How is Seasonal Change Linked to Climate?
Since early history, humans have been aware of seasonal changes in plant and animal life cycles. Phenology is the study of the timing of these changes. Animals hibernate or migrate, leaves grow, flowers bloom, insects hatch, and so on. After thousands or millions of years of evolution, these events are naturally matched with a species’ biological needs to find food, reproduce, and otherwise survive. Daylength — which changes predictably throughout the year — and a region’s climate (especially temperature and rainfall) determine when these events typically unfold. Plants and animals can handle natural variations in weather from season to season and year to year. For instance, some years are colder or wetter on average. But as long-term weather patterns (climate) have changed more rapidly – and dramatically – than ever before, the average timing of many life cycle events has shifted. This has put some species out of synch with food chains and other parts of the ecosystems they depend on.
