PhenoCam Images and Canopy Phenology at the Harvard Forest Witness Tree since 2014

The PhenoCam Network uses imagery from digital cameras to track vegetation phenology and seasonal changes in vegetation activity in diverse ecosystems across North America and around the world. Imagery is uploaded to the PhenoCam server at the University of New Hampshire, where it is made publicly available in near-real time, every 30 minutes from sunrise to sunset, 365 days a year. The data are processed using simple image analysis tools to yield a measure of canopy greenness, from which phenological metrics are extracted, characterizing the start and end of the growing season. These transition dates have been shown to align well with on-the-ground observations of tree phenology at Harvard Forest (HF003). Long-term PhenoCam data can be used to track the impact of climate variability and change on the rhythm of the seasons. This dataset contains one mid-day image for each camera. Please see the PhenoCam Network website (https://phenocam.nau.edu/webcam/) for more information and additional images.物候相机网络（PhenoCam Network）借助数码相机拍摄的影像，追踪北美及全球范围内各类生态系统中的植被物候与植被活动的季节变化。所有影像会上传至新罕布什尔大学（University of New Hampshire）的PhenoCam服务器，并以近实时形式公开发布：全年365天、从日出至日落时段内每30分钟更新一次。研究人员通过简易图像分析工具对数据进行处理，得到冠层绿度（canopy greenness）指标，进而提取物候参数，用以表征生长季的起止时间。上述物候转换日期已被证实与哈佛大学森林（Harvard Forest，HF003）的地面树木物候观测结果高度吻合。长期PhenoCam观测数据可用于追踪气候变率与气候变化对季节节律的影响。本数据集包含每台相机拍摄的一张正午影像。如需获取更多信息及额外影像，请访问物候相机网络官网：https://phenocam.nau.edu/webcam/