Global Change Abstracts The Swiss Contribution - SCNAT
Global Change Abstracts The Swiss Contribution - SCNAT
Global Change Abstracts The Swiss Contribution - SCNAT
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<strong>Global</strong> <strong>Change</strong> <strong>Abstracts</strong> – <strong>The</strong> <strong>Swiss</strong> <strong>Contribution</strong> | Terrestrial Ecosystems 105<br />
was low (max. 3 species). About 24% of the species<br />
were not contained in any of the hotspots. <strong>The</strong>se<br />
grasshopper species require species-specific action<br />
plans. As rarity hotspots were located in areas that<br />
are rather strongly affected by landscape change,<br />
species richness in rarity hotspots may decrease<br />
in the future. We conclude that, for grasshoppers,<br />
the hotspot approach on the 1 ha scale can be an<br />
effective way to conserve a high proportion of species<br />
richness.<br />
Biodiversity and Conservation, 2007, V16, N7, JUN,<br />
pp 2075-2086.<br />
08.1-177<br />
Floral free fall in the <strong>Swiss</strong> lowlands: environmental<br />
determinants of local plant extinction<br />
in a peri-urban landscape<br />
Stehlik I, Caspersen J P, Wirth L, Holderegger R<br />
Switzerland, Canada<br />
Plant Sciences , Urban Studies , Biodiversity , Ecology<br />
, Agriculture, Soil Sciences<br />
1. Local floras are being depleted by a host of human<br />
activities, including habitat destruction and<br />
fragmentation, eutrophication, and the intensification<br />
of agriculture. Species with particular ecological<br />
demands or life-history attributes are more<br />
prone to extinction than species with a broader<br />
niche. 2. We used an old herbarium from the municipality<br />
of Kusnacht (<strong>Swiss</strong> lowlands) as a historical<br />
record for comparison with contemporary<br />
plant diversity. This comparison revealed that 17%<br />
to 28% of all vascular plants that occurred between<br />
1839 and 1915 were extinct by 2003. 3. Species of<br />
different habitats and life-forms had significantly<br />
different rates of extinction: wetlands, disturbed<br />
sites and meadows lost most species, whereas forests<br />
and rocky habitats were least affected; aquatics<br />
and annuals were most prone to extinction,<br />
geophytes and hemicryptophytes were intermediate,<br />
and phanerophytes and chamaephytes were<br />
least affected. 4. Species adapted to nutrient-poor<br />
soils suffered highest extinction in all habitats,<br />
indicating that eutrophication poses an urgent<br />
threat to species diversity. Light and soil moisture<br />
requirements also had significant effects on extinction,<br />
but the direction of the effect varied by<br />
habitat. 5. When species were grouped into IUCN<br />
categories of the red list of Switzerland, the rank<br />
order of the observed extinction matched the red<br />
list assignment. 6. Because many of the remaining<br />
species had high estimated extinction probabilities<br />
and because extinction is often delayed<br />
(extinction debt), a substantial part of the remaining<br />
flora of Kusnacht is likely to go extinct in the<br />
near future. This will increase the dominance of<br />
the common species that already comprise 81% of<br />
the local flora. 7. <strong>The</strong> rates and patterns of extinction<br />
in Kusnacht are probably representative of<br />
surrounding <strong>Swiss</strong> lowlands and peri-urban landscapes<br />
in most developed countries. Studies such<br />
as ours can serve as a call for action and form a<br />
basis for future monitoring of biodiversity.<br />
Journal of Ecology, 2007, V95, N4, JUL, pp<br />
734-744.<br />
08.1-178<br />
Cooccurring Gentiana verna and Gentiana<br />
acaulis and their neighboring plants in two<br />
swiss upper montane meadows harbor distinct<br />
arbuscular mycorrhizal fungal communities<br />
Sykorova Z, Wiemken A, Redecker D<br />
Switzerland<br />
Plant Sciences , Biodiversity , Ecology<br />
<strong>The</strong> community composition of arbuscular mycorrhizal<br />
fungi (AMF) was analyzed in roots of Gentiana<br />
verna, Gentiana acaulis, and accompanying<br />
plant species from two species-rich <strong>Swiss</strong> alpine<br />
meadows located in the same area. <strong>The</strong> aim of the<br />
study was to elucidate the impact of host preference<br />
or host specificity on the AMF community in<br />
the roots. <strong>The</strong> roots were analyzed by nested PCR,<br />
restriction fragment length polymorphism screening,<br />
and sequencing of ribosomal DNA small-subunit<br />
and internal transcribed spacer regions. <strong>The</strong><br />
AMF sequences were analyzed phylogenetically<br />
and used to define monophyletic sequence types.<br />
<strong>The</strong> AMF community composition was strongly<br />
influenced by the host plant species, but compositions<br />
did not significantly differ between the two<br />
sites. Detailed analyses of the two cooccurring<br />
gentian species G. verna and G. acaulis, as well as<br />
of neighboring Trifolium spp., revealed that their<br />
AMF communities differed significantly. All three<br />
host plant taxa harbored AMF communities comprising<br />
multiple phylotypes from different fungal<br />
lineages. A frequent fungal phylotype from Glomus<br />
group B was almost exclusively found in Trifolium<br />
spp., suggesting some degree of host preference<br />
for this fungus in this habitat. In conclusion, the<br />
results indicate that within a relatively small area<br />
with similar soil and climatic conditions, the host<br />
plant species can have a major influence on the<br />
AMF communities within the roots. No evidence<br />
was found for a narrowing of the mycosymbiont<br />
spectrum in the two green gentians, in contrast<br />
to previous findings with their achlorophyllous<br />
relatives.<br />
Applied and Environmental Microbiology, 2007,<br />
V73, N17, SEP, pp 5426-5434.