Heaths “Marma Heath”

Analysis of change 1951, 1995 and 2001 within ”Marma Heath” and Marma Military Exercise Field on mission by The Foundation of Uppland.

Overgrowth and conservation issues for one of the most important butterfly localities in middle Sweden was the purpose of the mapping.

Parts of the area are under investigation as possible Natura 2000 object.

The heath at Marma Military Exercise Field was about 157 hectares in 1951 and about 22 ha (14 %) of that was sandy areas and about 135 ha (86 %) brush land. The mapping from the infra red photos from 1995 showed that about 65 ha mainly open heath land remained in 1995 (about 41 % compared to 1951). In this area about 42 ha were without visible overgrowth (bushes higher than 1.5 m) at all, that is 26 % since 1951 and 64 % of total 1995. The remaining 23 ha were in different degrees overgrown. The remaining parts of the heath in 1951 (56 %) had mainly been fully closed (or over closed) pine forest. The overgrowth of the heath was controlled in spring 2001. Most of the areas classified as “without visible overgrowth” were controlled (about 1 ha was not controlled). In fact only 2 ha (1.4 % since 1951 and 3.3 % of the area in 1995) were without overgrowth. About 23 ha of the heath (15 % since 1951 and 35 % of the area in 1995) were overgrown with coniferous bushes shorter than 1.5 m in different levels of closure. Heaths with coniferous overgrowth shorter than 1.5 m in 2001 covered 25 ha (16 % since 1951 and 39 % of the area in 1995) thus comparable to the aerial photo interpretations. If no measures for clearance are taken probably only 10 ha of the heath would remain in 20 years, the areas still open (2.1 ha) and the areas that has less than 10 bushes per 100 ha (7 ha).

The Foundation of Uppland has made analysis of change in the areas of open sand type and open brush land from the vegetation maps 1951 and 1995.

Vegetation map of Marma Military Exercise Field based on CIR-photos from 1995, clear cut updates from satellite photos from 2001 and the field 2003.

Vegetation map of the central heath area 1951 based on black and whites from 1951 and 1945.

The heath and pasture lands to the east were mainly free from trees. More to the west there were meadows and a high degree of old forests.

Preliminary base and method study for conservation estimation based on aerial photo analysis. The estimation summarizes stereotyped ecological values based on the vegetation types; ground vegetation according to the Swedish Forest Board, overgrowth trends, forest age, vicinity to deep ditches and presence of big trees automatically calculated in ArcInfo. Blue indicates high values and red low values.
     
 

 
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