City Creek Nature Notes – Salt Lake City

February 16, 2017

February 16th

Filed under: Astronomy, Common stonefly, Rock wren, Seasons — canopus56 @ 4:59 pm

Seasons

2:00 p.m. A new front approaches from the southwest, and during this pre-spring, this means high winds and warm temperatures. February is unseasonably warm near sixty degrees, and at picnic site 11, where two weeks snow banks drifted to two or three feet deep, the snow is gone. The air smells more like late spring than the end of winter. Wildlife is slow to respond, but plants keep their own time. I hear a robin singing at Guardhouse Gate; the first since winter started. Three miniature stoneflies brave the road. Groups of lunchtime lawyers who run in the canyon usually beginning in late March are on the road. The buds on trees are not responding. They know snow may return again.

Because of the exceptionally warm February, I am feeling the disconnect between the astronomical seasons and natural rhythms. In the modern era, we define the seasons using astronomical waypoints (Sept. 20th), and in writing about the Wasatch Front Range in the 1950s, Barnes in his “The Natural History of the a Mountain Year” used astronomical seasons. But there are other definitions of the seasons. In writing about Concord in the 1850s in his “Journal”, Thoreau used traditional definitions of the seasons common the 1800s: spring began on February 1st and summer on May Day, or May 1st, and “Midsummer”, June 22nd, is our modern astronomical first day of summer. June 22nd was the “midsummer” referenced in Shakespeare’s play. These traditional definitions were more aligned with seasonal ecological changes, and there are six ecological seasons in temperate northern latitudes:

• Prevernal, March 1st to May 1st – in which temperatures have risen sufficiently to allow microorganisms to function and to resume their work of reducing the autumnal leaf litter. During this ecological season, early bulb plants sprout, often still surrounded by snow.

• Vernal, May 1st to June 15th – when the majority of plants regrow. Sometimes with is subdivided into the preestival, or “before summer”.

• Estival, June 15th to August 15th – summer, the time of greatest heat.

• Serotinal, August 15th to September 15th – when seeds are released in response to environmental triggers such as summer warming or summer fire.

• Autumnal, September 15th to November 1st – when leaf death and autumnal colors occur.

• Hibernal, November 1st to March 1st – winter, the time of greatest cold with freezing rain and snow.

These six ecological seasons feel more connected with commonplace perceptions of the seasons.

In Thoreau’s “Journal” on February 16th, 1852, he notes that the air is no longer crisp and clear as in early winter.

On February 16, 1900, an ex-Salt Lake councilperson made the case for increasing the City’s water supply by tunneling into the canyons, including City Creek, would be the lowest-cost method of developing new water supplies for the City. (Salt Lake Tribune).

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1 Comment »

  1. My favorite season is September with its ideal weather and harvest fruits. But this pre-vernal time with alternating warmth and snow and lengthening days as spring shows it’s first shoots is a close second.

    I hope for a good snowfall matched with a sunny day after for good snowshoeing in the upper canyon.

    Comment by behiker57w — February 17, 2017 @ 7:31 am


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