RESULTS OF A REVIEW OF TREES IN A TWO BLOCK TRANSECT OF CARMEL
Prepared at the Request of:
Robert Tierney
Carmel Forest & Beach Commission
P.O. Box 414
Carmel-by-the-Sea, CA. 93921
Site Visit by:
Barrie D. Coate
Consulting Arborist
May 31, 2007
Job #01-07-020B
As suggested by Glen Flanik of CDF (California Department of Forestry) during a meeting of interested parties in May 07, Peter Quintanilla and I prepared an inventory of the trees in two blocks of Carmel. They are the blocks bounded by Lincoln St., 8th Ave., Monte Verde St., and 7th Ave., and bounded by Ocean Ave., 7th Ave., Dolores St., and Lincoln Street.
These two blocks are roughly equivalent to many parts of Carmel and so this arboricultural analysis may be considered a small representative of the condition of trees in the main portion of Carmel’s business district and nearby residential district.
We believe that all of the privately owned and publicly owned trees in those two blocks are included in this brief survey.
Forty-five trees were evaluated in the block bordered by Ocean Ave., on its north side, while 83 trees were found on the block bordered by 7th St., on its north side.
Note that the difference is primarily due to the first block being almost covered with business buildings, while the second is primarily residential with large landscape trees.
Indeed in the business block bordering Ocean Ave., 41 of the 45 trees are on public property (91%). While the block bordered by 7th Ave., which is primarily residential had 43 of the 83 trees on public property (51%).
In the block bordering Ocean Ave., 15% of the trees are coast live oak, 13% are blackwood acacia, 11% are American sweetgum, 11% are Monterey cypress and only 6% are Monterey pine.
In contrast, in the block bordering 7th Ave., 72% of the 83 trees are native species, 36% of them being Monterey pine, 20 of those exceeding 18-inch diameter.
The data indicates that in the block bordering 7th Ave., the following trees need immediate attention.
Of the trees in the block bordering 7th Street, live oak #56 must have drop-crotch pruning of endweights to prevent limb breakage.
Blackwood acacia #29 badly needs endweight reduction to prevent limb breakage.
Acacia #31 should be removed, since artists conk infections eventually result in tree failure.
Acacias #35 and 36 should have Resistograph or drill inspection to identify the extent of interior decay.
Sweetgum #12 must have endweight reduction to prevent limb drop.
Monterey pines #62 and 63 need endweight reduction to prevent limb breakage and have deadwood removed.
After analyzing all of the trees on private and public property on two blocks in downtown Carmel, it is apparent that one factor is controlling the health and size of these trees.
The exposed soil surface available to trees on private property far exceeds the exposed soil area available to street trees, and in many cases the small available soil space street trees have had is being covered with compressed decomposed granite which further inhibits oxygen availability for roots.
The reason that an open texture of the soil within the root zone is important is that most of the hair like absorbing roots which supply the foliage with water and minerals are in the upper 18 inches of soil.
Since they require a high proportion of soil oxygen (25% by volume is ideal) to function, restriction of the exposed soil surface directly affects the ability of the root system to absorb and transport water through the vascular tissue to the foliage canopy.
In essence, a soil surface which is restricted in surface area or by compaction restricts the trees ability to supply its needs.
The results of this soil oxygen restriction are readily visible in the poor health of many street trees in Carmel.
The data accumulation charts which accompany this report describe each of the subject trees. A tree’s overall condition may be determined by combing the chart rating for health and structure. A perfect structure of 1 combined with a poor health rating of 4 would yield a condition rating of 5 out of a possible 10.
This poor a health rating, however, should serve as a warning of tree health decline, even if the tree has a perfect structure.
Specific Trees
Northeast corner of Ocean and Dolores Street.
Tree #1 a Monterey pine (Pinus radiata) on Dolores Street at the northeast corner of Ocean and Dolores Street.
Sequoia pitch moth and pine pitch canker are present in this tree. Sequoia pitch moth insect is not a bark moth and is not life threatening even though it produces 2-3 inch mounds of tan and white pitch at branch attachment sites and on the trunk but of course pitch canker will gradually kill increasing proportions of the canopy.
Tree #2 is a small Brazilian pepper tree (Schinus terebinthifolius) which has been striped of its lower branches resulting in a poorly tapered trunk and very heavy canopy which is susceptible to limb breakage.
In addition, it has a girdling root which will someday result in failure.
Tree #3 is an example of a coast live oak (Quercus agrifolia) that has topped. This tree will not produce vertical growth without significant correctional pruning.
The temporary branches on the trunk have been removed and as a result the trunk has no taper.
Tree #4 a Brazilian pepper.
The maintenance procedures have not left side branches on this tree and as a result it has no taper but it does have a dense, canopy which is susceptible to limb breakage.
Tree #5 is a coast live oak in which the top has died. The structure and health is so poor that I would recommend its removal.
The trunk has been badly damaged at 4 feet above ground as well.
Note that the soil surface around trees #2-5 is a very dense impervious yellow sandy clay which appears to be compacted.
This creates an impervious soil surface which cannot absorb water or oxygen.
Tree #6 is a coast redwood (Sequoia sempervirens) in excellent health and growing vigorously. Note that this tree has approximately 35-sq. ft. of open soil surface which is exposed and coarse enough to absorb water.
This is in contrast with the approximate 12-sq. ft. of open soil surface surrounding trees #2-5.
Trees #7 and 8 are a Catalina ironwood (Lyonothamnus floribundus asplenifolius) and a coast redwood in better health than most of the specimens on the street. Notice that these also have much larger exposed open soil surfaces allowing much better root growth.
Notice as well tree #8 has a bubbler adjacent to the stem so it would be receiving adequate moisture.
Now at Piccadilly Park.
Tree #9 is a coast live oak of 22-inch trunk diameter.
This tree is healthy and vigorous although it has been severely overthinned.
The good health of this tree is no doubt related to the large open soil space that has been provided for it.
Unfortunately trunk injections have been used in the trunk of this tree at approximately 4.5 feet above grade.
Note that thirteen of these injections were used.
These injections cause significant tissue damage surrounding the injection site and should not be used since there are other noninvasive ways available to provide nutrition, fungicides, and insecticides without using invasive procedures.
Tree #10 is another healthy coast live oak which also has been overthinned but its health is better than many seen in town due to the large open soil exposure provided for it.
Trees #11, 12, 13, 14 and 15 are in the same park and also have more expansive than average open soil space available to them.
In each case the Catalina ironwood #11 and #14 are in excellent health and I can only suggest that the relationship between the exposed soil available for root growth and the excellent health are cause and effect.
Monterey pine #15 has minor infestations of pine pitch canker but is in much better health than the majority of trees in town.
There is an area of 110 feet in length with no street trees on either side of the street. When trees are removed entirely from an area like this it drastically changes the ambience of the street.
Tree #16 is a small American sweetgum (Liquidambar styraciflua) in average health. Note the girdling roots which will cause reduced vigor or failure as the tree matures.
Tree #17 is a blackwood acacia (Acacia melanoxylon) that has been overthinned and as a result will become more susceptible to limb breakage as endweight growth expands. This tree needs drop crotch pruning of endweights to prevent that breakage.
Tree #18 is deodar cedar (Cedrus deodara) in a 24-sq. ft. open soil area.
This tree is vigorous and is producing a foot of growth per year as this species should.
This is no doubt related to the area of open soil available.
Tree #19 is an American sweetgum which has been thinned but endweight reduction accompanied the thinning, resulting in a canopy which should be safe from limb breakage.
Note that the planter space available for it is only 12 sq. ft., and even that is filled with decomposed granite which has been compressed.
Tree #21 is a ginkgo (Ginkgo biloba) which is in excellent health and vigorous.
Note that it is planted in a watered planter bed with a large area of open soil available to it.
A tree which is not in one of the two blocks which are the subject of this report attracted my notice and deserves comment.
At the northeast corner of Monte Verde and 8th Avenue is a Monterey cypress of approximately 60-inch diameter at 3 feet above grade which has a severe crack in it extending from the ground to approximately 20 feet above grade.
This tree is hollow through the center of it and has the potential for splitting apart.
At the very least somebody should investigate the degree of integrity in the trunk of this tree.
It certainly will need some sort of structural assistance to prevent it from splitting.
You might investigate through-bolts at 6’, 10’, and 20 feet above grade as a method preventing a massive trunk failure.
We are now beginning at the southwest corner of Monte Verde St., and 8th Avenue and moving north on Monte Verde Street.
Tree #1 is a coast live oak in very poor health which has been severely overthinned and in a soil space which retains water poorly.
Tree #2 is on private property and is a scarlet gum (Eucalyptus ficifolia) which was badly damaged in at least one of the seasonal freezes in 1972, or 1990 or 1998.
This tree has a crack between the two main parts and at some point will probably split apart.
City owned trees #5 and 6 are a coast live oak and a Monterey pine within 6 feet of each other.
The coast live oak is in poor health and leaning out beneath the canopy of the Monterey pine.
The oak is heavily infested with lichen further reducing the light available to the foliage.
The Monterey pine is growing beneath the high power lines with low power lines growing through it and has an infection by western rust gall at 2 feet above grade causing a hip canker. This defect could eventually cause tree failure.
Now on private property trees #6, 7, 8, 9, 10 and 11 are four Monterey pines and two coast live oaks.
Note once again the two coast live oaks are in much better health than adjacent trees on city property due primarily to the availability of open soil to their root systems.
Note that Street tree Monterey pine #12 a mere 25 feet from the healthy pines on adjacent private property is a pitiful small specimen of very poor health with very little foliage but it is growing in a space of only 18 inches wide.
Coast live oak #14 is in the backyard of the same residence and has a dense crown of dark green healthy foliage.
It has not been as severely thinned as city owned trees have and is an excellent specimen.
Note that it is in an exposed soil area and not restricted as those on the street.
The two adjacent back garden trees are Victorian box (Pittosporum undulatum) and blackwood acacia (Acicia melanoxylon) both of which are in excellent health, again due to lack of overthinning and availability of open soil surface.
The next six trees are Monterey pines street trees.
These trees are in a 3 foot wide open planter strip which has not suffered compressed soil added on the surface.
The soil surface is open and has weed growth in much of it suggesting easy assess by roots to oxygen.
This implies that moisture and oxygen are reaching into the soil and the root zone.
This whole line of trees is growing beneath high power lines with low power lines growing through them.
None of them are in excellent health but most of them are in acceptable levels of health.
In the backyard of these two lots are two Monterey cypress (Cupressus macrocarpa) which are magnificent tall dense dark green specimens.
Note that they are not restricted by small planter spaces.
Tree #25 is a small coast live oak on private property that has been severely overthinned
The tree is healthy but its canopy is composed entirely of long poorly tapered limbs.
This style of pruning is called lion’s-tailing and should be avoided.
Tree #28 is a coast live oak on private property that is in a large open planter area and as a result is healthy but has been severely overthinned.
This lion’s-tailed pruning should be prohibited.
Trees #29 and 30 are coast live oaks on public property but note that the two of them are in a single planter that is 6 feet wide, allowing sufficient availability of water and oxygen.
In the adjacent apartment complex is a coast live oak #31 in the interior courtyard.
This tree is growing in a 2 ½ foot wide 6 foot long space which is very deep and open to large soil area beneath the planter and as a result the tree is very healthy.
Note that on the southeast corner of 7th and Monte Verde is a Monterey pine in much better condition than most we have seen.
Note as well however, that it is growing in a much larger planter space than most of the city trees.
In spite of that this tree is infected with pine pitch canker and will eventually succumb to that disease.
Tree #34 is a Monterey pine which is in better condition than most even though it is in a space 2 ½ feet wide by 10 feet long.
Unfortunately this tree has recently had the exposed soil covered with compacted decomposed granite.
Note that the base of the tree is infested with turpentine bettle (Dendroctonus valens) which will eventually cause its decline.
Adjacent of private property two coast live oaks #37, 38 in much better health than most.
Note that they are in a large exposed planter areas with irrigation.
Tree #39 is a newly planted incense cedar (Calocedrus decurrens). This might be a decent candidate for street tree use here since it would not have the same disease problems that Monterey pine and Monterey cypress have although it is certainly not indigenous to this part of California.
The next three city street trees Pittosporum eugenioides which are old specimens growing in 2 foot squares.
Unfortunately someone has recently installed impervious compacted decomposed granite in the small open spaces available to the roots.
Respectfully submitted,
Barrie D. Coate
BDC/sl
Enclosures:
Tree Data Accumulation Charts
Map – 2 block survey location
Assumptions and Limiting Conditions
Pictures
Kinked and Girdling Roots
WCISA Pruning Standards
Trees and Development, Matheny and Clark, p. 17
Drop-Crotch Pruning Specs
Pruning: a case against routing thinning, Bruce Hagen, Western Arborist Mag. Fall 2005
Arboriculture 2nd Edition, Richard Harris, p. 157-162
Definitions to Aid in Understanding the Preceding Analysis:
Drop-crotch pruning of endweights:
Endweight Reduction to prevent limb drop:
Pruning to Reduce (Drop Crotch)
"Reduction is the selective removal of branches and stems to decrease the height
and/or spread of a tree. This type of pruning is done to minimize the risk of failure, to reduce height or spread, for utility clearance, to clear vegetation from buildings or other structures, or to improve tree appearance."
(Source: http://www.laparks.org/dos/forest/pdf/TreeMaintGuideline.pdf)
“Crown reduction” pruning to reduce the height and/or spread of a tree by cutting to a lateral branch or limb at least one-half the diameter of the cut being made.
“Drop-crotch pruning” see crown reduction
(Source: http://www.ci.vancouver.wa.us/parks-recreation/parks_trails/urban_forestry/docs/stm.pdf)
Resistograph or drill inspection: Procedure to identify extent of interior decay:
“The RESISTOGRAPH® reveals it by electronically controlled drill resistance measurements.”
(Source: http://www.rinntech.com/Products/Resistograph.htm )
Sequoia pitch moth:
The sequoia pitch moth, Synanthedon sequoiae, infests most conifer trees; it is considered an “aesthetic pest.”
(Source: http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7479.html)
Pine pitch canker:
“Pitch Canker is a disease, which causes die-back of individual branches leading to a general decline in tree health, and, in some cases, premature death. This disease mainly affects pine trees in central coastal areas of California, but it has been found north of San Francisco in Mendocino County and as far south as San Diego County.”
Source: http://www.cnr.berkeley.edu/forestry/curr_proj/pitch/faqpitch.html#1
“Pitch canker is a disease of pine trees that is caused by the fungus Fusarium circinatum.”
“The fungus causes infections (lesions) that can encircle or girdle branches, exposed roots, and the main stems (trunks) of pine trees.”
Source: http://www.cnr.berkeley.edu/forestry/comp_proj/pnpitchcanker.pdf¬
Girdling root:
“Trees can slowly weaken and die over a period of years or decades because of root girdling. Roots begin to grow around the main stem of the tree and cut off or restrict the movement of water, plant nutrients and stored food reserves.”
(Source: http://ohioline.osu.edu/hyg-fact/1000/1139.html)
Bubbler:
Bubbler irrigation
"Bubblers typically apply water on a "per plant" basis. Bubblers are very similar to the point source external emitters in shape but differ in performance. Water from the bubbler head either runs down from the emission device or spreads a few inches in an umbrella pattern. The bubbler emitters dissipate water pressure through a variety of diaphragm materials and deflect water through small orifices. Most bubbler emitters are marketed as pressure compensating. The bubbler emission devices are equipped with single or multiple port outlets. Most bubbler heads are used in planter boxes, tree wells, or specialized landscape applications where deep localized watering is preferable. The typical flow rate from bubbler emitters is between 2 and 20 gph."
(Source: http://www.ag.ndsu.edu/pubs/ageng/irrigate/ae1243w.htm)
Trunk injections:
"Trunk injection is a way of protecting trees by increasing their inner defense mechanisms and defending them from plant disorders with
Maximum efficiency
Minimum dispersion of chemicals into the atmosphere"
(Source: http://www.arbocap.com/pdf/Arbocap_EN.pdf)
Western rust gall infection causing hip canker:
Western gall rust is caused by the fungus Endocronartium (Peridermium) harknessii.
Symptoms: "Rough, globular galls on trunk or branches. Galls are proportionate in size to the branches bearing them. When the fungus is fruiting (aecia), galls are orange or yellow. Galls may kill small trees but increase in size for many years on larger trees. Trees may break easily at the gall."
(Source: http://plant-disease.ippc.orst.edu/disease.cfm?RecordID=858)
Lion’s-tailing pruning: overthinning
Pruning to Thin
"Thinning is the selective removal of small live branches to reduce crown density. Branches are ¼ to 1-inch in diameter. 10-15 percent of live foliage can be removed at one time. If more pruning is desired, it should not exceed 25 percent in a single year. Excessive removal of small branches on the lower two-thirds of a branch or stem is called lion tailing and may have an adverse effect on the tree – it is not an accepted practice."
(Source: http://www.laparks.org/dos/forest/pdf/TreeMaintGuideline.pdf)
“Lion tailing” the poor pruning practice in which the limbs are thinned from the inside of the crown to a clump of terminal foliage.
(Source: http://www.ci.vancouver.wa.us/parks-recreation/parks_trails/urban_forestry/docs/stm.pdf)
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