Calibrating Nature’s Calendar
Think how often the behavior of plants and animals cues us to seasonal change: the green up of trees and the dawn chorus of courting birds announce spring, or leaf color change and the departure of migrants make us aware of the waning year.
For scientists these changes are more than anecdotal. Phenology is the scientific study of the timing of life cycle events in plants and animals: when budburst, flowering, and fruiting occur in plants, for instance, or when migratory birds arrive or seasonal insects hatch.
Why Phenology Matters
Phenological research yields vital information to guide our management of natural systems and to chart the impact of climate change on ecology. Phenological data guides farmers in knowing when to plant and fertilize crops. It can help resource managers anticipate and respond to the seasonal emergence of damaging insects. It helps health care professionals predict and prepare for allergy season and track pests like ticks and mosquitos. Long-term phenological trends guide the scheduling of cultural events like the National Cherry Blossom Festival.
Most importantly, phenological records allow scientists to assess the impact of climate change on our ecological systems. “Changes in phenological events like flowering and animal migration are among the most sensitive biological responses to climate change.” https://www.indianaphenology.org/learn
Calendars out of sync
Of particular concern is accumulating evidence that rapid climate change is producing mismatches in phenological events that can have negative impacts on plants and animals. This chart, for instance, depicts what happens when caterpillars, spurred by warmer temperatures, hatch too early, before migrating birds have given birth to the nestlings that need those caterpillars to survive.
https://nadiah.org/2015/05/23/migratory-bird-phenology
These phenological shifts can also have economic ramifications. In the southeastern United States in particular, unseasonably early heat from “false springs” has encouraged the earlier budding of fruit trees, making them more vulnerable to damage and crop loss from late season freezes. https://www.usanpn.org/files/reports/changes_in_phenology-se.pdf
The USA National Phenology Network https://www.usanpn.org/ is the chief clearing house for phenological information. It collects, organizes, and makes data available to scientists and decision makers. Click on this link to learn how phenological data is collected and to find out about how ARMN members are tracking phenological change in our regional plants.
Learn About Phenology | Conducting Phenological Research | ARMN Phenology Project