Nano-scale secondary ion mass spectrometry — A new analytical tool in biogeochemistry and soil ecology: A review article

Soils are structurally heterogeneous across a wide range of spatio-temporal scales. Consequently, external environmental conditions do not have a uniform effect throughout the soil, resulting in a large diversity of micro-habitats. It has been suggested that soil function can be studied without explicit consideration of such fine detail, but recent research has indicated that the micro-scale distribution of organisms may be of importance for a mechanistic understanding of many soil functions. Current techniques still lack the adequate sensitivity and resolution for data collection at the micro-scale, and the question ‘How important are various soil processes acting at different scales for ecological function?’ is therefore challenging to answer. The nano-scale secondary ion mass spectrometer (NanoSIMS) represents the latest generation of ion microprobes, which link high-resolution microscopy with isotopic analysis. The main advantage of NanoSIMS over other secondary ion mass spectrometers is its ability to operate at high mass resolution, whilst maintaining both excellent signal transmission and spatial resolution (down to 50 nm). NanoSIMS has been used previously in studies focussing on presolar materials from meteorites, in material science, biology, geology and mineralogy. Recently, the potential of NanoSIMS as a new tool in the study of biophysical interfaces in soils has been demonstrated. This paper describes the principles of NanoSIMS and discusses the potential of this tool to contribute to the field of biogeochemistry and soil ecology. Practical considerations (sample size and preparation, simultaneous collection of isotopes, mass resolution, isobaric interference and quantification of the isotopes of interest) are discussed. Adequate sample preparation, avoiding bias due to artefacts, and identification of regions-of-interest will be critical concerns if NanoSIMS is used as a new tool in biogeochemistry and soil ecology. Finally, we review the areas of research most likely to benefit from the high spatial and high mass resolution attainable with this new approach.     

Genetic Erosion – Examples from Italy<Superscript>1,2</Superscript>

Italy has been used as a country for estimating genetic erosion in crops. It was possible to compare early surveys (from the 1920s to the 1950s), especially on wheats, with results of later missions in the 1980s and 1990s. In the early years, a relatively high genetic erosion was observed (13.2% p.a.). From the 1950s until the 1980s erosion rates between 0.48 and 4% p.a. were estimated. In the little island of Favignana there was an erosion rate of 12.2% p.a. leading to the extinction of the last wheat landraces of this island. There have been no significant differences in erosion rates between field- and garden-crops though there has been the impression that garden crops are better preserved over the long run. Interestingly extinction rates of wild plants (0.13% in the Mediterranean) come close to the average erosion rates of crop plants in the area. ¹Dedicated to Erna Bennett on the occasion of her 80^th birthday ²Lecture presented during the XVII^th Congress of EUCARPIA in Tulln, Austria, 2004     

New versus old scientific names in strawberries (Fragaria L.)

New Potentilla synonyms of the Fragaria species names are discussed and considered to be dispensable. Further unnecessary nomenclatural changes based on the argument to recognize monophyletic but not paraphyletic taxa should be avoided to maintain nomenclatural stability for global communication about plant genetic resources. The new combination Fragaria×rosea (Mabb.) K. Hammer et Pistrick is presented for the hybrid Potentilla palustris (L.) Scop. ×Fragaria×ananassa Duchesne ex Rozier.     

Predictions of soil water and crop growth dynamics using the agroecosystem models THESEUS and OPUS

The agroecosystem models THESEUS and OPUS were tested with data obtained from three agricultural experimental field plots on sandy soils without groundwater located at the moraine landscape in East Brandenburg, Germany. At each of these plots, a separate agricultural management practice was applied. Measurements of soil water contents, pressure heads, above‐ground crop biomass, and crop yield from these three plots were compared with the corresponding simulation results of both models. The comparisons of simulated with measured outputs were analyzed using the modeling‐efficiency index IA. According to these analyses, both models simulated adequately the time courses of volumetric soil water contents and above‐ground crop biomass, but the time courses of pressure heads were predicted with a lower quality by both models. As for the pressure heads, the yields simulated with both models showed greater discrepancies in comparison with the observed ones. This indicates the need of a site‐specific parameter calibration of the crop‐growth modules, especially for that included in OPUS .     

Taxonomy and evolution of cultivated plants: Literature review 1985/1986

Summary Important papers on taxonomy and evolution of cultivated plants published in 1985 and 1986 were compiled and briefly discussed.

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Taxonomie und Evolution der Kulturpflanzen: Literaturübersicht 1985/1986

Zusammenfassung Wichtige Arbeiten über Taxonomie und Evolution der Kulturpflanzen aus den Jahren 1985 und 1986 wurden zusammengestellt und kurz kommentiert.

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¶rt; : 1985–1986

¶rt; , 1985 1986 . .

     

Räumlich differenzierende Berechnung großmaßstäblicher Erosionsprognosekarten - Modellgrundlagen der dABAG

A Spatially Differenciating Method for Computing High Resolution Maps of Soil Loss by Rain Wash - Fundamental Principles of the dUSLE The theoretical basis of a procedure to compute maps of the soil loss is presented. This procedure allows to estimate soil loss on a large scale (1:5000) for planning specific protection measures. The procedure uses the Universal Soil Loss Equation combined with a digital terrain model that consists of a triangulated, irregular network. In this way not only slope but also the influence of increasing soil loss down slope and the slope morphology are taken into account. Also, slope morphology is considered along the slope as well as across the slope. Therefore the procedure is called differentiating Universal Soil Loss Equation dUSLE. With the dUSLE it is possible to combine high resolution with high automatisation and reasonable computation time. The application of the USLE has the advantage of easy use and availability of data. Furthermore, most parts of the USLE have been adapted to and verified for German conditions in recent years. In part 2 the integration of the equations presented in the digital terrain model will be described. In a third part the application of the dUSLE in land reconsolidation and farmers extension service will be presented.     

Modeling protein functional properties from amino acid composition

Physicochemical and functional properties of proteins were modeled as a function of the contributions of each of the 20 coded amino acids to three (z-scores) or five (extended z-scores) amino acid principal properties using partial least squares regression. The five term models were in all cases stronger in both fit and prediction than the three term models, indicating that useful information is contained in the fourth and fifth property scores. Models predicting protein hydrophobicity (R = 0.932), viscosity (R = 0.737), and foam capacity (R = 0.880) from amino acid composition rather than sequence were obtained. It is likely that additional functional and physicochemical properties of proteins can be modeled in this way.     

Long-term trapping efficiency of a vegetated filter strip under agricultural use

In a hops-producing area long-term average trapping-effectiveness of a grassed filterstrip under agricultural use was measured. Copper, applied as fungicide, was used to identify the colluvium in a meadow below a hop garden. 9,5 t material were trapped during 17 years per m width of the filterstrip. This annual accumulation of 540 kg/m width represents a trapping efficiency of 55% of the computed annual soil loss of the hop garden. The results agree with other publications which report the trapping efficiency for a longer period, whereas the reported results of short-term experiments largely overestimate the efficiency.