What is Phenology?

Phenology is a branch of science which concerns itself with the observation and study of cyclical and sometimes predictable biological phenomena. You have probably practiced a bit of phenology yourself; every time you take note of a seasonal occurrence like emerging bulbs, fruiting trees, and the appearance of migratory birds, you are engaging in phenology. Many people believe that the study of recurring national phenomena could provide clues to upcoming weather conditions and the history of the Earth's weather, as many of these phenomena are dictated by the weather.

Budding, blooming, fruiting, and losing leaves are all examples of botanical phenology. Other examples of phenology include the emergence of animals from hibernation, breeding seasons, the shifting of migratory populations, and even the growth rate of crops. Many cultures have been deeply concerned with these events, using them to establish planting schedules and to make predictions about seasonal weather, and you may be familiar with some folk rhymes like “knee high by the Fourth of July” to describe the height which corn should have attained by this date.

Scientists have used phenology to try and reconstruct the globe's historical climate, utilizing things like harvest records for grapes as clues. The grape harvest tends to be a highly publicized and important event, and extensive records which include the dates of harvest date back hundreds of years in some parts of Europe, allowing people to estimate what the climate was like in various years. Other clues which have been used include the formation and breakup of winter ice, planting dates for various years, and the recorded emergence of blossoms, along with the date of the spring lambing.

Around the world, numerous scientific teams are also using phenology to track the modern climate, and to determine the impact of climate change on natural phenomena. These teams track things like seasonal festivals linked to events such as the emergence of the cherry blossoms, along with reports from individuals about the budding and blooming schedules in their own gardens. Such surveys often reveal very interesting information about regional microclimates.

Phenology surveys are one example of “citizen science,” collection of scientific information which includes non-scientists. Citizen science can be a really useful way to collect a great deal of data, and it encourages people to get involved with and interested in science. Many gardeners around the world participate in bud tracking programs, for example, inputting data about their gardens and reading reports from gardeners in other regions. Citizen science can also take advantage of people with years of nature experience, like farmers who record their planting data every year, or wildcrafters who are alert to the emergence of particular plants and fungi.