8 
for water courses, roads and other more sharp details, but about += 1,3 
mm on map for other more unsharp details. Supposing however the 
standard deviation of the map A to be the same as for the other three 
maps, then the standard deviation of the map A vould be about == 0.5 
mm on map (0.7: \ 2) for lakes, watercourses, roads and other more 
sharp details, but about + 0.9 mm on map (1.3: V2) for other more 
unsharp details. 
Comparing the maps A, B, C and D, it is obvious, that the map D has 
the greatest fullnes of detail, practically the same as the map A, and the 
map B the least one. However the difference between D and C is rather 
little. When using B and C the length of section lines is about 10—20 47 
shorter in comparison to A and D. 
The loss of accuracy when using the map B instead of A, C and D 
is quite little, about 6 %, for more unsharp details, but rather great, 
about 35 %, for more sharp details. 1t is obvious that many details of 
forested land are quite unsharp and so the question of accuracy is not 
a great one for those details. At reallotment work however it is neces- 
sary to determine geometric positions of boundaries, buildings and 
other very sharp defined details but also of unsharp details. For the 
sake of cost the same photographs ought to be used for all purposes but 
not necessary the same type of plotters or the same methods. 
The Swedish Land Survey has compiled many maps for reallotment 
of forested land. Our experience is that photogrammetry can be used 
advantageously for this purpose. The investigation now performed is 
quite a little one, so it seems hardly possible to state what scale of ne- 
gative is the best one. However a general experience is that our maps, 
compiled in the field, are quite detailed. In such a case the negative scale 
of 1:8 000 for mapping out purpose would be too large. On the other 
hand it is desirable to choose such a negative scale that distinct and 
sharp details can be determined with an accuracy necessary for staking 
out boundaries and fixing their positions for the future. That is ano 
ther question partly treated in the article, mentioned in 1.1. 
3. Forest site classification 
3.1. Introduction. It is possible to recognize and measure some tree 
and stand elements in aerial photographs and estimate topography and 
some soil conditions when studying them under mirror stereoscope. 
The question now is, if there is a dependence between those elements 
and conditions on one side and forest site quality on the other side. It 
will be expressed mathematically as a function of those elements; first 
as a function of elements, measured in the field, and second as a func- 
tion of elements measured in the photographs. 
Among othres site quality depends on soil nutriment, soil moisture 
and the hot condition of stand locality. Each of those three conditions