City Creek Nature Notes – Salt Lake City

December 23, 2016

December 23rd

Filed under: picnic site 2, picnic site 3, picnic site 4, Sounds, Stream — canopus56 @ 7:09 pm

Stream Sounds

1:00 p.m. The canyon has warmed considerably under morning bright sunlight, but the beginnings of a large storm front arrives at noon and quickly hides the Sun. It is a Friday before the Christmas holiday weekend, and the canyon is filled with the conversations of about thirty people and the sounds of city rumble. Many are traveling to their weekend destinations, but the distant noise of their vehicles, planes and trains do not lessen the sounds from the stream.

Listening closely to stream sounds between picnic site 1 and picnic site 5, I hear that they fall into three categories. The first sound is a like gentle pouring rain, and it is produced where the stream falls over a small three to six inch uniform ledge across the stream bed. The second second is a “plonk”, and it is produced where two rocks constrict the flow from both sides of the stream. There, the stream has carved out a six inch depression at the rocks’ base, and the falling water takes air to the bottom which then escapes to the surface to make the depth throat-ed popping noise. The third sound is rare, and it is the sound of two rocks striking each other. In front of a larger rock, a small horizontal eddy has formed, and within it a smaller rock rests. The current repeatedly lifts the smaller rock and strikes it against the larger, and this creates a deep thud.

Two bow hunters are walking out the canyon. They have successfully taken an elk. Each has one butchered hind-leg in their backpack. They left the remainder of the three-hundred pound carcass rotting in this watershed canyon. More waste of living things.

In Thoreau’s “Journal” on December 23, 1837, he notes a only one robin in his winter landscape. On December 23, 1856, he observes that on the coldest nights, the ground will crack with an audible sound, and on December 23, 1860, he observes larks during winter.


December 21, 2016

December 20th

The Canyon at Rest

12:00 pm and 5:00 p.m. It is the last day of Fall, and tomorrow the tilt of the Earth keeps the canyon furthest from the life giving Sun for the longest part of the day. Nature in the canyon is in a deep sleep. The trees are still; all natural sounds are silent. The air is warmer today, but not enough that snow and ice on the trees melts. Sun warmed ice melded with tree branches expands slightly and then breaks away. Instead of raining droplets as with the last storm, today trees rain tiny chunks of ice. There are two places in the lower shaded canyon where the stream freezes over. The first is the perpetually shaded bend between picnic sites 7 and 8. There the stream is completely frozen over for several hundred feet; the stream is milky white and stone-like. The second is between the up canyon end of Pleasant Valley at mile 1.8 to milepost 2.0. There the stream is eighty percent frozen over. At Bonneville Drive, about twenty percent of the surface of the flood retention ponds is frozen. At mile 1.3, where animal tracks make impressions that are kept partially in shadow, half-inch hoarfrost crystals sublimate, but then evaporate in the warmer late afternoon air. Although the canyon looks dead, the irrepressible force of life continues.

Lichens and mosses respond to the wet cold and grow both on the trees and on rocks in the stream. Digging some leaves up from underneath the snow, some show signs of the beginning of bacterial decay, but mostly the leaf litter and the microbes are dormant, waiting for spring’s explosion. At the surface, data by Whitman, Coleman and Wiebe at the University of Georgia suggests that there are about 3.5 x 10^15 microbes per square meter in woodlands and shrublands and about microbes 5.7 x 10^13 in each square meter of deciduous forests (Whitman 1998, Table 2). In 1995, Richter and Markewitz estimated that there were about 1.1 x 10^12 bacteria and fungal microbes in each gram of soil at the surface (Fig. 3a), and their density decreases to about 4.1 x 10^7 at 8 meters beneath the surface. In 2014, Raynaud and Nunan found an average of 8.9 x 10^9 microbes in the top 0.6 meters of each gram of agricultural field soil (Table 1).

But life does not stop there. Whitman et al also estimated that between 10 meters to 3,000 meters below the surface, there were on the order of 10^6 prokaryotes per cubic centimeter. They made an order of magnitude estimate that in a cubic centimeter column going from the surface down to 4 kilometers, there are a total of about 2.2 x 10^30 prokaryotes (id., 6579). But life exists even further down in the subsurface column beneath the canyon’s surface. In 2006, Li-Hung Lin, et al. discovered Archean microbes living at 2.8 kilometers beneath the Earth’s surface in a South African gold mile, and those microbes were genetically related to Archean microbes living the Yellowstone Hot Springs a few hundred miles north of the canyon. These subsurface microbes may comprise a substantial fraction of biomass in the canyon. Whitman et al estimated a wide first-order ratio of the mass of subsurface prokaryote carbon to plant surface carbon at 60% to 100% (id., at 6580).

I stand at the surface in the canyon, I and am part of this scene. In 2013, Bianconi et al estimated the number of cells in the human body at 37 trillion. In a 2016, Sender, Fuchs and Milo at the Weiztmann Institute for Science in Israel, revised estimates of the total number of cells in the human body and the number of microbes that inhabit each of us. They found that along with the approximately 3.8 x 10^13 (38 trillion) human cells in a 70 kilogram person, another 3.0 x 10^13 foreign microbes live (cooperatively but sometimes uncooperatively) within us or about 44% of the total (3.0/(3.0+3.8)). Because of the exponential power of these estimates, the 10^13 cells, both human and parasitic cell in me, are a minuscule portion of of 10^30 prokaryotes that are in just one 4 kilometer deep column of soil that is one centimeter square. Subtracting my 10^13 cells, there are still 9.999999…. x 10^29 prokaryotes under each square centimeter of subsurface. I measure the bottom of one of my shoes and find conservatively guess there are about 450 square centimeters in the soles of my feet.

Around and above me, even the air above the road contains some levels of bacteria, fungi, and pollen as part of the daily PM10 daily air particle count. In 2009, Wiedinmyer and colleagues counted on average 3.5 particles of DNA containing material per cubic centimeter of air collected from a mountain summit in the Rocky Mountains (Table 1) or about 3.5 million particles per cubic meter of air. Whitman et al estimated that there were about 1.8 x 10^21 microbes in each cubic meter of air from the surface up to 3 kilometers (id., 6580 reporting 5 x 10^19 per cfu). This continues into the high upper atmosphere. In 2013, DeLeon-Rodriguez and her colleagues at the University of Georgia and NASA found 5,100 cells per cubic meter in samples taken from air 10 kilometers above the surface of the Caribbean ocean.

Microbes also dominate the stream’s bedrock. In that aquatic environment, deep blue-green algae grows in thick mats, and at the stream’s edges, large mats of watercress thrive in the freezing water. Although no trout are seen in the lower canyon stream; they move upstream and a group of about fifteen congregate just below an old water head gate at mile 2.8. At the stream’s edge, horsetails are still green, and this indicates that photosynthesis is still occurring despite the cold.

At the retention ponds, a male-female pair of mallards (Anas platyrhynchos) rest. The female is in the sleep position with her head laying on her back. The males feeds on the algae on the pond’s bottom. At picnic site 2, there is a small unidentified sparrow that is not a European sparrow. Further up the canyon, near picnic site 3, there is a Belted kingfisher (Megaceryle alcyon)! No avid birder will probably believe this, since this kingfisher is far out of its winter range, and I am unable to take a photograph of it. I first had a fleeting view of this bird on December 7th at the south end of the circle where the Pleasant Valley reservoir once stood. Then it was too far away to see clearly. Today, I am able to watch it for several minutes at the top of a snag about 100 feet away. Then the bird sees me, spooks, and flies down canyon to another snag, and again I am able to catch up and watch it closely for another few minutes. At picnic site 4, I am greeted by a flock of mountain chickadees, and they sit in several trees calling back to each other. Below picnic site 5, a flock of six Black-hooded juncos feed and preen themselves on a red osier dogwood bush. The coldest winter makes some birds more tolerant of humans, and I am able to stand directly next to the bush and about four feet from juncos. They grab a piece of snow-ice from clumps of shriveled white berries that still cling to the tree. They eat part of the ice and then dip the rest into their feathers to clean themselves. Then they try to eat the sour fruit of the dogwood (see Nov. 6th), but most of the fruit seems to drop to the ground and not into their beaks. I again see an unidentified raptor that patrols the lower canyon just before twilight. At mile 1.3, a magpie can be heard in the distance. A series of tracks in the snow tell of two birds that had landed on two adjacent rocks that stick up out of the snow. They then hopped across the snow for about 20 feet.

At mile 1.0, high on the western ridgeline, a single anterless elk digs through the snow to green grass underneath. And, in the early morning hours as I am returning home on other business, two mule deer that are refugees from the canyon are grazing a few hundred feet from my urban front door. As for humans in the canyon, there is myself and about twenty other walkers, runners, and bicyclists.

In short, the canyon is asleep, but life cannot be stopped. Life can be attenuated from its peak productivity (August 31st), and today, like sunlight, life in the canyon is at its nadir.

In Thoreau’s “Journal” on December 20th, 1851, he observes a high-flying hawk that is patrolling for prey. He lists the colors of the winter landscape: red, white, green, and brown. On December 20, 1854, he feels that the winter sun has more relative warmth on his skin than the summer sun.

December 14, 2016

December 14th

Filed under: picnic site 3, Stream — canopus56 @ 6:55 pm

The Golden Ribbon

4:00 p.m., December 14th, 2016. Today, it is overcast with a light rain during the afternoon. At sunset, as I drive out of the canyon, the sunset behind the clouds makes the deepest of pink colors.

4:00 p.m., December 11th. Up and down canyon of picnic site 4 is a short stretch of straight stream, and on the far bank side the ground gently slopes upwards. When the setting Sun leaves the stream in shadow but the farside is still bathed in yellow light, the stream’s surface perfectly reflects the opposite bank. The stream then glows like a dusky ribbon made of gold. The stream is cold but looks like hot lava outpouring from some volcano. The effect only lasts for one or two minutes each evening, and one must be correctly positioned in order to see its brief appearance.

I have seen this effect just a few times since the start of Fall. The rareness of the experience is a matter of computation and probability. What are the chances that I will be jogging past the proper point on the road when the Sun is at a particular angle for a three or four minute period, given that I start jogging at random times between noon and six in the evening? Physics also reduces this to an optical effect of Snell’s ratio, another simple mathematical relationship. At a certain viewing angle, the angle of water’s refraction equals the angle at which light travels from the opposite direction. If the angle is higher, one sees through the water’s surface; if lower, the water’s surface appears black; and, if the angle is equal to Snell’s ratio for water, then the surface becomes a mirror. But this evening, there is more in the glowing surface of this stream than can be expressed by mathematical abstractions of the thing itself. It buoys the spirit against cold.

On December 14, 1914, City Engineer S.Q. Cannon reported that during a harsh winter, teams of men were employed to keep the canals from Parleys Canyon and City Creek that supplied water to the City open and free of ice and snow (Salt Lake Telegram).

December 12, 2016

December 12th

Filed under: Meadow Mile 2.1, picnic site 3, picnic site 6, Sounds, Weather — canopus56 @ 7:50 pm

Loud City Rumble

8:00 p.m., December 9th, 2016: After a hectic night and day of work, I am spent. Having aged, I am more aware that I should give myself a full day. My circadian rhythms are disrupted and to help them reset I go for a late night jog. The Moon is three-quarters full and the sky is partly overcast, so there is sufficient light that seeing is not a problem. It is late on a Friday night, it is at the height of shopping season, there is major sports game downtown, and jetliners taking off from the airport are routed over the canyon. To my surprise, city rumble noise (November 18th) is deafening deep into the canyon. I try to outrun it, but even at milepost 2.0, the mechanical noise level is still around 20 decibels. I have never heard it this loud; city rumble usually cuts out within the first one-third of a mile near picnic site 3. Although there is no healing solitude in the canyon tonight, I am rewarded with moonlit silvery shadows cast by myself and the trees. 5:00 p.m., December 11th, 2016: City rumble is still relatively loud. Going down canyon, I first detect it around picnic site 6. 5:00 p.m., December 12th, 2016: The noise of City rumble has retreated to below picnic site 3.

While noise becomes softer; temperatures rise: 8:00 p.m., December 9th. The arctic air pocket has dissipated, and the resulting higher temperatures have changed the snow. It is now partially melted and a shoe into its surface parts with wet compaction. It is what backcountry skiers would call a fast snow: skis glide at a high-speed through the snow, but there is a reduced ability to control turns. Almost all of the pack on the north west side of the canyon has melted away. 5:00 p.m, December 11th: Temperatures remain in the high thirties, and as a result the Gambel’s oaks are drying out and those trees of the half Black Tube (Entry, Dec. 11th) are becoming gray again. Yesterday’s rain has changed the snow. Now it has a crusty surface. A foot breaks through the surface, and the fast snow of yesterday is underneath. Backcountry skiers know this to be a difficult snow. The crust breaks in varying degrees of resistance, and on occasion, will pile up and grab a ski, thus bringing the skier to an immediate stop. 4:30 p.m., December 12th: Jogging up canyon, slopes that face down canyon and the Sun are free of snow. Upon reaching milepost 1.5, I turn around, and find the opposite is true. All of the north up-canyon are still frosted in snow. Snow only remains on the north facing slopes and in the very bottom of the canyon. Further up canyon at Black Mountain, heavy snow still covers the ground and the trees remain frosted.

In Thoreau’s “Journal” on December 12th, 1858, he observes large flocks of red polls, an eastern finch similar to the European house sparrow found in the western states.

November 22, 2016

November 22nd

Filed under: Box Elder Tree, Cottonwood tree, Maple tree, picnic site 3, Plants, River birch — canopus56 @ 10:19 pm

Broken Arrow

Noon. After a night of heavy cold rain, at picnic site 3, there is a new fallen thirty-foot tall maple tree that still retains its brown leaves. This is probable the same species of tree that still retain their brown leaves along the shadowed south ridge wall at mile 1.1. Unlike its relatives that grow vertically, this maple grew at a sixty degree angle in order to avoid the shade of an adjacent eighty-foot tall narrowleaf Mountain cottonwood and a fifty foot tall Boxelder tree. The angle of its growth is the undoing of the maple. With the recent snow and rain, the leaves became soaked, and the maple snapped about five feet above the ground. The eight-inch diameter trunk at the fresh break looks healthy and no disease is apparent. The weight of the water soaked leaves was just too much of the tree’s design, given that it was growing at an angle.

Many trees in the canyon grow at a similar angle, such as the River or water birches, but they and many other trees lose their leaves earlier in the year and before first snowfall (see October 24th). In addition to the reduction in light, this broken maple suggests another agent of natural selection that directs trees to lose their leaves earlier in the year – snowfall. Trees that do not lose their leaves are more susceptible to losing branches.

In Thoreau’s “Journal” on November 22nd, 1853, he notes geese migrating south. On November 22nd, 1860, Thoreau notes how the Fall light makes branches and twigs to seemingly glow.

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