City Creek Nature Notes – Salt Lake City

April 11, 2017

April 11th

Queen Bee

4:00 p.m. Below picnic site 6, an aging tree has toppled, but this was not from high winds. The amount of rain from the last storm was so large that the soil around the tree, which sat on the inclined road bank, failed, and the entire tree slide down the slope. This has occurred before for several large cottonwood trees. Either they fall across the road, are removed, and leaves a scalloped mark on the road bank or their bleaches trunks fall against their neighbor. They rest there for many decades until wind and insects take them away. Near mile 0.2, a two foot by four foot by three foot segment of the side-bed of the road has broken away and fallen into the stream, and the stream bank is reduced to two feet from the road. This is geologic erosion in real time. To erode the both sides of the stream bank of the first mile two feet back and ten feet down to the stream bed would take about 35,000 such events.

Jogging up canyon, a kingfisher that flies by also traveling higher, and he alights on the power lines strung across the canyon at Guardhouse Gate about two hundred feet above the ground. There, he sits and watches my progress. The opposite of the down-canyon flight behavior seen on April 6th occurs. As I reach underneath him, the kingfisher noisily flies off going up canyon. He lands one hundred feet away, and when I reach him a second time, he again flies up canyon for another one or two hundred feet. This repeats four times as we reach below the picnic site 4. Then the kingfisher loops back and starts flying close above the stream in one hundred foot stretches. As on April 6th, he is looking for dinner. A few moments later, an unidentified raptor with a five foot wing span glides down canyon below the western canyon wall. He or she is too far and too quick to make an identification.

Under the snow’s effect, the flowers of the glacier lily fields along the road have shriveled, and in one field, I can find perhaps seven intact blossoms. Their passing was too quick, and I have seen no pollinator working their flowers. Will they try for a second bloom?

On this overcast day, I choose to jog back down the Pipeline trail to Shark Fin Rock, and I come across loud single chirps from the Gamble oak forest and an unseen bird. Its single chirp is loud and piercing, and the calls registers 70 decibels on my sound meter. A few minutes of patient waiting reveals a pair of Black-capped chickadees. Several hundred feet up canyon, another chickadee responds to my new neighbor’s call. Then for some unknown reason, the kingfisher from the stream below joins in with its loud rapid fire call, and the three take turns calling.

Along this trail, I see the first large bumblebee of the season, and it has a black rump, dark brown wings, and a single orange abdominal band. It is almost one and one-half inches long, and the bee is grazing on the many open poison ivy blooms along this section of the trail. It is a Hunt bumble bee (Bombus huntii), and given its size and the month that it is active, this may be a queen (Koch 66-68). Koch’s annual timeline for this specie’s annual activity suggests that the queen will be active for one month. During this period, she is building her underground nest and laying the eggs of her future sister workers. In May, these workers will slowly become active as their queen retires underground. Returning to the road, the land dwelling shrimp, the common pill bug (July 31st), has returned and it plods along the road apparently oblivious to temperature.

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In Thoreau’s “Journal” on April 11th, 1852, he describes the close inspection of a stream bottom including micro-air bubbles in the water and yellow mica on the stream bottom. In the Riverside Edition of Thoreau’s “Journal”, new entries begin again on June 1st.

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On April 11th, 1904, the Utah Audubon Society noted a drop in the City Creek bird population (Salt Lake Telegram). On April 11th, 1904, George W. Root announces that he had located a gold ore vein in City Creek Canyon (Salt Lake Herald).

February 22, 2017

February 22nd

Tree Trunks

4:00 p.m. This a year of extremes: on February 21st, the temperature was sixty-six degrees and yesterday and last night and today, after raining for almost ten hours, the temperature has dropped to thirty-three degrees Fahrenheit. As I enter the canyon, it is snowing, but this is light snow that turns to water when it touches any physical object. The high ridgelines and Pleasant Valley are covered in snow dust, perhaps one-eight of an inch thick, but it will not last. This is the second sign of the coming spring now one month away: The battle between spring overtaking winter (September 22nd) has begun. There are other signs. At Guardhouse Gate, I see my first, fat and healthy Rock squirrel of the season. It runs across the road and is busily inspecting bushes for fresh buds. The constant rain has driven three earthworms on to the road, even though temperatures are freezing. High on the ridgeline near mile 1.1, I see my first mule deer in over a week. Even at this distance, it is skittish; it tentatively comes out of a copse, feeds, and then retreats for cover.

The lichens and mosses are the most responsive to the hours of light rain. Everywhere the orange, yellow and green colors of lichen and mosses have deepened, and a few trees become vibrant flames amongst winter’s brown, grey and white. Black cankers on tree branches that normally turn to dust when touched have become plump, fat and solid with water. It is the time of year for the simplest organisms, for the earliest life.

Tree trunks have so many varieties of forms. Above picnic site 6, some trees are like brothers and sisters. The trunks of two 4 inch diameter immature river birches intertwine in a playful embrace, and they spring from a common root. Next to the River birch, are three immature Box Elder trunks that also rise from the same root. These stand tall and vertical like two brothers. At and down-canyon of picnic site 6, large Mountain cottonwoods have large bulbous galls on their lower trunks, and this is evidence of old attacks by insects, bacteria, and fungi. Other trees in the lower canyon have partially or completely succumbed to age and disease. At picnic site 6, an ancient tree has been broken off to about four feet above the ground and spilt in half. The remnant remaining in the earth is pock marked with with trails and caves of insects that reminds me of the cave houses carved out of volcanic tufa in Cappadocia in Turkey. In the lower canyon, still half-alive cottonwoods have had much of their bark stripped away, and underneath the xylem and heartwood has taken on a sinuous, smooth, yellow texture like human skin. At Pleasant Valley and at picnic sites 9, 7, and 2, dead cottonwood snags are bleached grey-white. Where large trunk stubs are near the road, erosion has exposed their subsurface tap roots, and this reveals a tangle of gnarls that remind of Eastern paintings of nature. An example is below the Red Bridge.

Traveling down-canyon, a familiar pattern appears in the River birches, Box elder and Mountain cottonwood trees that line the stream. Multiple, large, mature trunks sprout from a single root, and at the base, numerous suckers rise. For these trees, the mixture of angled mature trunks and smaller shoots gives the impression of a circular fan opening or a fountain of water rising. In this respect, trees are simply a larger, woody version of the brome grass bunches in Pleasant Valley, further up canyon. I realize that my impression of trees as organisms that are born, grow, have a middle age, and the die is mistaken. Angled older branches grow and fall away, and this gives the young shoots an opportunity to grow and replace them. But both originate from the same tap root, from the same genetic material. In this sense, most of the trees in the lower canyon that surround the stream possess a form of immortality. My misconception of the lives of these trees is the result of my biased exposure to shade trees in the city. Those trees mimic the cultured form of an English oak forest. There, trees are manicured and husbanded as individuals by their human farmers. Those trees do experience an individual birth, a middle age, and a death. But the English form of a forest is only one classical European choice, and here in the canyon, the stream trees pass their lives in a cycle and not along linear time.

In Thoreau’s “Journal” on February 22nd, 1856, he observes the first insects of spring crawling over snow.

On February 22nd, 1910, the City Council debated whether to lease a second gravel pit in lower City Creek (Deseret Evening News). On February 22nd, 1894, an attorney sought permission from the City to hunt a mountain lion in City Creek Canyon. Permission was granted and the hunter took a cougar (Salt Lake Herald).

February 19, 2017

February 19th

Filed under: Blacked-Headed Chickadee, Horsetail, Lichen, picnic site 4, picnic site 6 — canopus56 @ 6:19 pm

Blue-Green Lichen

4:00 p.m. It rains into the afternoon, but around 3:00 p.m. the Sun reappears. Horsetails have tan pads that divide each green segment, and usually, these go unnoticed. But the rain makes the green more vibrant, and where horsetails hang over the stream, the beige segments are highlighted. Drops of rainwater stick to the cylindrical segments and randomly fall into the stream below. In response to the continuing warmth, the Black-capped chickadees have moved further up canyon to mile 0.6. Now that the snow is gone, it leaves behind a flattened mat barely 1/16th inch thick of soaked leaves. In the autumn, these covered the ground to a depth of four inches. Scraping at the mat with a stick, one small insect is dislodged. All is primed for leaves’ decay back into soil, and the ground only waits the addition of spring’s heat. Testing the Box Elder catkins, the helicopter seeds easily come loose and are awaiting the strong winds of March. At picnic site 4, an unusual lichen stands out. Lichen is uniformly orange on trees in the lower canyon, as was this specimen. But the lichen on this tree has changed in the last week; it now has an orange green tint. Examining the lichen closely, under the orange lichen miniature green moss-like leaves are fruiting. Interspersed with these plants are three-quarter inch circles of a kaleidoscopic blue-green lichen. The centers are slate blue, the border is light blue, and a splash of new growth light blue-green tops the mass. At mile 0.2, I find another “mystery hole” next to the road (December 3rd). This hole is only four inches in diameter, and on exploring it with a stick, it is at least eighteen inches deep.

In Thoreau’s “Journal” on February 19th, 1852, he notes that the lengthening of the days is a sign of the coming of spring. At night, he sees a bright auroral display that covers the entire northern horizon. On February 19, 1853, he finds more insect cocoons.

On February 19th, 2006, a moose wandered out of City Creek Canyon and into the Avenues where wildlife officers tranquilized it for removal (Salt Lake Tribune). On February 13th, 1913, 49 head of cattle were found illegally grazing in City Creek Canyon and were impounded by the City (Salt Lake Herald). On February 19th, 1912, Superintendent of Waterworks Charles F. Barrett recommended tunneling in City Creek in order to develop new water supplies for the City and to reduce current water shortages (Salt Lake Telegram). On February 19th, 1903, City Councilperson Hewlett recommended building a reservoir in City Creek Canyon (Salt Lake Tribune). On February 19th, 1896, Charles Stewart, the manager of a mine in Hardscrabble Canyon just on the other side of the City Creek divide, argued for the development of a road down City Creek Canyon from Morgan County (Salt Lake Herald).

January 7, 2017

January 7th

Filed under: Geology, Guardhouse gate, picnic site 6, picnic site 7 — canopus56 @ 10:02 pm

Volcanic Past

5:00 p.m. Temperatures in the canyon are in single digits and overnight the City fell to -2 degrees Fahrenheit. Three walkers and runners pass by mile 0.3, but then I have the entire canyon to myself. I am in the canyon looking for an example of Van Horn and Crittenden’s “Tv – Volcanic breccia (Tertiary)” described as “Primarily andesitic breccia consisting of angular clasts of purplish porphyrtic andesite in a fine-grained matrix. Locally, clasts are rounded and have undergone some fluvial transport.” In short, this means the layer is an intermediate form of not quite lava that includes embedded crystals. A Utah Geological Survey publication provides a photographic exemplar and is a guide to locating a sample, but I am unsure if I have found this type of rock. The Utah Geological Survey publication shows the layer between picnic sites 1 and 6 and then again from just below picnic site 7 up canyon to picnic site 9. None is visible below picnic site 6, but across from picnic site 7, I find a small that may be of the right material. About two-hundred feet below picnic site 7 and on the south bank of the stream, there is a large boulder that also may be made of a volcanic conglomerate. Van Horn and Crittenden date the age of this volcanic breccia layer between 35 and 37 million years old. Their 1987 geologic map shows extensive layers of this material going down to the red bridge. Another small outcrop of this breccia is shown on Van Horn’s map just north of the Little Twin Peaks. These deposits are geologically related to the tallest peak at the south end of the Salt Lake Valley, the 11,253 foot granite Lone Peak, and to the formation of Utah’s current geology.

Hintze and Kowallis of Brigham Young University, Willis of the Utah Geological Survey, and Stokes of the University of Utah describe how the Sevier Orogeny shaped the state’s modern landscape and the canyon, as originally proposed in 1991 by Richard Livaccari of the University of New Mexico. An orogeny is a mountain uplifting event that can last millions of years. The cause of the Sevier Orogeny was the Farallon continental plate. Currently, there are about fifteen principal continental plates, but there used to be a sixteenth, the Farallon Plate, between the well-known North American and Pacific Plates and their border, the San Andreas fault off of the United States west coast. According to Hintze and Kowallis, about 105 million years ago the Farallon plate began subducting under the west coast of the United States (Hintze and Kowallis, 67-77; Stokes, 144-145). The Farallon Plate takes its name from a remnant of the plate found at the Farallon Islands off of the coast of San Francisco. In 2012 using mathematical inverse image techniques to reconstruct the plate from seismic waves, Pavlis, Sigloch, Burdick, and colleagues visualized the remains of the Farallon Plate whose melting carcass is now embedded in the Earth’s mantle a thousand miles below the midwest (see Sigloch and Mihalynuk 2013). Willis likens the response of Utah’s surface from the Farallon Plate passing underneath to a boat riding a passing wave on water (Willis, 4). A more familiar visualization would be a resting surfer, seated on her board as a wave passes underneath.

As Utah and Nevada rode up the leading face of the wave between 105 and 80 million years ago, a cordillera – a vast north-south mountain range similar the the Canadian and United States Rockies – rose in Nevada and western Utah (Hintze, 67, Fig.s 98 and 103; Livaccari, 1106, Fig. 1(a)). Utah was compressed. Hintze and Kowallis conclude that Utah’s western border was about sixty miles closer to the current location of Salt Lake City during this event (Hintze, 5). Between 80 and 65 million years ago, those mountains eroded away and the crest of the Farallon Plate continued to migrate under Utah (Livaccari, 1106, Fig. 1(b), Hintze, 6). Central and eastern Utah, including the canyon, were part of inland sea, and the sandstones and the red conglomerates in the canyon, including the natural bridge at mile 0.9, were deposited from the erosion of the cordillera mountains to the west. Next, about 35 million years ago, the melting of the Farallon Plate as it passed under Utah resulted in a volcanic era, and volcanoes formed in west central Utah around present day Tintic (Hintze, 6). Where molten lava reached the surface, as at Van Horn’s “Tv” conglomerate layer between picnic site 6 and picnic site 9 at mile 1.1, breccia formed. Where molten lava remained trapped beneath the surface, the granite that formed Lone Peak was created (Ut. Geo. Survey, Pub. Info. 87).

Finally, as Utah slid down the backside of Fallaron wave, the land stretched (Hintze, 6). Utah’s western border expanded to its current location. As the land stretched east and west, north-south faults formed in the thin crust, and one of those lifted the Wasatch Front Mountain Range into the sky. The lifting was uneven between the canyon and Lone Peak. At the City Creek end, uplift exposed rock to the Tertiary era, but in the north in Farmington, uplift raised older Cambrian rock to the surface. At the Lone Peak southern end of Salt Lake Valley, the lifting was more extreme. Erosion removed the Cambrian rock entirely, and subsurface pockets of frozen, granitic lava were lifting to 11,000 feet. Thus, the lowly breccia in City Creek share the same parent as the lofty heights of Lone Peak.

In Thoreau’s “Journal” on January 7th, 1851, he enjoys how the winter sun lays a yellow tint on pine trees. On January 7th, 1852, he describes a sunset where one-half of the sky in the east is covered in white clouds and one-half of the sky is in west is blue and clear. On January 7th, 1853, he sees a sunrise where a white mist covers low lands. On January 7th, 1855, he describes an early thaw. The morning overcast sky is tinged with blue, green and red. On January 7th, 1857, he notes it is the fifth consecutive day of cold, windy weather, and he describes the renewing psychological effect of getting “a mile out town” and taking a walk in nature’s solitude. On January 7th, 1858, he again notes speckled crystals on the surface of fresh snow.

On January 7th, 1903, hunters collected County bounties on a total of twenty coyotes killed within or just outside the city (which then included the high Avenues). Hunter George McNeil stated that “City Creek canyon is full of them [coyotes,] and I killed two wildcats up there a few days ago.”

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 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 3, 2016

November 3rd

Helicopter Seeds

5:00 p.m. After a major storm on October 31st that involved wind gusts up to thirty-five miles per hour, today parts of the road are still covered in the lobe shaped seeds of Boxelder trees. The seeds are about three-sixteenths (4mm) in diameter, but are attached at the end of a half-inch “wing”. Overall, the seed and wing give the impression of a musical note. The seeds hang in symmetrical pairs on a catkin, a collection of about twenty seeds. Along the road in the first mile, there are many of Boxelders up to fifty feet in height that are covered in catkins. I walk up to one to pull a couple of seeds off, and each seed is surprisingly still strongly attached to its catkin, even though the tree is leafless. I can see why it took thirty-five mile per hour winds to dislodge the seeds that are on the road. I raise one above my head let it go. It starts to rotate quickly and like its cousin, the maple seed, it “helicopters” down to the ground. Testing several Boxelder seeds, they travel an average trajectory at about thirty degrees from vertical. As any middle or high school geometry student can tell you using a 30-60-90 degree right triangle, this means that a seed released from the top of a fifty foot tree might travel twenty-five feet horizontally from its parent tree. This is just enough to land outside the canopy of the mother tree.

During a wind gusts on October 27th, as I jogging past Boxelders near picnic site 6, a few of these “helicopters” would dislodge and float down will a light rain. One was freed from the highest branch by a first gust of wind, and as it floated to eye level, a second wind gust blew through. With that burst of wind, the helicoptering seeds stopped in mid-air and rose slightly, but as the gust diminished, it resumed its descent to the road.

Until relatively recently, the aerodynamics of these flying seeds was a mystery. Using the same principles of flight that govern birds and jetliners, the seeds should technically not float or “helicopter” slowly to the ground. The seeds should drop like a stone. Solving that mystery also explained other instances of creatures that should not fly and should not be able to hover, including several found in the canyon, i.e. – bees, dragonflies and hummingbirds.

In 1991, Lentink at Wageningen University of the Netherlands, Dickson and their colleagues determined that helicoptering maple seeds had a different mechanism of flight than that used by bird or man. As the seed helicopters, the leading edge of the seed’s wing generates a small, horizontal tubular vortex over the wing. This generates a low-pressure vacuum that lifts or sucks the seed upward. Unlike a bird, the wing has no familiar aerodynamic lifting shape. In normal flight like that of a bird or airplane, a smooth laminar flow over a wing’s special shape, similarly generates low-pressure above the wing, and the relatively higher pressure under the wing then lifts the wing and plane or bird into the sky. These horizontal vortices are called leading edge vortices or LEVs.

You may have seen analogous vortices when using a paddle in the water, when moving your arms while standing a pool, or when a plane lands through fog. Horizontal vortices form off the tips of paddles, your arms, or the tips of an airplane’s wing. In the case of the seed, a spinning vortex forms over the entire length of the wing’s flat surface.

In 1996, Ellington of the Vrije University in the Netherlands and his colleagues extended this concept to explain how many insects, like bees, moths and butterflies, can fly when aerodynamically, they should be unable to do so. They found the beating wings of moths generating the same leading edge vortices seen in helicoptering maple seeds. In 2000, Z. Jane Wang at New York University modelled flapping insects wing and noted that for some insects, two counter-rotating vortices are formed. One is a higher pressure vortex under the wing and it pushes up, and the second is a lower pressure vortex that “sucks” the insect up. In 2001, Lauder at the Harvard University built mechanical insect wings in order to better model the leading edge vortices. In 2004, Adrian Thomas at the Smithsonian Tropical Research Institute and colleagues studied dragonflies tethered inside wind tunnels, and they imaged the counter-rotating leading edge vortices (id. Fig. 11). In 2011, Liang and colleagues at Purdue University built mechanical wings with rigid veins similar to those seen in both Boxelder seeds and dragonfly wings, and they found that the ridge veins increased flight performance.

Wasps, bees and dragonflies have a different number of wings. Wasps only have two wings; dragonflies and bees have four. Bees have smaller fore-wings that lock into the larger back wings to form a single wing surface during normal flight. Only the dragonfly has two sets of independently moving wings, and only it moves the wings out-of-phase: while one wings goes up, the other flaps down. The dragonfly can rotate the angle of attack for each wing independently. In 2008, Z.J. Wang noted that the out-of-phase beating gives the dragonfly additional-enhanced lift. These results of Ellington, Lauder, Wang and Thomas give a clearer picture of how the dragonflies seen in the canyon hover and do their amazing acrobatic maneuvers (August 11th).

In 2005, Warrick at the University of Oregon and colleagues showed how hummingbirds also use leading edge vortices to feed while hovering in front of flowers.

In conclusion, the canyon currently hosts many examples of where nature has solved the problem of flight and hovering using leading edge vorticies instead of a bird’s flapping aerofoils or man’s propellers: Boxelder seeds, maple seeds, Variegated Meadowhawk dragonflies, red-rumped central bumble bees, Bald-faced hornets, Black-chinned hummingbirds, and several moths, butterflies and other flying insects. The first dragonflies, the massive Protodonata with 30 inch wingspans, appeared in the fossil record 325 million years ago. Flowering trees first began to dominate forests in the Cretaceous period beginning 145 million years ago, and they co-evolved with bees. Hummingbirds appeared 22 million years ago (McGuire et al. 2014).

Today in the canyon, even though the Boxelders where hammered by the strong winds, only a small fraction of their catkins were dislodged. Most Boxelders are still thick with seeds, and I can still look forward to more future showers of helicoptering seeds on windy days.

October 25, 2016

October 25th

Filed under: Cattails, Milk Weed, picnic site 6, Unidentified — canopus56 @ 7:58 pm

A Cat’s Tale

5:15 p.m. Today, a Tuesday, has been a warm, almost summer, day with clear skies. On the canyon road, there are about twenty-five walkers and runners, but only two cars with hunters. At milepost 1.5 and looking south, the foreground trees and background trees on the slope are all grey, with only four exceptions. Nonetheless, against the deepening turquoise sky, the leafless Pleasant Valley has its own appeal.

Jogging up canyon, I pass a small marsh below picnic site 6 on the west side of the road. The two stands of common cattails (Typha latifolia L.) in the canyon have almost turned completely brown. Some green remains at their bases. The first stand fills the flood retention pond where City Creek Canyon Road intersects Bonneville Drive. There the cattails are over six feet tall and are capped by foot long spikes. The second is a small stand of four plants in a small seep marsh where the road bends just south of picnic site 6. The few cattails here stand in here against two unidentified shrubs: the leaves of one are deep purple, and the other a dark wine red.

In the 1980s and 1990s, this used to be one of my favorite places in the lower canyons. This mini-marsh was thick with cattails, but in the early 2000s, a City front loader came in, scoured the ground clean, and removed the cattail grove. The City may have been concerned that the marsh was retaining too much water, and the water would seep underneath, the water would freeze and then destroy the road with winter heave. Now, fifteen years later, a few cattails have found their way back into the marsh, along with, Utah milkweed Utah milkweed, a less dramatic version of the common Showy milkweed (Asclepias speciosa), and a large grove of western poison ivy. Birds have probably carried the seeds the approximately seven-tenths of a mile between the flood retention pond at the canyon’s mouth and the seep. In another ten years, I hope to see the full cattail grove restored.

The common cattail is a world-spanning plant. University of New Mexico botanist H. D. Harrington, in his classic book “Edible Plants of the Rocky Mountains”, describes the many ways this edible plant can be used. The early shoots can be eaten raw and added to salads; the early tubular flower stalks can be boiled; pollen can be shaken from the mature flower tubes and the pollen is used as a flour; and, the mature roots can be leeched and then boiled like potatoes. The root tuber has such a high starch content that it causes illness if eaten without preparation. The tuber needs to be chopped and leeched of part of its starch, which leaves enough starch behind that cattail root is similar to a potato. And as noted here previously, cattail groves provide shelter and a hunting ground favored by hummingbirds (August 1st). After finishing today’s jog at the flood retention pond, I try to pull a cattail out of the marsh bottom. It breaks near the surface but brings out part of the root tuber. The tuber is a reflective, bright white, and the white appears similar to the children’s paste which is also made almost entirely of starch. I will have to return with a shovel in order to extract one.

October 19, 2016

October 19th

Watercress Foraging

1:00 p.m. During a post-storm cold but sunny day, four insects are on the road: a Praying mantis, immature Eastern Boxelder bugs, a Variegated Meadowhawk dragonfly, and an unidentified bee. The bee was possibly a domesticated honey bee with equal spaced black-dirty-yellow bands on its abdomen. While all trees have turned color, about fifteen percent of the trees along the road are now completely leafless.

Below picnic site 6, watercress beds line the north side of the road where a water seep runs year round. Watercress is also found there on the south side of the road in beds in the stream itself. The beds look mangy, but not because it is Fall and cold. Their tops are still uneven and chopped. In June, an extended family from one of the Southeast Asian countries came to the canyon over three weeks and harvested watercress in great leaf bags. It was a great family affair involving several generations – grandparents, parents, aunts, uncles, and young, playful, smiling grandchildren. Some of the elders were in traditional dress, and the children wore heavy metal tee shirts. It was unclear whether they were gleaning out of economic necessity or as cultural practice as they all piled into a large luxury SUV at the end of their gathering. But they took too much; the watercress beds have never fully recovered; and this is a metaphor for non-sustainable consumption that undercuts our confidence in modern post-industrial lifestyles.

According to local experts, and I am not one, there are many edible wild plants in the canyon in addition to the fruit tree cultivars. Pine needles and wild mint (Mentha arvensis) from the upper canyon can be used to make tea. Wild onion (Allum acuminatum Hook) and wild carrot (Lomatium dissectum) can be found in the spring. Blue elder berry bushes can be found along the upper canyon trail (Sept. 8th). With much labor, the bitterness of Gambel’s oak acorns can be leeched out, and the flour turned into pancakes. Stinging nettles (Urtica dioica) and thistles can be boiled and then used as greens. Mountain dandelion (Agoseris glauca Raf.) greens can be added to salads. Some say even oak and maple leaves are edible. Barnes notes that the Ute indians ate these and also the root of arrowleaf balsamroot (Balsamorhiza sagittata) that grows profusely on the ridge between City Creek and the Avenues and on the west side of the ridge between City Creek and Ensign Peak (“Four Seasons”, Sept. 1st). The bulb of the state flower, the Sego Lily (Calochortus nuttalli) is edible, and the Sego can commonly be found on the high-slopes and ridges of either side of canyon during spring. But not being skilled in plant identification and since some edibles are easily confused with look-alike poisonous plants, I have not tried any of these.

With next spring’s growth, the watercress beds should become even thick mats again.

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