Plant Propagation and Tree Management

Plant Propagation Methods

• Peeling involves removing strips of bark at least 8 inches wide.
• Intermediate Cuttings are made between the top and bottom of peeled bark strips.
• Harvesting of intermediate cuttings can occur in a pocket.
• Salvage cuttings are made from dead or diseased trees.
• Sanitation cuttings are made to remove injured or diseased sections of trees.

Tree Management

• Pruning involves cutting or removing branches of trees.
  • Natural Pruning occurs naturally due to physical or biotic factors.
  • Crown-shyness is a phenomenon where leaves space between adjacent tree crowns.
• Artificial Pruning includes techniques like:
  • Removing dry branches.
  • Selective treatment of trees.
• Removal of Forks involves removing tree forks where branches are roughly equal in diameter (less than 4 cm).
• Thinning is the elimination of some individuals in a stand to manage wood production.
  • Amount added in a given year is a crucial factor for thinning.
  • Current Annual Increment (CAI) is the amount added in a given year of the period.
  • Periodic Annual Increment (PAID) is taken over a short period, equivalent to a certain number of years.
  • Mean Annual Increment (MAI) is the average increment of material during the stand's lifetime.
  • Gross Increment is the material formed during the year but not present at the end.
  • Net Increment is the material present at the end of a period.
• Stand Density measures the amount of tree vegetation over a unit of land.
• Stocking indicates the proportion of tree vegetation in a given area.

Tree Thinning and Management Techniques

• Thinning Methods aim to manage tree stands.
  • Row Thinning involves cutting trees in lines or narrow strips.
  • Commercial Thinning extracts felled trees for useful products.
  • Free Thinning focuses on releasing crops without regard to their position in the crown canopy.
  • Thinning Schedule provides a systematic plan for a whole rotation, balancing vegetation benefits with desired products.
  • Release Operation treats young stands of desirable trees, focusing on freeing the crowns from competition.
• Stand Management Operations include:
  • Cleaning in a stand, not past the sapling stage, to free the best trees from undesirable individuals.
  • Weeding removes all plants competing with crop species (suppressing, endangering, or hampering growth).
  • Liberation Cutting frees young stands from overtopping older trees.
  • Girdling involves felling undesirable trees by severing the bark, cambium, and sometimes the sapwood in a ring.
  • Double Hacking involves removing a horizontal line of chips by striking downwards.
  • Notching involves cutting notch rings around the tree, halting upward water movement.

Thinning Methods in Forestry

• Parameters for thinning include:
  • Number of trees per unit area, the simplest parameter.
  • Basal area per unit, measuring the cross-sectional area of physiologically dead wood.
• Low Thinning, often the oldest method, is sometimes called thinning from below.
• Grades of Thinning:
  • A-grade low thinning removes dead or nearly dead trees.
  • B-grade low thinning addresses trees with partially dead or broken crowns.
  • C-grade low thinning removes co-dominant trees along with lower crown sections.
  • D-grade low thinning removes trees smaller or shorter than a given standard (sometimes called the French method).
• Types of Crown Thinning:
  • Crown Thinning removes trees from the middle and upper portions of their canopy.
  • Selection Thinning removes dominant trees, encouraging growth from lower portions of the trees.
  • Thinning of the dominants removes dominant trees in even-aged stands to stimulate lower crown growth.
• Other Thinning Forms:
  • Geometric Thinning uses a predetermined spacing pattern for removing or retaining trees.
  • Spacing Thinning selects trees at fixed distances for retention, removing all others, often used when a stand is overcrowded.