5,586 research outputs found
A medieval Commentary on Andreas Capellanus
No full textSargent-Baur Barbara Nelson. A medieval Commentary on Andreas Capellanus. In: Romania, tome 94 n°376, 1973. pp. 528-541
MIMOS 2024
No full textLilo Baurs Theater lebt von der starken körperlichen Unmittelbarkeit. Seelenregungen gerinnen bei ihr zu vielsagenden Haltungen und Gesten, in denen sie oft auch eine entlarvende Komik aufspürt. In Analysen und Gesprächen widmet sich der vorliegende Band Lilo Baurs Wirken als Regisseurin und Schauspielerin. Le théâtre de Lilo Baur vit d’un rapport au corps très intense. Avec cette artiste, les mouvements de l’âme se cristallisent en attitudes et gestes éloquents, grâce auxquels elle compose aussi souvent un comique révélateur. À travers des analyses et des interviews, cet ouvrage retrace la carrière de Lilo Baur en tant que metteuse en scène et actrice. Il teatro di Lilo Baur si nutre di un’intensa immediatezza fisica. Le emozioni trovano espressione in posture e gesti eloquenti, che spesso rivelano verità nascoste in chiave comica. Tramite analisi e interviste, il presente volume ripercorre la carriera artistica di Lilo Baur come regista e attrice. Lilo Baur’s theatre thrives on a powerful physical immediacy. Inner emotions crystallise into expressive postures and gestures, and a comedy emerges in which hidden truths are unveiled. With analyses and conversations, this edition is dedicated to Lilo Baur’s achievements as both director and actor
Distribution, life history, food choice and chemical ecology of the invasive box-tree pyralid "cydalima perspectalis"
No full textSUMMARY: The box-tree pyralid Cydalima perspectalis (Walker 1859) (Lepidoptera: Pyralidae)
is a new invasive moth species in Europe. Its larvae feed on box-tree leaves and
can cause severe damage within short time. Therefore, this species is of great
concern for park and public garden manager in Europe.
In the context of my PhD thesis, I examined the spread in the region of Basel,
the national distribution as well as the biology of this moth. The natural
dispersal speed was assessed using a public survey in the region of Basel.
The number of adult moths caught with light traps allowed the determination of
two distinct periods of appearance of adult moths: the first in July and the
second, less pronounced, from September to mid-October.
In collaboration with CABI Switzerland in Delémont, a geographic model based
on literature data from Europe and Asia as well as field and laboratory data was
developed. It shows the potential distribution, life-history and relative
abundance of the box-tree pyralid in Europe. The model suggests that the box-tree
pyralid might spread across most of Europe, except North Fenno-Scandinavia,
Northern Scotland and high mountain regions, where the overall temperatures are
too low to allow the completion of an entire generation per year. In most parts
of Central Europe, two generations of C. perspectalis may occur, whereas in
Northern and North-Western Europe, low temperatures allow only one yearly
generation.
In an experiment, a potential preference of the box-tree pyralid for a particular
box-tree variety was investigated. Female moths deposited their eggs preferably
on varieties with large leaves. Larval growth and survival did not differ between
the five most frequently planted box-tree varieties in Central Europe, suggesting
that the box-tree pyralid has a broad food acceptance in Europe. The discrepancy
between adult preference and larval performance could be explained by the fact
that the larval generation which was tested in this experiment was only about the
tenth in Central Europe, and that the adaptation to the new ecosystem is not fully
accomplished yet.
Another study involving chemical analyses showed that larvae take up toxic
compounds (alkaloids) from the box-tree leaves on which they feed and therefore
become unpalatable for predators. Young larvae contain twice as much alkaloids as
larvae in later instars. In box-tree leaves, the concentration of alkaloids
doubles between one year-old leaves and older leaves. This finding suggests a
preference of larvae for leaves containing a high concentration of alkaloids,
which may explain why damage on a box-tree most often starts in the lower part,
where the oldest leaves are found.
Finally, an instrument for decision-making when facing the choice of long-term
care and replacement of large box-tree plantations was developed using the example
of the cemetery “am Hörnli” in Riehen, close to Basel. The cemetery “am Hörnli”
would suffer a great financial damage due to the loss of box-trees, having
estimated 3.3 km of box-tree hedges and 650 solitary trees. Since a replacement of
all box-tree plants does neither come into consideration financially nor
materially, the municipal parks and garden department chose a financially more
attractive solution for the clearance, care, and replacement of box-trees,
following a concept of commensurability and efficiency: important trees from a
heritage point of view are management and functionally less important trees are
cleared and replaced by optically different but less pricy plants or not replaced
at all. This strategy proves to be the most cost-efficient: after only four years
this strategy is financially more attractive than a hypothetical care of all
box-tree plants.
The findings of this doctoral thesis suggest that it will become unavoidable to
monitor box-trees in gardens, parks and in natural sites and to treat them with
pesticides in case of need. ---------- Zusammenfassung: Der Buchsbaumzünsler Cydalima perspectalis (Walker 1859) (Lepidoptera: Pyralidae)
ist eine in Europa neu auftretende, invasive Schmetterlingsart, dessen Raupen sich
von Buchsblättern ernähren. Diese können innert kurzer Zeit grosse Schäden
anrichten und bereiten daher den Verantwortlichen für Parks und Grünanlagen in
Europa grosse Sorgen.
Im Rahmen meiner Dissertation untersuchte ich die regionale und nationale
Ausbreitung sowie die Biologie des Falters. Mittels einer Umfrage bei der
Bevölkerung der Region Basel wurde die natürliche Ausbreitungs-geschwindigkeit des
Buchsbaumzünslers erfasst. Mithilfe der Aufzeichnung von Lichtfängen an zwei
Standorten in Basel konnten zwei deutlich getrennte Perioden des Erscheinens der
Falter festgestellt werden: die erste im Juli und die zweite, weniger stark
ausgeprägte, von Anfang September bis Mitte Oktober.
In Zusammenarbeit mit CABI Switzerland in Delémont wurde ein geographisches Modell
erstellt, welches anhand von Literaturdaten aus Europa und Asien sowie Feld- und
Labor-Daten die potentielle Verbreitung, die relative Abundanz sowie den
jährlichen Rhythmus des Buchsbaumzünslers in Europa simuliert. Das Modell lässt
darauf schliessen, dass sich der Buchsbaumzünsler in ganz Europa ausbreiten kann,
mit Ausnahme vom nördlichen Fennoskandinavien, dem Norden Schottlands und hohen
Bergregionen wo die Temperaturen insgesamt zu niedrig sind, um eine komplette
Generation pro Jahr auszubilden. In weiten Teilen Mitteleuropas bildet der
Schädling zwei jährliche Generationen aus. In Nordeuropa erlauben die tieferen
Temperaturen hingegen nur eine einzige Generation pro Jahr.
Mit einem Experiment wurde eine allfällige Buchsbaum-Sortenpräferenz des
Buchsbaumzünslers untersucht. Legebereite Weibchen zeigten eine Vorliebe für
grossblättrige Buchssorten. Die Wachstumsrate und Sterblichkeit der Raupen zeigten
keine Unterschiede zwischen den häufigsten Sorten in Mitteleuropa, was darauf
schliessen lässt, dass der Buchsbaumzünsler in Europa eine breite Futterpflanzen-
akzeptanz aufweist. Die Abweichung zwischen der Präferenz der Falter und der
Wachstumsrate der Raupen kann daraus herrühren, dass die getesteten Raupen und
Falter erst etwa die zehnte Generation ist, welche in Mitteleuropa auftritt, und
die Anpassung an das neue Ökosystem noch nicht optimiert wurde.
In einer weiteren Untersuchung konnte anhand von chemischen Analysen gezeigt
werden, dass die Raupen giftige Stoffe (Alkaloide) aus den Buchsblättern aufnehmen
und speichern und deshalb für Frassfeinde ungeniessbar sind. Junge Raupen weisen
einen doppelt so hohen Alkaloidgehalt auf wie spätere Stadien. Beim Buchs sind
die Alkaloidkonzentration in einjährigen Blättern nur etwa halb so gross ist wie
in älteren Blättern. Diese Beobachtung legt nahe, dass Raupen Blätter mit hohem
Alkaloidgehalt vorziehen, was erklären mag weshalb der Frass an einer Buchspflanze
meist im unteren Bereich anfängt, wo die ältesten Blätter sind.
Es wurde ebenfalls ein Instrument zur Entscheidungsfindung zwischen Ersatz oder
langjähriger Pflege grosser Buchsbestände anhand des Friedhofes am Hörnli in
Riehen bei Basel entwickelt, da dieser mit seinen geschätzten 3.3 km Buchshecken
und 650 Solitärbuchsbäumen von einem erheblichen finanziellen Schaden durch den
Verlust von Buchs betroffen ist. Da ein Ersatz aller Buchspflanzen weder
finanziell noch materiell in Frage kommt, wird von der Stadtgärtnerei –
entsprechend dem Konzept der Verhältnismässigkeit – ein weit niedrigerer Betrag
für Rodung, Ersatz und Pflege aufgewendet: Denkmal-pflegerisch wichtige
Buchspflanzen werden erhalten und gepflegt, funktionell weniger wichtige
Buchspflanzen gerodet und je nach Situation gar nicht oder durch optisch
verschiedene aber dafür günstigere Straucharten ersetzt. Diese Strategie erweist
sich als die rentabelste: bereits nach vier Jahren ist diese Strategie finanziell
attraktiver als eine hypothetische Pflege des gesamten Buchsbestandes.
Aufgrund der verschiedenen Erkenntnisse, welche im Verlauf dieser Doktorarbeit
gewonnen wurden, wird es in Zukunft unvermeidlich sein, Buchspflanzen in Gärten,
Parkanlagen und an natürlichen Standorten zu überwachen und notfalls mit
Insektenschutzmitteln zu behandeln
The evolution of male and female reproductive traits in simultaneously hermaphroditic terrestrial gastropods
No full textOur understanding of postcopulatory sexual selection forcing reproductive trait evolution
continues to be illuminated by comparative studies. Inter- as well as intraspecific
comparisons offer the opportunity to study the long-lasting processes of diversification and
allow testing for correlated evolution between different traits. Moreover, morphological
studies provide important insights into the function and adaptive significance of specialised
reproductive organs.
In this thesis, I combined comparative studies on the inter- and intraspecific
evolution of female sperm storage organs (spermathecae) and sperm traits in
stylommatophoran gastropods with detailed studies on the influence of spermatheca
morphology on sperm storage patterns and the adaptive function of the bursa tract
diverticulum, an organ of the reproductive tract of snails associated with sperm digestion,
in the helicid land snail Arianta arbustorum.
In order to assess the pattern of sperm storage organ divergence across 47 species
of stylommatophoran snails and slugs partial 28S rDNA sequences were used to construct
a molecular phylogeny. Maximum likelihood as well as Bayesian methods were applied to
investigate the history of spermatheca origination and to test different hypotheses of
spermatheca evolution. The results revealed a large variation in the presence/absence of a
spermatheca and its structural complexity across stylommatophoran gastropods. The
evolution of spermathecae in the carrefour appeared to be associated with the evolution of
other peculiar morphological traits of the reproductive tract, e.g. love-dart shooting, as well
as with flagellum and diverticulum length. Moreover, a close relationship of spermatheca
presence with cross-fertilization as the predominant mating system was found. In addition,
the presence of complex spermathecae was coupled with several life-history traits,
including body size, reproductive strategy (semelparity vs. iteroparity) and reproductive
mode (oviparity vs. ovoviviparity), and with habitat specificity. Sperm length, highly
diverse in this species group, appeared to be adapted to the length of the sperm storage
organ. The results suggest an important influence of postcopulatory sexual selection on
spermatheca divergence. However, also life-history traits and habitat specificity might
have shaped the pattern of spermatheca distribution found across stylommatophoran
gastropods.
A closer look at male and female reproductive trait divergence, focussing on sperm
traits and sperm storage organ size, was taken using six natural populations of Arianta
arbustorum. The intraspecific variation in spermatophore volume, number of sperm
transferred and sperm length as well as in volume and length of the spermatheca and the
number of sperm storage tubules was quantified and the covariation between interacting
traits was examined. A significant among-population variation was revealed for all traits
except for spermatheca length. Furthermore, a positive association was found between the
number of sperm transferred and spermatheca volume. In accordance with the interspecific
study, these results indicate a strong influence of antagonistic coevolution on male and
female reproductive trait evolution.
Beside size and morphology of sperm storage organs, the physical properties of the
spermatheca may be important for the potential to exert cryptic female choice. This was
investigated by examining structure, volume and tubule length of empty spermathecae of
A. arbustorum and assessing differences in spermatheca size following a single copulation.
The study revealed that spermathecae of this species are expandable and can accommodate
more sperm than would be expected from measuring its initial volume. Moreover, neither
the volume of sperm stored in the spermatheca nor the amount of allosperm digested in the
bursa copulatrix were related to the size of the spermatophore received. These findings
suggest that the female function may be able to control sperm storage and sperm use.
Finally, the morphology and function of the bursa tract diverticulum, which serves
as a place of spermatophore uptake when present, was studied. Using histological,
histochemical and morphometrical methods it could be shown that the diverticulum is
involved in the digestion or at least in the partly breakdown of received spermatophores.
Furthermore, the positive allometry and the high phenotypic variation of diverticulum
length compared to shell size suggest directional sexual selection on this trait. Combining
evidence from this and previous studies indicates that the diverticulum is involved in the
coevolution of the complex reproductive traits of stylommatophoran gastropods
Human impact on the vegetation of limestone cliffs in the northern Swiss Jura mountains
No full textCliffs provide unique habitats for many specialised organisms, including
chamaephytes and slowly growing trees. Drought, high temperature
amplitude, scarcity of nutrients and high insolation are general characteristics
of exposed limestone cliff faces. The vegetation of limestone cliffs in the
Swiss Jura mountains consists of plants of arctic-alpine, continental and
Mediterranean origin. Several populations exhibit relicts from post- or
interglacial warm or cold climatic periods. Grazing goats and timber
harvesting influenced the forests surrounding the limestone cliffs in northern
Switzerland for many centuries. During the twentieth century, however, these
traditional forms of forest use were abandoned.
In recent years, rock climbing enjoys increasing popularity in mountain
areas at low elevation, where this sport can be performed during the whole
year. The limestone cliffs of the Jura mountains provide unique opportunities
for sport climbers. As a consequence, more than 2000 climbing routes with
fixed protection bolts have been installed on 48 rock cliffs in the region of
Basel, Switzerland.
Overgrowing forest, due to the abandonment of forestry and damages
due to recreational activities including rock climbing reduce the quality and
size of the cliff habitats. In my dissertation, I examined quantitative, spatial
and temporal patterns of human impacts on the cliff flora and on the genetic
population structure of two plant species on isolated cliffs in the Jura
mountains of northern Switzerland.
The assessment of plant cover and species density at various distances
from frequently used climbing routes in the region showed that plant cover
was significantly reduced at the base of climbing routes. Furthermore, species
density (number of species per m2) at the cliff base as well as plant cover and
species density on the cliff face tended to increase with distance from the
route.
The comparison of the vegetation at the cliff base and on the cliff face of
five frequently climbed cliffs with that of seven unclimbed cliffs indicated that
rock climbing significantly altered the plant composition. Specialised rock
species occurred less frequently on climbed cliffs than on unclimbed cliffs.
At the Gerstelflue, a popular recreational climbing site with rock climbing
activities since more than 40 years, plant cover and species density (number
of species per m2) were reduced in climbed areas. Rock climbing also
reduced the density (number of individuals per m2) of forbs and shrubs,
whereas the density of ferns tended to increase in climbed areas. In addition,
rock climbing caused a significant shift in plant species composition and
altered the proportions of different plant life forms.
Species diversity and cover of lichens, and possible associations
between lichens and lichen-feeding land snails were assessed in climbed and
unclimbed areas of 10 isolated cliffs. Total lichen species density was not
correlated with the complexity of the rock surface, climbing frequency and age
of the climbing route. The species density of epilithic lichens was lower along
climbing routes than in unclimbed areas, whereas no difference in species
density of endolithic lichens was found between climbed and unclimbed
areas. Furthermore, climbed and unclimbed areas did not differ in total lichen
cover. The dissimilarity of the lichen communities between climbed and
unclimbed areas increased with increasing climbing intensity on the focal
route in climbed areas, but not with the age of the climbing route. Within cliffs,
plots along climbing routes harboured fewer snail species and individuals than
plots in unclimbed areas.
The effects of forestry practices on the species richness and abundance
of vascular plants on the face, at the base and on the talus have been
investigated by comparing two different forestry practices (clear-cutting and
shelter tree cutting) with forest reserve (i.e. no management in the past 80
years)) on three cliffs. Plant species density and vegetation cover was higher
in the shelter-cut areas than in the forest reserves on the talus as well as at
the cliff base. Clear-cut areas showed a higher vegetation cover than forest
reserves on the talus. Shelter-cut areas harboured a larger proportion of
plants with high light demands and plant indicator species showed a higher
mean light score than in clear-cut areas and forest reserves.
The analysis of time-series of air photographs taken between 1951 and
2000 at six cliffs revealed an increase in tree cover from 60% to 85% between
1951 and 1964 after which the increase levelled off. The increase in tree
cover showed a distinct spatial pattern. It was significant in the talus and on
the cliff face, but not on the plateau (at the top of the cliffs).
Possible effects of isolation and the presumed colonisation history of
cliffs as well as of anthropogenic activities on the genetic population structure
of two plant species with different life-histories were assessed using RAPDpolymorphisms.
Fourteen populations of Draba aizoides L. and 12 populations
of Melica ciliata L. living on isolated limestone cliffs were examined. Analysis
of molecular variance revealed a high among-population variation of each
27% in the gene pools of both species. A clear isolation-by-distance pattern
and a separation of populations from the Jura mountains and the Alps were
found in D. aizoides. This provides evidence for glacial relict endemism in this
species, resulting from nunatak survival in the Jura mountains. In M. ciliata,
UPGMA-analysis showed clusters of plant populations growing on cliffs with
castles with shared historical incidents, indicating zoochorical dispersal
related to human settlements.
The various studies emphasise the uniqueness and vulnerability of the
limestone cliff ecosystem of northern Switzerland. Protection measures in
several fields of activity are needed to preserve the unique relict vascular
plant, lichen and animal communities. Adequate management actions should
be developed and implemented. Actions should particularly be directed to
cliffs with numerous arctic-alpine plant species to protect them from mechanic
disturbances by sport climbing and hiking. The prohibition of sport climbing on
cliffs with a high number of specialised plant or animal species and the
establishment of climbing-free protection zones in popular areas are the most
effective and adequate measures in this context. However, any management
plan should include a comprehensive information campaign to show the
potential impact of intensive sport climbing on the specialised flora and fauna
and to increase the compliance of these measures by the climbers. Forestry
practices that keep the supply of light on a high level at the lower parts of the
cliffs are required to preserve the relict plant species. Selective thinning on the
talus results in relatively large plots with good light conditions and therefore
promotes the rare, relict plant species with high light demands. Self
evidentely, forestry actions and climbing prohibitions should be executed in
coordination. Another measure to manage the lower parts of cliffs could be to
use them as temporal pastures for goats. Finally, the preservation of
mediaeval sites also connotes the conservation of plant species introduced
into the area during the time of human activities
Traditional versus sprinkler irrigation of mountain hay meadows in the Valais : consequences for biodiversity
No full textSemi-natural grasslands including hay meadows belong to the most species-rich habitats in central Europe and are therefore of high conservation value. The high biodiversity of these grasslands has been maintained for many centuries through the regular disturbance by traditional management practices. In the Valais, an arid mountain region of Switzerland, traditional management of hay meadows includes irrigation by open water channels. In the past decades, however, the traditional irrigation technique was increasingly replaced by more efficient sprinkler-irrigation systems or irrigation was stopped on marginal and poorly accessible areas. Within the scope of this thesis, four studies were conducted to investigate different aspects of these changes in meadow irrigation.
The aim of the first study was to examine whether land-use abandonment resulting from the cessation of irrigation influenced the biodiversity of hay meadows in the Valais. For this purpose, plant and gastropod surveys were conducted in three serial stages of succession (hay meadows, early abandoned meadows and young forests). Meadow abandonment resulted in an increase in gastropod species richness and a loss of plant and gastropod species characteristic for open grassland habitats. Furthermore, functional traits of plants (plant height, the start of seed shedding and the type of reproduction) and gastropods (shell size) were affected by abandonment.
Traditional meadow irrigation is assumed to distribute the water more heterogeneously than sprinkler irrigation, which might affect meadow biodiversity as well as the distribution of plants in a small scale. The aim of the second study was to examine whether the change from traditional to sprinkler irrigation affected the local biodiversity (plants and gastropods) of hay meadows in the Valais. A high plant species richness was found in the hay meadows investigated. The diversity and composition of plant and gastropod species did not differ between traditionally and sprinkler-irrigated meadows. However, the installation of sprinkler systems resulted in an increase in the grass-to-forb ratio and affected the leaf distribution and the start of seed shedding in plants.
The third study aimed to investigate whether the change in irrigation technique affected the small-scale distribution of plants and soil characteristics in these hay meadows. Three sampling plots consisting of 13 subplots of increasing size were installed in traditionally and sprinkler-irrigated meadows to assess plant species richness and soil characteristics within subplots. The type of irrigation technique did not affect the shape of the plant species-area relationship. Furthermore, spatial autocorrelation in the soil characteristics examined was low and their small-scale distributions were mostly not influenced by the irrigation technique. These findings indicate a pronounced small-scale heterogeneity in the distribution of plant species and soil characteristics in the hay meadows investigated. Therefore, as practiced in our study areas, the distribution of water by sprinklers might be less homogenous than commonly assumed.
The abandonment of traditional management practices of semi-natural grasslands is suggested to result in a reduced landscape heterogeneity, which in turn might contribute to the loss of local plant diversity. The fourth study aimed to investigate whether the change from traditional to sprinkler irrigation resulted in alterations in the surrounding landscape of species-rich hay meadows. Furthermore, we asked if plant diversity of differently irrigated meadows is influenced by landscape composition and the heterogeneity of the surrounding landscape. Landscape composition was more diverse for traditionally than for sprinkler-irrigated meadows, but did not differ prior to the installation of sprinklers. A diverse small-scale landscape composition in the close surroundings of hay meadows had a positive effect on the number of generalists but not on total plant species richness or the number of specialists. Finally, sprinkler-irrigated meadows had an increased number of generalist plant species.
The findings of this thesis suggest that the installation of sprinklers did not affect the local species richness of plants and gastropods in the hay meadows investigated. Nevertheless, the change in irrigation technique influenced functional aspects of plant diversity (plant traits, grass-to-forb ratio and generalist species). Furthermore, the installation of sprinklers was associated with a homogenization of the landscape, which may eventually result in an intensification of land use. For the conservation of the biodiversity of these hay meadows it is recommended to maintain the relatively extensive irrigation and management practices
Auer-Arbeitsblätter zur Firmung Erarb. von Andreas Baur und Mitwirkung von Hans Kögel u. Maria Schönherr
No full textAuer-Arbeitsblätter zur Firmung Erarb. von Andreas Baur und Mitwirkung von Hans Kögel u. Maria Schönherr
No full textAuer-Arbeitsblätter zur Firmung Erarb. von Andreas Baur und Mitwirkung von Hans Kögel u. Maria Schönherr
No full textAuer-Arbeitsblätter zur Firmung Erarb. von Andreas Baur und Mitwirkung von Hans Kögel u. Maria Schönherr
No full text- …
