Difference between revisions of "Dictionary"
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<br> | <br> | ||
Calculated as: | Calculated as: | ||
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<br> | <br> | ||
<math>dg = 100 \cdot \sqrt{\frac{4 G}{\pi N}}</math> | <math>dg = 100 \cdot \sqrt{\frac{4 G}{\pi N}}</math> | ||
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where | where | ||
<br><math>G</math> = Sum of basal areas of trees (m<sup>2</sup>/ha) (<math>G = \sum_{i=1}^n{w_i g_i^2}}</math>) | <br><math>G</math> = Sum of basal areas of trees (m<sup>2</sup>/ha) (<math>G = \sum_{i=1}^n{w_i g_i^2}}</math>) | ||
| − | <br><math>N</math> = Number of trees per hectar | + | <br><math>N</math> = Number of trees per hectar. |
| − | The multiplication with 100 is done to convert from m to cm. | + | <br>The multiplication with 100 is done to convert from m to cm. |
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Revision as of 13:36, 10 February 2016
Common terms and concepts used in Swedish forestry:
Volume definitions
m3sk
Tree stem volume above the felling cut. Includes bark and top of the tree, but not branches.
m3fub
Volume of log(s) excluding bark.
m3fpb
Volume of log(s) including bark.
m3to
Volume of log(s) as given by a cylinder, with diameter = top diameter of the log under bark.
Mean diameters
Dgv - Basal area weighted mean diameter
Basal area weighted mean diameter (cm):
where
= number of tree objects, and
= diameter at breast height for tree object i, and
= tree expansion factor for the number of trees that tree object i represents.
Dg - Quadratic mean diameter
The diameter that corresponds to the mean basal area of the trees (cm).
Calculated as:
where
= Sum of basal areas of trees (m2/ha) (
)
= Number of trees per hectar.
The multiplication with 100 is done to convert from m to cm.