Planting “Trees” – The Quiz from Natural Areas Program
June 17, 2012 2 Comments
We’ve been hearing that the Natural Areas Program would plant trees, one for one, for every tree they fell under the Significant Natural Resource Areas Program. Of course, we know this can’t be true. (Read our comment on the Draft Environmental Impact Report HERE for why not.)
But we were curious. What trees have they been planting, how many and where? So we made a Sunshine Act request, and got a prompt response. At first blush, it didn’t look too bad. They planted 676 trees over four years in “Natural Areas”: 218 in the year 2008/09; another 273 in 2009/10; 124 in 2010/11; and 61 in 2011/12, year to date. (We don’t have data on survival rates, but we won’t go into that now.)
What trees were they planting, we wanted to know. Here, the picture was less clear. The trees were, in alphabetical order: AESCAL, ALNRUB, HETARB, MYRCAL, PRUILI, QUEAGR, SALLUC, SALSPP, SAMEX, and SAMRAC. We’d never heard of them. Neither had Google.
It was clearly a code. We went back and asked (under the Sunshine Act) for a translation. If anyone did know, they weren’t telling.
BUT WHAT DID THEY PLANT?
So we called on our best detectives. It was complicated by multiple names, both latin and common. But we think we cracked the code. We started to read about them on the USDA’s website. Something seemed amiss.
- AESCAL is Aesculus Californica, or California Buckeye. “This native, deciduous shrub or tree reaches 12 m [i.e about 40 feet] in height with a broad, rounded crown… Do not plant buckeyes near apiaries as the flowers are poisonous to honey bees. No wildlife eat buckeye seeds except squirrels, such as the California ground squirrel.”
- ALNRUB is Alnus Rubra, or Red Alder. The trees are “medium-sized, reaching various heights from 15 to 30 meters tall when mature.” [50-100 feet]
- HETARB is Heteromeles Arbutifolia, or Toyon. “This evergreen shrub reaches up to 10 meters [35 feet] in height.”
- MYRCAL is Myrica Californica, or California Wax Myrtle, or Pacific Waxmyrtle. It is “a large evergreen shrub or small tree, 10 to 35 feet high.”
- PRUILI is Prunus Illicifolia, or Hollyleaf Cherry. This is “a small, evergreen shrub or tree that is native to California. The plants can reach 6 to 9 meters” [20-30 feet]
- QUEAGR is Quercus Agrifolia, or California Live Oak, or Coast live oak. An “evergreen tree 10 to 25 m tall” [35-80 ft].
- SALLUC is Salix Lucida, or Shining Willow. A “shrub or small tree to 4 m” (13 feet).
- SALSPP is Salix Speciosa or Pacific Willow. The USDA considers this the same as Salix Lucida.
- SAMMEX is Sambucus Mexicana or Blue Elderberry (also called sambucus caerulana, sambucus nigra, sambucus canadensis). “Shrubs growing 2-4(-8) m tall, [i.e. 6-13 feet tall, occasionally 26 feet]; less commonly small single-stemmed trees.”
- SAMRAC is Sambucus Racemosa, or Red Elderberry. “(Alternate common names include scarlet elder, stinking elderberry, stinking elder, red-berried elder, bunchberry elder, and red elder.) Shrub or small tree 10-20 feet tall.”
So what the Natural Areas Program is officially classifying as trees in its planting efforts is actually skewed to shrubs.
MOSTLY SHRUBS, NOT TALL TREES
How skewed? Well, about three-quarters merited the description of “large shrubs” in the USDA profiles.
If you think of a tree as being, say, 50 feet high, then of the 676 planted,
about under a quarter were trees: oaks and red alders. (For comparison, the trees they are planning to fell are between 90 and nearly 200 feet tall – Monterey Pine, Monterey Cypress, and Eucalyptus.)
The pie-chart here shows the number of plants in each size category. Nearly a third of the plantings will be
under 20 feet or less at maturity. [Edited to Add: We made a mistake with the pie-chart. Here's the correct one.]
WHAT DOES THAT MEAN?
Trees in urban areas provide cities with a whole bunch of benefits. We’ve listed nine of them in an earlier post. [Read: A Little Help From our Trees]
Shrubs are no substitute for many of the functions of trees. They sequester much less carbon, because that’s proportional to the dry weight of the tree. They trap less pollution, because there’s not as much leaf area, and for the same reason, make less oxygen. They do provide habitat for birds, animals and insects, but of a different kind than trees do.
Most importantly: When the Native Areas Program claims it will replace trees one for one - it may be considering replacing a tall Monterey Cypress or majestic Eucalyptus with an elderberry bush. Not necessarily in the same park.