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The third wall is formed by ray cells, which are groups of radiating cells oriented perpendicularly to the stem axis, dividing the stem into segments not entirely unlike the slices of a pie. These groups of cells are not continuous and vary in length, height and thickness, forming a
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are frequently called upon to analyze the danger posed to people or property by a damaged or decaying tree. By knowing how decay is likely to spread, such hazard tree analyses may be more accurate, thereby preventing unnecessary
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interior and exterior to the wound, thus slowing the radial spread of decay. This wall is the second weakest, and is continuous except where intersected by ray cells (see next section).
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Shigo expanded this theory to claim that when trees are wounded, they respond to the infected wood with both chemical and physical changes to limit the decay, which he called
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undergo changes to form "walls" around the wound, slowing or preventing the spread of disease and decay to the rest of the tree.
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Shigo, A.L. (1984). "Compartmentalization: A Conceptual
Framework for Understanding How Trees Grow and Defend Themselves".
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shows that a wound's proximity to leaf mass greatly influences compartmentalization as well as wound closure.
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By increasing understanding of how trees respond to decay, CODIT has had many applications. For example,
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in the early 20th century theorized the opposite was the case, and developed a new model for
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The second wall is formed by the thick-walled, lignin-rich cells of the latewood
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Except for the introduction, most of this article is based on information from
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above and below the wound. This tissue runs up and down the length of the
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Example of compartmentalization, with radial and circular walling, in an
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The first wall is formed by plugging up normally conductive
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Plant defense mechanism against wood-decay pathogens
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140:) is a model developed by plant pathologist
202:According to CODIT, when a tree is wounded
277:Work done by Dr. Edward F. Gilman at the
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58:"Compartmentalization of decay in trees"
134:Compartmentalization Of Decay In Trees
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47:adding citations to reliable sources
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