Cottonwoods, Populus trees, provide the foundation for riparian woodlands around the Northern Hemisphere but have declined partly due to river damming and water withdrawal. Cottonwood conservation requires periodic seedling replenishment, which depends upon coordinating river flows with the limited seed dispersal interval. Tracking seed dispersal phenology is laborious and we recognized a complementary approach with photographs and videos of prolific cottonwood seed release on internet websites. We searched the internet for ‘cottonwood seeds’ or ‘summer snow’, and about 800 images were posted since 2004. The 337 reports from North America with dates and/or locations revealed sequential seed dispersal in the American Southwest, the Pacific Northwest, the Great Lakes Region, and finally Alaska. Mean dispersal was June 3, with two-thirds of reports in the flanking four week interval. Dispersal was later at higher latitude and elevation, and a two-factor regression model provided 85% accuracy with reported peak dispersal from nine previous studies across western North America. The 49 Eurasian reports also revealed later seed dispersal with increasing latitude. This study revealed the utility of internet searching for tracking cottonwood seed dispersal, which could facilitate environmental flows for riparian restoration. More broadly, internet reports could reveal spatiotemporal patterns in other natural phenomena.

杨树，杨树树木为北半球周围的河岸林地提供了基础，但部分由于河水泛滥和取水而下降。保护杨木需要定期补苗，这取决于在有限的种子传播间隔内协调河流流量。跟踪种子传播物候很费力，我们认识到一种补充方法，它在互联网网站上发布了多种杨木种子释放的照片和视频。自2004年以来，我们在互联网上搜索了“棉籽”或“夏雪”，并发布了800张图像。来自北美的337份报告（带有日期和/或位置）显示了种子在美国西南部，西北太平洋，大湖区，最后是阿拉斯加。平均分散时间是6月3日，四周间隔的三分之二的报告。后来在较高的纬度和海拔高度分散，并且两因素回归模型提供了85％的准确度，并且报告了先前在北美西部进行的九项研究的峰值分散。欧亚的49份报告还显示，随着纬度的增加，种子随后会散播。这项研究揭示了互联网搜索跟踪三角叶杨种子扩散的实用工具，它可以促进环境流向河岸恢复。更广泛地说，互联网报告可以揭示其他自然现象的时空格局。欧亚的49份报告还显示，随着纬度的增加，种子随后会散播。这项研究揭示了互联网搜索跟踪三角叶杨种子扩散的实用工具，它可以促进环境流向河岸恢复。更广泛地说，互联网报告可以揭示其他自然现象的时空格局。欧亚的49份报告还显示，随着纬度的增加，种子随后会散播。这项研究揭示了互联网搜索跟踪三角叶杨种子扩散的实用工具，它可以促进环境流向河岸恢复。更广泛地说，互联网报告可以揭示其他自然现象的时空格局。