Decreasing rainfall frequency contributes to earlier leaf onset in northern ecosystems
Decreasing rainfall frequency contributes to earlier leaf onset in northern ecosystems
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DOI：
10.1038/s41558-022-01285-w
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发表时间：
2022-02
影响因子：
30.7
通讯作者：
Jian Wang;Desheng Liu;P. Ciais;J. Peñuelas
中科院分区：
文献类型：
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作者：
Jian Wang;Desheng Liu;P. Ciais;J. Peñuelas
气候变化大大提前了叶期（LOD）并调节植物的碳吸收。与温度不同，降水的影响在很大程度上仍然难以捉摸。在这里，我们使用碳通量测量、叶子展开的原位记录和卫星绿度观测来研究降水频率（Pfreq，雨天数）在控制北部生态系统（>30°N）LOD 中的作用。在过去三十年中，Pfreq 的广泛下降对 LOD 的进步做出了积极贡献，这可能是由于辐射暴露的增加，显示出对约 10% 区域的 LOD 的主导控制。较低的 Pfreq 还可能会增强夜间的寒冷和白天的变暖，从而导致更早的 LOD。我们进一步开发了一种加权降水生长度日算法，该算法预测的 LOD 通常比当前预测的更早。这些结果强调需要全面了解降水对 LOD 的影响，这对于改进预测是必要的。
Climate change substantially advances the leaf onset date (LOD) and regulates carbon uptake by plants. Unlike temperature, the effect of precipitation remains largely elusive. Here we use carbon-flux measurements, in situ records of leaf unfolding and satellite greenness observations to examine the role of precipitation frequency (Pfreq, number of rainy days) in controlling the LOD in northern ecosystems (>30° N). Widespread decreases inPfreqduring the past three decades positively contributed to the advance in LOD, possibly due to increased exposure to radiation, exhibiting a dominant control of LOD over ~10% of the area. LowerPfreqmay also enhance chilling at night and warming at daytime, consequently leading to earlier LOD. We further develop a weighted precipitation growing-degree-day algorithm that projected a generally earlier LOD than currently predicted. These results highlight the need for a comprehensive understanding of the impacts of precipitation on LOD, which is necessary for improved projections.