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431.
Dr. Christa Volkmar Prof. Dr. habil. Theo Wetzel 《Archives Of Phytopathology And Plant Protection》2013,46(4):317-324
Creation of the big trophical niches of the winter pine shoot moth (Rhyacionia buoliana Schiff.) on susceptible trees of Pinus silvestris L. provoked the mass outbreak of the pest in the south areas in Ukraine. In its turn, high density of the pest induced processes of the aggressivity's growth of population. In so doing the wide range of adaptive zones represented by groups of the pines with different resistance is favourable for formation of aggressive biotypes. The spreading of the pest from weakened to more resistant groups on the pines is similar to the process of “drift”. This problem will be considered more detaily in the second part of this article. 相似文献
432.
Summary This study presents a microfacies analysis and palaco-environmental interpretations of Early Oligocene carbon ates from the
Lower Inn Valley Tertiary (“Unterinntal-Terti?r”) of Austria. The well preserved biogenic components allow detailed investigations
of component relationships and controlling ecological parameters. The carbonates are dominated by coralline algae, corals,
small and large benthic foraminifers, bryozoans and lithoclasts. Bivalves, gastropods, echinoderms, brachiopods and serpulids
are subordinate. The limestones are present as A) autochthonous carbonates transgressing directly above the Triassic basement
and B) allochthonous debris flows within deeper-water marls. These carbonates are found within the Paisslberg Formation. The
Werlberg Member within this formation, pertains to the autochthonous carbonates and larger debris flows.
Five facies types are separated following fabric analysis and statistical treatment (correlation, cluster analysis, principal
components analysis) of semi-quantitative data consisting of component frequencies of thin sections. Facies distribution patterns
are principally controlled by variations in substrate characteristics, turbulence and light along a depth gradient. Reconstruction
of facies pattern distribution reveal both lateral and proximal-distal facies trends: coral-coralline algal facies, coralline
algal facies as well as foraminiferal facies were situated in shallower environments, laterally adjacent to each other. These
grade distally into coralline algal-bryozoan facies, bryozoan facies and finally into mollusc rich marls. Debris flows consisting
of reworked material from all of the known facies (bioclastic packstone facies) is restricted to the debris flow and possible
represents transport induced differentiation of components and grain size within distal debris flows. 相似文献
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437.
Belowground processes are essential for the overall carbon and nitrogen fluxes in forests. Neither the functioning of the soil food web mediating these fluxes, nor its modulation by environmental factors is sufficiently understood. In this study the belowground carbon and nitrogen mineralisation of four European coniferous forest sites (northern Sweden to north‐east France) with different climate and N depositional inputs was analysed by investigating the soil food webs using field observations and modelling. The soil fauna directly contributed 7–13% to C mineralisation, among which the testate amoebae (Protozoa) made the largest contribution. Microbial grazing was suggested to have an important indirect effect by stimulating bacterial turnover. Due to relatively high C:N ratios of their substrate, bacteria immobilized N, while the fauna i.e. testate amoebae, nematodes, microarthropods and enchytraeids, counteracted this N immobilisation. Despite similar food web biomass, the sites differed with respect to food web structure and C and N flows. Model calculations suggested a significant influence of food web structure on soil ecosystem processes in addition to environmental factors and resource quality. Mineralisation rates were lowest at the low N input boreal site with a food web dominated by fungal pathways. Further south, as N availability increased, bacterial pathways became more important and the cycling of C and N was faster. The bioavailability of degradable C sources is suggested to be a limiting factor for microbial activity and overall mineralisation rates. In this respect, above‐ and belowground interactions e.g. transfers of labile C sources from the vegetation to the decomposer system deserve further attention. Our study revealed the combined effects of climate and nutrient inputs to ecosystems and the subsequent changes in the structure and functioning of the systems. If decomposition, and therefore carbon loss, is stimulated as a consequence of structural and/or nutritional changes, resulting for example from continuous industrial N emission, the storage capacity of forest ecosystems could be altered. 相似文献
438.
The frog-eating bat (Trachops cirrhosus) is unusual among bats studied because of its reliance on low-frequency (<5 kHz) sounds emitted by frogs for prey localization. We investigated the ear of this bat in order to identify anatomical features that might serve as adaptations for low-frequency hearing. Trachops cirrhosus has a variety of anatomical features that might enhance low-frequency hearing, either by increasing sensitivity to low-frequency sounds or expanding the total frequency range to include lower frequencies. These bats have long pinnae, and a long and wide basilar membrane. The basal portion of the basilar membrane is much stiffer than the apical portion, and the basal portion of the tectorial membrane is more massive than the apical portion. There is also a concentration of mass in the apical portion of the cochlea. T. cirrhosus possesses the largest number of cochlear neurons reported for any mammal, the second highest density of cochlear neurons innervation known among mammals, and three peaks of cochlear neuron density. Other bats have two peaks of cochlear neuron density, lacking the apical concentration, while other mammals usually have only one. T. cirrhosus differs from most other small mammals and bats in characteristics of the apical portion of the cochlea, i.e., that area where the place theory of hearing predicts that low frequencies are detected. 相似文献
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440.
Volkmar Günzler Rudolf E. Schopf Hartmut M. Hanauske-Abel Hermann Schulte-Wissermann 《FEBS letters》1982,150(2):390-396
The effects of the transglutaminase inhibitor dansyl cadaverine (DC) and the polyamine antagonist methyl glyoxal-bis-(guanylhydrazone) (MeGbG) on the response of lymphocytes towards allogeneic and lectin stimulation and on the zymosan-induced chemiluminescence of neutrophilic granulocytes was studied. Application of DC resulted in dose-dependent suppression of chemiluminiscence and lymphocyte proliferation; no difference of inhibitory potential occurred with variation of incubation time in the latter system. MeGbG was inactive in granulocytes, but inhibited lymphocyte proliferation; its effect increased with time. The experiments provide further evidence for the importance of transglutaminases and polyamines for the function of immunocompetent cells. 相似文献