Vegetationskundliche Untersuchungen auf einer Schnellwuchsplantage mit Pappeln und Weiden nach Ackernutzung     

B. Heilmann  F. Makeschin  K. E. Rehfuess 《European Journal of Forest Research》1995,114(1):16-29

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Tree-ring: a suitable implement for spatial and temporal fire distribution analysis in savanna woodland and dry forest     

Franck Sinsin  Romain GlèlèKaka?  Bettina Orthmann  Brice Sinsin 《林业研究》2015,26(2):435-446

Based on 120 stem discs collected during3 months of fieldwork along a 12 km route,the history of fires in the Wari Maro Forest(09 1000 N–02 1000E) over the past century in savanna woodland and dry forest was reconstituted.Three major ecological areas are characterized:one highly burnt zone located between two relative less burnt areas.By analyzing tree rings,246 fire scars were identified.The scars were caused by 51 fire years,occurring at a mean interval of 2.23 years.From 1890 to1965,only 6 years with fires were recorded from sampled trees.Since 1966,no year has passed without fire.The fire frequency point scale reached 14 years.This was the case of Burkea africana,which has been identified as a species tolerant to fire and could be planted to create a natural firewall.In contrast,Anogeissus leiocarpa is highly sensitive to fire,and in a dry forest ecosystem that burns seasonally,it requires a special conservation plan.Two new concepts are described:the rebarking of trees after fire and Mean Kilometer Fire Interval.The first concept was tested with Daniellia oliveri(Rolfe) Hutch & Dalz trees,and the second concept was used to evaluate spatial fire distribution.We demonstrate that savanna woodland and dry forest were subject to a degradation process caused by destructive fires related to vegetation cover clearance and illegal logging.  相似文献   

Methods for the investigation of metabolic activities and shifts in the microbial community in a soil treated with a fungicide     

Bettina Heilmann  Michael Lebuhn  Friedrich Beese 《Biology and Fertility of Soils》1995,19(2-3):186-192

Samples from a sandy agricultural soil were treated with increasing amounts of a fungicide (Sportak). The effects on the soil microflora were investigated over several weeks by monitoring basal and substrate-induced respiration and basal and substrate-induced heat output. The microbial biomass, metabolic quotient (qCO₂), relative heat output (rqheat), lag phase of substrate use, and calorimetric: respirometric ratio were used as ecophysiological parametèrs. As structural and community-specific parameters, we recorded tryptophan contents and auxin metabolism, and calculated the ratios of fungal to bacterial respiration by antibiotic inhibition of substrate-induced respiration. Sportak either inhibited or stimulated the microbiota, depending on the length of exposure to the fungicide and the amount applied. Mineralization of dead biomass was reflected in increased soil tryptophan contents after the Sportak application. A shortened lag phase demonstrated inhibition and a prolonged lag phase stimulation of substrate use. This changed with the experimental phase. The rqheat and the calorimetric: respirometric ratio proved to be suitable parameters for the detection of stress metabolism (repair processes) in soil microbiota, because thermodynamic processes and catabolic and anabolic metabolism are taken into account at the same time. Following the application of Sportak, indole 3-acetic acid biosynthesis decreased while indole-3-ethanol biosynthesis increased, probably as a result of a transitional community shift from K-strategists towards r-strategists. It was not the fungicide but the formulation (mainly xylol) that damaged the organisms. A shift in the ratio of fungi to bacteria was also observed, suggesting that the bacteria were probably more sensitive to xylol than the fungi.  相似文献   

Carbon dynamics determined by natural C abundance in microcosm experiments with soils from long-term maize and rye monocultures     

Bettina John  Bernard LudwigHeiner Flessa 《Soil biology & biochemistry》2003,35(9):1193-1202

Understanding carbon dynamics in soil is the key to managing soil organic matter. Our objective was to quantify the carbon dynamics in microcosm experiments with soils from long-term rye and maize monocultures using natural ¹³C abundance. Microcosms with undisturbed soil columns from the surface soil (0-25 cm) and subsoil (25-50 cm) of plots cultivated with rye (C₃-plant) since 1878 and maize (C₄-plant) since 1961 with and without NPK fertilization from the long-term experiment ‘Ewiger Roggen’ in Halle, Germany, were incubated for 230 days at 8 °C and irrigated with 2 mm 10⁻² M CaCl₂ per day. Younger, C₄-derived and older, C₃-derived percentages of soil organic carbon (SOC), dissolved organic carbon (DOC), microbial biomass (C_mic) and CO₂ from heterothropic respiration were determined by natural ¹³C abundance. The percentage of maize-derived carbon was highest in CO₂ (42-79%), followed by C_mic (23-46%), DOC (5-30%) and SOC (5-14%) in the surface soils and subsoils of the maize plots. The percentage of maize-derived C was higher for the NPK plot than for the unfertilized plot and higher for the surface soils than for the subsoils. Specific production rates of DOC, CO₂-C and C_mic from the maize-derived SOC were 0.06-0.08% for DOC, 1.6-2.6% for CO₂-C and 1.9-2.7% for C_mic, respectively, and specific production rates from rye-derived SOC of the continuous maize plot were 0.03-0.05% for DOC, 0.1-0.2% for CO₂-C and 0.3-0.5% for C_mic. NPK fertilization did not affect the specific production rates. Strong correlations were found between C₄-derived C_mic and C₄-derived SOC, DOC and CO₂-C (r≥0.90), whereas the relationship between C₃-derived C_mic and C₃-derived SOC, DOC and CO₂-C was not as pronounced (r≤0.67). The results stress the different importance of former (older than 40 years) and recent (younger than 40 years) litter C inputs for the formation of different C pools in the soil.  相似文献   

Allele mining and haplotype discovery in barley candidate genes for drought tolerance     

András Cseri  Mátyás Cserháti  Maria von Korff  Bettina Nagy  Gábor V. Horváth  András Palágyi  János Pauk  Dénes Dudits  Ottó Törjék 《Euphytica》2011,181(3):341-356

In the present study, allele mining was conducted on a panel of drought related candidate genes in a set of 96 barley genotypes using EcoTILLING, which is a variant of the targeting induced local lesions in genomes (TILLING) technology. Analyzing approximately 1.5 million basepairs in barley a total number of 94 verified unique haplotypes were identified in 18 amplicons designed for 9 genes. Overall, 185 single nucleotide polymorphisms (SNPs) and 46 insertions/deletions (INDELs) were detected with a mean of 1SNP/92 bp and 1INDEL/372 bp genomic sequence. Based on overlapping haplotype sequences, markers were developed for four candidate genes (HvARH1, HvSRG6, HvDRF1, HVA1), which allows distinguishing between the main haplotypes showing either differences in amino acid sequence or which have larger INDELs in the promoter region. As “proof of concept”, the HvARH1 and HvSRG6 haplotypes were tested for the level of abscisic acid-induced gene expression in subsets of genotypes belonging to different haplotype categories. An integrated database was developed to contain information about the genes, genotypes, and haplotypes analyzed in this study. The database supplies profound information about the natural variation in the tested drought related candidate genes providing a significant asset for further mapping studies dealing with this highly polygenic trait.  相似文献   

Aroma quality differentiation of pyrazine derivatives using self-organizing molecular field analysis and artificial neural network   总被引：2，自引：0，他引：2  

Klocker J  Wailzer B  Buchbauer G  Wolschann P 《Journal of agricultural and food chemistry》2002,50(14):4069-4075

The encoding of various aroma impressions and the distinction between different aroma qualities are unsolved problems, as differences between aroma impressions can be described only in a qualitative but not in a quantitative manner. As a consequence, classifications of various aroma qualities cannot easily be performed by standard QSAR methods. To find a proper way to encode aroma impressions for SAR studies, a total of 50 pyrazine-based aroma compounds showing the aroma quality of earthy, green-earthy, or green are analyzed. Special attention is thereby turned on the mixed aroma impression green-earthy. Classifications on the whole data set as well as on smaller subsets are calculated using self-organizing molecular field analysis (SOMFA) and artificial neural networks (ANNs). SOMFA classifies between two or three aroma impressions, leading to models satisfying in predictive power. ANN analysis using multilayer perceptron network architecture with one hidden layer and nominal output as well as genetic regression neural network) with two hidden layers and numerical output both lead to a rather good performance rate of 94%.  相似文献   

Model immunization of mice for comparative testing of systemic and local administration of antigens. 1. Detection of antibody-producing cells and hemagglutinins following immunization with sheep erythrocytes     

G Müller  P Heilmann 《Archiv fuer experimentelle veterinaermedizin》1983,37(2):241-250

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Pasteurella multocida as the agent of atrophic rhinitis: significance of dermonecrotoxin in the suckling mouse test and in vitro demonstration of adherence properties     

P Kielstein  P Heilmann  T Magyar 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1987,34(3):216-226

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Rotavirus infections in calves. 1. Adaptation of calf-pathogenic strains of rotavirus to cell culture     

P Otto  H Günther  P Heilmann 《Archiv fuer experimentelle veterinaermedizin》1986,40(4):605-620

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Adhesion of Pasteurella to cells     

G Müller  H Rosner  D Schimmel  P Heilmann  J Prudlo  B Rohrmann 《Archiv fuer experimentelle veterinaermedizin》1988,42(1):1-11

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