Stand height mapping
The necessary condition for calculating water retention area of leaf
surface of different types of tree stands is to estimate the phytomass
value during the period of its maximum growth. The phytomass value, in
its turn, is determined by stand age correlated with height and a
bonitet class of the trees.
The tree height was measured by falling shadows with the use of the
ratio:
,
where lm - the length of the shadow (mm);
k - scale factor equal to 1/10000 of scale denominator;
n – coefficient of relative shadow length (Danilin I.M., 2003; Sukhikh
V.I., 2005).
The length of the shadow for free-standing trees and forest rows was
determined on the basis of the aerial imagery plans kept in the archives
of the branch of The Federal Service for State Registration, Cadastre
and Cartography (Rosreestr) of the Sverdlovsk region. In order to obtain
the average stand height, 3-5 heights of ”typical” trees in the forest
areas of the studied region were measured. The results of measurements
are shown in the picture (Fig. 6).