Difference between revisions of "Growth Results"

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====CAI net====
 
====CAI net====
The current annual '''net''' volume growth is the same as the volume change from one time (after harvest) to the next (before harvest). Mortilty is not included. CAI net is calculated as:<br>
+
The current annual '''net''' volume growth is the same as the volume change from one time (before harvest) to the next (before harvest). Mortilty is not included. CAI net is calculated as:<br>
  
 
<math>G_{t+a} = \displaystyle \frac{V_{t+a}- V_a + H_t}{a} </math>
 
<math>G_{t+a} = \displaystyle \frac{V_{t+a}- V_a + H_t}{a} </math>

Revision as of 06:23, 19 November 2021

This result group contains: Volume growth results.

Gross vs. net growth

Gross growth includes mortality while net growth only includes survived trees.

MAI and CAI

Reported for all species and per species.

Variable name Unit Description
CAI ... m3sk/ha,yr Current annual increment (from the beginning or midpoint of the previous period)
MAI ... m3sk/ha,yr Mean annual increment since year 0 or from the time for final felling of the previous rotation. Reset after final felling.

How growth is calcualated

Growth.png

CAI net

The current annual net volume growth is the same as the volume change from one time (before harvest) to the next (before harvest). Mortilty is not included. CAI net is calculated as:

where
Gt+a = Annual volume net increment from time t to time t + a, and
Ht = Volume harvested at time t, and
a = number of years

CAI gross

The current annual gross volume growth includes mortality and is calculated as CAI net but with mortality added:

where
Gt+a = Annual volume net increment from time t to time t + a, and
Ht = Volume harvested at time t, and
Mt = Mortality volume from time t to t+a, and
a = number of years

This is the same as the volume change from one time (after harvest) to the next (before harvest), plus mortality.

MAI

MAI is calculated similarly to CAI but the first time is set to year 0 or, if a final felling has been simulated, the year for the last final felling. The harvest and mortality variables in the equations are replaced with sums over the harvesting and mortality that occurs between the time points. The result is the same as taking the average of CAI.