Friends of the Urban Forest Tree Tour (9/10/08)

I have long been a fan of the organization Friends of the Urban Forest, and some time back when I was looking for ways to volunteer with them I stumbled upon their events page, which linked to their page on Tree Tours.  Having basically failed to RSVP for the event I showed up at the foot of the Transamerica Pyramid anyways at noon and sort of milled around idly until eventually the other people milling around and I amalgamated ourselves into a group of like-minded tree enthusiasts.  The weather was perfect, sunny and bright but not too hot; the crowd seemed to mostly be workers from the surrounding financial district, and skewed a little older than me and with more women than men.  Soon enough we were joined by Mike Sullivan, a past board member of the Friends whose web site is at sftrees.com.  Mike is the author of a book about trees in San Francisco, and he had signed copies with him which he parted with for less than their cover price.

After a few brief introductory remarks we were off on the tour.  The routine more or less went that Mike would walk us up to a particular tree, we would gather around, and he would tell us what sort of tree it was, where it came from, oftentimes a bit of botanical information about it, and often a history of the species in San Francisco.  We’d pause for a while for questions, if any arose, and then we were off to the next tree.

I was very interested in Mike’s miniature histories; apparently particular varieties of tree go in and out of fashion among city-planning types.  For instance, the ficus was once one of the most common species of tree in the city, but these days it’s no longer planted because it has a tendency to break up the sidewalk it is planted near.  When you see a ficus up close you will often find that the sidewalk within a few feet of it is of a different color than the surrounding sidewalk, because the ficus breaks up the concrete every few years, necessitating repairs.

These are the sorts of insights I find extremely valuable.  In this story the ficus has become a nexus of information which includes the history of San Francisco, city planning policy, the biology of a particular species of tree, and local detail which is rooted in the physical and particular concrete world.

A few other random tidbits I enjoyed from the tour: Australia and New Zealand have very similar climates to the city, and in fact we saw only one tree which was native to California.  Once a particular tree’s roots grow down low enough, they will hit the water table and the tree will no longer need to be watered.  This behavior is dependent on the species of tree; some trees still need water after they’ve reached the water table, but most species planted in sidewalks in the city are specifically selected for this biology.  Some trees are gendered.  There are lots of Ginkgo Biloba trees in San Francisco, but only a few female ones – one is planted near Schrader and Cole.  Female Ginkgo trees are uncommon here because when they bloom about once a year they emit an unpleasant smell.  I suppose I’d known of gendered plants before (from male and female pot plants, if you must know), but I’d never regarded trees as being male or female.

I was pretty interested in the city planning and policy aspects of who decides what trees are planted where, and I asked Mike about it but he didn’t go into too much detail – that was understandable as I’m sure it’s a complex matter and we didn’t have tons of time in between seeing particular trees.  I was a little surprised when I asked him whether the Friends of the Urban Forest lobbied the various city agencies (Parks and Rec for parks, a separate agency – the DPW? – for sidewalk trees) to get their policy positions on, ah, forestry, implemented and he described them more as working together to plant trees, almost as though the FUF were an unofficial arm of the city government.  But surely the FUF must have all sorts of policy positions on the varieties of trees to plant, where trees ought to go, and so on, and I’m certain the city agencies have plenty of opposing lobbies as well – San Francisco politics being what they are, I’m certain that an Enemies of the Urban Forest must exist somewhere.  In any event, this is all no doubt worthy of further research.

Altogether I had an excellent time at the tree tour.  I place a really high value on things which cause me to perceive familiar things in a new way, or put me in touch with a new geography by which to think about and navigate my surroundings, and this tour certainly did that.  My main regret is that although the tree talks were very interesting in and of themselves, I’m not sure I have the right combination of good memory and botanical skill to recognize these trees should I come across them again in my travels through the city.  But overall it was an excellent way to spend my lunch break and I would definitely recommend upcoming tree tours to anyone with the slightest interest in trees, botany, city planning, or local knowledge.