Wu Zhaofei, Fu Yongshuo H, Crowther Thomas W, Wang Shuxin, Gong Yufeng, Zhang Jing, Zhao Yun-Peng, Janssens Ivan, Penuelas Josep, Zohner Constantin M
College of Water Sciences, Beijing Normal University, Beijing, 100875, China.
Institute of Integrative Biology, ETH Zurich (Swiss Federal Institute of Technology), Zurich, 8092, Switzerland.
New Phytol. 2023 Nov;240(4):1421-1432. doi: 10.1111/nph.19229. Epub 2023 Aug 26.
Global warming is advancing the timing of spring leaf-out in temperate and boreal plants, affecting biological interactions and global biogeochemical cycles. However, spatial variation in spring phenological responsiveness to climate change within species remains poorly understood. Here, we investigated variation in the responsiveness of spring phenology to temperature (RSP; days to leaf-out at a given temperature) in 2754 Ginkgo biloba twigs of trees distributed across subtropical and temperate regions in China from 24°N to 44°N. We found a nonlinear effect of mean annual temperature on spatial variation in RSP, with the highest response rate at c. 12°C and lower response rates at warmer or colder temperatures due to declines in winter chilling accumulation. We then predicted the spatial maxima in RSP under current and future climate scenarios, and found that trees are currently most responsive in central China, which corresponds to the species' main distribution area. Under a high-emission scenario, we predict a 4-degree latitude shift in the responsiveness maximum toward higher latitudes over the rest of the century. The identification of the nonlinear responsiveness of spring phenology to climate gradients and the spatial shifts in phenological responsiveness expected under climate change represent new mechanistic insights that can inform models of spring phenology and ecosystem functioning.
全球变暖正在使温带和寒温带植物春季展叶的时间提前，影响生物相互作用和全球生物地球化学循环。然而，物种内部春季物候对气候变化的空间变异性仍知之甚少。在此，我们研究了分布于中国北纬24°至44°亚热带和温带地区的2754株银杏树枝条春季物候对温度的响应性变异（RSP；在给定温度下展叶所需天数）。我们发现年均温度对RSP的空间变异存在非线性影响，在约12°C时响应率最高，而在温度较高或较低时响应率较低，这是由于冬季低温积累减少所致。然后，我们预测了当前和未来气候情景下RSP的空间最大值，发现树木目前在中国中部响应最为强烈，而该区域对应着该物种的主要分布区。在高排放情景下，我们预测在本世纪余下时间里，响应最大值将向高纬度地区发生4度纬度的移动。确定春季物候对气候梯度的非线性响应以及气候变化下物候响应性的空间转移，代表了新的机理性见解，可为春季物候和生态系统功能模型提供参考。
