Die Larvalsystematik der Eulen(Noctuidae)

Ohne Zusammenfassung     

Numerical modeling of water balance for temporary landfill cover in North Germany

At the end of waste disposal in 2005, a temporary mineral system was constructed to cover the waste body of the municipal landfill in Rastorf (N Germany). The aim of this study was to evaluate the effectiveness of this temporary cover system in limiting the infiltration of surface water into the waste body. The numerical modeling for the hydrological year 2012 was performed in FEFLOW 6.0. The required input data for modeling were achieved by laboratory measurements of the saturated hydraulic conductivity and the water retention characteristics of the mineral layers. The assumed initial and boundary conditions were based on in‐situ measurements of matrix potential and volumetric water content at three different measuring points by tensiometers, FDR sensors and observed meteorological conditions. The model was applied according to Darcy's and Richards' equations for variably saturated flow. Our results allowed assessing the components of water balance for a temporary cover system, especially water seepage into the waste body. The correlation between the measured and modeled volumetric soil water content in the layered temporary cover system was observed (R² = 0.56 to 0.90). Deviations between the measured and modeled values are superficially related to the soil´s heterogeneity. In conclusion, the measured and modeled water balance parameters indicate that the temporary coverage system remains effective in limiting the infiltration rate. However, our studies revealed that the calculated and measured water seepage exceeded the values allowable by the German regulations. Additional studies have to assess variations in the soil water characteristics caused by weather‐related wetting and drying cycles and influence of waste settlement changing the profile of slope.     

Textural Stability of Intermediate‐Moisture Extrudates: Effects of Formulation

Effects of formulation on the textural stability of intermediate‐moisture, flour‐based, “jerky”‐type extrudates were assessed. Potato‐based extrudates containing various particulate‐meat concentrations and different plasticizers (sucrose, fructose, glycerol, and glucose) were produced and subjected to accelerated storage for three weeks. The elastic modulus of the samples was measured before storage and then weekly. The relative fluidity and moisture mobility of the specimens were assessed by dynamic mechanical spectrometry (DMS), electron spin resonance (ESR), and nuclear magnetic resonance (NMR). Samples were also evaluated by fluorometry and X‐ray diffraction to determine the extent of browning reaction and degree of molecular ordering, respectively. While elastic modulus increased appreciably during storage, firming was progressively reduced by entrained meat content and also by plasticizers, especially glycerol; plasticized and meat‐containing samples had correspondingly lower tan δ peak temperatures as measured by DMS. Textural results were also in keeping with fluidity and local viscosity as assessed by ESR measurements. NMR T1 relaxation values, reflecting moisture mobility, increased during storage. Diffraction spectra were consistent with published observations of hydrated starch, suggesting that water may have been released due to increased association of proteinaceous constituents. Fluorescence measurements confirmed moderate Maillard browning in all samples and significant chlorogenic browning in glucose‐containing samples, although these effects were unrelated to degree of firming. It was concluded that textural stability was optimized by interruption of the matrix by dispersed meat or by plasticization by low molecular weight constituents.     

In situ volatile collection, analysis, and comparison of three Centaurea species and their relationship to biocontrol with herbivorous insects

Centaurea solstitialis, commonly known as yellow starthistle, is an invasive plant listed as a noxious weed in the western areas of North America and is the target of classical biological control, which involves release of herbivores known to be specific to this plant. These insects often choose their host plant on the basis of the volatile organic compounds (VOCs) emitted. Accordingly, volatile analysis of host plants can provide insight into VOCs that may attract and/or repel the insect. To this end, solid-phase microextraction (SPME) and a customized collection bag were utilized to perform in situ volatile collection on intact and mechanically damaged leaves of Centaurea solstitialis, Centaurea cyanus, and Centaurea cineraria. Volatile identification was performed by GC-MS, and the VOC differences were determined. The plants C. solstitialis and C. cyanus have been reported to attract the weevil, Ceratapion basicorne, a candidate for biological control, whereas C. cineraria does not attract the weevil. Major VOCs unique to C. cineraria include the sesquiterpenes cyclosativene, alpha-ylangene, and trans-alpha-bergamotene. The compound trans-beta-farnesene was unique to C. solstitialis and C. cyanus.     

Slope position regulates response of carbon and nitrogen stocks to cattle grazing on rough fescue grassland

Purpose

Grasslands play a crucial role in offsetting greenhouse gas emissions and mitigating climate change. A moderate change in grassland carbon (C) and nitrogen (N) stocks may substantially alter the global C and N cycle and thereby influence climate. But how grassland C and N stocks respond to grazing and slope position remains uncertain. This research investigates how C and N stocks respond to cattle grazing along a landscape slope.

Materials and methods

We studied a grassland that has been grazed by cattle at four cattle stocking rates (0, 1.2, 2.4, and 4.8 animal unit months (AUM) ha^?1) since 1949, representing control (CK), light (L), heavy (H), and very heavy (VH) grazing intensities, respectively. Samples were taken from the top and bottom slope positions within each paddock (only the top position in CK); C and N stocks in soil, roots, litter, and standing crop were estimated. Soil C and N stocks were estimated based on equivalent mass (1500 Mg ha^?1). Root C and N stocks were estimated to the depth of 15 cm.

Results and discussion

All parameters, except for litter N stock and standing crop C stock, significantly responded to the interaction of grazing intensity and slope position. In the bottom position, soil and standing crop C and N stocks as well as litter C stock were higher with the L treatment than with VH, while no significant differences were found among the three grazed treatments for root C and litter N stocks. In the top position, soil and root C and N stocks were higher with the VH treatment than with L, whereas litter C and N stocks and standing crop C stock were lower with VH than with L.

Conclusions

Our results provide evidence that slope position plays an important role in regulating the response of C and N stocks to grazing and may need to be considered when developing optimal grazing management strategies.

     

Conversion of citronellyl diphosphate and citronellyl beta-D-glucoside into rose oxide by Pelargonium graveolens

Deuterium-labeled citronellyl diphosphate and citronellyl beta-D-glucoside were fed to Pelargonium graveolens. Both precursors were converted into cis-/trans-rose oxide. Citronellyl diphosphate is more effectively converted into rose oxide. The phloem exudate of P. graveolens was analyzed after enzymatic cleavage of the glucosidated and phosphorylated volatiles. It could be shown that glucosidically bound citronellol is translocated in the plant. Phosphorylated citronellol could not be detected.     

Foliar Phosphorus Applications in the Forms of Phosphate and Phosphite Have Contrasting Effects on Wheat Performance Under Field Conditions

Journal of Crop Science and Biotechnology - Since phosphite (Phi) cannot replace phosphate (Pi) as source of phosphorus (P) for plants, and grain crops might experience P deficiency after anthesis,...     

Screening techniques and improved biological nitrogen fixation in cool season food legumes

Dinitrogen fixation and legume productivity are greatly influenced through the interactions of legume host, Rhizobium, and the above- and below-ground environment. The benefits of improving legume N₂ fixation include reduced reliance on soil N, leading to more sustainable agricultural systems and reduced requirements for fertilizer N, enhanced residual benefits to subsequent crops, and increased legume crop yields. Most of the gains in N₂ fixation to date have been derived from management of legume cropping systems and through inoculation of legume seed with competitive and symbiotically effective rhizobia. Further gains are possible by developing plant cultivars with tolerance to soil abiotic factors, increased plant yield, and a broader and more effective matching of plant host and rhizobia. Techniques for screening material for superior N₂ fixation and examples of programs to increase fixed N, with attention to the major abiotic stresses, are discussed.