Trees and People
Bill Pramuk

Unusual Tree Stumps Arborist

Since my first job in the green industry, working as a landscape laborer, I found it fun and satisfying to learn the common and scientific names of plants.  Not only was it necessary to know plant and tree names to be sure they were planted at the right location according to landscape plans, it just appealed to my natural curiosity and sense of order.

I soon found myself reciting the botanical names of trees and shrubs wherever I went, and feeling challenged when I encountered ones I did not know.  I eventually got over the preoccupation with naming everything, but I still enjoy the challenge of identifying an unusual tree. That opportunity arose just recently.  So, here’s a little primer on my self-taught method for tree identification. It is based on a fair amount of familiarity with plants in our region and a process of elimination using a few reference books.

My big, fat Hortus Third, Dictionary of Plants Cultivated in the United States and Canada includes 20,397 species of plants. (I didn’t count them; it just says so in the Introduction). That is a daunting number, far beyond my ability or interest to memorize. I think I have yet to come across a plant species in a local landscape that is not listed in that book. So, if it is in a local landscape or forest, it is probably in the Hortus.   But how do you find it?

Here is the key:  Closely related species are grouped into genera.  In turn, closely related genera are grouped into families.  The 20,000-plus species of the north, Western Hemisphere are grouped into only 3,301 genera.  In turn, those are grouped into only 281 families.  Hortus lists each family with all of its genera, so it serves as a useful plant identification tool.  Using clues from plant anatomy, you can narrow down the possibilities by first identifying the family and then working your way down to the Genus and finally the species.

Tree identification is also simplified by the limitations of the climate of our region. Because any given tree species can survive only in a limited range of annual temperature extremes, the number of tree species is limited. There are only about 85 genera of trees that are common here in the San Francisco north bay area and these fall into only about 45 different families.

Identification is further simplified by the mere fact that most landscape designs repeatedly use the same species and our local forests and woodlands are dominated by just a few tree species.

After a few years of paying attention and running to the reference books, one can build up a pretty thorough knowledge of the local trees.

So, here’s how I was temporarily stumped on a recent, summer  garden visit, and learned of an interesting tree species that deserves more attention.

In a back yard, mixed in with the usual suspects - red maple, Japanese maple, purple leaf plum -  I noticed a small, handsome tree that just didn’t “ring a bell”.   The medium green leaves were divided into small leaflets, and there were a few blooming flower spikes, so I had something to work with for identification.

A closer look at the individual flowers revealed that they looked like tiny sweet pea, bean or Wisteria flowers.  Considering this, along with its compound leaves, I felt it must be in the “pea” family, Fabaceae.  Unfortunately, that family has over 200 genera!  At least that’s a lot narrower field than the total of 3,301 plant genera listed in the Hortus Third.

With some more reading, and following hunches I was able to pin it down.  The mystery tree is a Chinese Maackia (Maackia chinensis).  Not really all that mysterious, 2 species of Maackia are even described in the Sunset Western Garden Book: “Summer flowers resemble small sweet peas…”.

Sunset goes on to say “…not fussy about soil. Need minimal pruning.”  Other references indicate the Maackias have good potential as sturdy, small to medium-size shade trees for gardens, parking lots or street tree curb strips.

They might deserve broader planting around the region.  At least, I know where to find one good specimen.

(Bill Pramuk is a registered consulting arborist.  Visit his website, www.billpramuk.com.  Email questions to info@billpramuk.com, or call him at 707-226-2884)

Trees and People
BillPramuk

The Napa Urban Forest

Here, abbreviated and paraphrased, is an interesting letter I received last week:

Dear Bill:

There seems to be a strong tendency in Napa for large trees to simply be removed when they break sidewalks.

Why do sidewalk maintenance and tree stewardship seem to be more in conflict in the City of Napa, despite its Tree City USA status, than in many other cites?  Walking through Old-Town in Sacramento is a delight, while walking through my subdivision, planted with small-growing trees doesn’t make me very proud of my own city. Those trees will never create a true urban forest that mitigates heat-island effects, contribute to carbon sequestration in any substantive way, or provide habitat linkages to our oak woodlands and riparian corridors outside the city limits.  More often than not the “offending” tree - usually as soon as it has reached about 10-15 inches dbh, gets chopped down and replaced with the new flavor of the year.  Why not re-think sidewalk maintenance, the way Davis, Sacramento, and Alameda have done?

Maybe you can shed light on the following problems:

1) Institutional challenges i.e., Public Works engineers aren’t arborists. They have a different perspective from Parks managers, - hence, whatever causes maintenance and “public safety” problems moves to second priority, and Public Works trumps Parks.
2) Funding problems i.e., it’s cheaper to chop down a majestic shamel ash and replace it with a crape myrtle than find a way to save a mature tree. The City of Sacramento seems to have solved that problem via alliance with the Sacramento Tree Foundation. Do we have a similar institution here in Napa?
3) Lack of public awareness

I would consider getting involved once I have a better idea about the root causes of the symptoms I have described above.  Would you mind giving me some pointers based on your experience and knowledge?
RH

Dear RH,
This discussion should include trees in the city right-of-way and trees on private property.  For the space available today, we will stay with city-owned trees.

Cities earn the Tree City USA designation by establishing a tree ordinance, a tree committee - like Napa’s Tree Advisory Commission (TAC), which advises the City Council - and having an annual arbor day event.  That’s all.

It’s a good start, but it does not assure state of the art tree stewardship in the city.

Fiscal conservatism often translates into expedient resolution of tree-related problems without much creativity.  For example, large-growing tree species have a reputation for breaking sidewalks. The expedient resolution is to remove them and plant little crape myrtles.  The creative solution would be collaboration between city departments and the community for tree preservation and urban planning that allows for big trees.

The Public Works Department sometimes makes exceptions in sidewalk, curb and street conformation when an adjacent property owner wants to save a big tree that would otherwise be removed because of infrastructure damage.  That is the exception, not the rule, but it can happen when people speak up.

Many trees have been planted with inadequate soil volume, compacted soil, no irrigation in the intended root zone, no barriers to prevent roots from growing under sidewalks, inadequate space for the trunks and buttress root plates, and overhead obstacles. The common scenario is a property owner requesting removal of a problematic City tree adjoining their property.

Napa Parks and Recreation policy on tree removal applications gives the Tree Division Supervisor authority regarding trees under 24″ trunk diameter. Tree removal applications for larger trees go before the TAC.  Removal applications that are denied can be appealed to the TAC and then to the City Council.

Approved removals might be posted on the street, but sometimes take the neighborhood by surprise.  In those cases, activists in favor of tree preservation are too late, writing letters to the editor or complaining to the city, after the fact.

One approach to improving this situation is the “right-tree-in-the-right-place” movement, which has gained ground in recent years.  It is based on a good idea, but it has focused too much on selecting trees for small, inhospitable locations and not enough on finding and creating suitable sites for big trees.

Proactive planning and community based advocacy are needed for improving our urban forest.

Local non-profit organizations can be a great force for good tree planning and stewardship in cooperation with City government. In addition to the Sacramento Tree Foundation, good examples include Mountain View Trees,(www.mountainviewtrees.org , Canopy (www.canopy.org, Palo Alto), San Francisco Friends of the Urban Forest (www.fuf.net) , City Trees (www.citytrees.org, Redwood City), Baton Rouge Green (www.batonrougegreen.com, Louisiana) , LEAF (Local Enhancement & Appreciation of Forests (www.leaftoronto.org, Toronto, Canada, City of Orlando: Green Up (www.cityoforlando.net, Florida, Trees New York (www.treesny.com, New York City).  That is just a sampling.

Napa does not have such an organization.

California ReLeaf (www.californiareleaf.org), a nonprofit organization whose mission is to empower grassroots efforts and build partnerships to enhance urban forests, could be of enormous help here in Napa if a few citizens take interest and decide to get something going.

In a conversation with Rob Hansen, Supervisor of the City of Napa Department of Parks and Recreation, Tree Division, I found that he and his department would be happy to work with such a group if one is formed.

How about it:    Napa Shade  or  The Napa Tree Foundation?

(Bill Pramuk is a registered consulting arborist.  Visit his website, www.billpramuk.com, email questions to infor@billpramuk.com, or call him at 707-226-2884)