Shortcomings of Clearcutting and Coppice Systems in Forestry: A Comparative Analysis, Slides of Forestry

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Common Even-Aged Systems

Seed Tree

Shelterwood

Clearcut

Clearcutting

• Clearcutting: A method of regenerating an even aged stand

in which a new age class develops in a fully exposed

microclimate after removal, in a single cutting , of all trees in

the previous stand.

• Silvicultural clearcuts differ from ‗commercial clearcuts‘

Clearcutting changes the microenvironment

• Full sunlight conditions
  • Air and soil temperature near the surface increases
  • Humidity decreases and surface evaporation increases
  • Soil moisture increases because transpiration decreases
  • Precipitation interception decreases, more water reaches the surface
  • Water infiltration and percolation increases; subsurface flow increases
  • Decomposition increases (warmer and wetter), releasing more nutrients
  • Nutrients not taken up or bound to soil leach out of system

Clearcutting

• Edge effect

Alternative Clearcutting Approaches

Block clearcutting

Alternative Clearcutting Approaches

Alternate strip clearcut

Strip clearcuts, alternate or otherwise, are best oriented at right angles

to prevailing winds. The width of the strips will depend on seedfall

distances for the preferred species, wind hazard, and other factors

Progressive strip clearcut

Other considerations when using even-aged methods

• Stream Side Management Zones (SMZ‘s)
• Legacy trees
• Travel corridors for wildlife
• Management of viewscapes
• Alter shapes, adjacencies
• Limit harvest size

Clearcutting and Site Preparation

• Site preparation considerations for natural regeneration

• Some important questions

• Advantages of the clearcutting method/system
  • Commercially attractive
  • Ease of administration and implementation of regulated forest
  • Good method for most shade intolerant species
  • Clean site eases site preparation and pest control
  • Easy machine access eases harvesting
  • Total overstory removal reduces some pests (e.g. dwarf mistletoe)
  • Facilitates regeneration of species with serrotinous cones
  • Precludes blow down
  • Increases herbaceous cover (browse and cover for many wildlife species)

Shortcomings of clearcutting with natural regeneration

• Problems with dependable seed sources and seedling establishment
• Issues associated with no high forest cover and high light environment
• Reduced chance for genetic improvement

Coppice Silviculture

Coppice

• The term "coppice" is commonly applied to any regeneration

arising from sprouts or suckers—typically hardwoods of

young to moderate age

• As a method, it is where regeneration is solely from sprouts

or root-suckers

• Associated with short rotation production of pulpwood or

fuelwood

• Historically associated with charcoal iron production

Coppice

• Some coppice principles:

• Low stumps produce better quality sprouts
• Sprouting vigor tends to decline with age and size of stems
• Sprouting is most vigorous from dormant season cutting

Coppice

• Coppice for energy, bioremediation, environmental cleanup

• Repeated crops without replanting
• Vegetative propagation maintains genetic integrity of plantation
• Increased growth rates allow large volume production on limited land base
• Short cycle provides quick return on investment
• Second and third rotation often produces greater biomass in shorter time frame due to multiple stems from sprouts