Vegetation Management

Vegetation Management for Mulitiple Objectives

Timber

Facilitate timber stand establishment by reducing competition.

  • Site Preparation - before planting
  • Herbaceous weed control - first growing season
  • Seedling Release - Age 1+, control woody stems
  • Mid-rotation Brush Control - usually combined with thinning or fertilization

Wildlife

Alter vegetation structure to meet specific habitat needs:

  • Know which species you are managing for
  • What are their habitat requirements?
  • Herbicides can release desirable forages such as American beautyberry, ragweed, beggar’s lice, honeysuckle, blackberry, and muscadine.
  • Using fire, mechanical treatments and/or herbicides, you can create a mosaic of vegetation cover to optimize habitat diversity.

Ecosystem / Groundcover Restoration

Manage vegetative composition to restore native plants.

  • Herbicides can be used to select for desirable plants in seed bank - wiregrass in seedbed can be released by removing oaks (photo by Leslie Hawkins).
  • Herbicides are most effective in controlling invasive exotic plants.

For more information, see our Ecosystem Management page or read the Extension Publication: Restoring Longleaf Pine Sandhill Communities with an Herbicide.

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Mechanical Treatments, Grazing & Fire

Although mechanical treatments are generally not a long-lasting as chemical treatments, they may be cost-effective in some cases. 

Cultivation or Disking

This technique may be used to control competing vegetation on areas previously used for agricultural crops or where rocky soils, large stems, or stumps do not impede tillage.  To use cultivation, rows and spacings of planted trees should be wide enough to accomodate tillage equipment. 

Disks and harrows are most commonly used for forest cultivation. Soils are tilled between rows of trees, but may also be tilled between pines where spacings are wide and regular.  Tilling between rows will not control vegetation within the row itself. 

For wildllife objectives, periodic disking of established ground covers will enhance species and mast diversity. To avoid the disturbance of ground nesting species such as turkey and quail, and to promote the growth of important wildlife foods such as partridge pea, ragweed, and beggarweed, mowing and disking should be conducted during the winter months (November - February).

Mowing or Mulching

Mulching machines or tractor-mounted mowers, brush cutters, or hand tools may be used to remove competing vegetation in young pine stands.  Tractor-mounted mowers or "bushhogs" are commonly used where pines have been planted in open areas such as agricultural land. 

Although stands must be mowed several times during a growing season, pine survival can be enhanced significantly.  Mowing changes vegetation species composition to favor grasses and sedges which survive repeated mowings better than broadleaf species.  This can greatly improve forage for wildlife or livestock.  The remaining ground cover also decreases the potential for erosion.

Grazing

IFAS, Department of Animal ScienceIntegrating timber and livestock production (silvopasture) diversifies product output and may increase your revenues.  When incorporating grazing, we are concerned with soil compaction and damage to pines from browsing and trampling in young stands.  However, it has been suggested that livestock can be used to promote stand establishment as long as the number and distribution of animals and timing is carefully controlled. 

For grazing to work with timber management, palatable forage must be available to minimize grazing on pines.  Intensive site preparation improves native forage development.  Bahiagrass (Paspalum notatum) may be seeded after site preparation to improve the quality and availability of forage.

Also, keep these points in mind:

  • Canopy density will have a significant effect on forage yields. Therefore, tree spacing should be wide. Research has shown that a tree spacing of 4 x 8 x 40 feet (4 feet between trees in rows, 8 feet between rows, and 40 feet between pairs of rows) is an optimal spacing for both wood and forage yield.
  • Grazing during the late winter and in the early spring after planting should be avoided because palatable forage will be in short supply during these times. 
  • Placement of mineral blocks and feed stations can help control livestock distribution. 

University of Florida Extension Publications

Prescribed Fire

Prescribed fire has many uses in southern pine management.  The advantages of using fire to manage vegetation is low cost and versatility. Summer burns can control hardwood brush and favor the growth of herbaceous vegetation, which provides forage for wildlife.  Periodic summer or winter burns may encourage hardwood sprouting, which provides succulent browse for deer.

See our Fire page for more information about prescribed burns.

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Using Herbicides

Why Use Herbicides?

Herbicides Can
Herbicides Cannot
  • bring longer-lasting control of competing vegetation = increased economic return for landowner.
  • control tough invasive exotic plants.
  • retain biomass for soil protection.
  • avoid soil compaction.
  • be costly.
  • reduce slash accumulations after harvest.
  • regenerate fire-dependent species.
  • be used without caution:
    - application failure
    - drift to non-target crops
    - surface runoff
    - spills

Treatments in some of these publications, Web sites and tables below are not guaranteed to work everywhere.  Always apply herbicides according to the label.

Application Methods

For a herbicide to be effective and safe it must be applied by an appropriate method. There are three general types of application techniques that can be used for both foliar-active and soil-active herbicides: broadcast, banding, and spot treatments:

  • Broadcast treatments are applied to an entire area either from the air (with helicopter and less frequently fixed wing aircraft) or from the ground (with machine-mounted or hand-held equipment). Broadcasting is the method of choice for site preparation, but can also be used for conifer release and herbaceous weed control.

  • a tank and boom mounted to an ATV is an effective way to apply a banded herbicide treatmentBand treatments are applied in strips on or along rows of crop trees from the ground with machine-mounted or hand-held equipment. Band application is often as effective as broadcast treatment for herbaceous weed control in young plantations and may result in significant cost reduction. Banding is usually more effective in controlling annual than perennial weeds.

  • Spot treatments are applied to individual stems or small areas, usually with back-pack sprayers or other hand-held devices. They can be as effective as broadcast, yet use much less herbicide and thus can offer substantial savings in herbicide costs and have less impact on the environment. Spot treatments are very labor intensive, however, and usually can only be justified for small tracts or when a small number of problem spots are to be treated.

Foliar-active herbicides can be spot-applied as directed sprays or by various individual stem methods:

  • Dr. Patrick Minogue, UF-IFAS NFREC Quincy, demonstrating use of a backpack herbicide sprayerDirected spray is a spot treatment used mostly for conifer release and sometimes for herbaceous weed control. Spray is directed from back-pack sprayers to the foliage or stems of the target plants without contacting crop trees. Instead of spraying, the herbicide can be wiped onto the weeds with a wick applicator reducing the potential for drift or spraying non-target plants.
  • Individual stem treatments encompass various methods of applying herbicides directly to target plant stems.
    • Basal bark sprays involve spraying intact bark with a herbicide. Ester formulations dispersed in an oil carrier are most effective for this method.

      • Thinline (or streamline basal) spray involves applying a herbicide in a narrow band, 6-24” above the stem base and is used for small-diameter stems.
      • Spray-to-wet (or full basal) spray involves spraying the lower 12-20” of the plant to the point of runoff and can be effective for slightly larger-diameter stems.
    • Frill girdle (or hack & squirt) involves cutting or drilling through the tree bark into the sapwood and immediately applying a herbicide to the cut. This application is effective for larger-diameter trees and does not require an ester formulation.
    • Injection consists of injecting a herbicide through the bark into the vascular system of target trees using specialized injection devices.
    • Cut stump method consists of applying a herbicide to the entire cambium and inner bark of a stump, immediately after cutting off the stem. It is often used for woody species which have a tendency to re-sprout after being cut. It is usually more efficient to prevent sprouting than to control it later.

Soil-active herbicides (liquids and solids) can be spot-applied in a grid pattern, around individual crop trees, or at the base of individual stems of competing vegetation:

  • Grid application involves applying soil-active herbicide to an entire area using a grid pattern. Selection of a grid pattern and herbicide rate depends on soil texture and woody plant composition. It can be used for site preparation and conifer release, especially on sites with large numbers of stems per acre.
  • Spot-around and Tree-centered spots involve applying soil-active herbicides around the crop trees, in small spots or to a small area around a tree, respectively, to control woody and herbaceous vegetation, respectively.
  • Individual stem treatment (basal soil) involves applying herbicides to the soil in a close proximity to the stem of target woody plants.

Additional Resources

Extension Publications

Florida Forestry Information

Other Sites

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Additional Topics

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