Current issue: 58(4)
The Second World War revealed some weaknesses that affect also peacetime planning of military defence in Finland. One of the shortages were lack of maps applicable in military purposes in Northern Finland.
The state forests are mainly situated in the north. Consequently, cartographic material of Finnish Forest Service may be modified with little extra work for military purposes. Best suited for the purpose are forestry maps of different forest districts that have scales ranging from 1:20,000 to 1:100,000. In addition, general maps in the scale of 1:100,000 or 1:200,000 are available. The article discusses further the additions that can be made in the maps.
The PDF includes a summary in German.
The presence/absence data of 27 forest insect taxa (Retinia resinella, Formica spp., Pissodes spp., several scolytids) and recorded environmental variation were used to investigate the applicability of modelling insect occurrence based on satellite imagery. The sampling was based on 1,800 sample plots (25 m by 25 m) placed along the sides of 30 equilateral triangles (side 1 km) in a fragmented forest area (approximately 100 km2) in Evo, Southern Finland. The triangles were overlaid on land use maps interpreted from satellite images (Landsat TM 30 m multispectral scanner imagery 1991) and digitized geological maps. Insect occurrence was explained using either environmental variables measured in the field or those interpreted from the land use and geological maps. The fit of logistic regression models carried between species, possibly because some species may be associated with characteristics of single trees while other species with stand characteristics. The occurrence of certain insect species at least, especially those associated with Scots pine, could be relatively accurately assessed indirectly on the basis of satellite imagery and geological maps. Models based on both remotely sensed and geological data better predicted the distribution of forest insects except in the case of Xylechinus pilosus, Dryocetes sp. and Trypodendron lineatum, where the differences were relatively small in favour of the models based on field measurements. The number of species was related to habitat compartment size and distance from the habitat edge calculated from the land use maps, but logistic regressions suggested that other environmental variables in general masked the effect of these variables in species occurrence at the present scale.