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We synthesise the results of the papers in this Special Issue, place them within the context of current trends in floodplain research, and outline promising new avenues that emerge from the contributions. The indication system presented complements existing approaches by focussing on a quantitative indication of environmental parameters. A promising research line that emerges is an extension of the systematic comparison of taxonomic groups with contrasting traits in terms of their performance as quantitative indicators for different environmental parameters. The studies show similarities and dissimilarities in the traits explaining the functional response of plants, molluscs, carabids, and syrphids to site conditions but trait databases and studies on additional taxa are required before broad generalisations can be made. The rigorous study design developed for the RIVA project, of which all contributions in this Special Issue are a part, not only was essential for an improvement of the understanding of species environment relationships and the role biological traits play for it, it also provides a baseline for assessing future change as part of long‐term ecological monitoring of floodplains. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

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Germain G  Anctil M 《Tissue & cell》1988,20(5):701-720
Dissociation and Percoll sedimentation techniques were used to separate and pool the autofluorescent luminescent cells (photocytes) of the pennatulid anthozoan Renilla k?llikeri. Photometric recordings of luminescent activity of photocyte suspensions show that activation of flashing and glowing by KCl depolarization is suppressed in calcium-free sea water and by cobalt but enhanced by trifluoperazine, thus suggesting that luminescence excitation is dependent on extracellular calcium and calmodulin-mediated mechanisms. Of several neuroactive substances tested, adrenaline, dopamine, N-methyl-N-phenylethanolamine, serotonin and the native neuropeptide Antho-RFamide all induced photocyte responses at high concentrations (0.1-1 mM) only, whereas lower concentrations of adrenaline and Antho-RFamide are known to activate or enhance luminescence or muscular contractions in intact Renilla tissues (Anctil et al., 1982; Anctil, 1987). Hence, none of these substances is a likely neurotransmitter candidate for direct photocyte activation. Ultrastructural observations of dissociated photocytes reveal that they are musculo-epithelial cells containing numerous 0.2-mum vesicles resembling previously extracted and light-emitting lumisomes (Anderson and Cormier, 1973). Similar cells were traced ultrastructurally in situ in the endodermal luminescent zones, but not in non-luminescent endoderm.  相似文献   

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Natural disturbances, such as fire, windstorms and insect outbreaks, are important drivers of biodiversity in forest ecosystems, but at the same time cause large economic losses. Among the natural disturbances in Europe, windstorms cause the highest economic loss. After such storms, damaged forest stands are commonly salvage logged to restore economic value. However, such interventions could affect species assemblages of various taxonomic groups, including breeding birds. Despite these potential effects, investigations of the impacts of post-storm logging are largely lacking. We thus investigated assemblages of breeding birds in 21 logged and 21 unlogged windstorm-disturbed forest plots and 18 undisturbed, control forest plots using fixed-radius point-stop counts three, five and seven years after a windstorm within the Bavarian Forest National Park as part of the European Long-Term Ecosystem Research Network. We recorded 2100 bird individuals of 55 bird species. Bird assemblages were predominantly altered by the consequences of the windstorm and affected only to a minor degree by subsequent logging of storm-felled trees. Nevertheless, bird species richness was significantly reduced by post-storm logging within the first season. In general, the windstorm led to a shift in bird assemblage composition from typical forest species towards open- and shrub-land species. Assemblages of logged and unlogged disturbed plots consisted mainly of long-distance migrants and ground-foraging bird species, whereas assemblages of undisturbed control plots consisted of resident species that forage within vegetation. Both unlogged and logged storm-felled coniferous forest stands were inhabited by endangered or declining bird species, such as Water Pipit (Anthus spinoletta) on logged plots and Eurasian Redstart (Phoenicurus phoenicurus) on unlogged plots. Indicator species analyses suggested that species of unlogged storm disturbed plots depended on storm-created legacies, such as pits and snags, for foraging and nesting. Hence, we recommend reducing post-storm logging of these legacies to support species restricted to unlogged disturbed forest. To increase the diversity of breeding birds on the landscape scale, diverse logged and unlogged post-disturbance stands should be provided, which could be gained by a partial benign neglect strategy of storm disturbed forest stands.  相似文献   

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Pollution can be aggravated in industrial areas if traffic exhausts are mixed with industrial emissions under high humidity conditions. Plants growing in such environments may suffer from severe stress. The impact of vehicle emissions on urban vegetation in an industrial area in Qingdao, China, was investigated by studying seven plant species at visible, physiological and chemical levels. The traits of plant species in certain environmental conditions were compared between a clear area, Badaguan (BDG), and polluted area, Roadside (RS). We found that foliar sulfur uptake for all species was not significantly high at RS compared with BDG, although the sulfur content of atmosphere and surface soils at RS were much higher than those at BDG. For Ailanthus altissima Swingle, the content of foliar pigment and net photosynthesis rate (PN) decreased by 20%. Meanwhile, leaves became incrassate and no visible leaf damage was noted, suggesting this species could adapt well to pollution. A 50% decrease in PN occurred in Hibiscus syriacus L., but there was no statistical change in content of chlorophyll a and b and water uptake. Also, thickened leaves may prevent the pollutant from permeation. Foliar water content was still at a low level, although a water compensation mechanism was established for Fraxinus chinensis Rosb. reflected by low water potential and high water use efficiency. More adversely, a 65% decrease in PN happened inevitably with the significant decomposition of photosynthetic pigments, which exhibited visible damage. We also noted in one evergreen species (Magnolia grandiflora L.) that water absorption driven by low water potential should be helpful to supply water loss induced by strong stomatal transpiration and maintain normal growth. Furthermore, photosynthetic pigment content did not decline statistically, but supported a stable net assimilation. Two herbaceous species, Poa annua L. and Ophiopogon japonicus Ker‐Gawl., were very tolerant to adverse stress compared to other woody species, especially in assimilation through a compensatory increase in leaf area. A more remarkable decline in PN (decrease 80%) was noted in the exotic but widespread species, Platanus orientalis L., with serious etiolation and withering being exhibited on the whole canopy. Our results suggested, special for woody species, that most native species are more tolerant to pollution and therefore should to be broadly used in a humid urban industrial environment with heavy‐duty vehicle emissions. (Managing editor: Ya‐Qin Han)  相似文献   

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The two genes for -mannanase and cellulase of Bacillus sp. 5H have been cloned in Escherichia coli JM 109 by a shotgun method, though the cellulase gene was not expressed in Bacillus sp. 5H. The nucleotide sequences of the -mannanase gene and the cellulase gene revealed open reading frames of 1,086 and 1,503 base pairs, respectively, coding for a proteins of Mr 40,803 Da (-mannanase) and 55,420 Da (cellulase). The deduced primary structure of -mannanase comprised 362 amino acids which had a mature protein of 336 amino acids and a signal peptide of 26 amino acids and that of cellulase comprised 501 amino acid residues.  相似文献   

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On the occasion of the 50th anniversary of the international journal Photosynthetica in 2017 we briefly report on the establishment of this journal and on Dr. Zdeněk ?esták, the renowned researcher of photosynthesis processes who, in cooperation with the Czechoslovak Academy of Sciences, founded this essential science journal in Prague in 1967.  相似文献   

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Isolation and identification of native nematode-bacterial associations in the field are necessary for successful control of endemic pests in a particular location. No study has yet been undertaken to recover and identify EPN in metropolitan France. In the present paper, we provide results of a survey of EPN and their symbiotic bacteria conducted in Hérault and Gard regions in Southern France. Molecular characterization of isolated nematodes depicted three different Steinernema species and one Heterorhabditis species, H. bacteriophora. Steinernema species recovered were identified as: S. feltiae and S. affine and an undescribed species. Xenorhabdus symbionts were identified as X. bovienii for both S. feltiae and S. affine. Phylogenetic analysis placed the new undescribed Steinernema sp. as closely related to S. arenarium but divergent enough to postulate that it belongs to a new species within the “glaseri-group”. The Xenorhabdus symbiont from this Steinernema sp. was identified as X. kozodoii. All Heterorhabditis isolates recovered were diagnosed as H. bacteriophora and their bacterial symbionts were identified as Photorhabdus luminescens. Molecular characterization of these nematodes enabled the distinction of two different H. bacteriophora strains. Bacterial symbiontic strains of these two H. bacteriophora strains were identified as P. luminescens ssp. kayaii and P. luminescens ssp. laumondii.  相似文献   

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The feasibility of a process for the photoproduction of both H 2 and poly-b-hydroxybutyrate (PHB)-containing biomass has been tested utilizing semi-continuous cultures of Rhodopseudomonas palustris growing in a tubular system with limiting amounts of fixed nitrogen. A two-stage batch process, consisting in a first period of nitrogen-limited cell growth followed by a second period of cell cultivation under conditions of phosphorus shortage, showed the possibility to separate the H production phase from the PHB accumulation phase, making possible to carry out processes that otherwise would be in competition.  相似文献   

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Phytochemical study on the stems and leaves of Clausena dunniana H. Lév. led to the isolation and identification of 14 coumarins (114). Their chemical structures were determined on the basis of MS, NMR, and further supported by comparison with those reported in the literature. This is the first report that compounds 12, 4, 8, and 1214 are present in the genus Clausena, and all of these compounds were isolated from C. dunniana for the first time. The chemotaxonomic significance of these isolated compounds was discussed.  相似文献   

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1. When Bacillus cereus 569/H was grown in a casamino acid (casein-hydrolysate) medium containing zinc sulphate rapid production of extracellular beta-lactamase II preceded that of beta-lactamase I. 2. beta-Lactamase I was separated from beta-lactamase II by fractional precipitation with ammonium sulphate. 3. beta-Lactamase I was purified by a process involving chromatography on Celite and DEAE-cellulose and beta-lactamase II by chromatography on DEAE-cellulose after denaturation of beta-lactamase I by heat. Both enzymes were obtained in crystalline form. 4. beta-Lactamase II prepared in this way appeared to have a higher molecular weight than beta-lactamase I and required Zn(2+) as a cofactor for both cephalosporinase and penicillinase activities.  相似文献   

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The phytochemical investigation of Dendropanax morbiferus H. Lév. Led to the isolation of 28 known compounds: 4 alkaloids (14), 1 pyranoglucoside (5), 1 benzoic acid and 5 benzoic acid derivatives (611), 10 phenylpropanoids (1221), 4 flavone glucoside derivatives (2225), 1 neolignan (26) and 2 sesquiterpenes (2728). The structures of these compounds were identified using spectroscopic methods; their nuclear magnetic resonance spectra were compared with those previously reported. This is the first report on compounds 24, 10, and 12 isolated from D. morbiferus. Compounds 5 and 26 from the genus Dendropanax and 1, 69, 11, 13, 1425, 27 and 28 from the family Araliaceae were isolated for the first time. Additionally, to the best of our knowledge, this is the first comprehensive chemical investigation of D. morbiferus stems and leaf compounds. Chemotaxonomic relationship between D. morbiferus and other Dendropanax species is also discussed.  相似文献   

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A core from Töölönlahti, a bay close to the central business district of Helsinki, the capital of Finland, was analysed for its pollen stratigraphy. The extrapolated age-depth curve based on137Cs dating, sphaeroidal carbonaceous particle analysis and historical data suggests that the core goes back to the 17th or early 18th century. Four local pollen assemblage zones (LPAZ) were identified. Detrended correspondence analysis was used to detect the main phases of change represented by these zones. The basal LPAZ indicates that the vegetation was characterized by forest dominated byPinus sylvestris andPicea abies during the early history of the city of Helsinki and that human impact remained relatively minor until the end of the 19th century. A drastic change in vegetation took place at the turn of the 19/20th century when bothPinus andPicea declined rapidly while pollen values of several anthropogenic indicators rose. These changes were synchronous with the rapid expansion of population and urban area in Helsinki. Rarefaction analysis shows that palynological richness was highest during the early phase of increased human impact but then started to fall. During the 20th century the main vegetational trend has been the proliferation of introduced park trees. Palynological richness has decreased.  相似文献   

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