City Creek Nature Notes – Salt Lake City

September 20, 2016

August 31st

Peak Production

6:30 p.m. The canyon has passed its peak productivity. In the first two miles of the canyon, all the red fruit of a chokecherry bush (Prunus virginiana L.) has ripened to a dark purple. Box elder trees (Acer negundo L.) hang heavy with their helicopter seed pods. The white fruit of an unidentified berry bush extrudes vanilla smelling juice when squeezed. All thistles have bloomed into hairy grey tufts. Gambel’s oaks are dropping numerous acorns on the road. green crabapple trees, planted by the pioneers every third of a mile, are ripening fruit. Horsechestnut trees (Aesculus hippocastanum L.) are full of their green spiked seeds. Where is City Creek Canyon Road intersects Bonneville Drive, the mud flat in the stormwater pond is filled with 8 foot tall cattails (Typha latifolia L.) that are beginning to bloom. Along the pipeline trail, only one or two small birds are heard.

At meadows, grasses and weeds are parched varying shades of tan to dark brown. At one seep near mile 1.3, trees at its top are green and healthy while at the bottom all the water has been taken from the ground and the manzanita bushes (Arctostaphylos manzanita P.) are shriveled. Even for healthy Gambel’s oaks and cottonwood trees (Populus angustifolia James or Mountain Cottonwood), the unrelenting sun has burnt leaves on the top branches a curled brown. To escape the heat, the Box Elder trees on west facing slopes are turning their autumn pale red and light brown. But box elders with an adequate water supply on the canyon bottoms are still green.

Producers having peaked, the reducers now take over. In the scrub oak forest and in the meadows, crickets have multiplied. In the first two miles, I see five adolescent squirrels and hear another five scurrying through the brush. They have begun gathering and storing acorns for the coming winter.

 

August 10th

Filed under: Chokecherry, Colors, Crabapple trees, Gambel's Oak, Plants, Seasons, Thistle — canopus56 @ 10:49 pm

First Signs of Fall

4:00 p.m. The first day of Fall is not until September 22nd, but the early signs of the coming change of the seasons appear: At mile post 0.25 the fruit of a single chokecherry bush turns a deep purple-black. Higher up the canyon the fruit of similar bushes are still red. The first unripe green acorn from a Gambel Oak falls on the roadway. The first early green crabapple rolls across the pavement. On one bull thistle bush in the lower canyon, a single blossom explodes in a gray fountain of seeds. All the other blossoms on the same plant are still compact and purple.

August 8th

Pollinator

4 p.m. Principal insect pollinators in the canyon are butterflies and bees. Near the red bridge between picnic sites 6 and 7, two common roadside flowering weeds are next to the road: a purple tansyaster (probably Dieteria canescens, the hoary tansyaster)and a bull thistle (Cirsium vulgare). The aster is covered in a flock of 12 small cabbage white butterflies. Both the cabbage butterflies and the plants are invasive species. The other major butterfly pollinators of the canyon are the black and white Admiral butterfly and earlier in the season, the yellow tiger swallowtail. The thistle is covered with a red rumped bumble bees, probably the central bumble bee (Bombus centralis) The bumble bees do not have the usual yellow and black striped abdomen of the more familiar honey bee. These bumble bee abdomens are white and reddish-orange banded. Dragonflies also rest on the thistle and act as pollinators. Rarely, wasps can also be seen pollinating flowers. In past years, I have seen the large ground burrowing bumble bee emerging from their nests in the side of the road. This year there are none. I am not a trained botanist or biologist; these are the best amateur identification that I can make.

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