Deciduous forest types (greenish colours), old forest – over 140 years (dotted) close to Lake Hjälmaren . This cut shows 10 out of 6,533 km sq mapped in Västmanland..
Vegetation maps are over 30% of Sweden’s surface. The start-up of the Swedish mountain chain was carried out by Department of Physical Geography of Stockholm. Land Survey has worked with vegetation mapping since the 1980s. They now cover Norrbotten, Jämtland, the steppe of Öland, Västmanland and Värmland (completed in 2004).State-mapping has been carried out by LMV (click LMV and then select “Vegetation Data”). LMV mapping has typically been 70% state and 30% funded by the stakeholders. They are supplied nowadays especially as digital map databases.
NaturGIS AB has made vegetation maps on e.g. Orsa savings forest, Färnebofjärden, the Koster area, Florarna, Marma Military Exercise Field and the Båtfors area.
Some information about the usefulness of a vegetation data base can be found at the following Metria-link.
An analysis from the vegetation map about the distribution of herb rich coniferous and sandy coniferous forests can be seen here, it was made for the Swedish Forest Board.
The vegetation maps are based on the interpretability of infra red photos (CIR-photos).
To study the continuity, old photos have been used in the mapping as well as other reference material. Some vegetation types are difficult to interpret. The interpretability is partly dependent on when the photo was made. For example, herb rich coniferous forests and hardwood forests need controls in the field. The classification system is nowadays standardized.
The aim of the mapping is to create an over all covering data base, adjusted to support landscape analysis and physical planning of different kinds. The most important areas are forestry, conservation, terrain accessibility, nature resource monitoring and over viewing physical planning.
There is a more or less strong correlation between different organism groups and vegetation types/forest ages in the vegetation map. These kinds of correlations can also occur when different vegetation types exist close to each other. A very accurate image of vegetation types can be made classified into e.g. hardwood forest, forest on previous cultural or grazing land, humid or wet deciduous forests and swamp forests. These can be further classified depending on coniferous presence. These can also be divided into age classes. Rich coniferous forests are mapped all over the county. The bogs and heath lands are also very carefully mapped.
The map data base of Västmanland contains almost 200,000 described areas (polygons).
The forest age is mapped in all Västmanland. Examples of classes are clear cuts, young forests, forests over 80 years, forests with varying age with at least 30 % over 110 years, forests with varying age with at least 30 % over 130 years. Moreover groups (more than three) of large deciduous trees have been mapped, as well as large hardwood trees and large coniferous trees. Thus, there are great possibilities to find possible forests with ecological values.
The classification system is further described here.