Tree Safety Program

County Parks manages various properties with many recreational opportunities from remote forests to urban environments. Trees are a vital part of our park ecosystems for both visitors and wildlife. The purpose of the Tree Safety Program is to evaluate trees in areas with high human activity in order to promote safety, meet the Department’s natural, cultural and historical resource protection policies, and protect public, staff, and property.

The department’s philosophy is that native trees will be best off if left in their natural condition (where possible) and should not be managed on a tree-by-tree basis. However, the department also recognizes the inherent conflicts between public recreation and the natural condition of trees especially in areas of parks where people gather and/or linger. Due to this conflict, the department manages some trees, particularly in developed areas, in order to sustain their health, maintain a representation of the natural ecosystem, identify and minimize problems that might result in tree failure (death or limb detachment), visitor and/or park staff injury, and/or property damage. The following priorities will guide the department’s management activities:

• Protect natural woodland communities and forests;
• Maintain a representation of the natural setting;
• Manage trees in designated developed areas that experience high public use, or prolonged, stationary visitor uses (picnic areas, campgrounds, staging areas, etc.);
• Protect park facilities and cultural and historical resources.

Tree removal guidelines

The removal of trees or parts of trees can have a negative impact on a park. It is critical that every inspection and decision be made by Park personnel who are professionally trained to judge both the degree of risk and the probable effect of tree removals on a park. Due to diseases like Sudden Oak Death and other impacts to trees, Mt Madonna and Sanborn County Parks are inspected on an annual basis.

Sudden Oak Death

Sudden Oak Death (SOD) is an easily spread water mold that kills many native oak species. People spread this pathogen through the transport of infected soil and host plant material. SOD is also spread through water and wind-driven rain. Symptoms include leaf yellowing, shoot and stem dieback, cankers with oozing sap, and death. SOD kills tanoaks, coast live oak, California black oak, Shreve oak, and canyon live oak and causes foliar diseases on many other plants including California bay laurel. Trees that are not killed by SOD, like the California bay laurel, are frequently responsible for spreading the disease among other trees in the area. 

Our management strategy for SOD is prevention. Preventing the spread of the pathogen is accomplished by keeping soil and plant material from infected areas on site, sanitizing tools and boots before entering and exiting a site and avoiding working in infected sites during the rainy season. Parks visitors can also help prevent the spread of SOD by not moving soil or plant material from parks and by making sure they are not tracking mud between parks on their hiking shoes. 

Extensive mapping of SOD instances and applications like SODMap and SODMapMobile from the UC Berkeley Forest Pathology and Mycology Lab allow us to manage SOD in a data-driven way and assist us in preventing further spread.

Resources on Sudden Oak Death

• Sudden Oak Death locations in Santa Clara County parks
• SOD Blitz Project – UC Berkeley Forest Pathology and Mycology Lab
• CA Oak Mortality Task Force
• Sudden Oak Death management guidelines--UC IPM (ucanr.edu)