Fouilles et recherches nouvelles sur les travaux de César devant Alésia (1991-1994) = Neue Ausgrabungen und Forschungen zu den Belagerungswerken Caesars um Alesia (1991-1994) / mit einem Beitrag von Susanne Sievers
Siegmar von Schnurbein
Verlandungsbereiche stehender Gewässer, Hülen und Tümpel
- Mit dem Biotopschutzgesetz, einer Novellierung des Naturschutzgesetzes (NatSchG) von Baden-Württemberg, ist diesem „Gewässersterben” seit dem 1. Januar 1992 Einhalt geboten. Zudem wurden auch die Verlandungsbereiche größerer Stillgewässer unter Schutz gestellt. Doch nach wie vor unterliegen diese Biotope zahlreichen Gefährdungen. Sie aufzuzeigen, ist eine wichtige Aufgabe dieses Heftes. Als ebenso wichtiges Ziel aber soll über die Eigenart und Vielfalt dieses sensiblen Lebensraums informiert werden – getreu dem Motto, dass man nur das richtig schätzen und schützen kann, was man kennt.
Die Entstehung des engl. Phonems [S] : zugleich ein Beitrag zur Geschichte der Quantität
Hermann M. Flasdieck
Simulium feeding upon Chrysalids
Hermann August Hagen
The single self: feminist thought and the marriage market in early modern Venice
Taxonomical study of oribatid mites from Taiwan (Acarina: Astigmata) (I)
- This study treats 76 species, in which 58 species and 14 genera are described as new. The species are arranged in 28 families and 56 genera. The oribatid or cryptostigmatid mites are cosmopolitan group of more than 6500 species relegated to approximate 700 genera and 134 families. The body length of most oribatid species ranges 300-1200 μ. The oribatid mites are darkly coloured and covered with a rigid exoskelecton. The life cycle consists of egg, larva, protonymph, tritonymph, deutonymph and adult. These mites are best known as inhabitants of litter and upper soil strata, their small size and shunning of light caused them to receive little attention for many years. In recently studies of soil fauna, it has been shown that is an economic importance for human, i.e. many species feed on surface plant detritus, and may therefore play a major role in maintaining the fertility of soils; they could become an indicator of soil physical and chemical characters. Some species have also been shown to act as vectors of various tapewonns; they feed almost exclusively on tyroglyphid mites and attack the parasitic hymenopteran, Polynotus zosini; and several species are associated with plant, they have been reported to damage the leaf, the foot and the stem of potato, strawberry, turlip, citrus and mushroom. Systematic studies of these mites are scarcely found in Taiwan. The present paper deals with 76 species, 56 genera in 28 families, among them, 58 species and 14 genera are described as new. The author hopes that this study constitutes an example to show that the wealth of fascinating information could be gained and also hopes that this finding might be useful for elucidating the taxonomy of oribatid mites in Taiwan.
Quer durch Karien
Walther von Diest
A multispecies extension to the Beverton and Holt theory of fishing, with accounts of phosphorus circulation and primary production
Knud Peter Andersen
- Interaction between species in a marine ecosy stem is described by expressions for food consumption and grazing mortality which are consistent with each other and with the Beverlon and Holt model of the population dynamics ofindividual species. A model of primary production is introduced in order to make possible an account of nutricnt circlliation (as examplified by phosphorus) within and nutrient flow through the system. It is demonstrated in an application to North Sea fishencs that recent changes in total yield can be described in some detail under the terms of the model as a function of fishing mortality alone. The composition of the North Sea fauna in the virgin state is discussed and also the conditions under which total yield could be increased above the 1970 level.
Techniques for collecting, handling, preparing, storing and examining small molluscan specimens
Daniel L. Geiger
Bruce A. Marshall
Winston F. Ponder
- Micromolluscs are small-sized molluscs (< 5 mm), and include the great majority of undescribed molluscan taxa. Such species require special collecting, sorting and handling techniques and different storage requirements to those routinely used for larger specimens. Similarly, the preparation of shells, opercula, radulae and animals poses some challenges for scanning electron microscopy (SEM). An overview of experiences with various techniques is presented, both positive and negative. Issues discussed include those relating to storage of dry specimens and interaction of specimens with glass, gelatine and paper products, handling techniques and storage in various fluids. Techniques for cleaning shells for SEM are described and compared, as well as those for radular extraction. The interactions of chemicals used for the dissolution of tissue with calcareous micromolluscs are described. Methods for handling and mounting small radulae for SEM are detailed and brief guides to SEM and light photography are given. An appendix listing details of frequently-used chemicals is provided. Key words: Review, methodology, collection, preservation, storage, museology, SEM, radula, shell. Byne's disease