A. Quaglino : Index of Environmental Quality for Land Management
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20%
Layer
5
20%
Layer
4
20 %
Layer
3
20 %
Layer
2
20%
Layer
1
Figure 1. Layer thickness.
2.3 Third step: analysis of height distribution
The sample tree height variability was calculated by using the folJowing equation:
where:
Hr = reference height,
n = number of samples,
Hi = tree height,
Sh r = reference height mean spread.
(3.1)
The Shr value was weighed with reference to the height and expressed in
percentage as folJows :
(3 .2)
One then had to evaluate whether the parameter SHr% as determined in (3.2) was
able to describe, with sufficient precision, the distribution of tree heights in the
different layers.