Educational and Technical Resources


Oahu Urban Tree Canopy Assessment

Urban Land Use features are shown along with existing tree canopy cover

Urban Land Use features are shown along with existing tree canopy cover


To view the final report from the Spatial Analysis Lab, click here.

Kaulunani has conducted two Urban Tree Canopy Assessments of the major urban centers of O‘ahu. The study area includes 250 square miles of Leeward and Windward O‘ahu. The initial assessment completed in 2012 identified where trees are located, the extent of the canopy, as well as ownership and potential planting sites for enhancing the urban tree canopy. In 2016, we conducted a second Urban Tree Canopy analysis to assess the degree of change our a four year period from 2010 through 2013. What we found was alarming.

Honolulu is losing tree canopy; in fact, we lost nearly 5% of our total urban tree canopy over four years. The majority of losses were in non-public zoning areas. Net Residential losses alone totaled 355 acres representing 39% of all the tree canopy loss. All land use areas saw decreases; even our conservation areas saw a 1% loss in tree canopy.  Close to 98% of the losses were less than a quarter acre each and spread widely across the landscape. These losses equate to at least 76,600 trees. New plantings did occur totaling about 230 acres, which is far short of what is needed to keep pace with the losses, especially considering the time required to grow a canopy.

Honolulu is not alone; urban forests are declining in many cities, and studies show a direct connection to declining human and environmental health because of it.

Trees and tree-lined streets lead to more livable and cooler communities as well as healthier people. In addition, trees not only improve air quality, stormwater control and coastal water quality but also enrich businesses and provide energy savings.


View an interactive map of the data at the City & County of Honolulu HOLIS (UTC online map)


Take a Virtual Tour of the UTC map layers.

You can download a copy of the 2012 primary report and 2016 Change Analysis report  in Adobe PDF format. 

To read the stakeholder proceedings from the presentations, click here.


The Urban Tree Canopy Assessment is part of the long range Hawai‘i urban forestry strategy planning initiative conducted by Smart Trees Pacific in collaboration with the USDA Forest Service; the State DLNR Division of Forestry and Wildlife, the Kaulunani Urban and Community Forestry Program; the City and County of Honolulu, Department of Parks and Recreation Urban Forestry Division, and the Department of Planning and Permitting, Honolulu Land Information System.

City of Honolulu, Hawai‘i Municipal Forest Resource Analysis

2007 Technical report by the Center for Urban Forest Research, which combines results of a partial citywide inventory with benefit-cost modeling data. Value is calculated for benefits such as energy savings, CO2 reduction, air quality improvement, stormwater runoff reductions, aesthetic, property value, social, economic and other benefits.  The report is based on 43,000 inventoried street trees and thus represents only a fraction of the entire urban forest of Honolulu. Nonetheless, the value of these benefits is still substantial.

Click here to view our summary info graphic:

Annual Benefits of Tropical Urban Trees


Orr Mansfield Rd Silver Spring MD 7Urban Forestry Emergency Operations Planning Guide for Storm Response

This user friendly guide provides urban forestry professionals concrete approaches when preparing for natural disasters that impact the urban forest. 

Planting Tips

Maui County Planting Plan

“The Maui County Planting Plan (MCPP) was prepared by the Maui County Arborist Committee… to serve as a guide for government officials, design and landscape professionals, and the public. It provides information on the planting, replanting, care, pruning, preservation, and disposition of Exceptional Trees, trees in general, and other landscape plants in Maui County parks and public rights-of-way.” (MCPP Preface)

Planting Details and Specifications (International Society of Arboriculture)

Dr. Ed Gilman from University of Florida, Jim Urban, FASLA, and Brian Kempf and Tyson Carroll of the Urban Tree Foundation have developed a modern, up-to-date, and peer reviewed set of details and specifications in AutoCAD, PDF, and Microsoft Word formats for the green industry. These are designed specifically for landscape architects, engineers, architects, contractors, urban foresters, arborists, municipalities, and state agencies.  All these files are open source, free, and can be edited by the user.

Exceptional Tree Program

“In 1975, the Hawai’i State Legislature found that rapid development had led to the destruction of many of the State’s exceptional trees and passed Act 105 – The Exceptional Tree Act. The Act recognizes that trees are valuable for their beauty and they perform crucial ecological functions. It mandates each county to establish a County Arborist Advisory Committee which enacts regulations to protect trees of exceptional stature. Each county has its own program, set of rules and operating guidelines.” More information can be found with the City & County of Honolulu’s Department of Parks & Recreation 

Web Map (City & County of Honolulu GIS) showing parcels with Exceptional Trees.


How Hawaii’s Counties Regulate Trees: Urban Forestry County Regulation Reference Guide (Reference Guide 415KB PDF)

The purpose of this summary paper is to serve as a broad overview of all existing county regulations that function to regulate trees in some way for four of Hawai´i’s counties: City and County of Honolulu, Maui County, Hawai´i County, and Kaua´i County. The supplemental excel tables are to function as a county tree regulation reference of ordinances, charter sections, and general plan policies and objectives. 

How Hawaii’s Counties Regulate Trees: Urban Forestry Research Tables (Downloadable Sheets 344KB  Excel .xlsx)

The supplemental excel tables are to function as a county tree regulation reference of ordinances, charter sections, and general plan policies and objectives. Please also download the Reference Guide above. 

 Deflecting the Wave: Using Coastal Vegetation to Mitigate Tsunami and Storm Surge(Final Report 40MB PDF)

The goals of the research described in this report was to focus on Hawaii and other Pacific islands to: (1) conduct research on the type of vegetation that has survived past tsunami and storm surge events, (2) gather information on vegetation that grows near the shore in Hawaii given different environmental factors; (3) examine whether past or existing vegetation has had an effect on mitigating beach erosion due to wave impact; and, (4) establishment of experimental coastal reforestation plots for evaluation of coastal re-vegetation planting strategies. 

Coconut Rhinoceros Beetle eradication effort (Pamphlet 1.76MB PDF) Information on the eradication effort for this pest recently discovered on Oahu and how to help!

Why Would Anyone Cut A Tree Down (Downloadable Book 1.6 MB PDF ) “we may not want to, but sometime we need to…” A children’s book about the benefits of trees and why, sometime we have to cut them down. Includes tips for choosing and planting right.