Nicola Arndt und Matthias Pohl - Neobiota

only 73 km 2 . In a general way the ecological regions along the north-south and continental-Atlantic
gradients are well depicted.
DMEER at a 0,8 Euclidean distance has 79 classes (Figure 7). In this map 17 major classes represent
80 % of the total area. The mean polygon area of the smallest cluster falls to 42 km 2 .
On the other hand, only in the Balkans there are 37 classes, having a mean area of 31,000 km 2 , in
contrast to the 877,500 km 2 of the largest DMEER class in this map.
At 0,7 Euclidean distance the number of classes increases to 106 ecological regions. The main 26
classes cover 80 % of the DMEER map area. Major disaggregations are in Central Europe – Germany
and Poland, while the Highlands in Great Britain become a different class altogether (Figure 8). The
Balkans retain 47 classes, with an average area of 19,000 km 2 , 30 % less than the average area they
had on previous aggregation level.
Figure 6 (Left): The main 11 classes of DMEER 46 classes covering 80 % of the total area.
Figure 7 (Right): The largest cluster of DMEER 46 depicted in DMEER 79 (split at about 60º latitude).
DMEER with 133 ecological regions is the result of the dendrogram at 0,6 Euclidean distance
(Figure 9). The 29 main classes take up 80 % of the map area. The new classes are mainly formed by
river courses, small areas near coastlines, and other small island polygon clusters. The Balkans keep
64 of those classes, and in the Iberian Peninsula the main classes describe the south Mediterranean, the
west Atlantic, the continental areas of the east, and some mountain areas. It is also possible to
distinguish some of the largest river courses.
Only when disaggregation reaches 156 DMEER classes is the main ecological region in France split to
form another important one in the northwest of the country (Figure 10). This is virtually the only large
scale change that happens in the map at 0,5 Euclidean distance on the dendrogram.
The last map, presenting the entire dendrogram, has 189 DMEER classes, but no large-scale change
compared with the 156 DMEER classes. It takes 43 clusters to represent 80 % of the DMEER area, the
mean polygon area of the last 40 clusters is smaller than 100 km 2 . The clusters tend to be composed of
several small polygons instead of forming larger continuous homogenous ecological regions
(Figure 11).
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