What to make of an early spring

    They blanket the lawns of older homes; small lavender flowers that seem to pop out of nowhere in the beginning of spring, and then disappear just as unobtrusively a few weeks later. They are Crocus tommasiniensis, and they’re quite early this year.

    The scientific term for the observation of milestones in the lives of living things is phenology. Amateur phenologists all over the world record the dates that certain flowers open, birds begin nesting, butterflies hatch, and leaves get fall color. This collected data is particularly useful when compared with seasonal and annual variations in temperature, and even more valuable when the data can be tracked for centuries. Recording annual temperatures and plotting them with the emergence of oak leaves, for example, gives a very real indication of how climate change is affecting the environment.

    These crocus, sometimes called Tommies by gardeners, aren’t native to the US, so their blooming earlier or later may not create the same environmental consequences as when native species’ timetables get out of whack. The vulnerable species are the ones like certain migratory birds who have evolved to reach their summer destination as a particular food source is abundant. If this food source (a caterpillar or a berry, for instance) has already come and gone, the result can be population collapse.

    The absence of anything much resembling winter weather in Philadelphia recently has made it pretty easy for the earliest blooming plants to get a head start. So often a mild January is followed by at least one arctic blast sometime before March, arresting the show of spring ephemerals. This year it just doesn’t seem like winter is going to suddenly remember she forgot to make us a visit. I think I’ll follow the lead of the crocus, and decide that it’s spring.

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