Nicola Arndt und Matthias Pohl - Neobiota

4 Do proposed sites cover the range & variation of the habitat?
A minimum requirement is that the sites proposed for a given habitat should cover both the geographical
range and the known biological and ecological variation. In theory it is easy to overlay a map of
sites over a map of the habitat distribution but often such distribution maps do not exist. Where EPNV
mapping units correspond to Annex I habitats it is possible to compare proposed sites with potential
distribution of habitat.
The EPNV mapping unit 'C19 Larch-Pine forests (Pinus cembra, Larix decidua) in the Alps, partly
with Picea abies, Pinus mugo or P. rotundata, with Alnus alnobetula, partly alternating with
Rhododendron scrub (Rhodendendron ferrugineum) or Juniperus communis ssp. alpina'
approximately corresponds to Annex I type '9420 Alpine Larix decidua and/or Pinus cembra forests'
(Forests of the sub-alpine and sometimes montane levels, dominated by Larix decidua or Pinus
cembra; the two species may form either pure or mixed stands, and may be associated with Picea
abies or Pinus uncinata) although '4060 Alpine & subalpine heaths' may also be included. Figure 3
shows the distribution of this vegetation type and proposed sites for a part of the Western Alps. Note
that some proposed sites do not correspond to the equivalent natural vegetation. This may be due to
stands being incorrectly identified but more likely reflects isolated stands too small to be mapped at
1 : 2,500,0000.
Figure 3: Distribution of the EPNV mapping unit 'C19 Larch-Pine forests' (yellow) and of sites proposed as
pSCI for the Annex I habitat '9420 Alpine Larix decidua and/or Pinus cembra forests' by France and Italy in
the western Alps (stars) by 2000.
In many cases, although there is no 'one to one' relationship, a group of mapping units corresponds to a
group of Annex I habitats. For example units P1.1 to P1.4 (12 units of West European & Mediterranean
dunes) correspond to Annex I types 2110 to 2270 (17 types) as shown in Table 1.
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