ateam - Potsdam Institute for Climate Impact Research

ATEAM final report Section 5 and 6 (2001-2004) 33
species richness. This scenario also produces the greatest variability across Europe while B1-HadCM3
appears to produce the lowest species loss and species turnover by pixel.
These projections were also averaged and mapped by biogeographical regions (using the
environmental classification proposed by Metzger et al. 2004). Assuming no dispersal, the regions most
at risk under A1-HadCM3 are Mediterranean mountains, the Lusitanian and Pannonian regions (mean
percentage of species loss = 55%), while the regions in which the lowest extinction by pixel is expected
are the Alpine north, Mediterranean south, boreal and Atlantic regions (Figure 25). The ranking of
regional sensitivities was consistent across scenarios.
The detailed examination of the projections for plants in 2050 under the full dispersal hypothesis
revealed that 93% of species were projected to have overlapping populations with current distributions,
while 2% had totally non-overlapping future distributions and 5% lost all available habitat (Araùjo et al.
2004). These changes meant that, over a range of reserve selection methods, 6% to 11% of species
modelled would be potentially lost from selected reserves in a 50-year period.
The modeling framework used here was developed to allow reserve area selection to optimize the
protection goal of nature conservation areas under restricted resources and changing climate. A flexible
management of nature reserve areas is necessary to maintain the conservation effect under changing
conditions.
Numerous papers have been produced which are listed in Annex 2, including a contribution to Nature.
6.2.2.6 Mountains
Principal investigators: Harald Bugmann and Bäbel Zierl
Mountains and their ecosystems provide many goods and services to European societies, including
freshwater supply, carbon storage, protection from natural hazards, and tourism related services such
as maintaining a reliable snow cover for skiing. Some of these services have been dealt with in previous
sections (carbon storage, water), this section provides an additional Alpine focus, based on a special
approach that is suited for mountainous systems. The continued capacity of mountain regions to provide
ecosystem services is threatened by the impact of environmental change. Therefore, the objective of
our contribution to ATEAM was to perform high-resolution case studies in mountain catchments in order
to assess the vulnerability of sectors that rely on mountain ecosystem services to global change.
We used five catchments representing different major climatic zones in the Alpine area: the Alptal, the
Hirschbichl, the Dischma, the Saltina and the Verzasca catchment (Table 9). Plans to extend the
approach to other mountain ranges of Europe had to be abandoned because of time constraints and
limited data availability.
Table 9. Description of case study catchments from various climate zones in the alpine region. The category ‘rest’ in the
column ‘land cover’ includes predominantly rocks, but also sealed areas such as cities, streets, or parking places.
case study
region area precipi- altitude land cover (%)
catchment
tation
(km 2 ) (mm) (m) Forest Grass Rest
Alptal (CH) western prealpine 46.75 2110 1150 (850 – 1860) 52 42 6
Hirschbichl (D) eastern prealpine 44.61 1640 1460 (680 – 2560) 49 36 15
Dischma (CH) high alpine 43.16 1310 2370 (1680 – 3110) 10 54 36
Saltina (CH) inner dry alpine 77.02 1340 2010 (680 – 3400) 35 34 31
Verzasca-
Lavertezzo (CH)
southern prealpine 44.13 2320 1680 (540 – 2500) 64 19 17
The simulation system RHESSys (http://typhoon.sdsu.edu/Research/Projects/RHESSYS, Tague and
Band, 2004, Band et al., 1993) was used for simulating the fluxes of water, carbon and nitrogen through
mountain catchments. First, the model was adapted to alpine conditions, particularly regarding
maintenance respiration, phenology, snow accumulation and melting; second, it was validated against