Forestry Terms & Definitions

A few terms to brush up on...

Below is a list of terms and definitions pertaining to wildfire mitigation.

Removing Fuel

Fuel is anything that can catch fire. Keep combustible items at least 5 feet from the entire perimeter of your house. Keep pine needles and leaves off your gutters and roofs.

Limbing Trees

Limbing is cutting off branches too close to the ground, typically, for flat areas, they are limbed up at least 6 to 10 feet above the ground. These are cut since ground fire can ignite low hanging branches resulting in fire getting into tree crowns enabling fire to jump from treetop-to-treetop where firefighters cannot extinguish flames.

Thinning of Trees

- 14 trees..too crowded...stressed trees

- Branches too close to ground

- 6 trees with improved spacing

- Branches cut to be higher from ground

Wildfire thrives on densely packed trees; the more fuel, the hotter and faster fire will burn. We reduce density of trees by cutting smaller diameter trees to establish safer distances between individual trees and between clusters of trees resulting in less intense fire.

Diseased Trees

- Densely packed trees result in weak and unhealthy trees that are more susceptible to infestations.

- Primary tree diseases in the Ridge are Mountain Pine Beetle and Dwarf Mistletoe. Pine Beetles fly to nearby trees in the Spring and infect other Ponderosa Pines with a parasite that frequently causes rapid death to infected trees. They are identified by pitch tubes leaking sap on the trunk. Cutting down recently infected and sometimes adjacent trees helps slow the spread. Dead trees are removed when unsafe.

- Dwarf Mistletoe is a small, leafless parasitic flowering plant that slowly kill Ponderosa Pine Trees by robbing the tree of food and water. Typically, in August each year their spores open and spray out at 60 MPH covering 50 feet or so and are covered with a sticky substance to help adhere to adjacent trees.

- Dwarf Mistletoe can induce abnormal tree growth at infection points producing a “witches’ broom” or other disruptions of the branching structure. The weakness they cause in the Ponderosas enables Mountain Pine Beetles to invade the tree resulting in a much quicker death.

- Management prescriptions depend on the severity of the infestation and vary from cutting off just the few infected branches on a mildly infected tree to removing a tree that is infested from top to bottom.

Dead Trees

Dead trees are useful to wildlife and will be removed when there are safety reasons

Mastication of Areas

Forestry mastication is where heavy duty machines are used to grind up trees and other vegetation to provide fire breaks and to reduce the density of the forest to help slow and minimize the spread of wildfire. The output of the machines are essentially wood chips which can be carted away or safely spread across the forest floor to improve the biomass and health of the soil.

There are many different types of mastication machines to support various terrains and forest needs

Defensible Space

Defensible Space defines the density and location of trees and other fuel in distance zones around a house. Defensible Space helps our firefighters defend our homes against fire. For example, in the first zone (0-5 feet from the house), no combustible material is permitted. Other zones are 5-30 feet and 30-100 feet

Home Hardening

The more flammable materials present on outer surfaces of our homes, the higher the probability a wildfire will ignite the home. Home Hardening eliminates areas that can catch fire from accumulating falling embers (which can fall from the sky 1-5 miles in front of a wildfire) as well as nearby landscape flames: keep pine needles from accumulating in gutters or roofs, install gutter guards, install 1/8" steel screen mesh over vents and other openings into the home, place metal barriers between decks and home, place metal on any horizontal wood surfaces, etc.