Carleton Cronin: Our urban forest, our piece of heaven.

“Since When Have Trees Existed Only for Rich Americans?” ask Ian Leahy and Yaryna Serkezin the July  4, 2021, Sunday Review section of the New York Times.  They provide the answer in a full page display of the disparity in urban tree cover in twelve US cities.  The differences are quite startling – unless you might have lived in one of those cities.  Boston and Buffalo have both been home for me in years past and Denver I have come to know fairly well.  These are three of the cities illustrated in the article.  Sure enough, depictions of tree cover indicate that the tonier sections of all twelve cities have far more of the urban forest than do the low-income areas.  I just checked the greenery outside my house.  Sure enough, lots of trees – but rich? Certainly not most of the households on this block of Dorrington Avenue. 

And, incidentally and importantly, the July issue of the National Geographic magazine’s cover story evokes the same question and provided answers with great detail how Los Angeles City and country have decided where the trees should go – and grow.  With a fold-out map the article takes us on a ride along major streets from the edge of Beverly Hills to the environs of East Los Angeles with a series of photographs depicting the lush parkways  of the Westside (including West Hollywood) to  the bare parkways and sidewalks in the more Eastern regions of the city.  It’s an enlightening journeyand brings up the question: Considering that much of the eastern areas of Los Angeles were settled earlier than much of the western sections, why are they so sparsely green?  Concrete replaced greenery rapidly in the last century and apparently few noticed the disparity.  

Let’s look at WEHO. The city has put together a remarkable catalogue of its urban forest, one that puts my Sunset Western Garden Guide to shame.  I find that there are about 9000 street trees in the city, comprising some 192 species.  The majority of these trees were inherited when we became a city in 1984.  The tree with the highest number on our streets is the jacaranda, closely followed by the Chinese Elm and the Indian Laurel. The second and third species often grow quite large, and by my estimation are not really in scale with surrounding buildings and our narrow streets.  While outside my wee house now sits a very large  Indian Laurel, the same space on the parkway was home to two Chinese Elms.  Before cityhood the county removed both because of the damage they had down to the street and underground utilities – including my sewer line.*  While such large trees offer shade to reduce the urban heat sinks, give us the oxygen we need to breathe, and absorb lots of air-borne pollutants, it can also prohibit the growth of many plants and ground cover which may require more sun.  They require constant (every two years) “pruning” which does not interfere with their growth and such trees require much water.  According to one source, a 30 foot tall tree  needs a minimum of 120 gallons of water per week, based on a rule of thumb that suggests a water requirement of 30 gallons per 1” of tree  trunk diameter measured at the base.  A healthy tree can retain between 30% and 50% of its own weight in water.  When water is plentiful a 30’ tree can absorb as much as 150 gallons in a day; in times of drought, that’s a lot of water.  Water is essential, of course, and its roots will seek it out anywhere they can.

While I have often referred to the Indian Laurel outside my house  as a “gigantic weed” it has become so from supping heartily from my twice replaced sewer line and sipping from my small irrigation lines and shading out much of my front garden, it is a necessary element in our “rich” city.  I have pondered ways to surreptitiously   kill it, I have to admit. Of course, I could not. A common use of the upper story of my weed, its canopy, is the home to a variety of smaller birds some of which thrive on the insects which also make a home up there. .  My Audubon membership would be in peril if I did something harsh to the tree.  Thus, we live together and I have something to be cranky about while grudgingly admiring it.  The “weed” will long outlive me and, unless my current dwelling is replaced when I’m gone with one of those “box houses”, it will not be in jeopardy of removal.  

Since about 85% of the city’s residents live in apartment or condo buildings, some of the above may not matter much. – unless one looks around. Those who take walks will  more likely notice the trees, their variety, their seasons of lushness, of the later nuisance of dropped fruit on sidewalks and of annual decline and the withdrawal of their greenery.  Take more notice.  Our city is rich in a green canopy, our urban forest. A well-cared for tree is a gift.  And that statement brings back a dusty memory for me.

The Tree of Heaven

When I was five years old my family experienced a severe economic distress which sent us to the backstreet slums of South Boston and into the arms of the welfare state.  Our new home was a cold water flat in a three storywalkup in an area facing the waterfront.  Everything was dingy and gritty and grim. Our first winter there was fearsome.  But for the largesse of James Michael Curley, the Robinhood -like mayor of Boston in 1937 we might have gone hungry or even homeless.  As the Spring rains subsided we kids found reason to go outside more often.  On one such trip we discovered a tree growing brown branches with green spiky leaves just barely showing.  How exciting!  It was the only living flora within blocks.  My grandmother said, upon viewing it: “It’s an ailanthus, which the Chinese call The Tree of Heaven.”   I have since seen that treemany times, mostly in Eastern US cities and always in the their poorer sections. Must be part of a plan, Heaven keeping an eye on us

*The West Hollywood Urban Forest Guide has explicit rules regarding the removal or altering of street trees. Be careful.