Scanning Electron Microscopy and X-Ray Microanalysis

A new method to simulate the hydrological state of soil under natural conditions

As micro, macro e mesofaunas no solo respondem frequentemente a variacao das condicoes ambientais, o que resulta em alteracoes na abundância e na estrutura da comunidade. Os efeitos das alteracoes nos parâmetros do solo sao normalmente determinados com amostras recolhidas no campo e trazidas ao laboratorio, ou seja, onde as condicoes ambientais naturais podem nao ser aplicaveis. Criamos um metodo (STAFD - tubos de amostra de solo para inundacoes e secas artificiais), que simula o estado hidrologico do solo in situ com nucleos implantados. As amostras de controle foram comparadas com amostras de tratamentos em que foram simuladas inundacoes de 15, 30, 60 e 90 dias e secas de 60, 90 e 120 dia…

Responses and adaptations of collembolan communities (Hexapoda: Collembola) to flooding and hypoxic conditions

Standard ecological methods (pitfall traps, trunk eclectors and soil cores) were used to evaluate collembolan community responses to different flooding intensities. Three sites of a floodplain habitat near Mainz, Germany, with different flooding regimes were investigated. The structures of collembolan communities are markedly different depending on flooding intensity. Sites more affected by flooding are dominated by hygrophilic and hygrotolerant species, whereas the hardwood floodplain is dominated by mesophilic species. The survival strategies of the hygrophilic and hygrotolerant species include egg diapause and passive drifting. The physiological adaptations to hypoxic conditions of sever…

Field distribution ofSorosphaera viticolain commercial vineyards in Germany

In the year 2000, resting spores of a previously undescribed plasmodiophorid were found in roots of Vitis spp. This plasmodiophorid was identified as a member of the genus Sorosphaera Schroeter and described as Sorosphaera viticola Kirchmair, Neuhauser, Huber. To attain information on the field distribution of Sorosphaera viticola, a selective screening was conducted in two commercial vineyards in Germany. A study to determine a correlation of Sorosphaeraviticola infection to grapevine growth was also performed.

Wasserhaushalt, Osmo- und lonenregulation sowie Exkretion

Mit den Teilgebieten Wasserhaushalt, Osmo- und Ionenregulation und Exkretion werden wichtige Grundfunktionen von Insekten behandelt, die masgeblich zu ihrer erfolgreichen Evolution beigetragen haben. Wesentlich hierfur ist die Fahigkeit zur Regulation im Hinblick auf eine ausgeglichene Wasser- und Stoffbilanz, die es ermoglicht, die vielfaltigsten Lebensraume im aquatischen und terrestrischen Bereich zu besiedeln. Mit dem Wasserhaushalt werden Phanomene der Wasserzufuhr, des Wasserverlustes und der Verteilung des Wassers zwischen den groseren Kompartimenten des Insektenkorpers besprochen. Insekten sind als relativ kleine Tiere mit einem grosen Oberflachen/Volumen-Verhaltnis oft extremen Anf…

Nanochlorum eucaryotum: a Very Reduced Coccoid Species of Marine Chlorophyceae

Nanochlorum eucaryotum was isolated from a sea water aquarium housing different sponge species, cucumarias, small crustaceans and annelids. This bright green marine alga differs from all other known coccoid species. Its most prominent features are its very small cell size (1.5 pm) and its reduced cellular organization. Its cell contains one nucleus, one chloroplast, one mitochondrium and small vacuoles. Sometimes a Golgi apparatus can be seen. No other subcellular features have been observed. The cell wall is thin and smooth and does not contain any material of high electron density; only dividing cells show a rougher surface. The cells split into two daughter cells. No sexual reproduction …

Zur feinstrukturellen Anpassung des Transportepithels am Ventraltubus von Collembolen bei unterschiedlicher SalinitÄt

Das Transportepithel am Ventraltubus verschiedener Collembolen-Arten —Podura aquatica, Lepidocyrtus ruber, Sminthurides aquaticus undTomocerus vulgaris — wurde auf salinitAtsabhAngige VerAnderungen der Feinstruktur hin untersucht. Als Beispiel langfristiger Adaptation wurdePodura aquatica aus zwei Populationen von Salzlaken des Neusiedlersee-Gebietes mitLepidocyrtus ruber aus dem Supralitoral der Mittelmeerkuste der Insel Elba/Italien verglichen. Die Tiere von stark salzhaltigem Substrat zeigten eine Ruckbildung der fur Transportepithelien typischen Strukturen, in erster Linie eine Reduzierung des apikalen Faltensaumes und der Mitochondriendichte. Auf einer Salzlake geringerer SalinitAt erg…

Effects of ecological flooding on the temporal and spatial dynamics of carabid beetles (Coleoptera, Carabidae) and springtails (Collembola) in a polder habitat.

Within the scope of the Integrated Rhine Program an ecological flood gate and channel was inserted into the polder “Ingelheim” to enhance animal and plant diversity. In 2008, carabid beetles and springtails were collected, using pitfall traps, to measure the effects of ecological flooding and a strong precipitation event at a flood-disturbed and a dry location in this area. At both localities, xerophilic and mesophilic carabid beetle species were dominant throughout the study period. The total number of individuals of hygrophilic species was comparatively constant, while species number increased, partly due to the changed moisture conditions caused by ecological flooding and str…

Respostas e adaptações de comunidades de colêmbolos (Hexapoda: Collembola) a condições de inundação e hipoxia

Standard ecological methods (pitfall traps, trunk eclectors and soil cores) were used to evaluate collembolan community responses to different flooding intensities. Three sites of a floodplain habitat near Mainz, Germany, with different flooding regimes were investigated. The structures of collembolan communities are markedly different depending on flooding intensity. Sites more affected by flooding are dominated by hygrophilic and hygrotolerant species, whereas the hardwood floodplain is dominated by mesophilic species. The survival strategies of the hygrophilic and hygrotolerant species include egg diapause and passive drifting. The physiological adaptations to hypoxic conditions of sever…