Cal. Public Resources Code § 4799.11

(a) The department shall provide technical assistance to urban areas with respect to all of the following: (1) Planning for regional, county, and local land use analysis projects related to urban forestry. (2) Preparation of urban tree plans and the selection of trees in landscaping and reforestation efforts. (3) Development and coordination of training programs for neighborhood and local agency tree planting and maintenance crews. (4) Advice and guidance to cities, counties, districts, and regional entities, homeowner neighborhood groups, and nonprofit organizations on tree disease, insect problems, tree planting, maintenance, and best practices and metrics as developed by the department, for maintaining urban forest health. (5) The role of forest ecology in planning for the future of urban areas, including climate change and greenhouse gas emission reductions, carbon sequestration, air quality, watershed problems, and energy conservation. (6) Improvement and enhancement of local water capture for urban forest maintenance. (7) Retention of native trees and riparian habitats. (8) Any other matter relating to the purposes of this chapter. (b) The department and other state agencies are also authorized to assist local tree maintenance and green waste utilization programs by making equipment available on loan where feasible and not detrimental to department or other state agency operations. That equipment may be used only to support regional or local urban forestry efforts consistent with this chapter, including by nonprofit organizations involved in urban tree care or urban green waste utilization efforts.