到数十年和更长时间尺度的数据的约束。在这里，我们通过对树状气候和花粉推断的上一千年干旱，森林组成和生物量的重建与五个生态系统模型的模拟进行比较，来量化生态系统对百年尺度水气候变化的敏感性。在观测和模型中，生态系统对水气候变化的响应中的空间格局都受生态系统敏感性而不是气候暴露的强烈支配。模型中的生态系统敏感性高于观测值，而简单模型中的生态系统敏感性最高。模型数据比较表明，生物多样性之间的相互作用，人口统计学和生态生理学过程削弱了森林组成和生物量对气候变化和变化的敏感性。将生态系统模型与超越工具记录的时间尺度的观测结果相结合，可以更好地理解和预测在复杂多变的世界中调节森林对气候变化敏感性的机制。