Nature's Calendar: Spring Check - phenological observations made by Citizen Scientists

Nature's Calendar (www.naturenskalender.se, in Swedish only) is run by the Swedish National Phenology Network (SWE-NPN), a consortium of Swedish universities, governmental agencies and non-governmental organisations. The Swedish University of Agricultural Sciences (SLU) hosts the network and is part of the Climate program within the environmental monitoring and assessment activity branch of the university. The main task for the Nature's calendar is to collect observations of different spring and autumn signs appearing during the vegetation season. SWE-NPN is connected to the monitoring of the Swedish Environmental Objectives, mainly concerning the objective Reduced Climate Impact, but is also collaborating with networks in Europe (through the Pan-European Phenology database - PEP725) and internationally (through the International Society of Biometeorology).

Data about the nature's calendar is collected in two ways, the long-term environmental monitoring through "Calendars", where phenological observations are reported all through the year, and through "Checks", where phenology observations are reported during short-time campaigns, giving a snapshot of the phenological status at a certain time of the year. The long-term environmental monitoring is performed by citizen scientists and professional observers at research stations and like. Since 2015, a campaign called "Vårkollen" (i.e. "Spring Check") has also been run April 30 - May 1 every year. In the Spring Check, Citizen Scientist's have reported observations of how far the development of the flowering of Liverleaf, Colt's-foot, Wood Anemone, Goat Willow and Bird Cherry, and budburst of birch have progressed. All species has also been reported in the historical dataset mentioned below.

The Spring Check campain is performed by two SWE-NPN partners, SLU and the Swedish Botanical Association (SBF), where SLU provides the technical platform and data analyses and SBF produce folders and by hosting regional contacts for the press. The results are made available to the public by press releases directly after the campain is finished.

Aims
The aim of the Nature's Calendar is to collect phenological data from the first spring sign to the last autumn sign, to be able to offer nation-wide data to everyone interested, to facilitate research, environmental assessments, the evaluation of environmental goals, etc, to be better prepared to meet the effects of climate change. Observations reported to the Nature's Calendar can be compared to similar observations collected for more than 100 years ago (see the Swedish Historical Phenology Dataset in "Related Reseach Data"), to detect evidence of phenological shifts over time that can be connected to climate change.

The aim with the data collection of the Spring Check is to obtain nationwide data that can provide information to understand, track changes and predict effects of climate change on natural plants in Sweden by studying the progress of some species all over the country at one and the same date every year, and compare the current progress with what have been seen in historical records of the same plants.

The dataset includes one file with observation data (spring_check_2015-2024.csv), one PDF file (metadata_spring_check_2015-2024.pdf) with metadata that describes how the included parameters should be interpreted and lists of included species and phases, and one PDF file (Varkollen_folder_2024.pdf) which is the instruction given to the observers (in Swedish, only). The observation data file includes totally 69,668 observations.

《自然日历》（www.naturenskalender.se，仅提供瑞典语版本）由瑞典国家物候学网络（Swedish National Phenology Network, SWE-NPN）运营，该网络是瑞典高校、政府机构与非政府组织组成的联合共同体。瑞典农业科学大学（Swedish University of Agricultural Sciences, SLU）为该网络的托管单位，隶属于该校环境监测与评估分支下的气候项目组。《自然日历》的核心任务是收集植被生长季内出现的各类春季与秋季物候信号观测数据。SWE-NPN的监测工作与瑞典环境目标深度绑定，主要聚焦于“减缓气候影响”这一核心目标，同时还与欧洲（通过泛欧物候学数据库Pan-European Phenology database, PEP725）及国际（通过国际生物气象学会）的相关网络开展合作。

该平台的数据采集分为两类途径：其一为通过“日历”开展的长期环境监测，全年持续上报物候观测数据；其二为通过“核查”开展的短期专项观测，在限时活动中上报特定时段的物候状态快照。长期环境监测工作由公民科学家与研究站等机构的专业观测人员完成。自2015年起，每年4月30日至5月1日还会开展一项名为“Vårkollen”（即“春季核查”）的专项活动。在春季核查活动中，公民科学家需上报獐耳细辛（Liverleaf）、款冬（Colt's-foot）、林银莲花（Wood Anemone）、山羊柳（Goat Willow）、稠李（Bird Cherry）的开花进展，以及桦树的芽萌动情况。上述物种的相关观测数据也收录于下文中提及的历史数据集内。

春季核查活动由SWE-NPN的两家合作方——SLU与瑞典植物学会（Swedish Botanical Association, SBF）共同开展：SLU负责提供技术平台与数据分析支持，SBF则负责制作活动手册，并对接媒体的区域联络工作。活动结束后，相关结果会通过新闻稿直接向公众公开。

### 项目目标
《自然日历》的目标是收集从首个春季物候信号至末次秋季物候信号的全季候物候数据，为所有有需求的群体提供覆盖全国范围的数据集，以助力科研、环境评估、环境目标成效评估等工作，从而更好地应对气候变化带来的影响。用户上报至《自然日历》的观测数据，可与距今一百多年前的同类观测记录（详见“相关研究数据”中的《瑞典历史物候学数据集》）进行对比，以识别与气候变化相关的物候变化趋势。

春季核查的数据采集目标则是获取全国范围的观测数据，通过在每年同一日期对全国范围内部分物种的物候进展进行观测，以了解、追踪并预测气候变化对瑞典本土植物的影响，并将当前的物候进展与同类物种的历史观测记录进行对比。

本数据集包含三份文件：1. 观测数据文件（spring_check_2015-2024.csv），共计收录69668条观测记录；2. 元数据PDF文件（metadata_spring_check_2015-2024.pdf），用于说明文件内各参数的解读方式，并列出所包含的物种与物候阶段；3. 活动手册PDF文件（Varkollen_folder_2024.pdf），即向观测者提供的操作指南（仅提供瑞典语版本）。