Mechanical Brush Control

Brent J. Racher, Ph.D.Restoration Solutions, LLC

Corona, NM

Mechanical Brush Control

• Physical removal of target woody plants to allow more desirable plants spp. to grow

Plant Ecology

• Brush = perennial, woody plants

• Growth form–Non-sprouting–Resprouting

• basal buds (budzone)• Axillary buds (roots)

Non-sprouting Species

• Top removal kills plant

• Not necessary to remove stump/roots

• Generally evergreens– Ponderosa pine– One-seed juniper– Pinon pine

Resprouting

• Budzone–Generally

taprooted–Removal =

mortality

Resprouting (cont.)

• Axillary buds– Fibrous roots– Remove stumps &

roots = mortality– Broken roots

require maintenance

Resprouting (cont.)

• Broadleaf trees/shrubs–Saltcedar –Mesquite –Russian olive

Mechanical Brush Control• Top removal

– Non-sprouting spp.

– Resprouting spp.

• Desirable ???

• Maintenance (root:shoot ratio)

Mechanical Brush Control

• Cut root system

• Removal of budzone and/or roots

Control Objectives

• Desired plant community

• Thinning vs. complete removal

• Precision of control technique

• Scope of treatment

• Treatment effectiveness

• Cost

Shredding/Mowing

• Top removal • Generally smaller shrubs• Control of non-sprouters• Reduce influence of resprouters

Roller chopping

• Top removal• Small diameter

shrubs• Control of non-

sprouters or where resprouting of browse species is desirable

Mastication• Top removal• Mulching of woody

material• Generally used on

medium to large shrubs/trees

• Controls non-sprouters; used to deal with woody biomass of resprouters

Cutting• Examples: chainsaw,

feller buncher, tree shears

• Top removal• All sizes of plants• Control of non-

sprouters; used in conjunction with other methods for control of resprouters

Chaining & Cabling• Top removal and can pull large

shrubs and trees out under proper moisture conditions

• Medium size and larger shrubs• Control of non-sprouters and some

resprouters

Disking• Top removal with

some cutting of roots below ground

• Small shrubs (sagebrush)

• Control of non-sprouters

Grubbing• Removes top and stump• Shrubs w/ budzone or

where stumps are not desirable

• Control of some sprouters and non-sprouters

Dozing & Brush Raking• Removal of top and

stump• Frequently used to

control and pile PJ• Control of some

sprouters and non-sprouters

Root Plow• Cuts roots below

ground• Very non-selective• Deep soils• Mostly used for

sprouters

Root Rake• Removes roots from

below ground• Mostly used in

conjunction with dozing and root plowing for strong sprouters

Ripping, Furrowing, Disk Diking

• Limited brush control use• Utilized to improve

infiltration in compacted or tight soils

• Increases competition by improving moisture conditions along treatment

Extraction

• Removal of stem, stump, and can get adventitious roots

• Selective• Used on all sizes of

trees and shrubs• Control of

sprouters and non-sprouters

Chipping & Grinding

• Not specifically for brush control

• Used to reduce woody material

• Provides opportunities for reducing soil exposure or removal of biomass material

Mechanical Costs• Equipment size (HP)• Equipment

maintenance• Site topography &

soils• Scale of treatment• Selectivity

Mechanical Control in IPM

• Define objectives• Scenario to fit

objectives• Integrated

management– Biological– Chemical controls– Cultural methods