Dennis Yniguez TREE DECISIONS Berkeley, CA 94709 ......Registered Consulting Arborist ... proposed...

Dennis Yniguez

Registered Consulting Arborist [email protected]

Tree Health & Risk Assessment ♦ Forensic Examination & Case Analysis ♦ Appraisal of Tree Value

Insurance Claim Evaluation ♦ Land Development Consultation ♦ Resolution of Tree-Related Disputes

TREE DECISIONS 1428 Spruce StreetBerkeley, CA 94709

510-649-9291

January 10, 2015 Aaron Sage, Planner City of Berkeley Planning Department Berkeley, California Re: Application for Building Permit for 122 Avenida Drive in Berkeley, California Applicant: Peter Gilbert, Architect, 10415 Greenview Drive, Oakland, California 94605 Dear Mr. Sage, I’m writing this letter at the request of Peter Gilbert, Architect/Applicant, who informed me that the City of Berkeley would like an arborist opinion evaluating the potential effect of a proposed modification of construction plans on the health of coast redwood trees on the adjacent properties to the south of 122 Avenida Drive. I prepared an arborist report dated June 16, 2014, that has already been submitted by Mr. Gilbert as part of the permit application process. I think that it would help the reader to conceptualize the entire project if the reader could briefly review that report before reviewing this supplementary letter. The June 16, 2014 arborist report concluded that if the proposed home were to be built in accordance with the plans submitted to the City of Berkeley at that time, “there will be no detriment to the health or stability of any of the neighboring coast redwood trees if the tree protection measures incorporated in both the project design and this report are implemented.”

Proposed Site Plan Modification I was recently informed by the applicant that the modified plans would require a 24-inch shift in the footprint of the home in the direction of the coast redwoods on the adjacent properties to the south of 122 Avenida Drive. I was asked to reevaluate the proposed plans to see if this two-foot shift in the footprint of the home would have a significant detrimental effect on the neighboring coast redwood trees.

Discussion and Professional Opinion My professional opinion is that the two-foot southward shift in the proposed footprint, and minimal additional coast redwood root disruption, will have no significant detrimental effect on the health or stability of the line of coast redwoods on the neighboring properties to the south of 122 Avenida Drive.

ATTACHMENT 7 ZAB 01-22-15 of 26

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Research in Support of Professional Opinion In support of this professional opinion, I refer the reader to several articles referenced in the Discussion section of the June 16, 2014 arborist report, and referenced in the Appendix to that report, which address the extraordinary ability of coast redwoods to compensate for disruptions to their root systems. Two University of California at Berkeley forestry professors stated that, “What continues to surprise us is that so much of the root system [of coast redwoods] can be removed without any noticeable reduction in vigor.” (Stone and Vasey, 1962). Moving the home 24 inches nearer the line of coast redwoods would require some additional pruning of encroaching redwood branches to accommodate the structure of the new residence. Recent studies of the effects of coast redwood pruning confirm that this species responds with extraordinarily resilience even after severe pruning treatments. "Several studies report increasing sprout production with increasing pruning severity. These are evolutionary adaptations that allow trees to quickly rebuild crowns after disturbances such as defoliations and branch damage." (O'Hara and Berrill 2009: p.6) "Sprouting was unaffected by pruning severity except at the most severe pruning treatments. Sprout numbers and sizes were nearly constant from the control trees to trees receiving treatments that left only approximately 40% live crown." (O'Hara and Berrill 2009: p.6) "In summary, pruning apparently has relatively minor effects on increment in coast redwood as represented by basal area increment, height increment, and volume increment." (O'Hara 2012: p.532) "The response of coast redwood to pruning varies from typical responses of conifers. The typical decreasing increment with increasing pruning severity pattern was not observed in these study plots despite the inclusion of very severe pruning treatments. Instead, redwood growth is less sensitive to pruning and reductions in crown size than other conifers." (O'Hara 2012: p.537)

Conclusion My professional opinion is that the proposed construction of a home 24 inches closer to the line of redwoods on the adjacent properties to the south of 122 Avenida Drive will have no significant detrimental effect on the health or stability of the coast redwoods on the adjacent properties. Respectfully submitted,

Dennis Yniguez Registered Consulting Arborist


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REFERENCES

O’Hara, K.L. and J.P. Berrill. 2009. Epicormic Sprout Development in Pruned Coast redwood: pruning severity, genotype, and sprouting characteristics. Annals of Forest Science 66 (4): 409.

O’Hara, K.L. 2012. Coast Redwood Responses to Pruning. In Proceedings of Coast Redwood Forests in a Changing California: A Symposium for Scientists and Managers. U.S. Forest Service General Technical Report PSW-GTR-238.

Stone, E. C., and R. B. Vasey. 1962. Studies Related to the Physiology and Vigor of Old-Growth Redwood: Root Regenerating Capacity of Mature Plants. Redwood Ecology Project. Annual Report. Wildland Research Center, University of California. California Department of Parks and Recreation.


PROTECTION OF TREES ON ADJACENT PROPERTIES DURING CONSTRUCTION OF A RESIDENCE AT

122 AVENIDA DRIVE IN BERKELEY, CALIFORNIA

SUBMITTED TO

PETER DAVID GILBERT, ARCHITECT/APPLICANT 10415 GREENVIEW DRIVE

OAKLAND, CALIFORNIA 94605 STUDIO 510.969.7295

FOR

LANDMARK CONSTRUCTION

BY

DENNIS YNIGUEZ, REGISTERED CONSULTING ARBORIST TREE DECISIONS, 1428 SPRUCE STREET

BERKELEY, CALIFORNIA 94709 [email protected]

JUNE 16, 2014

Dennis Yniguez

Registered Consulting Arborist [email protected]

1428 Spruce StreetBerkeley, CA 94709

510-649-9291 Tel 510-649-9292 Fax

TREE DECISIONS


CONTENTS

Executive Summary 1

Background and Assignment 1

Observations and Discussion 2

Size, Location and Ownership of Neighboring Trees 2

Characteristics and Resilience of Tree Root Systems 4

Specialized Adaptations of Coast Redwood Root Systems 5

Recommendations for Tree Protection 5

Effects of Construction on Coast Redwood Roots And Branches 5

Grading 6

Avoiding Unnecessary Compaction 6

Protective Tree Fencing 6

Conclusion 7

References 8

Photographs 9

Qualifications, Assumptions, and Limiting Conditions 21

Exhibits:

A. Site Map

B. Location of Trees, Proposed Structure, and Protective Fencing

C. Discoloration and Decay in Trees

D. Tree Root Severance


PROTECTION OF TREES ON ADJACENT PROPERTIES

DENNIS YNIGUEZ TREE DECISIONS JUNE 16, 2014

EXECUTIVE SUMMARY

The Applicant proposes to construct a single family dwelling on an R-1 zoned property at 122 Avenida Drive in Berkeley, California. A row of coast redwood trees (Sequoia sempervirens) are growing on two adjacent properties parallel to the southernmost boundary of the site. I was asked to evaluate the potential effects of the project on the health and stability of the trees by reviewing construction documents and visiting the site to examine the location and condition of the coast redwoods on adjacent properties. My professional opinion is that there will be no detriment to the health or stability of any of the neighboring coast redwoods if the tree protection measures incorporated in both the project design and this report are implemented.

BACKGROUND AND ASSIGNMENT

On December 17, 2013, I was contacted by Mr. Peter Gilbert, the architect and applicant for this project, who asked me to meet with him at 122 Avenida Drive in Berkeley to evaluate the possible effects of residential construction on coast redwood trees that are growing on two adjacent properties. On December 18, 2013, an associate and I met Mr. Gilbert at the site. We reviewed architectural site plans and related documents and discussed the condition and location of redwood trees that appeared to be growing on neighboring properties alongside an unmarked common boundary. I took photographs and agreed to return to the site to evaluate the exact location of the redwoods after a boundary line survey could be completed by a licensed surveyor. In January 2014, after the surveyed boundary was delineated, an associate and I returned to the site. We installed metal stakes and heavy white twine along a surveyed offset line that is located parallel to the surveyed southernmost boundary and 24 inches into the property at 122 Avenida Drive. We used this offset parallel line to measure the distance between the line and redwood trunks on an adjacent property to determine whether the trunks encroached over the property boundary into 122 Avenida. The results of our measurements are indicated in a table in this report and also on a site plan map submitted by the Applicant. Please review the site plan and 12 full-page captioned photographs that are included at the end of this report to more clearly visualize conditions at the site.




OBSERVATIONS AND DISCUSSION The following table lists the size, location, and ownership of trees growing on or adjacent to the southernmost boundary of 122 Avenida Drive:

Trees at Southernmost Boundary of 122 Avenida Drive

Tree I.D.

Species Estimated

DBH (inches)

Surveyed Property Line to Trunk

(inches)

Tree Ownership

Comments

A Coast redwood (Sequoia

sempervirens)

16" 29" Davis Tree A is 14.5 feet from the edge of Avenida Drive.

B Blue gum eucalyptus (Eucalyptus

globulus)

26" 0 Landmark/ Davis

This dead eucalyptus trunk

straddles the property line

(about 9 inches onto the Landmark

side) and is therefore co-

owned by Landmark and

Davis. C Coast redwood

(Sequoia sempervirens)

15" 29" Davis

D Coast redwood (Sequoia

sempervirens)

22" 17" Davis

E Coast redwood (Sequoia

sempervirens)

22" 26" Anderson

F Coast redwood (Sequoia

sempervirens)

23" 9" Anderson

G Coast redwood (Sequoia

sempervirens)

10" 19" Anderson

H Coast redwood (Sequoia

sempervirens)

39" 0 Anderson The base of Tree H touches the

property line, but appears to be




solely owned by Anderson.

I Coast redwood (Sequoia

sempervirens)

23" 4" Anderson

J Coast redwood (Sequoia

sempervirens)

12" 18" Anderson

K Coast redwood (Sequoia sempervirens)

36" 2" Anderson

L Coast redwood (Sequoia

sempervirens)

24" 14" Anderson

M Coast redwood (Sequoia

sempervirens)

20" 8" Anderson

N Coast redwood (Sequoia

sempervirens)

21" 0 Anderson The base of Tree N appears to

extend 1.5 inches over the property line, but may be solely owned by

Anderson. O Coast redwood

(Sequoia sempervirens)

27" 7" Anderson

P Coast redwood (Sequoia

sempervirens)

20" 11" Anderson

Q Coast redwood (Sequoia

sempervirens)

27" 9" Anderson

R Coast redwood (Sequoia

sempervirens)

33" 0 Anderson The base of Tree R appears to

extend 3 inches over the property line, but may be solely owned by

Anderson.




I was asked to evaluate potential effects of construction on the root systems of trees along the southernmost boundary of 122 Avenida Drive. The following discussion describes the general characteristics of tree roots as well as the extraordinary resilience of coast redwood root systems.

Characteristics and Resilience of Tree Root Systems Roots provide anchorage, absorption and conduction of water and minerals, storage of carbohydrates, and production of hormones. Roots are opportunistic and will proliferate where environmental conditions such as water, soil oxygen, and nutrient availability are favorable. Root growth patterns vary widely between trees of different species growing under diverse environments. Lateral woody roots extend outward from the tree base and provide anchorage and support for the tree. Depending on tree size or species, the lateral roots often decrease in diameter at a distance within about 2 meters of the trunk base at sites called "zones of rapid taper" (Costello 2012; Helliwell 1989). Lateral roots branch into secondary roots that continue to bifurcate, and can extend well beyond the dripline. Fine roots greatly increase the tree's underground surface area for acquisition of water and minerals from the soil. Sinker roots extend straight or obliquely downward from primary and secondary lateral roots and increase stability. More than 90% of the root mass will be found within the top meter of soil (Harris et al. 2004). Frequent injury to and death of roots from many agents is ongoing throughout the life of a healthy tree, and new roots often form rapidly after injuries (Perry 1992). Root pruning stimulates roots to regenerate at or just behind the cut (Wilson 1970). When a tree's root, trunk, or branch tissue is disrupted by pruning or other wounds, microorganisms begin to infect the site. The tree responds by forming chemical and physical barriers around the wound to slow or prevent the spread of disease or decay. This process is called compartmentalization. Roots are strong compartmentalizers. In a study of the effects of root severance on four species of deciduous hardwoods, different roots were severed at one of four locations: at the root flare or at distances of 1, 2, or 3 meters from the trunks. Five years later, the roots were excavated and examined. Severed roots of all sizes showed only minimal decay. The author concluded that, unlike in branches where leaving a stub can lead to more extensive decay, severing the roots did not cause substantial deterioration from root decay, and the minimal decay after 5 years posed no threat to the long-term health and stability of these four species (see Exhibit C). Another review of tree root severance studies concluded that many trees with adequate vigor and vitality can withstand severe root pruning and that horizontal roots can usually be safely cut up to the point where their diameter begins to increase markedly near the trunk (see Exhibit D).




Specialized Adaptations of Coast Redwood Root Systems Coast redwoods are surprisingly capable of compensating for disruptions to their root systems. One research scientist concluded that "The coast redwood species (Sequoia sempervirens) is rather remarkable in its ability to adapt to soil conditions, to sprout profusely, to respond to increased light, and to survive and grow under certain stresses imposed by man. …Coast redwood resists well attack by natural agents and adjusts remarkably well to changes in the environment, especially by growing of new roots and new foliage" (Sturgeon 1964). The coast redwood's tolerance to developmental impacts is rated as good (Matheny and Clark 1998).The redwood has a large rooting area that extends in all directions from the tree (Olson et al 1990). Strong lateral roots, as employed by coast redwoods, disperse aboveground wind-loading forces to soil and provide traction to resist uprooting (Coutts 1983; Mattheck and Breloer 1994; Stokes and Mattheck 1996). Two forestry professors at the University of California at Berkeley commented that "the mature redwood is apparently able to overcome the loss of a large portion of its root system by rapidly regenerating a new root system. What continues to surprise us is that so much of the root system can be removed without any noticeable reduction in vigor" (Stone and Vasey 1962).

RECOMMENDATIONS FOR TREE PROTECTION

Effects of Construction on Coast Redwood Roots and Branches The proposed design features closest to the line of coast redwoods include

Foundation construction at a distance of 15 feet from the southernmost boundary line;

Excavation of a 2-foot wide by 2-foot deep drainage trench alongside the

south house perimeter;

Narrow excavation alongside the established south side garage wall;

Installation of concrete entry stairs not more than one foot below grade; and

Pruning back encroaching coast redwood branches to allow use of the

property and clearance from structures.




If coast redwood roots are encountered and cut at the above-indicated distances and depths, the effect will be insignificant to the health or stability of the trees. Neither absorbing roots nor structural roots will be significantly disrupted. Similarly, pruning back lower branches of the coast redwoods will have no effect on the health or stability of the trees. Redwood branches respond to shortening by resprouting vigorously from latent buds. Photographs in this report show that encroaching redwood branches periodically fall onto the property at 122 Avenida Drive, most likely during windy weather. One photograph shows a large branch that had apparently been charred and weakened when the previous home at 122 Avenida Drive was destroyed by fire. Encroaching coast redwood branches should be inspected and pruned back accordingly if similarly charred and weakened areas are observed. Grading Grading must conform to technical and safety requirements, and will not encroach on, or be necessary within, the Tree Protection Zone described below. Avoiding Unnecessary Compaction Although coast redwoods are resilient trees with multiple adaptive capabilities, their resilience can be overwhelmed by extreme environmental stress. Extreme and widespread soil compaction can reduce oxygen diffusion and moisture availability to roots, limit drainage, encourage the proliferation of undesirable soil microorganisms, and reduce a tree’s capacity to respond favorably to many kinds of biotic and abiotic stress. Significant soil compaction will be avoided on this project if the protective measures set forth herein are implemented. These measures include the installation of protective tree fencing to prevent compaction of the soil above essential structural and absorption roots. Protective Tree Fencing A Tree Protection Zone (TPZ) has been delineated on the site plan included in this report as Exhibit B. The TPZ would be created by driving five-foot steel survey stakes at least one foot into undisturbed soil not more than 10 feet apart. Attached to these stakes would be continuous orange polypropylene fencing with a minimum height of four feet. Stakes and fencing would remain before and throughout construction to prevent soil compaction or damage to the trunks of protected trees.




Weatherproof signs at least 17" X 11" must be affixed not less than fifteen feet apart along the TPZ fence, including the section of the fence that faces Avenida Drive. Each sign would read:

TREE PROTECTION ZONE Do Not Move this Fence

No parking or storing of vehicles, construction trailers, equipment, machinery, chemicals, excavated soil, or construction materials shall be permitted within the defined Tree Protection Zone. Over 15 years ago, I was the retained arborist for a commercial construction project at 63 Mountain Boulevard in Oakland, California. The project architect employed a cantilevered pier and grade beam foundation that was installed less than 10 feet from a row of sizable and revered redwoods along the boundary of an adjacent community park. Photo Number 12, included in this report, shows the row of redwoods adjacent to the cantilevered building. The redwoods exhibited no signs of stress during construction or at any time thereafter.

CONCLUSION

The Applicant proposes to construct a single family dwelling on an R-1 zoned property at 122 Avenida Drive in Berkeley, California. A row of coast redwood trees (Sequoia sempervirens) are growing on two adjacent properties parallel to the southernmost boundary. I evaluated the potential effects of the project on the health and stability of the coast redwoods by reviewing construction documents and visiting the site to examine the location and condition of the coast redwoods on adjacent properties. My professional opinion is that there will be no detriment to the health or stability of any of the neighboring coast redwoods if the tree protection measures incorporated in both the project design and this report are implemented. Respectfully submitted,

Dennis Yniguez Registered Consulting Arborist




REFERENCES

Costello, L. R. 2012. Tree Root Systems: Types of Roots, Root System Architecture, and Distribution of Roots. Western Arborist 38(1):36–42.

Coutts, M. P. 1983. Root Architecture and Tree Stability. Plant and Soil 71(1–3):171–188.

Hamilton, D.W. 1988. Significance of Root Severance on Performance of Established Trees. Journal of Arboriculture 14 (12): 288-292. [Appendix C]

Harris, R. W., J. R. Clark, and N. P. Matheny. 2004. Arboriculture: Integrated Management of Landscape Trees, Shrubs, and Vines. Upper Saddle River, NJ: Prentice Hall.

Helliwell, D. R. 1989. Tree Roots and the Stability of Trees. Arboricultural Journal 13:243–248.

Matheny, N., and J. R. Clark. 1998 Trees and Development: A Technical Guide to Preservation of Trees during Land Development. Champaign, Illinois: International Society of Arboriculture.

Mattheck, C., and Breloer, H. 1994. The Body Language of Trees: A Handbook for Failure Analysis. London: The Stationery Office.

Olson, D. F. Jr., D. F. Roy, and G. A. Walters. 1990. Coast Redwood. In Silvics of North America, Vol. I, Conifers, 541–551. U.S. Forest Service Agricultural Handbook 654.

Perry, T.O. 1992. Tree Roots: Facts and Fallacies. Fremontia 20(4):3–12.

Stokes, A., and C. Mattheck. 1996. Variation of Wood Strength in Tree Roots. Journal of Experimental Botany 47:693–699.

Stone, E. C., and R. B. Vasey. 1962. Studies Related to the Physiology and Vigor of Old-Growth Redwood: Root Regenerating Capacity of Mature Plants. Redwood Ecology Project. Annual Report. Wildland Research Center, University of California. California Department of Parks and Recreation.

Sturgeon, E. E. 1964. The Effects of Use, Impact and Other Factors on Coast Redwood. Report for National Park Service. Mimeo.

Watson, G. W. 2008. Discoloration and Decay in Severed Tree Roots. Arboriculture and Urban Forestry 34(4):260–264. [Appendix B]

Wilson, B. F. 1970. Evidence for Injury as a Cause of Tree Root Branching. Canadian Journal of Botany 48:1497–1498.


DENNIS YNIGUEZ PROTECTION OF NEIGHBORING TREES DURING CONSTRUCTION 9 TREE DECISIONS JUNE 16, 2014

1. The dotted yellow line in this Google aerial photo indicates the location of the lot at 122 Avenida Drive in Berkeley.



2. The covered parking pad at 122 Avenida Drive, as viewed from the street. A home had existed at the site uphill of the parking pad until it was destroyed by fire.



3. The blue arrow indicates a 15-foot coast redwood branch on the ground at 122 Avenida Drive, one of several large branches that had recently split off and fallen onto the property from a row of coast redwoods (Sequoia sempervirens) growing on neighboring properties alongside the southernmost boundary line.



4. The blue arrow indicates heavy white twine that was installed on a surveyed parallel line 24 inches in from a surveyed boundary line along the southernmost border of 122 Avenida Drive. This offset line was helpful for measuring and determining whether the trunks of coast redwoods encroached from neighboring properties.



5. The blue arrow indicates heavy white twine that was installed on a surveyed parallel line 24 inches in from a surveyed boundary line along the southernmost border of 122 Avenida Drive. Orange stakes were placed by a licensed surveyor in January 2014 to demarcate the boundary line and 24-inch offset line.



6. The blue arrow indicates heavy white twine that was installed on a surveyed parallel line 24 inches in from a surveyed boundary line. The red arrow indicates a survey monument that had been permanently affixed in an earlier survey of property boundaries by Ahmad Moghaddas, a licensed Civil Engineer.



7. This is the survey monument (indicated by a red arrow in the previous photograph) that had been affixed near the southernmost boundary line of 122 Avenida Drive in an earlier survey of property boundaries by Ah-mad Moghaddas, Civil Engineer (License No. 27185).



8. The blue arrow indicates heavy white twine that was installed on a surveyed parallel line 24 inches in from the surveyed southernmost boundary line.



9. This row of coast redwood trees is growing on an adjacent property near the surveyed southernmost boundary of 122 Avenida Drive. The branch on the foundation sill had recently split off and fallen onto the property from the row of coast redwoods.



10. A closer view of the end of the fallen coast redwood branch seen in the previous photograph.



11. Close-up view of the fallen coast redwood branch shown in the previous photograph. The red arrow indi-cates charred wood, an apparent remnant of branch damage from the earlier house fire at 122 Avenida Drive. Encroaching redwood branches should be inspected for additional damage and weakness caused by the fire.



12. Row of coast redwoods adjacent to a parking structure at 1963 Mountain Boulevard in Oakland,

California. More than 15 years ago, the cantilevered pier and grade beam foundation was installed 10 feet or less from the redwood trunks to protect roots, and the trees continue to thrive.




QUALIFICATIONS, ASSUMPTIONS, AND LIMITING CONDITIONS

Any legal description provided to the consultant is assumed to be correct. Any titles or ownership of properties are assumed to be good and marketable. All property is appraised or evaluated as though free and clear, under responsible ownership and competent management. All property is presumed to be in conformance with applicable codes, ordinances, statutes, or other regulations. Care has been taken to obtain information from reliable sources. However, the consultant cannot be responsible for the accuracy of information provided by others. The consultant shall not be required to provide additional consultation or documents, give testimony, or attend meetings, hearings, conferences, mediations, arbitrations, or trials unless subsequent contractual arrangements are made, including payment of an additional fee for such services. In the absence of a specific contract, all services subsequent to this report will be invoiced at the expert’s standard hourly fee and will be due and payable upon receipt of an invoice for such services. This report and any appraisal value expressed herein represent the opinion of the consultant, and the consultant’s fee is not contingent upon the reporting of a specified appraisal value, a stipulated result, or the occurrence of a subsequent event. Sketches, drawings, and photographs in this report are intended for use as visual aids, are not necessarily to scale, and should not be construed as engineering or architectural reports or surveys. The reproduction of information generated by architects, engineers, or other consultants on any sketches, drawings, or photographs is only for coordination and ease of reference. Inclusion of said information with any drawings or other documents does not constitute a representation by Dennis Yniguez or Tree Decisions as to the sufficiency or accuracy of said information. Unless otherwise expressed: a) this report covers only the examined items and their condition at the time of inspection; and b) the inspection is limited to visual examination of accessible items without dissection, excavation, probing, or coring. There is no warranty or guarantee, expressed or implied, that structural problems or deficiencies of plants or property may not arise in the future.


Dennis Yniguez TREE DECISIONS Berkeley, CA 94709 ......Registered Consulting Arborist ... proposed...

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