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 −1 , 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 The network is no longer active.

中文翻译：

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芬兰国家物候网络 1997-2017：从观察到趋势检测

在芬兰大陆的 42 个地点收集并涵盖 1997-2017 年的植物物候数据集被呈现并分析了时间趋势。n = 16,257 个观测值的数据集代表 11 个植物物种和 15 个物候阶段，并产生 40 个不同的变量，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 年的研究期间至少包含 10 个观察结果。检测到春季和初夏物候提前的明确信号，十年 -1 天为 3.4 天，由 4 月至 6 月发生的物候期的高比例负趋势证明。纬度相关表明研究区北部的春季和初夏物候信号较强。与其他季节观察到的相比，秋季信号不太一致，并且显示出更大的现场变化。超过 60% 基于单棵树/监控方格的日期与站点内多棵树/监控方格的平均值完全相同。特别是，秋季物候学数据的可靠性通过每个地点的多次观察而增加。网络不再活动。