Ecosystem Phenology: Integrating Traits and Processes Beyond Observable Events

Phenology—the study of seasonal biological events shaped by climate variability—has long offered critical insights into the impact of climate change on ecosystems. Traditionally, phenological research has focused on discrete and observable events such as budburst, leaf-out, flowering, and migration. Yet ecosystems are not driven by isolated events alone, but by continuous shifts in functional traits and biogeochemical processes. The event-based phenology framework often overlooks this dynamic variability in traits and processes. To completely understand the temporal change in ecosystem functioning, we propose an expanded concept—ecosystem phenology—which integrates functional traits and biochemical processes beyond visible events. By capturing the full temporal spectrum of ecosystem dynamics, the ecosystem phenology framework provides a comprehensive understanding of ecosystem responses to climate change, with significant implications for forecasting ecosystem function and informing climate policy.