Posts tagged Trees

The bench in front of the Engelmann Oak at the Los Angeles Arboretum. All photos by Kathy Rudnyk.

Just as my family tree in the San Gabriel Valley has changed over the generations, the various native plant communities within the same area have also been compromised. None more apparent than Southern Oak Woodland.  This community includes principal trees such as the Engelmann Oak (Quercus engelmannii), Coast Live Oak (Quercus agrifolia), Black Walnut (Juglans californica).  Of those three, the Engelmann Oak has suffered the greatest impact, but it has the treasured opportunity to be recognized for its beauty and unique distinction to San Gabriel Valley.

Once found throughout the San Gabriel Valley, the Engelmann Oak has most recently suffered greatly from insect and fungal pathogen damage, followed by poor cultural practices like overwatering. Urbanization and stress caused by drought and fires have also posed a greater threat to these legacy trees. The population has also been afflicted by a lack of availability in the trade until now. I was so inspired by seeing beautiful Engelmann Oaks at The Huntington Botanical Garden, Los Angeles County Arboretum, and this year’s Theodore Payne Annual Native Plant Tour, that I wanted to learn even more about its roots within the Southern Oak Woodland native plant community.

On the right: A young Engelmann Oak at the Huntington Library Botanical Garden.

For some unknown reason, my family and I have always enjoyed learning about our ancestors. Maybe it’s because we are all scientifically and oddly inquisitive – a family of nerds right at home in the land of JPL, CalTech and SpaceX. And we are all also surprisingly of sturdy stock like an oak tree.

My late grandfather respected the oak so much that he asked that the California Live Oak (Quercus agrifolia) be etched onto his tombstone. He also planted a White Oak (Quercus robur) close to his home. Exploring the genealogy of the Genus – Quercus and its relationships has helped me learn more about my own roots within Southern California.

Sadly, you can’t just go to Ancestors.com for answers about the roots of an actual tree. You need to go to a library of natural history. So off I went on a Saturday to the Los Angeles Arboretum. I culled the stacks and found a manuscript written by Bruce M. Pavlik titled, A Natural History of Southern California Oaks, with Emphasis on Those Occurring within the District.  After reading it, I hiked around the park for further inspiration about the Southern Oak Woodland native plant community.

Published in 1976, Pavlik’s manuscript shared many of the same concerns about the California native oaks within the Los Angeles district that are threatened today. Most significantly, he called for the protection of Engelmannn Oaks in response to the rapid urbanization of the San Gabriel Valley in the 1970s.  Prior to development, Engelmann Oaks were only threatened by horse and cattle grazing, which destroyed any opportunity for seedlings to flourish into trees around the valley floor. The young trees survived only along the ridge lines, because it was too dangerous for cattle and horses to graze upon their foliage.

Within its family tree/taxonomy, the Genus amongst California native oaks resides in the order of Fagales, consisting of the families Betulaceae and Fagaceae.  Birch (Betula), Alders (Alnus), and Hazelnut (Corylus) reside in the family of Betulaceae, and they are the closest of relatives of California native oaks.  Within the family Fagaceae are the Genus of oaks and their relatives, such as Chrysolepis, Quercus, and Lithocarpus.

The mid-sized, evergreen Engelmann Oak has the distinct characteristics of a California Live Oak, yet, instead of green leaves that are slightly serrated, it has vibrant blue-grayish-green leaves that are rather long in length and relatively unserrated edges.  The tree’s acorns have a slightly hairy underside on the cap. The acorns of this particular tree were harvested last by the native peoples for food, as acorns from other species like the Valley Oak (Quercus lobata) and Coastal Live Oak (Quercus agrifolia) tasted better or offered more nutrients.  Unfortunately for the Engelmann Oak, it was most preferred by the locals as firewood, as its wood seemed to burn the longest of all local hardwood trees.

An Engelmann Oak finds a few admirers during the 2017 Theodore Payne Native Plant Tour.

These impressive trees are rarely found north of Pasadena, and only along the northern side of a foothill, generally in thick stands within shallow soil supporting aromatic plants White Sage (Salvia apiana), California Buckwheat (Eriogonum fasciculatum), and California Sagebrush (Artemisia californica).  Along the valley floors and around mesas, Engelmann Oaks were surrounded by California Poppies (Eschscholzia californica) and Purple Needle Grass (Stipa pulchra) growing around the base of these majestic trees. I bet this was a very beautiful sight my ancestors enjoyed living in San Marino, Sierra Madre, and Monrovia prior to the mid-1850s. Engelmann Oaks were once spotted along a 50 mile wide beltway from Pasadena, all the way to Mexico, always at least 15 to 20 feet from the nearest coastline.

The Engelmann Oak shares the growth rate of the Coastal Live Oak, growing about 8’ in 5 years.  Of all the oaks, the Valley Oak grows the fastest at 15’ in 5 years. Lucky for us, the Engelmann Oak is now available to purchase from a local tree nursery, and it can still be found around growing within neighborhoods of Duarte, Pasadena, Azusa, and Glendora. The Los Angeles Arboretum and the Huntington Botanical Garden have a few that you can see, touch, study, and enjoy.  I really found walking through the tree’s dense pillow of foliage debris lining the way toward a bench underneath the massive tree at the LA Arboretum unlike anything I have ever done in Los Angeles.

Two Engelmann Oaks discovered in Pasadena using Google Earth.

I went onto Google Earth to continue searching for more EEngelmann Oaks within the area, looking out for a particular hue that helps identify the trees from others.  The Engelmann Oaks are fairly easy to spot based upon their color of foliage depicted on Google Earth.  It was like finding members of your family tree that you did not know existed. The activity made me want to look for even more Engelmann Oaks and determine how to enable further protection of them or build more colonies of these special trees unique to San Gabriel Valley.

Engelmann Oaks can help make the San Gabriel Valley a better and more beautiful community, while strengthening the native plant community of the Southern Oak Woodland. So hopefully everything I’ve shared above will compel others to appreciate and plant some of these wondrous native oaks.

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At one time massive oak trees like this one captured growing from Orange Grove Avenue in Pasadena, circa 1890 held prominent presence. Check out The Oak Trees of Southern California: A Brief History over at LOST LA. Courtesy of the Photo Collection, Los Angeles Public Library.

How long ago did trees of significant size cease to be identified and used as wayfinding elements? I still harbor romanticized memories of large specimen trees holding court in the center of small towns, or trees of substantial size guarding the entry of a home’s long dirt driveway back in the “olden days.” Besides the scarcity of space for trees of significant size and age in most urban centers today, I have to wonder how many people could actually even identify a Jacaranda or Coral tree, especially when it was not flowering?

This very question arose last week while attending, “Movement Matters: Wayfinding: what, how, where and why?”, a seminar sponsored by Steer Davie Gleave. Seminar presenters, Evan Weinberg, Policy and Advocacy Manager, Toronto Financial District BIA and James Brown, Principal Consultant, Steer Davies Gleave led what turned out to be an interesting discussion about the importance of wayfinding elements in our cities – from economic benefits, to the physical interaction with one’s city.

I especially enjoyed the Legible London project that they described, a project envisioned with the goal to give people the “confidence to get lost.” The very legible wayfinding signs stationed right outside all the Tube Station stops in London proved extremely helpful during a recent trip, a firsthand account of the benefits of wayfinding elements in a city.

The other point I was glad to hear during the seminar was that Weinberg and Gleave still recommended producing an actual map of the area. Perhaps one that was extruded, or be presented on a dynamic digital board, but nevertheless advocate the production of an actual map of an area. They said many clients immediately ask for an app as a wayfinding tool; but these consultants still abide by the conviction, a “map before the app.”

On a related note, I still distinctly remember preparing for my first – and sadly only – visit to Venice, Italy. Travel advice I read soothed concerns about getting lost as a visitor, since it was a small island; my fears were allayed by promises that any small alley would eventually reveal signs to guide visitors back to open identifiable sections of the city. Venice proved a great locale to safely give into this “confidence to get lost” – to go without a map, wander, and simply explore.

Photo by Stumpy Sad; CC-BY-SA-2.0

Creative Commons photo by Stumpy Sad; CC-BY-SA-2.0

Do you remember the story in the New York Times about Jean J. Hsu, a woman who lost her class ring down a grate? It was a rather funny tale, one documenting how Ms. Hsu navigated New York City’s labyrinth of red tape to retrieve her lost jewelry from the bowels of a busy downtown corridor.

While walking through DTLA or through the beautiful City of Glendora downtown corridor, I’ve noticed all sorts of different types of tree grates. It has a role as one of today’s favorite urban landscape features, but times are a changing. There are all sorts of stories that you can muster up about why or why not a tree grate was removed: it was stolen, the tree outgrew the space, the storefront had it removed.

Who needs a tree when extra asphalt is on hand to fill a previous tree well?

Who needs a tree when extra asphalt is on hand to fill a previous tree well? Photo by Kathy Rudnyk.

I’ve noticed some sidewalks interrupted by empty square cutouts filled with compacted soil or asphalt, like the one pictured here on the right. I sometimes like to imagine buried treasure awaiting to be found underneath. But more so, I’d prefer such an empty space being occupied again with a thriving tree, one that could offer ample shade from the glaring glass curtain walls along 7th Street, provide a respite for urban birds, or offer a great spot for tourists to take a photo.

The City of Glendora’s downtown corridor – Glendora Avenue – is lined with meticulously clipped Ficus microcarpa nitida, ‘Green Gem’ (Green Gem Indian Laurel Fig) pruned into the shape of gumdrops. These trees were made famous by a commercial for Southern California’s fast food chain, Jack in the Box.

Most of the tree grates on this stretch of Glendora Avenue have been since removed, with only two tree grates remaining. The two trees surrounded by tree grates are much smaller in size than the rest of sculptured trees. Some creative tactics were taken by shopkeepers to keep the area tidy and to prevent dogs from doing their business along the double row of trunks. Now poinsettias line the boxes (just in time for the holidays!).

America is not alone in its fetish for tree grates. In Spain, I fell into a few missing tree grates spaces while admiring the beautiful architecture of the country. Let me tell you, those empty spaces once occupied by a tree grate were rather deep; their planting specs must call for a much deeper tree well than the American version!

Gumdrop trees lit up for the annual Holiday Stroll on Glendora Avenue in Glendora

Gumdrop trees lit up for the annual Holiday Stroll on Glendora Avenue in Glendora. Photo by Kathy Rudnyk.

Maybe it is time we question why even have tree grates in the first place? Other questions floating in my head:

* Is the lack of tree care, alongside their respective tree grates, just another form of “demolition by neglect”? Perhaps, the tree grate is a much more of beautiful ornament than the tree it was originally intended for – something I have seen in NYC with their treasured and historical art deco tree grates. Maybe the expense went into buying the best of the best tree grates, but a low bid or a slashed budget made getting the best tree impossible.

* Maybe the tree and its protective tree grate are considered an annoyance now? Maybe for some people a tree might be considered a hindrance, limiting access from car to building or onto a train platform.

* Why not utilize plants around a tree rather than selecting an expensive tree grate. At a cost of approximately $2,000 a piece, these grates were designed to protect the tree’s apron of roots. But when you walk through a forest, you might observe small shrubs or perennials naturally growing around trees in the wild. Why not recreate the same natural relationship in an urban setting? It would enhance the urban landscape and provide even more natural curiosity. 

* Does every city street need to look like a New York City sidewalk?

filled-tree-grate

Photo by Kathy Rudnyk.

But there are some really good reasons for tree grates. First, in urban areas with a high density of people who park close to trees or walk by one, these grates keep the surrounding soil around the tree from being compacted. Besides lack of water, pests/disease, or pruning at the wrong times, compacted soil is a major reason why trees suffer in urban settings. Tree grates also shade the soil over the tree’s roots, slowing down the evaporation of the water around the tree. And in a drought like we’re experiencing now, that is a definite benefit.

Tree grates can be rather appealing aesthetically . Their ornate traditional designs are quite adaptable, coming in all sorts of shapes. Some even have lights built right into the design. Most are fabricated with metal, but maybe in the future tree grates will be printed using a 3-D printer and laser cutters, using other types of materials to add to curb appeal. What if grates were made from silicone, plastic, recycled tires, and other renewable resources like bamboo or cork? Or maybe they could light up when stepped upon. One wonders due to the fact tree grates have so long gone unchanged, their utility for tree and shrub health is now forgotten or overlooked. Perhaps tree grates need a Project Runway-style redesign representing the times of today. Or maybe it’s just time to say farewell, noting they’re a feature of yesterday?

Expanded tree well on Glendora Avenue in Glendora covered with Astroturf. Photo by Kathy Rudnyk.

Expanded tree well on Glendora Avenue in Glendora covered with Astroturf. Photo by Kathy Rudnyk.

Cities are already challenging themselves to use alternatives, including artificial grass, art, and pavers instead of tree grates. If you lose a piece of fine jewelry – like Jean J. Hsu’s class ring from the aforementioned story above – recovering it will be much easier when mulch, ground cover, shrubs, or artificial turf surrounds the tree. Even in Manhattan, the city now shuns using tree grates, replacing them with more advantageous methods of protecting valuable urban trees.

Well-designed tree grates permit water, air, debris, and the occasional unfortunate class ring through its grill. But the space between the tree grate and the soil should be periodically cleaned; if an excess of debris gets trapped between these sections, it can  prevent air and water from entering the basin or result in soil building up around the trunk, both causing undue harm to the tree.

A Ficus tree trunk that grew way beyond the diameter of the tree grate.

A Ficus tree trunk that grew way beyond the diameter of the tree grate. Photo by Kathy Rudnyk.

Most of the time when tree grates are installed, they’ll never be moved again. But occasionally a tree grow will outgrow its once spacious ring, requiring it be removed or entirely replaced. Tree roots will grows upward if there is insufficient room for it to grow outward. Everyone in Los Angeles has seen a sidewalk like this at one time or another. Unless there is an effective root barrier in place or regular root pruning, trees without enough space to grow can push a sidewalk upward, causing a hazardous feature. Occasionally the affected sidewalk area is cut out and expanded, with the tree grate removed to expose the surrounding soil to promote the tree’s health.

Professor of Environmental Horticulture Dr. Edward F. Gilman of University of Florida, Gainesville offers some excellent advice: Tree grates should be considered a short term solution lasting about 15 years. Dr. Gilman advises widening sidewalk spaces around trees, planting clusters of trees, channeling roots to grow toward soil, using alternative material around the tree and gravel as a subsurface rather than compacted soil or other types of materials. He believes planting the tree at least 2 feet away from the sidewalk is beneficial, alongside planting the tree away from the curb, or elevating the sidewalk around the plantings to give tree roots a place to grow. If the space/lot permits, Dr. Gilman believes planting trees in groups is superior to a lone specimen; trees have been observed to work together to help improve surviving the numerous challenges in an urban environment.

Tree well on Glendora Avenue in Glendora, filled with mulch, art, and a few small plants.

Tree well on Glendora Avenue in Glendora, filled with mulch, art, and a few small plants. Photo by Kathy Rudnyk.

It can be odd walking down the street and noticing the trunk of a single palm tree and an evergreen tree shoved into a tree grate. It seems a better idea to plant a natural buffer of spiky-looking plants to help encourage pedestrians to walk around rather than over the space. Consider working deterrents like Dietes ‘NoLa’ (Katrina™ African Iris) or Dianella ‘DR5000’ (Little Rev Flax Lily). 7th Street in Downtown Los Angeles on 7th Street is ripe for such a display of plants and trees living harmoniously together. The streetscape already offers a wide sidewalk, with exposed brickwork that could be quickly refilled with trees and shrubs. More could be done to create a beautiful, urban enriching botanical buffer, just ripe for pollinators. I suspect that property values would also rise, and such urban flora would encourage more people to traverse on the plant-lined side of the street versus the opposite lined with brightly lit stores. Already I’ve noticed traveling on the side of the street with Whole Foods because I’m naturally drawn to their lovely basins filled with trees and Dietes ‘NoLa’ (Katrina™ African Iris), contrasting the bleak parking garage across the street devoid of any plantings.

Tree grates are amazing urban accessories, but a landscaping tool due for a change. I am sure landscape and urban designers can find great uses for tree grates, as well as exploring what we can do to make our shrinking urban planting spaces last longer than ever by incorporating plants, trees, shrubs, art, rainwater runoff, and most importantly, our imaginations. Just remember, the next time you see a tree grate, somewhere underneath may be a ring that will never again reunite with its rightful owner. All I know is I’m not sure who I would call if my ring fell through a tree grate here in Downtown Los Angeles…

 

A Los Angeles sunset, captured by Jacob Avanzato (Creative Commons)

A Los Angeles sunset, captured by Jacob Avanzato (Creative Commons)

Click infographic to preview  full size.

Click infographic to preview full size.

I stand at our office window at the end of the day, watching autumn’s golden light descend onto the city. Even in the daytime hours, I can view from my perch the patterns of angled light and shadow against the buildings and sidewalks – nature’s quiet pronouncement of a new season at hand. However, when I step outside the unwelcome heat reminds me summer has her own calendar. The city emanates our area’s lingering heatwave. The Southland’s record breaking temperatures puts many of us into hibernation mode, as we escape to our air-conditioned offices, homes, or shopping centers in hopes the heatwave will finally end.

Any day now,” I tell myself. “Soon.”

It’s no surprise discussions about the heat leads to the hot-button topic of climate change. While a surprisingly significant portion of Americans remain unconvinced about the subject, scientists have reached a consensus about global warming. Scientists turn to historical data on climatic patterns to understand the precipitation and temperature changes we are experiencing today. Nature, as it turns out, has been recording environmental changes for us.

The tree rings of old trees provide dendroclimatologists (the climate scientists who study trees) with up to hundreds of years of data, cycles of dry and wet seasons recorded into a concentric database of wood. Dendroclimatologists study the pattern of wide and narrow rings to measure extreme weather cycles of heat and drought, including their frequency and length. This information, and layers of other historical data, are fed into forecast models for anticipating future possibilities, including drought, and water management.

models-observed-human-natural-largeThe debate on climate change does not end with people’s acceptance or denial. I am fascinated by the question amongst “believers” about whether human activities have contributed to this condition. Studies have examined the natural cycles of the earth’s temperature and scientists cannot explain the warming trends of the last 50 years based upon natural causes alone.

Sunsets out my window. #sunset #DTLA #bird #positivity

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We are told however that it is not too late for action on climate change. But if the debate is being shaped by culture versus science, can we close the cultural divide in time to develop solutions that will make a difference to the planet?