Helama Samuli, Tolvanen Anne, Karhu Jouni, Poikolainen Jarmo, Kubin Eero
Natural Resources Institute Finland, Ounasjoentie 6, 96200, Rovaniemi, Finland.
Natural Resources Institute Finland, University of Oulu, P.O. Box 413, 90014, Oulu, Finland.
Int J Biometeorol. 2020 Oct;64(10):1783-1793. doi: 10.1007/s00484-020-01961-6. Epub 2020 Jul 6.
Plant phenological dataset collected at 42 sites across the mainland of Finland and covering the years 1997-2017 is presented and analysed for temporal trends. The dataset of n = 16,257 observations represents eleven plant species and fifteen phenological stages and results in forty different variables, i.e. phenophases. Trend analysis was carried out for n = 808 phenological time-series that contained at least 10 observations over the 21-year study period. A clear signal of advancing spring and early-summer phenology was detected, 3.4 days decade, demonstrated by a high proportion of negative trends for phenophases occurring in April through June. Latitudinal correlation indicated stronger signal of spring and early-summer phenology towards the northern part of the study region. The autumn signal was less consistent and showed larger within-site variations than those observed in other seasons. More than 60% of the dates based on single tree/monitoring square were exactly the same as the averages from multiple trees/monitoring squares within the site. In particular, the reliability of data on autumn phenology was increased by multiple observations per site. The network is no longer active.
本文展示并分析了1997年至2017年间在芬兰大陆42个地点收集的植物物候数据集的时间趋势。该数据集包含n = 16257条观测数据，涵盖11种植物和15个物候阶段，产生了40个不同变量，即物候期。对n = 808个物候时间序列进行了趋势分析，这些时间序列在21年的研究期内至少包含10条观测数据。通过4月至6月出现的物候期有很大比例呈现负趋势，检测到春季和初夏物候提前的明显信号，为每十年提前3.4天。纬度相关性表明，研究区域北部春季和初夏物候的信号更强。秋季信号不太一致，且与其他季节相比，站点内变化更大。基于单棵树/监测方块的日期中，超过60%与站点内多棵树/监测方块的平均值完全相同。特别是，通过每个站点的多次观测提高了秋季物候数据的可靠性。该网络不再活跃。
