Mulch. It’s Cool.

This August USA Today reported that more than 560 wildfires were burning in California. It is officially fire season, although it has been said we are constantly in a fire season.

For more than five years, the City of Laguna Beach has partnered with Laguna Canyon Foundation on fuel modification projects that create fire breaks which serve to protect entire neighborhoods from wildfires. Project areas include South Laguna, Laguna Canyon along Laguna Canyon Road and the Arch Beach Heights neighborhood.

We call it “Fuel Mod.” Modifying fuel modifies potential fire behavior.

Hand-crews on steep terrain

Hand-crews are contracted to work in high value habitat areas. It is difficult work, often on very steep terrain and in areas fraught with poison oak and bush rue. Prior to the crews’ arrival, Laguna Canyon Foundation staff and biologists conduct nesting bird surveys. They flag the area for native plants to thin and invasive plants to remove.

As the daughter of a firefighter and a homeowner whose house abuts a canyon under fuel modification protocols, I am grateful for this work on many levels. Fuel Mod provides extra time and access for firefighters should a fire occur. Fuel Mod adds a layer of protection to my home. Fuel Mod restores native habitat.

As the crews leave, you may see debris left, which is a strategic step with specific requirements. Only native plant cuttings are left and they must be cut down to a certain size and spread around to be no deeper than 12 inches off the dirt. This is the mulching step and to understand why mulching is so important, a few fire science facts and terms might be helpful.

Aerial Fuel and Surface Fuel

Aerial fuel is all live (and dead) vegetation above ground, including tree branches, twigs, brush and leaves.

Surface fuel is loose debris on the ground consisting of twigs, small branches, and leaves.

Converting aerial fuel to surface fuel is achieved by laddering up (thinning) native plants and removing invasive plants. Fires will still burn but with smaller and slower flames. Because the surface fuel is low to the ground and dense, it retains humidity and doesn’t dry out as fast, reducing fire behavior.

Surface Fuel and Erosion

The native plant mulch (surface fuel) our crews leave is very strategically placed. Mulch protects the soil against rain drop impingement. 0Instead of rains blasting the bare soil, washing it out, with mulch, the water trickles through the debris and is absorbed more easily, reducing erosion.

Mulch and an Advantage for Native Plants  

By creating moisture for the remaining native plants, the mulch not only provides a rich soil for native root growth but also retards the development of non-native seeds, giving native plants a significant advantage.

Native and Non-native Plants

A native Matilija Poppy is flagged to remain.

Around the canyons and in Laguna Beach there are many beautiful native plants and several ubiquitous non-natives that can deprive the native plants of the resources – water, space, soil – they need to thrive.  This, in turn, reduces the resources – food, protection, nesting areas – native wildlife needs to survive.

Invasive plant removal, an important step in the fuel modification process, has the extra benefit of making our canyons healthier for the local flora and fauna.

Non-native plants include:  Fennel, Mustard, Tree Tobacco, Cape Ivy, Artichoke Thistle

Native plants include: Coyote Brush, Sticky Monkeyflower, Twiggy Wreath, California Sagebrush, Black Sage, White Sage, California Buckwheat, Laurel Sumac, Toyon, Lemonadeberry, Wild Cucumber, Matilija Poppy, Prickly Pear Cactus, Cholla, Dudleyas.

Native Trees: Sycamore, Coastal Live Oak, Willow.

What to learn more about native plants?  Check out California Native Plant Society.

The mulch not only helps the native habitat and the fuel modification efforts, it is a requirement. Removal of mulch violates conditions of the Coastal Development Permit and could expose the property owner to Coast Act and other liability if they remove the material.

So, if you see mulch around your home from our Fuel Mod projects, please leave it undisturbed.

It’s cool.