When the early City of Los Angeles immigrants came to the area in the 1800's, the area originally settled was for the most part devoid of trees. The only native tree species were largely confined to riparian (water courses) regions and to the Santa Monica Mountain range. A person standing along Mulholland Drive in 1850 ad looking south to the Los Angeles floodplain or north to the San Fernando Valley would have viewed chaparral and other scrub plants and a nearly treeless landscape.
Now, of course, a person standing in the same location would see hundreds of thousands of trees on either side of the Santa Monica range. Nevertheless, the vast majority of the City's urban forest is man-made.
This emphasizes the importance of the regions native trees. There are numerous native tree species but the Coast Live Oak (Quercus agrifolia) species is predominate. The post-World War II through the early 1970's building boom impacted the Oak population as the City expanded further and further into the Oak woodland habitat. In response to the declining Oak population, the City of Los Angeles enacted an Oak tree protection ordinance in 1982. Although the ordinance slowed the Oak tree decline, the Oak population, and other native tree species, continued to decline. In an effort to further slow the decline of native tree habitat, the City amended the two Los Angeles Municipal Code sections in April 2006. The amended Native Tree Protection Ordinance became law on April 23, 2006 .
The new law:
Protects all native Oak tree species (Quercus spp), California Sycamore (Platanus racemosa), California Bay (Umbellularia californica), and California Black Walnut (Juglans californica)
Trees four inches or greater in diameter at 4.5' above ground (DBH)
Multiple trunk trees are calculated by cumulative diameter
Trees on any lot size are protected
Protected tree report shall be submitted by a:
Registered Consulting Arborist (RCA) by the American Society of Consulting Arborists (ASCA), or;
Landscape Architect who is ALSO International Society of Arboriculture (ISA) Certified Arborist, or;
Pest Control Advisor who is ALSO ISA Certified Arborist
Protected tree removal requires a removal permit by the Board of Public Works. Any act that may cause the failure or death of a protected tree requires inspection by the UFD.
Although the law does not require protected tree pruning be permitted, the UFD encourages residents intending to perform any type of work to a protected tree first consult with a RCA or Certified Arborist. The pruning of protected trees must be performed carefully. Any work above or below ground that will occur within five feet of a protected tree's drip line (link to definition), the root protection zone, should not be performed until after UFD is consulted.
UFD hopes this webpage supplies you with all of the information needed to understand the Native Tree Protection Ordinance. If you need further information please contact the Division at (213) 485-5675.




