City Creek Nature Notes – Salt Lake City

July 21, 2017

July 19th

Crossed Cottonwoods

6:00 p.m. Afternoon thunderclouds threaten, but it is for nothing near City Creek Canyon. Where the road first enters the canyon, it gives vistas of the valley and sheets of water can be seen lowering from the clouds across southern and western ends of the Salt Lake Valley. But at the valley’s northern end, no water falls, and the weather station at the airport records only a trace of moisture. The clouds tease the parched land, dried grass and thirty trees. One canyon tree is well-adapted to this climate; it grows large; it puts down deep roots that search for underground water.

Narrowleaf Rocky Mountain cottonwood (Populus angustifolia J.) are numerous in the first mile and are easily identified by their linear, willow-like leaves. True Freemont’s cottonwoods (Populus fremontii) with their broad triangular cordate leaves are more difficult to spot, and the home range of Freemont’s cottonwoods is further to the south in New Mexico and Arizona. Like the F2 generations of Cottam’s hybird Gambel’s oaks that dominate the drier land of the canyon (July 3rd, 4th and 5th), the Narrowleaf Rocky Mountain cottonwoods and Freemont’s cottonwoods have been hybridizing. Like the Gambel’s oak, it makes numerous hybrids along the canyon’s bottom whose leaves are of intermediate forms between the parent types (Lanner 1984). Their more common cross, Populus angustifolia x fremontii S. Wats, have intermediate ovate leaves that look like a larger version of a Western water or River birch leaf and resemble other common native and introduced trees (Arizona State University and Baker 1993). This confuses identification of trees in the first canyon road mile.

There are many trees in the canyon, and learning tree identification can be eased by examining known exemplars. The following is a list that cross-references some known trees species in the canyon with local examples at the University of Utah and Westminister College in Salt Lake City. The list is weak on conifer exemplars:

List of Exemplars for Trees in City City Creek Canyon at University of Utah, Westminister College Emigration Creek Natural Area and Miscellaneous (2017)

At the University of Utah (University of Utah Tree Tour))

• *Horsechestnut (Aesculus hippocastanum) (University of Utah Tree Tour. No. 5, located at the southwest corner of the George Thomas Building on President’s Circle. Lat. 40.763604, Long. -111.8539387.)

• Rocky Mountain juniper (Juniperus scopulorum) (University of Utah Tree Tour. No. 7, located at the southwest corner of the George Thomas Building on President’s Circle. Lat. 40.763848, Long. -111.8522112.)

• Big Tooth maple (Acer grandidentatum). (University of Utah Tree Tour No. 8. Located south of the George Thomas Building (the old Natural History Museum) and east of University Street. Lat. 40.76375, Long. -111.851917.)

• *Norway maple (Acer platanoides) (University of Utah Tree Tour No. 15. Located north of the George Thomas Building on north side of President’s Circle Drive. Lat. 40.764604, Long. -111.8536557.)

• *Purpleleaf plum (Prunus cerasifera) (University of Utah Tree Tour No. 21. This is similar to the cultivar Newport flowering cherry plum (Prunus cerasifera Newportii) found in the canyon. On the north side of the President’s Circle at the intersection with Lat. 40.7646614, Long. -111.8506819.)

• Gambel’s oak (Quercus gambelii) (University of Utah Tree Tour. No. 24 located northwest of the Talmage Building on President’s Circle Drive. Lat. 40.764621, Long. -111.8521057.).

• *Norway Spruce (Picea abies) (University of Utah Tree Tour. No. 28 located south of the Widtsoe Building on the south side of President’s Circle Drive. Norway spruce were planted in City Creek Canyon around May 1st, 1918 by the City (Salt Lake Tribune). Lat. 40.765321, Long. -111.8526205.)

• *Siberian elm (Ulmus pumila). (McPherson and Graves (1984, 66-67) No. 46. A massive Siberian elm in the quad at the east end of the Bookstore. Lat. 40.764521 Long. -111.8500557. There is also grove of these elms in Lindsey Gardens at the north east corner of M Street and 7th Avenue. Lat. 40.777452 Long. -111.8659852.)

• Serviceberry (Amelanchier x grandiflora) (University of Utah Tree Tour No. 64. Located on the back east side of the Pioneer Memorial Theatre. This is similar to the native Saskatoon serviceberry (Amelanchier alnifolia) found in the canyon. Lat. 40.762741, Long. -111.8512532.)

• Chokecherry (Prunus virginiana) (University of Utah Tree Tour No. 82. Between LINCO and Business Buildings along walkway from Marriott Library. Also along South Campus Drive Traffic Roundabout. Lat. 40.765543, Long. -111.8441142.)

• Cottam’s F1 Hybrid Cross of Gambel’s oak and Arizona shrub oak. (Author taken July 2017 at 1760 South Campus Drive, University of Utah, Lat. 40.760233, Long. -111.8415315.)

At Westminister College Emigration Natural Area Tree Project: Trees)

General directions: At Westminister College on one-eighth mile stretch where Emigration Canyon Creek crosses the campus (Harrison 2002). Park in the main visitor parking area along 1300 East and walk to the starting point in front of Giovale Library at Lat. 40.730536 Long. -111.8558192. Refer to Owens 1999 map for location descriptions.

• Narrowleaf cottonwood (Populus angustifolia). (The Narrowleaf Cottonwood is on the south bank of the stream surrounded by other species in Owen’s Reach No. 2. Look for the narrow leaves from the viewing point. Saplings are closer to the top of the stream bank. Go across the footbridge near Giovale Library and head east to viewing point at Lat. 40.730154 Long. -111.8570887.)

• Hybrid cross between Freemont’s poplar and Narrowleaf cottonwood (Populus angustifolia x fremontii). (Go down the stairs to the west of Giovale Library to the trail that overlooks Emigration Creek. Go to the Nunemaker Amphitheater along the trail in Owen’s Reach No. 3. Hybrids are along the back of the stage. Compare the intermediate forms of these leaves that are between the parent Narrowleaf and Freemont poplars. Lat. 40.730537 Long. -111.8585217.)

• Freemont’s poplar (Populus fremontii). (Freemont’s poplar is located further west along the trail near the end of the parking lot structure on the north border of the trail in Owen’s Reach No. 6. Lat. 40.730521, Long. -111.8588057.)

• Box elder (Acer negundo). (Box Elder trees are prevalent in Salt Lake City An exemplar can be found east of the footbridge. From in front of Giovale Library, go along the sidewalk at the east of the residence hall to the east. Lat. 40.73029, Long. -111.8552372.)

Other

• Coyote willow (Salix exigua) (There is Coyote willow along east Bonneville Drive about one-quarter mile after the turning on to the one-way Bonneville Drive from 11th Ave. Lat. 40.7826391 Long. -111.8825331.)

Source: University of Utah, Department of Facilities Management (2017). Tree Tour (Web). Link (GIS Map Tour of trees in the Walter Cottam Tree Collection spread throughout the University of Utah campus.), McPherson and Graves 1984, Harrison 2002, Boogert 2017, Owens 2000, and Author. * – Cultivar or invasive.

The Westminister College Emigration Creek Natural Area is a deep gulch about 1,000 feet long that holds one of the Salt Lake Valley canyon streams. The four streams flowing from the north and east of the City, Red Butte, Emigration, Parley’s and City Creek, are for the most part encased in underground conduits, but where Red Butte, Emigration and Parley’s Creeks cross soft soils on the elevated east bench of the City, they cut small gorges in which it was impractical to build. There four mini-canyon parks provide short, cool walks under the shade of native trees during the oppressive heat of afternoon summers. Red Butte Creek runs through the Miller Natural Park near 1100 South and 1700 East and from there it continues on bordered by private lands to Liberty Park. Emigration Canyon Creek runs through Wasatch Hollow Nature Area near 1500 South and 1700 East, then the Blaine Street Nature Area, and then on through the Westminister College Natural Area described above. Parley’s Canyon Creek flows through a small gorge Hidden Hollow Nature Area surrounded by office towers and a shopping center near 2100 South and 1300 East. In this way, City residents always have some form of City Creek Canyon always close at hand.

The Westminister College Emigration Creek Natural Area is a deep gulch about 1,000 feet long that holds one of the Salt Lake Valley canyon streams. The four streams flowing from the north and east of the City, Red Butte, Emigration, Parley’s and City Creek, are for the most part encased in underground conduits, but where Red Butte, Emigration and Parley’s Creeks cross soft soils on the elevated east bench of the City, they cut small gorges in which it was impractical to build. There four mini-canyon parks provide short, cool walks under the shade of native trees during the oppressive heat of afternoon summers. Red Butte Creek runs through the Miller Natural Park near 1100 South and 1700 East and from there it continues on bordered by private lands to Liberty Park. Emigration Canyon Creek runs through Wasatch Hollow Nature Area near 1500 South and 1700 East, then the Blaine Street Nature Area, and then on through the Westminister College Natural Area described above. Parley’s Canyon Creek flows through a small gorge Hidden Hollow Nature Area surrounded by office towers and a shopping center near 2100 South and 1300 East. In this way, City residents always have some form of City Creek Canyon always close at hand.

* * * *

Eckenwalder at the University of Toronto is credited demonstrating prolific ability of poplar’s to hybridize, including Fremont’s poplar-cottonwood (Eckenwalder 1984), but he did specifically cross-breed Fremont’s cottonwood and the Narrowleaf cottonwood. In 2002, Schweitzer, Martinsen and Whitham at the University of Northern Arizona crossed and back-crossed Fremont’s poplar and the Narrowleaf cottonwood (Populus fremontii x P. angustifolia) using trees along northern Utah’s Weber River. They found that in terms of seed mass and seed weight, the F2 back-crosses fell between the more productive Fremont’s poplar and the less productive Narrowleaf cottonwood. Thus, they concluded that the hybrids were at least as productive as one of the parent trees.

Sparks and Ehleringer at the University of Utah used Narrowleaf cottonwood, Fremont’s poplar-cottonwood and Coyote Willow to investigate whether trees maintain lower or higher levels of photosynthesis at different elevations (Sparks and Ehleringer 1984). This is a deceptively simple question. As elevation increases, carbon dioxide is less dense and leaves may thicken to protect against harmful ultra-violet radiation. The stoma (pores) in leaves may also restrict in order to better retain water at the lower pressure of higher altitudes. Conversely, higher altitude mountain plants get more water. How do these factors balance? Contrary to other studies, Sparks and Ehleringer found that Fremont’s poplar and Narrowleaf cottonwoods in Big Cottonwood Canyon do more photosynthesis as altitude increases.

* * * *

On July 19th, 1895, a Mr. Taylor reported to the city council that he intended to develop 26 mining claims in the canyon and then force the city to buy him out in order to protect its water supply (Salt Lake Herald).

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July 11, 2017

July 4th

Hybrid Gambel’s Oak – Part II

4:00 p.m. Determined to find a sample of the oak cross in the wild, I go behind the University Hospital, where in 1958 Professor’s Cottam’s graduate student, Rudy Drobnick, located a grove of F1 hybrid oak crosses (Drobnick 1958). It is located on a steep slope above the Bonneville Shoreline Trail. Climbing the slope in the 100 degree heat and under the afternoon sun, after two attempts and twenty minutes of climbing, I finally find a copse of the cross. It was worth the climb. This F1 cross developed at the end of the last ice age about 7,500 years ago when in a wetter and warmer climate, both true Gambel’s oaks and the Arizona shrub oak existed at its northern limits around the Salt Lake Valley. (Ehleringer and Phillips suggest that the F1 cross may have occurred as little 750 years ago (Frates 2008).) As the post-glacial valley dried out, the true Gambel’s oaks and the Arizona shrub oak were forced further south. Now only four patches of the F1 hybrid remain.

I also want to verify if this F1 hybrid grove is the same dimensions as found by Drobnick in 1958. This requires climbing up a steeper slope and around of wall of oaks to the grove’s backside. This whole mis-adventure has been one comedic event after another. Today, I am under-geared. I am also jogging, so I am wearing sneakers and not my usual bushwhacking hiking gear. For bushwhacking in the Wasatch Front Mountain Range, I usually have walking poles and my favorite now well-worn thirty-year old pair of calf high leather boots with industrial grade soles. You can walk up-hill and over any grade and any condition with those boots. The slope is forty-five degrees and covered in a combination of dry cheatgrass and Winter rye grass (Secale cereale L.). The stems of both invasives are biased pointing downhill. About fifty feet up, I lose my footing and begin a quick fifteen mile-per-hour slide downhill. But I am smiling. This is the summer version of a fall and back-side slide on dense spring snow while back-country skiing in the mountains. My feet go out in front and I am able to self-arrest as I reach the edge of the oak grove. Another try, and I am around to the back of the grove.

In 1958, Drobnick recorded is size at 25 x 15 x 8 feet, and this is similar to what I find today. At the back of the hybrid copse, is a small sapling, three feet high. The hybrid copse is continuing to reproduce.

Later in the evening after a nap to recover from the heat, I return to City Creek Canyon and the stream. Cool canyon and stream breezes make of a pleasing walk to milepost 1.0. Since it is a holiday weekend, the canyon is nearly empty except for a few hand-in-hand strolling couples and families. Tracks reveal a mule deer has come down a steep slope and rested on a clump of crushed horsetails. I count four Broad-tailed hummingbirds in the first mile. Why have they come now, since all of the nectar producing flowers have gone? They also eat insects, and evening air is now thick with Variegated Meadowhawks (Sympetrum corruptum). For sugar, they drink the sap that the summer heat will shortly begin to boil from the Big tooth maple trees.

I have touched the canyon’s living past; I have touched the canyon’s living future; and this evening, I stroll in its present.

* * * *

Per Thoreau’s “Journal” on July 4th, 1852, he describes a summer sunrise. He hears a blackbird and sees a kingfisher. As the Sun reaches him, flies and mosquitoes rise. A humming bird passes by. He notes water lilies are damaged by insects. On July 4th, 1858 at night, he hears a loon, a screech-owl, and cuckoo.

* * * *

In 1954, University of Utah graduate botany student Rudy Drobnick noticed the existence of hybrid oaks along the Wasatch Front due to differences in the late fall foliage between the hybrid oaks and other Gambel’s oaks along the mountain range (Drobnick 1958, Cottam, Tucker and Santamour 1982 at 1). University of Utah botany professor Cottam dispatched Drobnick to locate all the patches of these hybrids in Utah (Drubnick 1958). There had been a long-standing debate in amongst botanists about what exactly Gambel’s oak (Quercus gambelii Nutt.) was. At the turn of the century, P. A. Rydberg had classified eleven types of Gambel’s oaks, including Quercus utahensis, Quercus submollis, Quercus gunnisonii, Quercus vereelandii, Quercus novo-mexicana, etc., but by 1942, it was generally recognized that Quercus gambelii Nutt. had an amazing variety of leaf shapes (Christensen 1949, Christensen was another of Cottam’s graduate students). Thus, all of Rydberg’s previous species were collapsed back into one species – Quercus gambelii Nutt. (id., Tucker 1961), and Rydberg’s former names were abandoned.

Cottam and Drobnick and University of California at Davis botany professor John Tucker sought some explanation of the bewildering array of leaf shapes of the Gambel’s oak throughout the west. Their provisional hypothesis was that in the post-glacial era about 7,500 years ago, Gambel’s oak and Arizona shrub oak co-existed in northern Utah (Drobnick 1958, Cottam, Tucker and Drobnick 1959, Tucker 1961, Tucker 1963, Tucker, Cottam and Drobnick 1961, Tucker 1963). As Utah’s climate became drier and in order to better adapt new conditions, Gambel’s oak and Arizona shrub oak hybridized into the F1 form, the hybrid copse that I viewed today. But the F1 hybridized form, with its spiked ends and shallow lobes did not explain multitude of forms of Gambel’s oak leaves seen today. Another of Cottam’s University of Utah botany graduate students, Robert R. Ream, could find no north-south pattern in the variation of Gambel’s oak leaves (Ream 1960).

Doctor Cottam retired from the University of Utah, but in his retirement he continued to work as an emeritus professor on a cross-breeding hybridization experiment of western “white” oaks in part to demonstrate that the current Gambel’s oak forest in northern Utah was a hybrid of other species (Cottam, Tucker and Santamour 1982). Using his grandchildren to nurture hundreds of seedlings, he undertook a massive block experiment to examine first (F1) and second (F2) generation of cross-breeds of western white oaks including Gambel’s oak (Quercus gambelii Nutt.), Arizona shrub oak (Quercus turbinnell Greene), Quercus douglasii, Quercus lobata, Quercus macrocarpa, Quercus robur, Quercus virginia, and six other lesser oak species. Two-hundred and forty-one cross-breeding experiments (id. at 61) and ten years later, Cottam, Drobnick and Tucker had their answer: only one F2 generation cross between Quercus gambelii Nutt. and Quercus turbinnell Greene was stable (Cottam, Tucker and Santamour 1982). This result supported, by brute force experimentation, the post-glacial hypothesis that the three investigators formulated in 1958.

Cottam’s F1 hybrid generation shows some remarkable adaptations that place it squarely between Quercus gambelii Nutt. and Quercus turbinnell Greene. Quercus gambelii has deep penetrating roots adapted to northern Utah’s snowmelt high-water season that is followed by drying summers. Quercus turbinnell is shallow rooted and adapted to the summer monsoons of northern Arizona. Quercus gambelii x Quercus turbinnell have roots of intermediate depth (Ehleringer and Phillips 1996). Electron microscopy of the leaves of the hybrid and of its parent plants confirm how the F1 hybrid has taken on the waxy upper surface and hairless underside of Quercus gambelii (Cottam, Tucker and Santamour 1982 at 62, 70 and 71), but the gross shape of the F1 hybrid follows Quercus turbinnell (id. at 72). Similarly, measurements of the F1 hybrid’s lobe ratio (the ratio of a lobe’s vein length to its lobe length), puts the hybrid statistically between Nuttal and turnbinnell (Tucker, Cottam, and Drobnick 1961).

* * * *

On July 4th, 2007, the City announces that City Creek Canyon will be closed for four days during July in order to host various road races (Salt Lake Tribune). On July 4th, 2006, legendary local endurance runner Heikki Ingstrom, who trained daily in City Creek Canyon, was reported to have passed away (Deseret News) On July 4th, 1999, City managers describe plans to update the City’s Watershed Management Plan, including for City Creek Canyon (Salt Lake Tribune). On July 4th, 1993, the City proposes a 100 mile bikeway system that will connect regional parks, including a bikelane from the University of Utah to City Creek Canyon (Salt Lake Tribune). On July 4th, 1908, Fisher Harris of the Commercial Club and Lon J. Haddock of the Manufacturers and Merchants’ Association urged that the Ensign Peak area should be turned in a large park (Salt Lake Herald). The Commercial Club provided $10,000 towards the expense of improving City Creek Road and along 11th Avenue to Fort Douglas (id). On July 4th, 1883, City Surveyor Jesse Fox and City Waterworks Superintendent G. M. Ottinger surveyed City Creek Canyon in order to determine possible locations of the construction of new higher water reservoir tanks (Salt Lake Herald).

June 23, 2017

June 17th

Filed under: Douglas Fir, Gambel's Oak, Lodgepole pine, Maple tree, People, Runners, Wild bunchgrass — canopus56 @ 4:25 am

Masters of the Wasatch Steeplechase

8:00 a.m. It is Saturday, and in the cool morning air, birds are active. Black-headed grosbeaks and Song sparrows are the most common. This morning is also the 39th running of the Wasatch Steeplechase (Adams 2017). The Wasatch Steeplechase is purist running event whose 17 mile path goes up the south part of the Salt Lake salient, over the limestone knife edge at the top of Little Black Mountain, down Smuggler’s Gap, and then out the City Creek Canyon Road. Over the course, about 3,000 feet in elevation is gained and lost. Unlike other Salt Lake City running events, there is no registration packet, no inflated air start and finish line blasting loud rock music, and no prize money. About 200 runners just show up at Memory Grove Park at 6:00 a.m. and start. Participants tend to be lean ectomorphs between the ages of 25 to 50 years old, and the best finish the race in about two hours and fifteen minutes. Last place finishes in about six hours. The purist ethic of the race is reflected in its liability waiver agreement:

“Whereas, participation in the annual Wahsatch Steeplechase is a privilege and sacred ritual in celebration of the Summer Solstice and, whereafter, the undersigned acknowledges the uniquely and hazardous nature of the race course, including raging streams at full flood, wicked sagebrush, poisonous snakes, and precipitous crags, and has inspected the course or in the alternative freely assumes the risk or failure to inspect the course” (Adams 2017).

I am a stocky American football player-like endomorph. Although I have solo-run the track (in reverse direction) about nine times in the last forty years, my best jogging time was somewhat more than six hours, but each time the route was both an inspirational and mystical experience. First, the route goes up seven miles along the City Creek Canyon Road to the end of the paved road through both the Gambel’s oak and maple forest. Then a near vertical trail leads 2,000 feet through an upper montane forest of Douglas firs and Lodgepole pine trees that is thick with Stellar jays. Then the route goes along a knife-edge ridgeline for one-half mile along the top of Little Black Mountain. Here, one must boulder back and forth along limestone ledges that tilt downhill and away from the direction of travel. In most places, a slip means a fall of ten to twenty feet onto a sixty degree slope. Survivable, but something to be avoided given the difficulty of extraction from this high mountain. Next is a about ten miles stretch under the watchful eyes of hawks and eagles that descends back through a Pinyon Juniper forest, along the Wild bunchgrass southern salient past the Little Twin Peaks, and then back through the Gambel’s oak forest to the canyon bottom. Along the summit and south salient, expansive views of the urbanized Wasatch Front cities, the Great Salt Lake, and the Bonneville flats extend at most one-hundred and fifty miles. In some years, dramatic summer storms flow across the Great Salt Lake dropping streamers of lightening from gray and black clouds. The route is a tour-de-force of the many of the Great Basin’s habitats. The Steeplechase is less of a run and more of a spiritual experience brought on by fatigue, dehydration, strong summer sunlight, and exertion at altitude. After each traverse of the route, I fall into a meditative, contented state for one, and if I am lucky, two days.

In September, another extreme race, the Wasatch 100, goes from 100 miles from Farmington, north of City Creek Canyon, along the upper headwaters of the canyon, and onto Park City, Utah, a mining town turned upper income ski-resort. The maximum allowed finishing time is 36 hours. Unlike the Steeplechase, the Wasatch 100, which is beyond my physical capabilities, has a more tradition competitive road-race feel, and by disposition, I have always favored the Steeplechase.

* * * *

Per Thoreau’s “Journal” on June 17th, 1852, he notes that crickets sing loudly in the morning after hot summer nights. He sees or hears a brown thrasher, a red-eye, an oven-bird, and a wood thrush. Citus are blooming. He notes how a boulder has made a micro-habitat in which several tree seedlings have taken root. On June 17th, 1853, he notes that pogonias, adder’s tongue, blue-eyed grass, lambkill and mountain laurel are at their peak. He records an egg in a night-hawk nest has hatched. On the morning of June 17th, 1854, he feels dew covered grasses and sees cobwebs hanging across the grass.

* * * *

On June 17th, 2000, the First Congregational Church planned to hold its annual outdoor service in City Creek Canyon. On June 17th, 1915, P. J. Moran was awarded the contract to build the reservoir at Pleasant Valley for the sum of $18,209.59 (Salt Lake Telegram). On June 17th, 1915, a locomotive was hauled to the capitol grounds along newly constructed track along the west side of City Creek (now East Capitol Street) to begin grading for the new state capitol building (Salt Lake Herald). On June 17th, 1894, the City changed from having a staff of full-time water tankmen (who clean water tank filters) to a part-time staff of day and night patrols (Salt Lake Herald).

June 1, 2017

May 29th

Memorial Day

3:00 p.m. Today, I drive up to mile 4.2, picnic site 20, and jog in the upper canyon to mile 5.1, and the Weeping Rock Cave. While the lower canyon and city are in the summer-like eighties, the upper canyon remains in the low sixties. In the lower canyon, all Gambel’s oaks have leafed out, but at milepost 2.0, most are not leafing. There is distinct band of bare oaks or oaks that have leafed out by twenty to thirty percent, but the canyon’s appearance is still a heavily wooded green, because all of the other deciduous maples, ash, and cottonwood have leafed out. These create an illusion of green around the stream, but the maples, together with Douglas fir and Norway spruce, block the view of the oaks further away from the road. The higher one goes in the canyon, the less leaves that oaks have until a glimpse of slope at milepost 4.5 and Lower Rotary Park shows all the oaks to be leafless. The upper canyon transitions from oak woodland to a mountain fir habit, and by mile 5.0, over half the trees are firs or spruces.

Although the stream is at first wider than the lower canyon, near mile 5.0, the canyon narrows as vertical limestone fins, turned by earthquake faults (Sept 1st). The canyon closes in further and the stream turns into a white, turbulent mass as it crosses younger volcanic rocks. This western canyon feels more like an eastern forest because it is directionless. Green meets the eye in all directions, and only the flowing of the stream gives a sense of location or direction. American wild mint (Mentha canadensis) grows by the roadside, and I gather a few leaves to make tea with at home.

The butterflies have taken refugee here, having followed the thermocline up canyon. Fifteen Desert elfin and Spring azure fly intertwined a dance. Mourning cloaks abound. Blue-eyed barner dragonflies are seen. Unlike the hotter lower canyon, the shaded upper canyon with its step sides is flooded with insect life. Numerous small biting flies and other insects force me to move on after stopping for a few minutes. Picnickers light fires to keep the insects at bay. There is enough life here to keep small birds well fed.

Bird communities along the road are dispersed, homogeneous and larger than in the lower canyon. Warbling vireos dominate near mile 5.1. Song sparrows are at mile 4.8. The large group of vireos allows me to spend sometime listening to their calls with some assurance of matching unusual calls to a species. A bird will make familiar textbook Warbling vireo call, followed by another unrecognized call. I hear three distinct vireo calls that I cannot match with catalogue recordings for this bird. A single female Broad-tailed hummingbird (Selasphorus platycercus) hovers a few inches off the ground inspecting a dandelion. A few flashes of blue streaking into the forest reveals Stellar’s jays. A Rock squirrel peaks from around a bush. Returning down canyon, a mallard pair floats in the flood retention ponds below mile 3.0, but I see no chicks.

At Weeping Cave, the stream is split in two. The western stream carries about 12 cubic feet per second of water down-canyon in a torrent. The eastern branch consists of about 2 cubic feet per second of subterranean flow that emanates from a vertical Mississippian limestone fin. The fin itself is distorted into melted lines of red and browns, not from water, but from extreme heat when this outcrop was buried far underground. On one volcanic boulder in the stream’s middle, a Red maple and a Norway spruce shrub are growing from crevasse in the bare rock. Backlit by the southwest sun, the maple casts a reflection of a pure light green on the flat water’s surface.

Returning down canyon, a mallard pair floats in the flood retention ponds below mile 3.0. I see no chicks. The heat, the sunlight, and that it is a holiday, make everyone in the city lethargic. No one is focused, including myself, and a day of relaxation is the rule.

* * * *

All parts of City Creek Canyon function as a place of remembrance and grieving. We connect death with a return to nature, and it is not uncommon to read about, hear of, or pass small informal wakes in the canyon. Memorials are also left by people grieving the loss of loved ones along City Creek Canyon road. Physical memorials typically consist of cards or a handwritten note with flowers left at the base of a tree. A specific part of the canyon, Memory Grove, has been set aside for grieving and formal remembrance of war dead.

The origins of Memory Grove begin in 1912 as a general use park, similar to Liberty Park. On April 14th, 1912, a petition from citizens proposed the creation of a park system for the city, including establishing a park at the canyon’s mouth, now Memory Grove (Salt Lake Tribune). Memory Grove was created in the context of the construction of the State Capitol Building and the aftermath of World War I during the 1920s. In 1920, the Gold Star Mothers of the Service Star Legion asked the city to donate land at the mouth of City Creek Canyon to create a memorial park for their sons who died in WWI (Salt Lake Tribune and Goodman, May 30, 1993). On April 25th, 1920, the Salt Lake Herald published an artist’s rendering of a proposed iron bridge that would cross City Creek at 7th Avenue. A similar proposal was suggested by G. A. Iverson of Northeast Bench Improvement Association on May 24th, 1920 (Salt Lake Telegram). The bridge was to be part of a proposed memorial WWI war dead at what is now Memory Grove. By the end of 1920, the Gold Star Mothers had purchased 300 trees and planted them near the mouth of the canyon (Salt Lake City Tribune and Goodman, July 31st, 1994). On November 5th, 1920, a subcommittee of the City Planning Committee, including Mayor Clarence Neslen, outlined plans to create a new park at the canyon’s mouth (later Memory Grove) and to turn City Creek Canyon into a large park (Salt Lake Telegram). By 1926, Mrs. E. O. Howard, a Gold Star Mother, raised 60,000 USD from private donations, a state appropriation and contributions from the city and county for the park and Memorial House construction (Salt Lake Tribune and C. Monson, Sept. 16, 1994; Salt Lake Tribune and Goodman July 31st, 1994), or about the equivalent of 830,000 USD in 2017. The Memorial House was to be constructed by renovating the abandoned Salt Lake City Waterworks maintenance shed. On December 17, 1926, the Salt Lake Telegram reported that a mature horse chestnut tree, that was being dug up at the corner of 100 South and 300 East, was being donated and relocated to Memory Grove Park in City Creek Canyon. On May 30th, 1927, Governor George Dern (grandfather to actor Bruce Dern and great-grandfather to actress Laura Dern) dedicated a monument to the Mormon Battalion at the southeast corner of the Utah State Capitol grounds that overlooks lower City Creek Canyon and Memory Grove (Monument plaque visited May 2017). The sculpture was rendered by Chicago artist Gilbert Riswold (id).

Memory Grove Park was constructed in increments from 1920 through 1927, and Memorial House served as the meeting place and wedding chapel for the Gold Star Mothers for several decades thereafter (Salt Lake Tribune, July 31, 1993). In 1920 and 1924, trees were planted (Salt Lake Herald, April 16, 1920; Salt Lake Telegram, April 15, 1924). On June 14, 1926, the Memorial House was dedicated (Salt Lake Telegram). On June 27th, 1926, a tablet containing the names of 732 Utahans killed in WWI was unveiled (Salt Lake Telegram, June 24th, 1926). In a March 1927 ceremony, Gold Star Mothers R. W. Fisher and Clesson Kinney noted the contributions of “Mayor Nelsen, Councilman Crabb, Mr. Slater of Liberty Park, Mr. Parkinson of the U.S. Forest Service” to the park’s creation (Salt Lake Tribune, July 31st, 1994). On October 8, 1927, the Austin Artillery Memorial was dedicated (Salt Lake Telegram). The Austin Artillery Memorial, an obelisk to the north of the pink meditation chapel, commemorates Capt. James Austin and three other Utah officers who were killed in the Argonne Forest during WWI (Salt Lake City Tribune and Dawn House, May 26, 2003). During this period, the Rotary Club constructed the related Rotary Club park at miles 4.5 and 5.5 of City Creek Canyon (Salt Lake Telegram, August 17, 1927).

Riswold sculpted the art deco female reliefs on the columns at the entrance to the Grove. They set the grove’s tone. In a west relief, a Grecian clothed mother looks over her shoulder to a military cross in the background. Riswold also did the sphinxes on the entrance to the Masonic Temple near 700 East South Temple (Utah Capitol Preservation Board 2017). In 1932, a second round greek style structure was added to the south of meditation chapel. It holds an octagonal bronze plaque that lists about 732 Utahans killed in WWI (Plaque visited 2017).

On April 2nd, 1935, Gold Star Mother E. O. Howard of the Salt Lake Gold Star Mothers Committee presented the Committee’s opposition to a City Street Department Plan to build a bridge across City Creek Canyon above Memory Grove (Salt Lake Telegram). They supported a plan to build stone stairs on the east side of Memory Grove to the Avenues.

World War II saw the addition of other monuments. On July 28th, 1948, the war dead chapel was dedicated at Memory Grove in front of a crowd of 10,000 (Salt Lake Tribune and John Ure, November 9th, 1997). This is the pink granite chapel in the center of the park. The Memorial Chapel was donated by the family of Ross Beason Jr., a pilot killed off the coast of Italy in WWII, but whose body was not found (House 2003). The Beason family dedicated the Memorial Chapel to all soliders whose bodies were never found (id). A step leading to the Chapel reads “In memory of 42 brave sailors who followed me to their death. C.A. ‘Red’ Beam, USN (ret.).” Beam dedicated the step in memory of his platoon that was wiped out, except for himself, during a WWI raid on Tarawa Island (House 2003). This step could not be found in 2017. 1,405 Utahans died or were missing in action in WWII (United States Military Archives 2017).

In May 1983, the park was damaged during a 100 year flood of City Creek. On February 3, 1991, the City Parks Department considered proposals to renovate the then abandoned Memorial House in Memory Grove (Salt Lake Tribune). On October 4th, 1994, the Utah Heritage Foundation reopened the renovated Memorial House, where its offices remains today (Salt Lake Tribune, October 16th, 1994). On November 9th, 1997, the Memory Grove Foundation announced its plans to raise $500,000 to renovate war memorials in Memory Grove (Salt Lake Tribune). On May 9th, 1999, the successful completion of the Memory Grove Foundation’s program to repair monuments in City Creek Canyon was reported (Salt Lake Tribune). On August 11, 1999, trees in the park were substantially destroyed by a tornado (Salt Lake Tribune, August 18, 1999).

On September 24th, 1999, Rep. Ralph Becker announced a $250,000 grant from the Metropolitan Water Conservancy District to rehabilitate Memory Grove following its destruction by a tornado (Salt Lake Tribune and Jim Woolf, Sept. 24th, 1999). On September 30th, 1999, City Director of Public Utilities LeRoy Hooten, Jr. announced the construction of a six-by-six foot concrete pond near Memory Grove in which dogs can wade (Salt Lake Tribune). Dogs entering City Creek’s stream have quadrupled the coliform count. On July 20st, 2001, City Planning Director Stephen Goldsmith noted that a gate had been added at Memory Grove to control traffic (Salt Lake Tribune).

In 2003, a Korean War Dead monument was added to the park (Plaque visited 2017). (The Vietnam era memorial is on the west capitol lawn. The Iraq Afghanistan war memorial is in Cedar City, Utah.) 141 Utahans died in Korea (Salt Lake Tribune. Apr. 25, 2013). 370 Utahans died in Vietnam (Virtual Wall). Through 2010, an unofficial count for Iraq and Afghanistan was 39.

A stone monument listing 6 Utah Medal of Honor recipients was also added. Recipients include George E. Wahlen, after whom the Salt Lake Veteran’s Hospital is named. Medic Wahlen was shot several times during the Battle for Iwo Jima such that he was unable to walk. Nonetheless he crawled across a battlefield under enemy fire to give assistance to other wounded soldiers. Whalen survived. George T. Sakato, a member of the WWII Nisei battalion led a charge against repeated enemy attacks. Brian Miles Thacker, still living, defended Firebase 6 in Vietnam as it was being overrun by North Vietnam regulars. He stayed behind and provided cover fire that allowed all other base members and wounded to evacuate. He evaded the NVA as the base was overrun and made his way back to US held territory through hostile ground. Jose F. Valdez’s WWII platoon of six was attacked by German tank. Valdez drove the tank off using only a carbine. The German army counter attacked with two companies (160-500 men). Valdez volunteered to and stayed behind to hold off the attack, allowing his platoon mates to escape. He was shot more than once, but still managed to evade capture and return to US lines. Valdez later died from his wounds sustained in the counter attack.

Battle deaths, meaning military deaths on both sides of a conflict plus collateral civilian deaths, were: WWI, 17 million; WWII, 60 million; Korea, 1.2 million; and Vietnam, 2 million (Lacina and Gelditsch 2005), or a total of about 80 million persons.

On February 1st, 2011, the Salt Lake Rotary Club, who built Rotary Park in upper City Creek Canyon in 1921 and who renovated the Ottinger Hall in 2005, the former fireman’s association meeting house near Memory Grove, celebrated its 100th anniversary (Salt Lake Tribune and Mike Gorrell, Feb. 1st, 2011). Ottinger Hall is now a youth center.

In counterpoint to the Memory Grove memorial to war dead, Salt Lake City hosts another unique memorial indirectly related to the non-combatant victims of war: the International Peace Gardens in Jordan Park at 1000 South and 900 West. The Peace Garden was conceived in 1939 by Mrs. Otto Wiesley and the Salt Lake Council of Women as a beautification project for the 1947 Utah Centennial (Salt Lake Council of Women 2017). Construction was halted by WWII, resumed in 1947 after the end of WWII, and the peace garden was dedicated in 1952. The garden contains monuments donated by 28 different countries. The United States’ “Peace on Earth” statute in the gardens features heroic images of mothers that was created by Mormon sculptor Avard T. Fairbanks. The statute is dedicated to “the hope we can leave a more peaceful future to our children.” Inscriptions on the statute read “Our Hope to the Children”, “Peace on Earth”, and “The Dawn of a New Era”. After the 2002 Winter Olympics, 84 “Peace Poles” were installed at the entrance to the gardens: one for each country participating in the winter Olympics. (Other sources list 78 countries as participating in the 2002 olympics.) There are about 156 similar peace gardens and another 146 larger peace parks around the world (peace.maripo.com)

Political scientist J. R. Rummel of the University of Hawaii (d. 2014) specialized in systematically counting civilian non-battle deaths – those deaths in conflicts not between two states – and he total an astounding 262,000,000 losses from 1900 to 1999 (Rummel, 1994, 1997, 2002). Examples include the Khmer Rouge in the 1970 and Stalin in the 1930s. The world population increased by 5.5 billion persons between 1900 and 1999, that is the net of live births less deaths. Therefore, Rummel’s 262 million represent at at most 5 percent of all persons alive during that century. Using more sophisticated estimates, some experts place the figure at less than 1 percent of all persons who were alive during the twentieth century.

Many more days are devoted in the United States to remembering military battle dead as compared to civilian battle dead, other civilian victims of conflict violence or life in general. Memorial Day is one of the three official United States’ holidays that are related to war and the solemn remembrance of war dead: Memorial Day (May 30th), Independence Day (July 4th), and Veterans Day, (November 11th). Veteran’s Day was originally Armistice Day that remembered the war dead of World War I, and four other days are now observed primarily by the United States military: Pearl Harbor Day (December 7th) marks the beginning of World War II; the less well-known Armed Forces Day (May 21st); D-Day (June 6th) marks the landing of allied forces on the French coast; and V-J Day marks the end of World II (September 2nd). German Remembrance Day, the German day for remembering war dead, is observed annually around November 14th at Fort Douglas cemetery at the monument to 41 German WWII prisoners of war who died in Utah. From the view of First Peoples, Columbus Day (October 9th) marks the beginning of Euro-American genocide against native Americans and is also a day of remembrance. From the view of United States working people, Labor Day (September 4th), celebrates a compromise that ended violent conflict between labor and upper classes. Although not widely observed in the United States, International May Day celebrations began in Chicago in 1886 with celebration of labor’s declaration for the eight-hour work day, but was quickly followed by the violence of the Haymarket Massacre on May 4th. Today, it is observed worldwide as a day commemorating the struggle between labor and capital.

In contrast to the seven days commemorating war dead, two unofficial and one official United States holiday celebrates life and nature: Earth Day (April 22nd), Arbor Day (April 27th), and Christmas near the first day of winter. These are supplemented by two other unofficial days related to the movement of life through the seasons: the first day of spring and autumn. No official United States holiday commemorates civil battle dead or other civilian victims of conflict violence. In 1981, the United Nations established the International Day of Peace on September 21st of each year (United Nations, 1981). Small observations around the globe are coordinated by the International Peace Day organization.

* * * *

On May 29th, 2009, Utah Governor John Huntsman, county Mayor Peter Corroon and Salt Lake City Mayor Ralph Becker held a press conference in City Creek Canyon to announce a new planning process administered by Envision Utah called “Wasatch Canyons Tomorrow” (Salt Lake Tribune). On May 29th, 1993, James R. Cook, in a letter to the editors of the Salt Lake Tribune, proposes to transform Traverse Ridge at the south end of Salt Lake Valley into a nature reserve similar to City Creek Canyon at the north end of the valley. (By 2017, Traverse Ridge was transformed in a luxury subdivision). On May 29th, 1914, City officers visited the newly completed City-Creek Wasatch Boulevard in anticipation of its opening on May 30th (Salt Lake Telegram, Salt Lake Tribune). City Creek Canyon Road has been widened to Pleasant Valley (id).

May 18, 2017

May 14th

Filed under: Ants, Cricket, European earwig, Maple tree, People, Pleasant Valley, Raptor, Spider, Unidentified — canopus56 @ 4:32 pm

First Cricket

2:30 p.m. In the lower canyon, there are no butterflies except for one dusky brown and no songbirds. The song birds have moved to the warmer air at Pleasant Valley, and there I hear six or seven calling unseen from the groves. The first cricket of the season is heard at the lower field in Pleasant Valley. In two months, their chorus will be as loud as the song birds. Near mile 0.4, in the disease hollowed-out base of a 50 foot tall Red maple tree, a 1.5 millimeter black and brown spider has spun a web over the hollow’s entrance. A live victim struggles in its web. At the edges of the road, several one-half inch odd black bugs are active. They have a many-segmented abdomen and small pincers near their tails. These are immature European earwigs (Forficula auricularia). At the slightest disturbance, they bolt beneath rotting leaves. They have come to feed on smaller insects, like aphids. Three small black-winged ants are also dispersed evenly along the first mile. These may be male Carpenter ants searching for a new queen.

It is Mother’s Day and the canyon road, normally frequented by runners and ultra-bicyclists, is full of the unfit. The obese and elderly enjoy the canyon with more attention to their surroundings than the racers. After a clear and sunny morning, the evening canyon is overcast. The stream runs at maximum; the flood retention pond is within four feet of cresting the road even though this is not a flood year; and water streams five or six inches smoothly above the rock barrier that makes the pond at picnic site 5. As an experiment, I through progressively larger junks of wood into the swift moving waters, and from this the stream moves at an estimated twelve to fifteen miles per hour, about the speed of a bicycle on flat terrain. A bicyclist returning at a leisurely pace from the end of the road at mile 5.75 can run parallel to the same drop of stream water for one-half hour. On my United States Geological Service map for the canyon, the two ridgelines on either side of the canyon are collectively labelled the “Salt Lake Salient”, i.e. – a piece of land that juts out at an angle. In this case, the canyon and its two ridgelines jut out a forty-five degree angle from the larger wall of the Wasatch Front Mountain Range, and this northern salient defines the upper end of the Salt Lake Valley. At its southern end, another salient, the Traverse Ridge, juts out at a right angle, and it marks the valley’s lower end. Both are generated by earthquake faults, but in the case of City Creek, the fault line partially runs down the middle of the salient. Unlike Traverse Ridge, this allowed water to gain a foothill, to split the salient in two, and to crave out the cooler canyon below.

This evening, along the western ridgeline about a third of a mile away, a flock of 10 unidentified raptors are soaring on the wall’s updraft. They are two distant to identify, and over the next ten minutes, the recede up-canyon until the small points of their bodies can no longer be seen against the grey sky.

On May 14th, 1903, E. H. Airis sued the City to prevent it from diverting City Creek Canyon water such that Airis would not longer have irrigation water (Salt Lake Tribune). On May 14th, 1896, the Salt Lake Herald reported several active mines in City Creek Canyon (May 14, 1896).

April 19, 2017

April 17th

Filed under: Gambel's Oak, Maple tree, Squirrel — canopus56 @ 2:45 pm

Squirrel Hole

1:30 p.m. Today’s overcast skies keeps temperatures in the sixties, but overnight temperatures for the last two days have been above freezing overnight. As a result, the stream is again running at its highest, as measured by its water mark on the Zen Rock (January 4th). At Guardhouse Gate, the three mature horsechestnut trees bloom together. To mile 0.2 along the road, the Gambel’s oaks are starting to bloom. They, like the river birch, have a small compound tubular inflorescence of about twenty ovaries. Along the roadway for the first mile, numerous herbaceous plants that have stalks and leaves arranged like corn have grown about one-foot tall. What will they become? At mile 1.2 above picnic site 8, a Red maple tree has blossomed. The radiating blossoms are similar to the green blossoms of the Box Elder tree, but in the maple, they are dusky red in color.

Going down-canyon near mile 0.4, I hear scurrying on the road bank and catch a glimpse of a young Rock squirrel. I have often wondered where their burrows are, and today, above picnic site 5, I find a three or for inch diameter burrow hole on the west side of the road bank. There is fresh dirt around the entrance. I mark this site (40°47.889′ N, 111°52.420′ W) for watching. Perhaps I can confirm its inhabitant is a squirrel.

The parking lot is full, but the today only holds bicyclists.

* * * *

On April 17th, 1991, residents in Memory Grove sought closure of Canyon Road to reduce “cruising” traffic (Deseret News). On April 17th, 1900, city prison labor is used to build the boulevard around City Creek, now Bonneville Drive (Salt Lake Tribune).

January 16, 2017

January 15th

River Birch Rivendell

(Originally October 20th) 3:30 p.m. Rivendell was the mythical land of the elfin in Tolken’s “Lord of the Rings.” The canyon’s Rivendell is a short stretch of stream located about 100 feet along a trail at the end of the picnic site 11. There the stream runs slow, flat and wide across moss laden rocks. The stream banks is covered in dense scouring rush horsetails and is surrounded by ten to fifteen river birches with green and yellow leaves. The trail runs parallel to and about 20 feet north of the stream. The trail is overhung by less water tolerant Rocky Mountain maples with bright red leaves. The trail itself is covered in a patchwork of fallen Red Maple and yellow River Birch and Box Elder leaves. Shafts of low-angle afternoon sunlight pierce through the upper branches of trees and illuminate parts of the stream. Black-Hooded Chickadees flit between nearby branches.

From this canyon Rivendell, the trail winds parallel to the road through moves groves of horsetails until it opens into the northeast end of Pleasant Valley.

In Thoreau’s “Journal” on January 15th, he again sees numerous fleas on top of winter snow. On January 16th, 1857, he describes how a winter sparrow’s song lifts his spirits, and he sees tracks of mice on top of winter snow.

On January 15th, 1926, the University Hiking Club announced a planned hike to the top of Black Mountain and then to slide down over the snow in City Creek (Utah Daily Chronicle).

December 11, 2016

December 11th

Filed under: Colors, Gambel's Oak, Maple tree, milepost 1.5, Plants, Weather — canopus56 @ 4:17 pm

Rain Drops and the Half Black Tube

3:00 p.m., December 10th, 2016. The clouds from last night have thickened and it has rained for most of the afternoon. The half-day of rain has created new color contrasts in the canyon. As I drive to the gate and at the 11th Avenue and Bonneville Drive turn, hues from the grasses on the west slope of the lower canyon have turned from a bleached light-tan to a golden-brown. They contrast with the Gambel’s oak that have turned coal black from the soaking. This effect continues up canyon as I jog under my rain poncho up to the oak forest at milepost 1.5. The first mile is a “half-tube” of black oaks on the north and west side of the road. Compare the green tube (comment, Nov. 11th), the yellow tube (Oct. 11th), the brown tube (Oct. 24th) and the white tube (Nov. 24th). At mile 1.3, again the maple trees high on the south slope that retain some brown-orange leafs have a good contrast with the now wet dark tan hillside (November 19th). But the Gambel’s oaks show more subtle colors. The tips of the groves are tinged red-brown and the green of the lichen is emphasized. For some oak groves, the lower trunk is soaked black, the mid-trunk remains a dry gray, the upper third is green with lichens, and the top is reddish-brown. But from a distance, these subtleties are lost, and the groves look a deep black. In just a few days, the orange lichens near picnic site 9 (December 6th) have reverted back to a greenish color.

On closer inspection, the reddish-tinge at the oak grove’s fringes are this year’s new sprig growth. Each sprig is a light brown color, as compared to the grey of the trunk, branches and smaller twigs. The sprigs contain the unopened buds that are ready for next year’s resurrection.

The buds are discontinuities on the smooth twigs and sprigs. Here the water collects into small droplets that contain miniature inverted images of the hillside in the distance. The size of the twigs are such that water tension prevents droplets forming along its length. Further down the canyon, the smaller and smoother twigs of the red dogwood bushes allow water to retain sufficient tension that the droplets form like beads along all of that species horizontal twigs.

The rain is light and the droplets are large. I stop at the pool at picnic site 6 and watch the sporadic droplets make large expanding ripples on the surface. The drops and their expanding ripple circles cover more than one-half the pool, interfere with each other, cancel one another, and then fade out of existence. This type of experience inspired thought experiments by physicists that led to the modern understanding of the dual nature of light a particle and a wave.

In Thoreau’s “Journal” on December 11th, 1855, Thoreau revels about winter nature and states that, “[w]inter with its snow is no evil to be corrected.”

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.

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.

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