Wu Zhaofei, Wang Shuxin, Fu Yongshuo H, Gong Yufeng, Lin Chen-Feng, Zhao Yun-Peng, Prevéy Janet S, Zohner Constantin
College of Water Sciences, Beijing Normal University, Beijing, China.
Systematic & Evolutionary Botany and Biodiversity Group, MOE Key Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, China.
Front Plant Sci. 2022 May 10;13:887226. doi: 10.3389/fpls.2022.887226. eCollection 2022.
Climate warming-induced shifts in spring phenology have substantially affected the structure and function of terrestrial ecosystems and global biogeochemical cycles. Spring phenology is primarily triggered by spring temperature and is also affected by daylength and winter chilling, yet the relative importance of these cues across spatial gradients remains poorly understood. Here, we conducted a manipulative experiment with two daylength and three temperature treatments to investigate spatial differences in the response of ginkgo budburst to temperature and daylength, using twigs collected at three sites across a spatial gradient: a control site at a low latitude and low elevation on Tianmu Mountain (TM), a low latitude and high elevation site on Tianmu Mountain (TM), and a high latitude site on Jiufeng mountain (JF). The mechanisms were also tested using phenological observations of ginkgo along latitudes in China. We found that, compared to TM individuals, budburst dates occurred 12.6 (JF) and 7.7 (TM) days earlier in high-latitude and high-elevation individuals when exposed to the same temperature and daylength treatments. Importantly, daylength only affected budburst at low latitudes, with long days (16 h) advancing budburst in low-latitude individuals by, on average, 8.1 days relative to short-day (8 h) conditions. This advance was most pronounced in low-elevation/latitude individuals (TM = 9.6 days; TM = 6.7 days; JF = 1.6 days). In addition, we found that the temperature sensitivity of budburst decreased from 3.4 to 2.4 days °C along latitude and from 3.4 to 2.5 days °C along elevation, respectively. The field phenological observations verified the experimental results. Our findings provide empirical evidence of spatial differences in the relative effects of spring temperature and daylength on ginkgo budburst, which improved our understanding of spatial difference in phenological changes and the responses of terrestrial ecosystem to climate change.
气候变暖导致的春季物候变化已对陆地生态系统的结构和功能以及全球生物地球化学循环产生了重大影响。春季物候主要由春季温度触发，同时也受日照长度和冬季低温的影响，然而这些线索在空间梯度上的相对重要性仍知之甚少。在此，我们进行了一项控制实验，设置了两种日照长度和三种温度处理，以研究银杏芽萌发对温度和日照长度响应的空间差异，实验使用了在一个空间梯度上三个地点采集的嫩枝：天目山（TM）低纬度和低海拔的对照地点、天目山（TM）低纬度和高海拔地点以及鹫峰（JF）高纬度地点。还利用中国沿纬度的银杏物候观测对相关机制进行了测试。我们发现，在相同温度和日照长度处理下，与TM的个体相比，高纬度和高海拔个体的芽萌发日期分别提前了12.6天（JF）和7.7天（TM）。重要的是，日照长度仅在低纬度地区影响芽萌发，长日照（16小时）使低纬度个体的芽萌发相对于短日照（8小时）条件平均提前8.1天。这种提前在低海拔/低纬度个体中最为明显（TM = 9.6天；TM = 6.7天；JF = 1.6天）。此外，我们发现芽萌发的温度敏感性分别沿纬度从3.4天/°C降至2.4天/°C，沿海拔从3.4天/°C降至2.5天/°C。野外物候观测验证了实验结果。我们的研究结果为春季温度和日照长度对银杏芽萌发的相对影响存在空间差异提供了实证依据，这增进了我们对物候变化空间差异以及陆地生态系统对气候变化响应的理解。
