Compartmentalization of Decay in Trees CODIT Compartmentalization of Decay in Trees

Outer BARK Bark is all the tissue from outer edge of cambium Protects tree Seals out oxygen Saturates moisture levels in cambium

Heartwood Heartwood is chemically altered, nonliving wood in a static state Inner xylem Decay resistant elements are deposited through dying sapwood into heartwood Phenols in angiosperms Resins and terpenes in conifers Not all species form heartwood Some maples have living cells in the center of 3 foot diameter tree

heartwood Some species heartwood is not resistant to fungi Heartwood has no biological function and limited structural Strength primarily comes from outer sapwood

CODIT Compartmentalization of decay in trees Requires energy Discoloration of wood response to microorganisms Decay breakdown of tissue by fungi

CODIT Trees is low energy state have diminished capacity to compartmentalize Requires energy

CODIT Large cuts expose increased heartwood and sapwood Pruning reduces photosynthetic tissue In addition to the additional loss of energy to compartmentalize

FOUR WALLS OF COMPARTMENTALIZATION Tree surrounds injury with chemical boundaries Translocates sugars to seal

FOUR WALLS OF COMPARTMENTALIZATION Resists vertical spread by plugging xylem

FOUR WALLS OF COMPARTMENTALIZATION Resists inward spread by depositing chemicals in cells

FOUR WALLS OF COMPARTMENTALIZATION Inhibits lateral spread by activing ray cells to resist decay

FOUR WALLS OF COMPARTMENTALIZATION Forms along the edge of outermost growth increment when tree injured Referred to as barrier zone

FOUR WALLS OF COMPARTMENTALIZATION Reaction zone Walls 1, 2 and 3 Barrier zone Wall 4 The strongest of all four walls

Wall 4 Tree can’t use sugars for new growth Sugars have difficulty moving across Trap starches and other energy inside tree Can feed organisms that get inside

Wall 4 Structurally brittle Ring crack may follow wall 4 around trunk Radial cracks can form along ray Cracks can become direct pathways into tree

Best Management Practices Avoid excessive pruning that weakens tree and opens wounds Removing large limb could cause more damage than reducing length Remove the least amount of live branches possible Reduces sugar production and storage capacity