A phenological data set collected by citizen scientists from 1970 to 2018 in Latvia is presented, comprising almost 47 000 individual observations of eight taxonomical groups, in addition to agrarian activities and abiotic parameters, covering in total 159 different phenological phases. These original data published offline in annual issues of the Nature and History Calendar (in Latvian, Dabas un vēstures kalendārs) have been digitized, harmonized, and geo-referenced.Overall, the possible use of such data is extensive, as phenological data are excellent bioindicators for characterizing climate change and can be used for the elaboration of adaptation strategies in agriculture, forestry, and environmental monitoring. The data can also be used in cultural–historical research; for example, the database includes data on sugar beet and maize, the cultivation of which was imposed on collective farms during the Soviet period. Thus, such data are not only important in the Earth sciences but can also be applied to the social sciences.The data significantly complement current knowledge on European phenology, especially regarding northern regions and the temporal biome. The data here cover two climate reference periods (1971–2000; 1981–2010), in addition to more recent years, and are particularly important in monitoring the effects of climate change. The database can be considered the largest open phenological data set in the Baltics.The data are freely available to all interested at https://doi.org/10.5281/zenodo.3982086 (Kalvāne et al., 2020).

中文翻译：

---

来自北欧拉脱维亚的多分类群、农业活动和非生物参数的长期物候数据集

介绍了 1970 年至 2018 年拉脱维亚公民科学家收集的物候数据集，包括对八个分类群的近 47 000 个个体观察，以及农业活动和非生物参数，涵盖总共 159 个不同的物候阶段。这些原始数据离线发表在《自然与历史日历》的年度刊物上（拉脱维亚语，Dabas un vēstures kalendārs) 已被数字化、协调和地理参考。总的来说，这些数据的可能用途是广泛的，因为物候数据是表征气候变化的极好生物指标，可用于制定农业、林业和环境方面的适应战略监测。这些数据也可用于文化历史研究；例如，该数据库包括甜菜和玉米的数据，在苏联时期，集体农庄强制种植甜菜和玉米。因此，这些数据不仅在地球科学中很重要，而且还可以应用于社会科学。这些数据极大地补充了欧洲物候学的当前知识，特别是关于北部地区和时间生物群落的知识。这里的数据涵盖两个气候参考期（1971-2000 年；1981-2010 年），除了最近几年，而且在监测气候变化的影响方面尤为重要。该数据库可以被认为是波罗的海地区最大的开放物候数据集。所有感兴趣的人都可以免费获得这些数据：https://doi.org/10.5281/zenodo.3982086（Kalvāne 等，2020）。