Plant Phenology Icons

I was looking at this very heavy textbook on phenology that I can’t imagine any of you opening up to read. I’m not going to get to read it through either,  but I find the subject fascinating and there is plenty of information online to keep me busy.

It always makes me sad that we are not the observers of nature that people were in earlier centuries. People paid much closer attention to the world around them and how the plants were changing with the seasons and what phase the Moon was in what the animals and insects were up to. And a long time before we had a scientific name for it, people recorded signs of the seasonal changes.

Today we call this phenology – the study of seasonal change as reflected in plant and animal life. (Not to be confused with the phrenology – a definitely fringe study from the Victorian era when doctors believed they could tell everything about a person from mapping out the bumps and oddities of the human skull.)

Phenology is the study of plant and animal life cycle events, which are triggered by environmental changes, especially temperature.

You would note the first openings of leaf and flower buds, insect hatchings (fly fisherman do some of this) and the return or departure of birds and insects.

I think that this has become a bit more popular the past few decades as the they might be seen as indicators of the impact of local and global changes in weather and climate on the earth’s biosphere.

The father of modern phenology is Englishman Robert Marsham who began recording signs from nature in 1736 and continued for 62 years. The word is derived from the Greek phainō, “to show, to bring to light, make to appear” and logos for “the study of.”

I do my own amateur phenology because I am a gardener and because I enjoy being out in nature and keep my own little field guides and calendars of my little local biosphere. I record the emergence of leaves and flowers, the first flight of butterflies and the first appearance of certain migratory birds.

Spring is a time full of these events. I also record when I start my vegetable seeds, set the plants out and harvest the first crop. Of course, those dates are somewhat in my control and not phenology. But I start those seeds and set out those plants based on my observations from past years of frosts and the appearances of other plants and flowers in my area.

I read that viticultural records of grape harvests in Europe have been used to reconstruct a record of summer growing season temperatures going back more than 500 years.

Some of what I learned growing up might border on folk wisdom, but seem to hold true. Dandelions in full bloom means it is time to plant potatoes. My father told me we could plant peas on St. Patrick’s Day if the soil wasn’t muddy, but I got burned on that a few times. Safer to wait for the full flowering of forsythia to put the peas into the ground.

Frost dates are the usual way to go on planting, but those dates don’t change very often in books and guideseven though they vary quite a bit in my little local records.

Chicory-FlowerObserving insects is a bit harder, but sometimes that mixes with the plants.

If you have the pretty blue wild chicory blooms nearby in summer, it is time for squash vine borers who just love to attack unprotected squash and pumpkins.

Insects are often used as weather predictors. You probably have heard some version of observing insects flying lower to the ground before a storm, or that insects can sense the onset of very wet weather. They will be observed in monsoon and rainy areas invading buildings for shelter before a storm. Some ants will pile up dirt around the entrance to their underground homes to keep out water.

Phenology has gone from being a fringe science to a real way of understanding climate change. It also a citizen scientist activity and there are lots of websites that allow you to record your garden, bird and insect observations into a database which gives scientists a huge amount of data to work with.  Project Bud Burst in the U.S. and Nature’s Calendar in the U.K> are two examples. In the US, you can also participate in the reporting program conducted by the National Phenology Network.  There is the University of Berlin’s International Phenological Gardens that collate observations from 89 gardens in 19 European countries.  And Earthwatch programs in Australia and other countries will increase the database.

A term that I picked up in my reading is “season creep.” People are observing birds laying their eggs earlier and buds appearing on some trees much earlier.  Northern hardwood forests have been leafing out sooner and retaining their green canopies longer and the agricultural growing season has also expanded by 10–20 days over the last few decades.

Does this prove climate change or global warming. Probably not. The Earth goes through long cycles and we are probably on a warming trend now. The many droughts and violent storms are also indicators. Of course, the climate change argument really centers on whether or not it is man’s activities that have caused this change or is it just nature. I side with the blame people side on this because the changes seem to be progressing unnaturally fast.

All that Big Science on temperature, moisture, and changing sea levels is important. But, I am really “thinking globally, acting locally” with my calendar and journal and more interested in getting people to reconnect to plants and animals. My posts on the Full Moons and even those on weather lore are really just part of that idea of observing the place where you live.

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