A VIEW OF THE FUTURE FOREST OF THE CITY 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 7, 2007
Job #01-07-020A
Residents and visitors alike for many years have taken home the memory of Carmel as a tall forest of lush pines as umbrellas protecting the elegantly rustic downtown and residential areas. This mental image has been replicated in travel brochures, distributed worldwide.
The very heart of Carmel is defined by its lush, green forest of pines, oaks and cypress.
If we open our eyes to today’s City of Carmel forest, we see a different image than the one our parents brought home and, unfortunately a different image that is gradually changing from the one which is so attractive to visitors.
The forest of a city is composed of trees on publicly owned and private property.
In Carmel, they combine to form an interrelated canopy which “reads” as a common canopy with all of the parts serving a part of the function of providing shade, ambience and a home for myriad birds and insects.
If the City of Carmel forest is to continue to contribute to the ambience that is Carmel to its residents and to visitors it is absolutely essential that a long-term program be designed, implemented and funded to begin the process of replacing the over-mature trees which are gradually dying out.
Cause of Decline
It must be understood that the longevity of the existing forest is affected by not only natural factors such as pine pitch canker disease in Monterey pines and California oak moth in coast live oaks but, just as importantly by conditions created by we humans. Most of these natural tree enemies are only partially manageable but the man made conditions are within our control.
The root zone allowed for each street tree is restricted by many factors including the available open soil around the trunk and since a tree’s ability to absorb minerals and water is directly related to the root systems access to oxygen and water, the current practice of filling increasing proportions of the open soil around street trees with pavement, simply accelerates the decline which these trees are experiencing. Note that the most vigorous coast live oak trees in town are those in private landscape sites with pavement over only small proportions of their root systems.
Pruning
Excessive pruning of the mature Monterey pines and live oaks often contributes to their decline as well.
When a live oak has all of the interior branches removed, the limbs can only produce new growth at the ends, and as a result long limbs which grow into adjacent trees and buildings and over streets are produced. This structure is a common cause of limb failure.
The most common cause of branch failure in Monterey pine is overthinning of the interior branches, resulting in excessive branch endweight.
These pruning errors could be prevented by demanding that arborists working in the City comply with ISA (International Society of Arboriculture) pruning procedures.
Since the trees on private property comprise such an important proportion of the Carmel Forest and since excessive pruning is practiced on private trees, the impetus to control the quality of pruning on privately owned trees should be high as well.
Replacement Species
Selection of replacement tree species should be a subject of serious concern, since well chosen species could be gracing the City throughout the 21st Century and conversely poorly chosen, disease prone or structurally unsound trees will continue to plague the City for many years as well.
If Monterey pine is to continue to be the “signature tree” or just one increment in the new forest, it will be inclement that a program of production and availability of specimens of relatively disease resistant Monterey pines exclusively for the use of the City of Carmel begin.
Expansion of the tree list should be considered but only within the parameters of acceptability by the Coastal Commission.
Installation
The quality of the plants which are purchased and the installation procedures used are incremental factors in the later performance and the longevity of trees.
If severely root bound trees are accepted from wholesale growers the major roots begin to girdle the trunk at about the same time the trees begin to contribute to the canopy and they begin to fall over just as they begin to mature resulting in loss of trees just when they begin to provide the greatest benefits.
If the installation procedure is careless, leaving the rootball below surrounding grade, and the rootball surface covered with site soil, irrigation water runs off that surface and around the rootball, creating drought stress in the newly installed tree which, at best, results in stunted, weak trees or at worst results in death.
If backfill installed around the rootball is composed of sawdust, as seen in a recently planted tree, the new tree roots may never grow out of the rootball into native soil.
Only native sandy soil should be used as fill soil around rootballs in Carmel.
Obviously there are many subjects from philosophical to practical which should be addressed if the “new” Carmel forest is to have a maximum longevity at smallest long term cost combined with the greatest contribution to the ambience of one of the most beautiful parts of the California Coast.
The rejuvenation of the forest must begin with an inventory of the current forest. This should include identification of all publicly owned and privately owned trees, measurement of the trunk diameter, height and branch spread, and evaluation of insect or disease pests as well as a professional estimate of remaining useful lifespan. Measurements of privately owned trees could be estimated from beyond fence lines. Volunteers familiar with computer data collection could reduce the cost of this portion of the project.
Next must come an evaluation of the forest based on the inventory information. This should include conclusions about, a) the areas which are most quickly losing existing forest, b) what species best fulfill the tree needs in each area, c) define the standards required for purchased tree quality and installation standards, d) estimate cost for ongoing tree purchase and installation, e) define post installation maintenance procedures, for irrigation, pruning and pest control.
Lastly, but perhaps most important must be an ongoing, long-term commitment by the city to fund each part of the program. A temporary lapse in funding for a tree program often results in an inability to reestablish city council enthusiasm for the program and the work done by previous city councils and planning commission to arrange for design, inventory, implementation and funding is forgotten.
Respectfully submitted,
Barrie D. Coate
BDC/sl
Reference:
Barrie D. Coate and Associates
23535 Summit Rd.
Los Gatos, CA 95035
408/353-1052
No comments:
Post a Comment