Table 1. The NF1 and FBD estimates of some mean characteristics in an area of 52000 
hectares. 
Mean tree stem volume (m 3 /ha) 
NFI 
FBD 
- of pine 
47.4 
37.7 
- of spruce 
43.0 
56.8 
- of broad leave trees 
18.7 
13.7 
All tree species 
109.1 
108.2 
Development classes ( % ) 
- open area 
2.4 
3.2 
- seed tree or shelterwood stand 
1.0 
0.9 
- small seedling stand 
9.2 
10.3 
- advanced seedling stand 
17.6 
21.0 
- young thinning stand 
32.6 
24.4 
- advanced thinning stand 
25.0 
24.2 
- mature stand 
12.3 
13.1 
- seedling stand with seed trees 
- 
1.6 
- low yielding stand 
- 
1.9 
The estimates of the total mean tree stem volume are about the same with both 
methods. Some differences occur however in tree species proportions. The percentages 
of different development classes in both data are fairly close to each other except the 
groups ’advanced seedling stand’ and ’young thinning stand’. One reason, in addition to 
the possible confusion, may be that the definitional boundary between these groups is 
not same in different inventory systems. One should also remember that FBD-estimates 
are based on visual assesment.. 
However, this preliminary test shows that the satellite image-aided inventory method 
may work fairly well at the communal level. Differences in tree species proportions are 
rather high. The reasons must be traced in the future. The testing will continue with 
other variables and other data. If systematic errors occur, the applicability of new 
features and perhaps new classifiction techniques will be tested. The final conclusions 
can be derived after thoroughly-measured test data are available. 
6. THE ADVANTAGES OF THE METHOD 
The satellite image-aided NFI method is expected to make it possible to: 
1 ) estimate all the variables of the national forest survey lor each point of the country; 
I'he variables include the properties of site type, soil, growing stock, mortality, cuffing, 
and damages and diseases. If is anticipated that some improvement in estimates of 
all variables can be expected compared with the current situation. The estimates of 
variables concerning a single pixel may be unreliable. However, the communal level 
estimates, and in the case of some variables possibly also the forest holding and stand 
estimates, are expected to be applicable. 
2) keep the data up-to-date in the whole country; Clouds prevent obtaining imagery