Global Change Abstracts The Swiss Contribution - SCNAT

Global Change Abstracts – The Swiss Contribution | Terrestrial Ecosystems 95
08.1-153
Are the living collections of the world’s
botanical gardens following species-richness
patterns observed in natural ecosystems?
Pautasso M, Parmentier I
England, Switzerland, Belgium
Biodiversity , Plant Sciences , Ecology , Urban
Studies
Botanical gardens aim to promote the awareness,
study and conservation of plant species diversity,
but little is known about the species diversity of
botanical gardens themselves. We therefore investigated
whether the species richness of the
world’s botanical gardens is related to their size,
age and geographical location by compiling data
from gardens in 124 different countries. The data
show that even in these highly managed ecosystems,
species richness can be described in terms of
a relatively small number of large-scale patterns.
As with most natural ecosystems, there were positive
species-area and species-age relationships.
There was also a positive latitudinal gradient in
species richness, which contrasts with the trend
observed in natural ecosystems. This discrepancy
may be due to the use of heated greenhouses at
high latitudes, the rarity of old botanical gardens
in the tropics, and the problem of poverty in developing
countries, where most hotspots of plant
biodiversity are located. There is thus a need to allocate
more funds to botanical gardens in speciesrich
regions. This study also calls for an increase
in the coordination of data management between
botanical gardens.
Botanica Helvetica, 2007, V117, N1, JUN, pp
15-28.
08.1-154
Common species determine richness patterns
in biodiversity indicator taxa
Pearman P B, Weber D
Switzerland
Biodiversity , Ecology , Zoology , Plant Sciences
Identification of spatial patterns of species diversity
is a central problem in conservation biology,
with the patterns having implications for
the design of biodiversity monitoring programs.
Nonetheless, there are few field data with which
to examine whether variation in species richness
represents consistent correlations among taxa in
the richness of rare or common species, or the
relative importance of common and rare species
in establishing trends in species richness within
taxa. We used field data on three higher taxa
(birds, butterflies, vascular plants) to examine the
correlation of species richness among taxa and
the contribution of rare and common species to
these correlations. We used graphical analysis to
compare the contributions to spatial variation in
species richness by widely- distributed (‘common’)
and sparsely- distributed (‘rare’) species. The data
came from the Swiss Biodiversity Monitoring Program,
which is national in scope and based on a
randomly located, regular sampling grid of 1 kM2
cells, a scale relevant to real-world monitoring
and managerrient. We found that the correlation
of species richness between groups of rare and
common species varies among higher taxa, with
butterflies exhibiting the highest levels of correlation.
Species richness of common species is consistently
positively correlated among these three
taxa, but in no case exceeded 0.69. Spatial patterns
of species richness are determined mainly
by common species, in agreement with coarse resolution
studies, but the contribution of rare species
to variation in species richness varies within
the study area in accordance with elevation. our
analyses suggest that spatial patterns in species
richness can be described by sampling widely distributed
species alone. Butterflies differ from the
other two taxa in that the richness of red-listed
species and other rare species is correlated with
overall butterfly species richness. Monitoring of
butterfly species richness may provide information
on rare butterflies and on species richness of
other taxa as well.
Biological Conservation, 2007, V138, N1-2, AUG,
pp 109-119.
08.1-155
Earthworm populations in two low-input
cereal farming systems
Pfiffner L, Luka H
Switzerland
Agriculture, Soil Sciences , Ecology
Earthworm populations in low-input integrated
crop management (ICM: no application of insecticides,
fungicides and growth regulators) and organic
farming systems were compared. The study
was performed as a 3-year field survey using a
paired-farm approach in six different locations in
northwestern Switzerland. Earthworms were extracted
from soils sampled from 24 winter cereal
fields using a combined method of extraction by
mustard flour solution and handsorting. Earthworm
communities differed between these farming
systems. Over all sites, the mean biomass, abundance
and species richness of earthworms found
in the low-input ICM fields were significantly lower
than in the organic fields. Adult earthworms
in organic fields were 114% more abundant than
in ICM fields, but the frequencies of most species
within the respective systems were similar in both