A unit of Lasting Forests evolving since March 30, 1999
A Total Forest Management Plan and Wildland Management Decision Support System
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The Forest Canopy

See stem density

Tree stems or the main boles and how they are spaced is a major problem for the forester. The width of the spacing determines the width of the tree crown and its intermixing with neighboring crowns in their competition for insolation. If the plantings are square, the crown diameter is, on average, the width of that planting. Planting in hexagonal configurations or observing natural spacing that tends over time toward hexagonality, the spacing issue become a little more complicated. Careful spacing allows foresters to take intermediate distance stems for profit, thus thinning the stand for the final stem growth.

Selecting the optimum spacing (thus canopy width) seems a straight-forward decision but history has shown a poor fit between studies and resulting stands and their products. Dean and Clark (1996) observed that " even though no better predictor of the next rotation exiats than the performance of the previous rotation, history data does not exist for every stand, and the combinations of species, density management, soils, and topography create a matrix too large to test with spacing studies. Furthermore, changes in cultural treatments, product specifications, and the physical environment diminish the predictive value of field trials. " They recommended concentration on " the dynamics of tree crown dimensions" and average spacing.

The ratio of the above-ground phytomass to the total phytomass of a forest is 0.64 (E.P.Odum,1971).

The forest canopy or forest crown typically has 4 gross classes:

• Dominant
• Codominant
• Intermediate
• Overtopped

Topics being investigated

Percent tree height - typically one-third of a tree height in canopy is required for full vigor

Intercept of precipitation

Phenology (seasonal development delated to insects as forage for birds and suitability for insecticide applications for controlling invasive or harmful insect species)

Canopy characteristics for squirrels and other mammals and bird species

Canopy characteristics for the arthropod encephalitis vectors

Canopy characteristics related to Fog drip

Canopy cover classes used elsewhere ( careful, they have diverse intervals)

Canopy Interval	Interval Within Each Class
1-5	5
6-25	20
26-50	25
51-75	25
76-95	20
96-100	5

References Dean, T.J. and B.V. Clark, Jr. 1996. Crown management and stand density p. 148-159a-e [159ii revised]in M.C. Carter, ed. Growing trees in a greener world: industrial forestry in the 21st century; 35th LSU forestry symposium, 1996, Baton Rouge, LA, Louisiana State Univ Ag Center

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This Web site is maintained by R. H. Giles, Jr.
Last revision January 17, 2000.