Fig. 2: Time series of scaled NDVI-values of pine forest biotopes in the surroundings of the opencast mine of Nochten
which are shown in Fig. 2. The visual impression, accor-
ding to which the highest values of NDVI have been
found in 1990 and 1995 while 1992 standed for the lo-
west ones, could be proved by statistical analyses (Fig.
3). More comparing investigations between the reference
biotopes and those ones in the opencast mining impact
zones are carried out during the vegetation period of
1996.
With exception of the low values found in 1992, the mean
NDVI values from both, single pine forest types and total
area clearly indicated an increase of vitality for the time
period considered ( 1988-1995). The main reason for this
Mean values of NDVI for pine forest
biotopes
0,8
0,6
B 1988
0,4 B 1990
0.2 1992
01995
total type5 type6 type7 type 8
Fig. 3: Monitoring of vegetation for different pine forest bi-
otopes in the area of Nochten
was due to the meteorological situation. Owing to great
precipitation deficits during spring and summer 1992, it
explains also the lower NDVI values. Because of the
deindustrialization and reinforced protection measures
against pollution, extreme declines in dust and sulphur
dioxid emissions were observed (between 60% and 90%)
which also proved to be important for the vegetation
changes.
3 VEGETATION CHANGES ON SUCCESSION AREAS
Parallel to the preservation of nearly natural landscapes
with high biotope and species diversity like, for instance,
pine-moor forest and nado-callunetea in the surroun-
dings of opencast mines, it is of interest, to utilize the
specific site conditions which are characteristic to open
post mining areas for a natural development. For such
areas of renaturation which have been abandoned to
natural succession, 15% of the dump areas are planned
to get this status after closing of the mining activities.
Such processes of natural settlement have been obser-
ved both by high spatial resolution satellite data and by
field work on vegetation to serve as input for monitoring
systems.
The investigation area selected has been the former
opencast mine of Schlabendorf (see frame 1 in Fig. 1),
whose northern part was closed in 1977. 1640 hectares
out of 2490 hectares excavated area were given back to
agriculture. 717 hectares were reforested and 133 hecta-
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996
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