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growth_calculation_projection [2012/04/05 19:04] ddrummond created |
growth_calculation_projection [2013/11/04 14:21] (current) ddrummond |
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| ====== Growth Calculation & Projection ====== | ====== Growth Calculation & Projection ====== | ||
| + | Use the following method to determine the growth percent using basal area. | ||
| + | This method can also be used to project basal area, diameters, and volume. | ||
| + | |||
| + | Procedure: Use a prism, bark gauge and a diameter tape to obtain growth | ||
| + | information from a representative sample of trees (preferably all the | ||
| + | trees within prism range at pre-selected points; for examle, every fifth point). | ||
| + | |||
| + | The following information is obtained from each tree: | ||
| + | | ||
| + | a. Radial bark thickness | ||
| + | b. Diameter at breast height (D.B.H. outside bark) | ||
| + | c. Radial growth during the last 5 years (have the data or estimate it) | ||
| + | | ||
| + | D.I.B. (D. Without bark) = D.O.B (D. With bark) - 2 X radial bark thickness.\\ | ||
| + | |||
| + | d.i.b. = D.I.B. - 2 X radial growth during last 5 years\\ | ||
| + | |||
| + | The term: Σ(d.i.b./D.I.B.)<sup>2</sup> is the ratio of basal area 5 years ago to the present basal area.\\ | ||
| + | |||
| + | Example: | ||
| + | ^Tree No. ^D.O.B ^D.I.B ^d.i.b. ^d.i.b./D.I.B. ^(d.i.b./D.I.B.)<sup>2</sup> | | ||
| + | |1 |8.4 |7.6 |5.8 |.763 |.582 | | ||
| + | |2 |6.7 |6.0 |4.0 |.667 |.445 | | ||
| + | |3 |10.2 |9.3 |7.8 |.839 |.704 | | ||
| + | |4 |12.0 |11.0 |9.6 |.873 |.762 | | ||
| + | |5 |9.6 |8.7 |6.8 |.782 |.612 | | ||
| + | ^ Total^^^^^3.105 | | ||
| + | |||
| + | % growth = 1 - (Σ(d.i.b./D.I.B.)<sup>2</sup> /total trees in sample)\\ | ||
| + | % = 1 - (3.105/5) = 1-.621 = .379\\ | ||
| + | % = .379 or 37.9% (for 5 years)\\ | ||
| + | % annual growth = 37.9/5years = 7.58%\\ | ||
| + | |||
| + | ^Present ^Projected to next 5 Years | | ||
| + | |(Basal Area) |(Basal Area Increase) | | ||
| + | |(Volume) X 37.9% = |(Volume Increase) | | ||
| + | |(Average Diameter) |(Average Diameter Increase) | | ||
| + | |||
| + | Example: Estimated volume at end of 5 years: | ||
| + | <file> | ||
| + | Present volume/acre = 1450 board feet | ||
| + | % growth in 5 years = 37.9% | ||
| + | Increase in volume in 5 years = 550 board feet | ||
| + | Present volume/acre +1450 board feet | ||
| + | Volume/acre at end of 5 years =2000 board feet | ||
| + | </file> | ||
| + | | ||
| + | |||
growth_calculation_projection.1333652675.txt.gz · Last modified: 2012/04/05 19:04 by ddrummond
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