Pinguine – Überlebenskünstler in der Antarktis. Klimawandel

The future of penguin population development in the Western Antarctic Peninsula (= WAP) is largely depending on ecological factors like food availability (mostly krill) due to primary production of algae which itself depends on sea ice conditions, water‐ and air temperature and salinity. The extraordinary rise in temperature in the WAP area seems to cause a change in population numbers of Adelie and Gentoo Penguins: Adelies are declining in the north and Gentoos were occupying these sites instead. Gentoos have already reached the southern polar circle. These trends occurred in parallel with regional long‐term warming and significant reduction in sea ice extent. There is a lack of available information for penguin populations breeding possibly more south in the WAP area. We still have large gaps in our present knowledge in Adelies and Emperor Penguins southernmost breeding distribution.     

Siebengebirge – im Saum der Großlandschaften. Die Exkursion

The Siebengebirge Mountains, facing Bonn and situated between the Lower Rhine Bight and the well known Middle Rhine valley, cover an area of only some 4800 ha, but represent a fairly unusual complex with respect to landscape and nature. Already some famous exploring travellors of the 18th century such as Georg Forster, Johann Wolfgang von Goethe, and Alexander von Humboldt consistently emphasized the striking diversity and natural beauty of this area. No other part of Germany has hitherto been dealt with by a comparable array of special (geologically as well as biologically centered) investigations and compiling contributions. An excursion proposal recommends a closer inspection of that fascinating landscape.     

Synanthrope Pflanzengesellschaften aus der Burgwallzeit (8.—10. Jh.) in der Tschechoslowakei

In der Burgwallzeit (8.—10. Jahrhundert) entfalteten sich im Gebiet der CSSR praktisch alle Unkraut- und Ruderalgesellschaften (incl. Ufersäume) wie in der Neuzeit (ohne Neophyten). Die archäobotanischen Funde sind leider meist an Getreidevorräte gebunden. Nur in Mikulcice (Süd-Mähren, 8. bis 9. Jahrhundert) wurden pflanzliche Makroreste der Ruderalsteilen und anthropogen beeinflußter Ufersaumgesellschaften gefunden. In Mikulcice müssen wir neben den allgemein bekannten Segetal-Gesellschaften auch mit weiteren Typen der Unkrautgsellschaften (Hackunkraut-Gesellschaften in Weinbergen, Gemüse-und Obstgärten) sowie mit Trittrasen rechnen. Die Unkrautgesellschaften können wir als Chenopodium album—Setaria viridis (glauca-)Assoziationen bezeichnen. Weiter behandelt werden die Arten, die im Osten von Mitteleuropa häufiger sind und Facies-Unterschiede (quantitativ und qualitativ) zwischen den synanthropen Gesellschaften im Raum der CSSR und in den westlicher gelegenen Regionen (Adonis aestivalis, Fumaria vaillantii, Glaucium corniculatum, Vaccaria pyramidata, Caucalis lappula, Galium tricorne, Papaver rhoeas usw.) aufgezeigt. Die Segetal-Gesellschaften der Burgwallzeit unterscheiden sich von denen aus älteren prähistorischen Funden nur wenig.     

Zehnfußkrebse – Pioniere der Evolution

Decapod Crustaceans Decapod Crustaceans, which are by origin a marine group that still occurs mainly in the sea, invaded during their evolution also firm land and freshwater habitats. Stress factors associated with those non‐marine environments have successfully been countervailed by long‐lived benthic juvenile and adult life‐history stages, which were able to evolve structural and physiological adaptations. By contrast, the adaptability of the short‐lived planktonic larval stages has been much weaker, remaining physiologically fragile and mostly dependant on planktonic food sources. Terrestrial as well as limnic decapods have evolved various ”export strategies" based on extended migrations. These are performed by the adult females and/or the first larval stage, being aimed at an avoidance of stress conditions during the larval phase. In order to successfully complete the larval phase in freshwater, already the earliest developmental stages must express special structures and physiological functions aiding to the maintenance of osmotic homeostasis and to an independance from planktonic food sources.