Difference between revisions of "Dictionary"
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| − | ==Mean | + | ==Mean diameters== |
| − | ====Dgv==== | + | ====Dgv - Basal area weighted mean diameter==== |
Basal area weighted mean diameter (cm):<br><br> | Basal area weighted mean diameter (cm):<br><br> | ||
<math>dgv = \frac{\sum_{i=1}^n{w_i d_i^3}}{\sum_{i=1}^n{w_i d_i^2}}</math> | <math>dgv = \frac{\sum_{i=1}^n{w_i d_i^3}}{\sum_{i=1}^n{w_i d_i^2}}</math> | ||
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<br><math>d_i</math> = diameter at breast height for tree object ''i'', and | <br><math>d_i</math> = diameter at breast height for tree object ''i'', and | ||
<br><math>w_i</math> = tree expansion factor for the number of trees that tree object ''i'' represents. | <br><math>w_i</math> = 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.<br> | ||
| + | <br> | ||
| + | Mean square diameter: | ||
| + | <!--<math>\bar{g} = \frac{\sum_{i=1}^n{w_i d_i^2}}{\sum_{i=1}^n{w_i}}</math>--> | ||
| + | <math>\bar{g} = \frac{G}{N}</math> | ||
| + | <br> | ||
| + | <math>dg = \bar{g} = \frac{G}{N}</math> | ||
| + | |||
| + | |||
| + | <br><br> | ||
| + | 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>d_i</math> = diameter at breast height for tree object ''i'', and | ||
| + | <br><math>w_i</math> = tree expansion factor for the number of trees that tree object ''i'' represents per ha. | ||
| + | |||
| + | --> | ||
Revision as of 12:44, 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.
where
= Sum of basal areas of trees (m2/ha) (
)
= diameter at breast height for tree object i, and
= tree expansion factor for the number of trees that tree object i represents per ha.
-->