Understanding Foresry Disc Mulchers

What are Mulchers?


Mulchers cut and chop or grind vegetation into particles that are usually left on-site as mulch. The primary purpose of mulching is to lower the vertical height of fuels, shift fuel volume into the 1- and 10-hour size classes, as an alternative to chemical treatment of competitive species, for aesthetic treatments, right-of-way maintenance, and range rehabilitation.

Mechanical Configurations

Mulchers are mounted on a variety of chasses including skid steers, excavators, farm tractors, four-wheel drive loaders, and dozers. They may also be purpose-built machines based on any one of those machine forms.

Mulchers come in two basic forms, vertical shaft, and horizontal shaft. A horizontal shaft mulcher is basically a chipping drum or disc mounted on a carrier. The drum is continuously spinning as the machine moves through the material. Some mulchers have push bars to push the severed trees away from the machine, but other than that there is no control over the direction of fall.

Mulchers mounted on skid steers, tractors, four-wheel drive loaders, and dozers are pushed through the stand. As they sever the stems, the stems fall in front of the machine and are shredded as the machine drives over them.

Mulchers mounted on excavators and wheel loaders are capable of mulching standing trees. This provides more control over the process and prevents running the head into the dirt.

At Advanced Forest Equipment our Rotary Disc Mulching (RDM) Technology is much more than a spinning disk with cutting teeth. The secret to this proprietary technology is the innovative design which transfers maximum power to the attachment using only the existing hydraulics of the carrier. This results in a mulching attachment that can handle thick undergrowth and trees up to 20 inches in diameter without binding or clogging.

Safety Concerns

The biggest safety concern with mulchers is flying objects thrown by the head. Most mulching occurs at ground level, so the chance of picking up rocks or other debris is high. Most mulchers have shrouds that direct the material towards the ground. When the mulching head is lifted into the air however, the shroud may become ineffective. It is important that adequate guarding is mounted on the carrier to protect the operator from flying debris.

Heavy Equipment Armor is the first and only company dedicated to building ballistic windows and doors, top guards, and cab guard products for heavy equipment. Heavy Equipment Armor was created because of the need for additional guarding on heavy machinery like Excavators and Skid Steers.

Another safety concern is cutting standing trees. Mulchers capable of lifting the head and cutting trees from the top down are a safer option when larger standing trees need to be mulched.

Treatment Options

Excavator mounted mulchers can be used on steeper slopes, greater than 30%, or where it is important to minimize soil compaction. The excavator does not need to travel everywhere it is mulching, which is an advantage over the other machine forms. This style of mulcher is safer where larger standing trees are being mulched.

Deciding which mulcher should be used is a matter of the number and size of standing trees need to be cut and the slope. Mulching of larger pieces, greater than 3 inches in diameter, should be minimized to retain coarse woody debris and to optimize efficiency.

There are certain treatment factors that can affect the cost of treatments. Some key things to consider are:

Applications of forestry mulching

Right-of-way clearing and maintenance: Forestry mulching is used in the right-of-way clearing and maintenance for roads, highways, pipelines, and other service lines. This process often requires complete removal of standing trees, stumps, and vegetation.

Land clearing: Forestry mulchers can be used in commercial and residential land clearing projects such as site preparation and development, cutting and clearing brush, nature and recreational trail and seismic exploration.

Wetlands and riparian habitat conservation: Forestry mulching has become popular among nonprofit riparian conservation organizations, government agencies, hunt clubs, and private landowners in attempts to maintain habitats for pheasants, doves, elk, deer, and various other animals. Maintaining an animal habitat encompasses several different aspects: food, water, shelter, and space, and there are many products that can help reclaim and maintain wildlife habitats for these animals.

  • Food: Forestry mulchers and forestry mowers are often used for removing underbrush and invasive species, such as buckthorn and multiflora rose, to allow the rejuvenation of grasses and other eating sources.
  • Water: Forestry mulchers and tree shears can be used to restore water source access that has been blocked due to tree and understory growth, allowing animals to access the water.
  • Shelter and space: Mulching can remove invasive underbrush that prevents the growth of the grasses required by certain animals for shelter, breeding, escaping the summer heat, and protecting themselves from cold temperatures.

Invasive species control

Some common invasive plants such as tamarisk (salt cedar), Pinyon-juniper (pj), Russian olive, Juniperus virginiana, buckthorn, and multiflora rose can invade a natural habitat, soak up a tremendous amount of ground water, and need to be removed to reestablish the native habitat or to preserve the water table. Invasive insects such as pine beetles can also devastate forests, leaving behind rotting trees with diminishing timber value and that may become falling hazards if they lose their ability to stand up against wind.

Wildfire prevention and management

  • Proactive mulching: Mulching reduces the potential for wildfires by eliminating small leafy plants, fallen or rotten trees, and other fuel sources. If left untreated, these fuel loads increase potential for fire, increase the heat intensity, and serve as fire ladders that enable fire to elevate quickly to the tops of trees which is where a fire can spread most quickly. Mulching can also be used to create a coarse grind finish that can create a more ideal controlled burn.
  • Reactive mulching: In addition to proactive thinning of vegetation to mitigate fire fuels, forestry mulching can be used for reactive cutting of lines on active fires. Larger forestry mulchers leave minimal cleanup requirements and can help reduce the overall costs of active fire mitigation.
  • Cleanup: After the fire is out and cleanup efforts are under way, tracked forestry mulching machines, mulching attachments, and an excavator with a mulching attachment can provide a top layer of mulch to prevent soil erosion on slopes and minimize water pollution.