aimed at developing methods for replacing conventionally drawn maps by 
aerial photographs. Nevertheless, the old type of map has been retained, 
chiefly because in the course of a century of development it has attained 
a practical form and has become an integral part of the administrative 
apparatus. It is also worth noting that the personnel of the State forest 
administration is not permanently stationed in one and the same location 
as is the personnel of private forest administrations and consequently does 
not possess the same close knowledge of the forests he is dealing with. In 
such circumstances good maps of well known type are of particular value. 
For the same reason the Forest Service retains detailed descriptions of 
stand characteristics to supplement the maps. 
Aerial photos have been employed for many years, however, in the pro- 
duction of drawn maps and stand characteristics descriptions. Methods 
'ary greatly in the northern and the southern parts of the country. 
Northern Sweden. Three methods have been established here in the 
course of development of the last five years. 
Method a. Map and description are prepared along conventional lines, 
except that aerial photos are carried along in the field to facilitate field 
work. 
The preparation of maps drawn on conventional lines proceeds as fol- 
lows: 
Property boundary lines are used as base lines, sometimes with the 
addition of straight base lines within the block or with the addition of transit 
runs along roads etc. Details sketched in the field are stand boundaries, 
figures of improductive areas, trails and hatchings. This work is performed 
with the assistance of a crew of one compassman and two chainmen. Parallel 
survey lines are run at a distance of 100—200 m. At the same time stands 
are numbered and described. When it is a matter of revising an existing 
map, the first measure is to bring stand boundaries and descriptions up 
to date. The assistance of a crew is seldom needed, as all orientation for 
sketching can be based on well defined objects of the locality, such as trails, 
unchanged figures for swamps etc. 
When aerial photographs are used in this method it is mainly to 
speed up the work. A photo gives at a glance a good idea of stands and 
enables the stand boundaries to be properly defined on the map without 
extensive reconnaissance. Descriptions are made in shorter time and as 
regards information concerning average values like average density etc. 
— more accurately than formerly. An extra advantages is that the photo 
facilitates better orientation within and between stands, swamps ete. Often 
it is only when difficulties arise during mapping that the photos are taken 
into use. Sometimes the photos are used continuously throughout, parti- 
cularly when orientation is difficult. Photo prints for use in this method 
are inexpensive contact prints on the standard scale 1:20 000, or in more 
important cases enlargements on the same scale as the forest map 
(1: 10 000). In this connection it may be mentioned that stereovision takes 
up a considerable amount of time and is not used regularly for field work. 
The time occupied in field work has been reduced by approximately 10 
per cent by using photos on this method. At times the photos have been 
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