The Slow Science of Phenology

More incontrovertible signs of spring arrived this week: spring peepers and chorus frogs began their eons-old ritual of calling, mating and reproducing, road construction crews are similarly multiplying, and Peterborough County is choking under its first smog alert of the year.

I’m most interested in the frogs.  For a number of years, I’ve been informally recording in my journal the date of their annual appearance.  Last year, they first gave song the evening of 28 March; the year before it was 3 April.  This year, mostly owing to the depth of the snow cover, it was 14 April. This relates to a fascinating subset of climate change science, a small revival of phenology, an old methodology describing the rhythms and changes of the seasons and their recurring effects on the natural environment, including plant and animal life. It’s an approach which draws on natural history methods of drawing inferences from simple observation over a number of years, and involves looking at selected indicators.  So, for example, an observer might record the dates of ice breakup on her local stream, or the first flowering of the red maple on her front lawn.  Observations over time provide evidence of the effect of climate change on the environment as a whole.

Canadian records, alas, are scarce, though there is an effort to begin such recordkeeping on a mass scale through the Plantwatch program. A similar project is ongoing in the United States. In Britain, where observations have been kept for much longer — indeed, the science of phenology was a sort of national pastime in the 19th Century — some disturbing changes in the seasonal cycle have been noted.  In southern England budding oak leaves are bursting some 26 days earlier than in 1950, and several butterflies which normally make an appearance in April are being spotted as early as January.  The impact of this change on the ecosystem, combined with a dramatic loss of natural habitat in Great Britain since the Second World War, is anybody’s guess.  The data is highly suggestive: climate change, it would seem,  has being going on for far longer than what is conventually imagined, marked by the minute, subtle changes in plant growth and animal behaviour.

Harbinger of the future

The cool thing about phenology is that it’s climate change science anyone can do, armed only with pen and and a stout notebook (or for moderately computer literate, a simple spreadsheet).   You can think of it as a scientific version of the Slow Food movement.  Patience and consistency are necessary.  But even the simplest observations, over a number of years, are invaluable. You can collect data for Plantwatch, or you can create your own list of indicators. 

My own list looks like this below.  You will notice it’s short and simple, and is based on what I can easily observe given my own time constraints.  (Serious phenologists have lists numbering in the hundreds.) It’s probably appropriate for rural areas of eastern Canada and northeastern U.S.  In urban areas, the list would contain, I think, more ornamental plants. I will set up a page on this weblog containing my own observations.

Ice off pond (Normal early April)
Spring peeper song (Normal mid-April)
Trout Lily (Erythronium americanum) bloom (Normal late April)
Sugar maple (Acer saccharum) bloom (Normal early May)
Trillium (Trillium grandiflorum) bloom (Normal mid-May)
Last Spring Frost (Normal 3rd week May)
Lilac (Syringa vulgaris) bloom (Normal late May)
Crabapple (Malus sp.) bloom (Normal late May)
First sighting of Monarch Butterfly (Normal mid-June)
New England Aster (Aster nova-angliae) bloom (Normal late August)
First killing frost (Normal mid/late September)

The Dawning of the Age of Asparagus

Meanwhile, back in Peterborough County, winter has settled in for an extended engagement until mid-June, approximately, because we’re all enjoying it so much. The snow, which ought to be gone, or nearly so, stretches across the fields, an infinity of tiresome whiteness. No one can remember so much snow on the ground this late in the year… Continue reading