Tracking Nature's Cycles
Phenology is the study of recurring biological cycles such as plant budding and animal migrations. The earliest known phenological records were compiled by the Chinese approximately 1000 BC. Today, USGS Remote Sensing Phenology scientists use satellites to track seasonal changes in vegetation on regional, continental, and global scales. Remotely sensed phenological data are useful for assessing crop conditions, drought severity, and wildfire risk as well as tracking invasive species, infectious diseases, and insect pests. Because phenological events are sensitive to climate variation, these data also represent a powerful tool for documenting phenological trends over time and detecting the impacts of climate change on ecosystems at multiple scales.