Forests mean different things to different people. The following information is for use in helping to meet the increasing demand for manipulation of forest vegetation to prevent catastrophic wildfires while preserving and enhancing natural forest values such as watershed, soils, and wildlife protection. By incorporating technological advances in forest vegetation management these forest values can be protected. In addition, the general public will be protected from the wildfire threat and further protected by reduction in smoke emissions from burning activities.
Links to Vegetation Treatment Methods
Whole Tree Yarding (link to page 2)
(includes biomass operations)
Cut to Length (link to page 3)
Mechanical Fuel Modification
Tub Grinder (link to page 4)
Mastication (link to page 5)
Tractor Crushing/Excavator Clearing (link to page 6)
Non-Mechanical Fuel Modification
Grazing (link to page 7)
Herbicide (link to page 8)
Firewood (link to page 8)
Although the following information is derived from fuel treatments in the forest setting, substantial portions of this data apply to the treatment of agricultural crop waste, such as orchard waste wood.
Forest stand conditions needed for Whole Tree and Cut to Length logging operations:
Forest stand conditions that promote catastrophic wildfires are perfect candidates for whole tree and cut to length logging operations. A typical forest in California, consist of a mixed conifer overstory with an understory of pole timber and submerchanatable trees. This frequent California forest scene results in an overstocked stand of trees which are competing for limited water, sunlight, and nutrients. Whole tree and Cut to Length logging operations are the most efficient techniques available for thinning of diseased and suppressed overstory and understory trees. By removing enough trees to eliminate interlacing crowns and sub - merchantable ladder fuels the threat of catastrophic wildfire is greatly reduced. These operations also have the capability to remove a portion of the surface fuels such as cull logs. One of the main products created from these operations is biomass. Biomass material is the organic material left over from the tree after sawlogs and/or pulplogs are created.
Mechanical Treatments Whole Tree Logging – Involves cutting and skidding the entire tree with the limbs still attached to a landing to be developed into a usable product.
Equipment needed for whole tree yarding.
Harvesters for cutting the timber (Cutting heads = shear, bar saw, and hot saw)
Skidders and/or tractors for taking the whole trees to the landing.
Delimber for making sawlogs or pulplogs.
Chipper for making wood chips for biomass plant.
Flail chipharvestor for making clean pulp chips.
Tub grinder for making wood chips for biomass plant.
g. Log & chip trucks
Sawlogs – delivered in log form to sawmills.
b. Pulplogs – delivered in log form to pulp mills, particleboard plants, or ports for over seas shipment
c. Biomass(hog fuel) – delivered in chip form, which includes bark and foliage, to cogeneration plants.
Pulpwood – delivered in chip form, which does not include bark or foliage, to particleboard plants and pulpmills.
Pulplogs - $25.00 a green ton to $35.00 a green ton
posts – (by product of CTL operation) additional cost occurs with rework at transfer yard
firewood – (by product of CTL operation) additional cost occurs with rework at transfer yard.
Equipment suited for processing very small material
Low ground pressure
Low potential for stand damage due to specialized equipment.
Fuel removal and modification
Improved stand vigor
material that does not make a product stays in the forest and adds to the ground fuels (limbs and needles)
Slow production rate
cost more than whole tree logging
If not done under proper conditions follow up burn projects could damage residual trees.
Tub Grinder - When whole tree logging operations are processing sawlogs only, large delimber piles are created from the material that does not make a sawlog. A tub grinder can turn these large piles into biomass chips for delivery to cogeneration plants or landscape mulch producers. In addition there usually is material left over from a biomass operation that is to small to be processed through a chipper but can be processed with a tub grinder. Forest stand conditions needed for the removal of biomass chips and/or landscape mulch:
The stand descriptions listed for whole tree and cut to length logging operations apply to tub grinding operations since the slash piles are a by-product of those logging operations.
Chaparrals and other brush species can also be utilized with a tub grinding operation.
The following information below is equipment needed to chip the slash piles. It does not include equipment or cost to create the slash pile or bring the material to the landing.
Equipment needed for tub grinding operation to deliver product
Biomass Chips – (assume 14 bone dry tons per load)
$22.00 a bone dry ton to $32.00 a bone dry ton plus haul.
b. Landscape/mulch - Contact companies listed as landscape/mulch producers for costs.
Utilizes material that can not be processed in a chipper (Example: slash piles)
Allows for increase fuel removal in forest
Lower quality chips due to potential of rocks and dirt to be intermixed in material.
Mastication– involves the use of mobile brush cutters, crushers, and choppers to masticate brush and sub merchantable material from standing ladder fuels to ground fuels. This operation puts the vegetation (both green and dead) on the ground where it will have less chance of contributing to a crown fire. The material after treatment remains in the woods and is not removed as a product. Type of Equipment and forest conditions where mastication is used:
Hot saw feller bunchers: ($140 to $190 per hour)
This equipment can be used in overstocked conifer stands where the objective is to thin the smaller trees in preparation for a future controlled burn. The hot saw will cut mostly sub-merch ladder fuels, (less than 8” diameter breast height) and move the cut material away from the base of the trees. The material can then be run over by the hot saw and compacted to allow for a more efficient burn. Care must be taken to monitor the amount of slash put on the ground to avoid to hot of a controlled burn which could kill the standing leave trees. The benefit of this treatment is to compact and dry the fuels, which will allow for a more efficient burn while reducing the smoldering phase.
2. Crushers and choppers:$ ? per hour
This equipment is used in areas with slash, brush, and small trees, less than 5” diameter breast height. This equipment is used generally after a thinning logging operation and usually on flat terrain. This equipment works best with dead material or during winter months when the material is frozen. Machine crushing or chopping is an effective treatment for reducing the fire danger of the forest while returning many nutrients back to the soil. This is also an effective pretreatment for controlled burning by reducing the ladder fuels and evenly distributing the fuels.
3. Timbcos and excavators with masticating heads: ($130.00 to $200.00 per hour)
This equipment is used in areas with heavy brush and slash and can also be used to thin trees less than 8” in diameter. Although there are several types of masticating heads, the slashbuster head is one of the most effective tools used for forest fuels treatment. The slashbusting head is typically mounted on a tracked timbco or excavator and can work effectively up to slopes of 45%. The slashbusting head is a dull circular saw with teeth that due to high rpm’s breaks apart the brush and small trees into chunks less than two feet in length. This equipment is very effective in masticating live green material. This equipment is the most efficient tool for developing fuel modification areas in brush fields and on steeper slopes. It is also a very effective tool for thinning trees and brush in plantations. This equipment is an excellent tool for maintenance of fuelbreaks. This equipment is used frequently to thin natural stands and as an effective pretreatment before controlled burning
a. Minimal ground disturbance and reduced germination of brush species
a. Costly treatment, which may require a follow-up herbicide treatment
Additional - Mechanical Treatments
Tractor crushing – (Cost varies by size of tractor - $60 to 140 per hour)
This technique is used as a preburn treatment to kill portions of the live vegetation and to compact the ground fuels. This technique is than followed up with a prescribed burn to reduce the fuel loading. Crushing and compacting the fuels allows for a more uniformed burn and allows for increased consumption of the fuel profile. Smaller tractors such as D3s to D6s can be used in forest stands. The smaller tractors are needed in a forested stand to prevent damage to trees. Larger tractors such as D7 or D8 work effectively in brushfields to crush and compact the vegetation.
a. Compaction and drying of fuels reduces the smoldering phase in burning thus reducing smoke emission.
b. Allows for burning in wetter conditions when atmospheric conditions are more conducive to smoke dispersal.
Compactions of soil may occur if operated under wet conditions.
Damage to may occur.
Excavator bucket/rake clearing ($130 to $170 per hour)
This equipment is used both for fuels reduction and site preparation work. This equipment is usually track mounted with associated low ground pressure. The excavator has the ability to reach 25’ to each side without moving which allows for fuels to be picked up and placed into piles with a minimal amount of movement. This type of equipment can work effectively on slopes up to 50%. This equipment is very effective at piling fuels 2” and larger while leaving the smaller fuels and organic matter in place.
Piles are free of dirt and burn quickly thus reducing smoke emissions.
No compaction due to low ground pressure equipment.
Smaller fuels and organic matter is left on site.
a. Can not work side hill or downhill effectively
b. Slow moving equipment
Non- Mechanical Treatments
Grazing – the use of animals to control the composition and rate of growth of brush and grasses (live fuels). Forest Stand conditions appropriate for grazing: Cattle – Cattle have a limited range of palatable vegetation Grasses and forbs are preferred, however a number of perennial woody brush species are also palatable. For instance, deer brush ceanothus (Ceanothus intergerimus) is highly valued forage for cattle. Cattle can be used on large free-range areas to control rate of growth of vegetation
Goats – Goats have a much wider range of forage species. In addition to grasses and forbs, goats will consume many brush and tree species. Goats can be used in smaller confined area to control species composition, rate of growth, or elimination of vegetation.
Equipment needed for grazing.
Generally need permanent or temporary fencing. Some species can be staked.
Cost of Service
Cattle – With adequate fencing and forage quality, should expect payment from rancher. Smaller areas without facilities may be offered for free grazing.
Goats – Goat contractors charge on various basis. $/acre, $/day/herd
Fire wood – sub merchantable and cull material woody material that is removed primary for private heating purpose.
Forest stand conditions needed for the removal of firewood:
The stand descriptions listed for whole tree and cut to length logging operations apply to firewood operations since the material that is used to produce biomass chips or pulwood logs can also be used to produce firewood.
Equipment needed for firewood operations: The amount of equipment needed varies from small operations to large operations. In addition, the cost and revenue derived from firewood operations varies greatly. Contact several firewood contractors prior to starting operations.
a. Small operations – pickup & chainsaw.
b. Large operations – firewood is removed in association with mechanical logging.
Equipment used in the mechanical logging process can be used to bring the material to convenient location to be processed into firewood.
a. This is a very effective way to reduce fuels on smaller urban interface jobs while
reducing smoke emissions from burning projects.
b. Firewood can be removed on large and small jobs when there is not a market for
biomass chips or pulp logs.
a. Time consuming to remove substantial amounts of fuel on small projects.
b. Larger operations may need transfer yard to process firewood.
c. Some contractors operate without proper insurance and/or state permits.
Herbicides – involves the use of chemicals to control brush and grasses.
Herbicides can be used to maintain fuel breaks after logging and/or burning.
Contact your local Agricultural Department for legal requirements requiring the use of herbicides.
Herbicide techniques used to reduce and delay burning projects.
a. Brown and burn – This technique involves killing brush and grasses prior to burning.
The benefits of these techniques are the dead fuels are drier, which allows for a more efficient burn with a reduction in the smoldering phase. It also allows for burning in wetter conditions when the atmospheric mixing conditions are good for smoke management.
b. Fuels maintenance – After a logging or burning operation, the disturbance causes a flush of vegetative growth. Herbicides can be used to control the vegetative growth thus prolonging the need for maintenance burns.