Early Intervention for Invasive Ailanthus altissima in Angeles National Forest Watersheds
Summary
SCH Number
2026090323
Public Agency
Los Angeles County
Document Title
Early Intervention for Invasive Ailanthus altissima in Angeles National Forest Watersheds
Document Type
NOE - Notice of Exemption
Received
Posted
9/9/2026
Document Description
Agriculture Access has spent a number of years observing, monitoring, and hiking within the Texas Canyon watershed. Based on communications with both the Angeles National Forest and the Mountain Recreation and Conservation Authority (MRCA), who jointly own and manage portions of the Texas Canyon watershed, it seems likely that conservation of this watershed region is a high priority. Therefore, an investment in an invasive weed control project for the control and prevention of Tree of Heaven populations makes common sense over the long-term. By targeting both the largest ‘parent trees’ (having the tallest, most mature leaf canopies) and newest ‘root sprouts’ (having the most active growing leaf canopies) within this half-acre site, the project proposes to “suppress photosynthesis” and its “source-sink” relationship. By selecting the use of Integrated Pest Management (IPM) protocols that remove large parent canopies and root sprouts, and “block sunlight” over periods of 3-6 months to prevent their regrowth, the control of this invasive weed site will be achieved. Without sufficient sunlight, Tree of Heaven is unable to assimilate carbohydrates and distribute them to newly growing root sprouts. Thus, severely hindering new growth or expansion of the weed site. The main advantage of early intervention of Tree of Heaven weed sites, is that the population size is small (<1.0 acre), is thus is economically feasible and efficient to control and manage over the long-term. If by controlling photosynthesis within leaves, crowns, and root sprouts of this Tree of Heaven weed site at an early-intervention stage of development, then it should be feasible to stop the expansion, and arrest the growth of the entire site within the Texas Canyon Watershed.
Contact Information
Name
Geoff Burch
Agency Name
LA County ACWM
Job Title
Deputy Agricultural Commissioner/Sealer
Contact Types
Lead/Public Agency
Phone
Email
Name
Roger Haring
Agency Name
Agriculture Access
Job Title
Project Coordinator
Contact Types
Project Applicant / Parties Undertaking Project
Phone
Location
Coordinates
Cities
Agua Dulce
Counties
Los Angeles
Regions
Southern California, Unincorporated
Cross Streets
Forest Rte 5N14 and Forest Rte 5N18
Zip
91390
Total Acres
0.5
Other Location Info
Project location within the Texas Canyon Watershed and Rowher Flats Off-Road Vehicle Recreation Area
Notice of Exemption
Exempt Status
Categorical Exemption
Type, Section or Code
15333 – Small Habitat Restoration Projects
Reasons for Exemption
This project is exempt because it will improve habitat suitability for native plant species and does not directly disturb five acres or more of land. There will be no significant adverse impact on endangered, rare, or threatened species or their habitat. There are no hazardous materials at or around the project site that will be disturbed or removed. Also, the project will not result in significant impacts in connection with past projects, current projects, or probable future projects in the same location.
County Clerk
Los Angeles
Attachments
Notice of Exemption
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