Europes ecological backbone.pdf

Biodiversity
For each habitat type, further information is
provided on ecological characteristics; values,
roles and land uses; and influencing political
and socioeconomic factors. Similarly, various
requirements are listed for individual priority
species. With regard to conservation status, for the
boreal montane and moorland habitats, statements
relate only to the broader habitats, so it is generally
not possible to be more specific about the status
of, and threats to, these species specifically in
mountain areas. For the other two habitat types,
priority birds, all with unfavourable conservation
status, are listed, together with threats. There
are 46 priority species in montane forests, with
an increase in the species richness of breeding
priority birds from west to east, with the highest
numbers in Romania, Slovakia and Slovenia;
and also in France. Over a 20-year timeframe,
widespread threats to these forests (affecting at
least 10 % of the total habitat type) were judged
to be inappropriate forest management and
overgrazing; regional threats (1–10 % of the total
habitat type) were logging, habitat fragmentation,
air pollution and severe or frequent fires. In
montane grassland, there are 33 priority species,
of which a third are dependent on this habitat type
in Europe. Comparably, widespread threats were
high stocking levels, recreation, and atmospheric
nutrient pollution; regional threats were land
abandonment and reductions in livestock carcasses.
There has been further research on a number of
these threats, such as the impact of ski areas on
high-altitude bird communities (Rolando et al.,
2007; Lowen, 2009); as well as the more recent
threat posed by wind farms (for example, Bright
et al., 2008). In 2004, BirdLife International (2004a)
identified 13 montane grassland species that had
an unfavourable conservation status and therefore
qualified as Species of European Conservation
Concern. Of these, populations of three were
declining, populations of seven were stable, and
the status for three was unknown.
A habitat-based approach was also taken by Heath
et al. (2000) in their comprehensive evaluation
of all IBAs in Europe. One of the levels of
analysis considered sites with biome-restricted
species, i.e. sites 'known or thought to hold a
significant assemblage of species whose breeding
distributions are largely or wholly restricted to
one biome' (Heath et al., 2000, p. 11). There are five
of these, including the 'Eurasian high-montane
(alpine) biome', with 10 species restricted to this
biome, which includes 14 IBAs in Switzerland,
12 in Italy, five in both Greece and Spain, two in
the former Yugoslavia, and one in each of Bulgaria,
France, Germany, Poland, Slovakia, Slovenia, and
Turkey. Most of the analysis within this volume
is for habitat types, but only one of these is
unequivocally mountainous: alpine/sub-alpine/
boreal grassland, which is present in 7 % (263)
of the 3 619 IBAs at the time. More recent work
(Huntley et al., 2007) recognises biogeographical
elements in Europe's avifauna, grouping species
according to the overall similarity of their recorded
breeding distributions recorded in 50 x 50 km grid
squares. However, none of the 19 elements can
unequivocally be compared to mountain areas;
and Huntley et al. (2007) note that one of the two
groups whose geographical distribution could
not be modelled using this approach comprised
species whose distributions were restricted to
areas of very high relief, given the relatively
coarse resolution of both distribution data and
climatic data (cf. Section 5.2). In summary,
while information is available regarding the
distribution of, and threat to, priority bird species
and the habitats of IBAs, and of the distribution
of bird species in general (for example, BirdLife
International, 2004a), further work needs to be
done to evaluate both distributions and threats
specifically in Europe's mountain areas.
8.3 Impacts of climate change
Mountain species and habitats are subject to many
stresses and vulnerabilities due to anthropogenic
factors, including land-use practices and changes,
freshwater abstraction, tourism and recreation,
infrastructure development, the introduction
and expansion of alien species (Box 8.2), and air
and water pollution (Huber et al., 2005; Nagy
and Grabherr, 2009; Price, 2008). Increased
concentrations of atmospheric CO 2
, the primary
cause of climate change, may eventually have
significant impacts on alpine plant biodiversity
because of species' differential responses (Körner,
2005). The likely changes in the climate of Europe's
mountains, outlined in Chapter 5, will influence
their biota both directly and indirectly, for instance
through changes in the availability of water,
as discussed in Chapter 6. For vegetation, the
two main climatic drivers are temperature and
precipitation. More emphasis is usually placed on
temperature because, as discussed in Chapter 5,
there is more consistency in prediction. Various
model-based studies of changes in vegetation have
been undertaken, often with temperature as the
sole driving factor (Nagy and Grabherr, 2009).
However, precipitation is also an important factor,
and observed changes in precipitation in the Alps
have already been associated with changes in
vegetation (Cannone et al., 2007).
152 Europe's ecological backbone: recognising the true value of our mountains