Environmental Engineering Reference
In-Depth Information
Recent studies have suggested that changes in temperature and precipitation
would lead to a shift towards vegetation types currently found under drier and
warmer conditions in Mediterranean mountains (Gritti
et al.,
2005). Transformation
of vegetation belts, for example, has been reported in the Spanish Central Range
(Sanz-Elorza
et al.,
2003), where high-mountain grassland communities dominated
by
Festuca aragonensis
, typical of the cryo-Mediterranean belt, are being replaced
by shrub patches of
Juniperus communis
ssp.
alpina
and
Cytisus oromediterraneus
from lower altitudes. Upward movements of species across the elevational gradi-
ent have also been reported in other Mediterranean mountain regions, such as the
Montseny range in northeast Spain (Penuelas
et al.,
2007), although the reorgani-
zation of species' geographical ranges is likely the effect of different factors in-
cluding climate change but also human management. Altitudinal changes in the
distributions of butterfly species have also been reported in the Sierra de Guadar-
rama, central Spain (Wilson
et al.,
2005), and, in the specific case of the
Parnassius
apollo
butterfly, elevational changes in phenology influenced the temperatures expe-
rienced by larvae, and could also affect local host-plant favourability (Ashton
et al.,
2009), thereby increasing the risk of this butterfly suffering population declines and
local extinctions.
In the Apennines, bird species' distributions have changed in the last 20 years
(Florenzano, 2004), and both diversity and composition of plant species have suf-
fered significant transformations (Stanisci
et al.,
2005). Climate warming may also
imply drastic changes in the ranges of species, potentially leading to species inhabit-
ing the upper belts to go extinct. Mountain conifer species such as
Pinus sylvestris
,
P. uncinata
and
Abies alba
, and other temperate species, especially
Fagus sylvat-
ica
and
Quercus petraea
, were predicted to suffer a reduction in their range in
the Iberian Peninsula (Benito-Garzon
et al.,
2008). Specifically for the mountain
conifer species, models predict reductions of 90% in the area of suitable climatic
conditions under the most pessimistic scenarios for 2080. A recent study modelling
distributions of European plants in relation to climate (Thuiller
et al.,
2005) re-
ported that mountain species, mainly those located near the Mediterranean Basin,
were disproportionately sensitive to climate change (approximately 60% of species
potentially lost by 2085), although these results should be interpreted cautiously
due to the coarse resolution used. Similar results could be found for non-European
Mediterranean mountains.
Cedrus atlantica
seems to be quite sensitive to climatic
change, and modifications in the cedar's potential and real area of distribution will
be considerable for 2100: models predict that
Cedrus atlantica
will find little refuge
in the Atlas (Demarteau
et al.,
2007).
Climate change is also affecting plant productivity. For example, growth of
beech trees in the Apennines (Piovesan
et al.,
2008) has declined in recent
decades, in correspondence with increased drought. The patterns uncovered in that
study suggest that long-term drought stress has reduced the productivity of beech
forests in the central Apennines, in agreement with similar trends identified in other
Mediterranean mountains. There are also changes in species phenology in relation
to climate change, with changing dates in almost all the studied phenophases in
