Referenzierung - eine Möglichkeit zur Korrektur des Laborbias bei der Bodendauerbeobachtung am Beispiel der Nationalen Bodenbeobachtung Schweiz (NABO)

In der Nationalen Boden¬be¬ob¬ach¬tung der Schweiz wird seit Beginn Mitte der 1980-er Jahre für die Schwermetallanalytik ein Re-fe¬ren¬zie¬rungs¬system zur Korrektur des Labor¬bias angewendet. Dieses Vorgehen ist wesentlich aufwän¬diger als die Ver-wen¬dung von Standardproben zur Korrektur des Laborbias und es stellte sich die Fra¬ge, ob dieser Mehrauf¬wand gerecht¬fer¬tigt ist. Zur Be¬antwortung wurden 15 Jahre nach Beginn der Zeitreihen sämt¬liche Ar¬chiv¬pro¬ben erneut aufgeschlossen und zu¬sam¬men mit den Proben aus der ak¬tu¬ellen Er¬he¬bung erneut analysiert. Damit steht ein Datensatz zur Verfügung, der es er¬laubt, verschiedenste Frage¬stel¬lun¬gen im Zu-sammenhang mit der Re¬pro¬du¬zier¬bar¬keit und Korrektheit von Zeit¬rei¬hen in der Bo-dendauerbeobachtung zu über¬prüfen. So kann gezeigt werden, dass das Ana¬ly-tik¬labor im Verlaufe der Zeit besser wurde, die zufällige Variabilität wurde stets ge¬rin-ger. Der Verlauf der zeitgleich gemessenen Wer¬te stimmt mit dem Verlauf der re¬fe¬ren-zierten Werte überein und bestätigt damit die Korrektheit. Die Referenzierung elimi-niert den Labor¬effekt weitgehend. Die Er-geb¬nisse zeigen, dass sich das Prin¬zip der Re¬ferenzierung in der Praxis be¬währt. Ohne Referenzierung kann der effektive Ver¬lauf der Gehalte über die Zeit nicht korrekt abgebildet werden. Dies kann im Ein¬zelfall zu nicht gerechtfertigten Mass-nah¬men durch die Vollzugsbehörden füh-ren

Species turnover reveals hidden effects of decreasing nitrogen deposition in mountain hay meadows

Nitrogen (N) deposition is a major threat to biodiversity in many habitats. The recent introduction of cleaner technologies in Switzerland has led to a reduction in the emissions of nitrogen oxides, with a consequent decrease in N deposition. We examined different drivers of plant community change, that is, N deposition, climate warming, and land-use change, in Swiss mountain hay meadows, using data from the Swiss biodiversity monitoring program. We compared indicator values of species that disappeared from or colonized a site (species turnover) with the indicator values of randomly chosen species from the same site. While oligotrophic plant species were more likely to colonize, compared to random expectation, we found only weak shifts in plant community composition. In particular, the average nutrient value of plant communities remained stable over time (2003-2017). We found the largest deviations from random expectation in the nutrient values of colonizing species, suggesting that N deposition or other factors that change the nutrient content of soils were important drivers of the species composition change over the last 15 years in Swiss mountain hay meadows. In addition, we observed an overall replacement of species with lower indicator values for temperature with species with higher values. Apparently, the community effects of the replacement of eutrophic species with oligotrophic species was outweighed by climate warming. Our results add to the increasing evidence that plant communities in changing environments may be relatively stable regarding average species richness or average indicator values, but that this apparent stability is often accompanied by a marked turnover of species

Developing the Swiss mid-infrared soil spectral library for local estimation and monitoring

Information on soils' composition and physical, chemical and biological properties is paramount to elucidate agroecosystem functioning in space and over time. For this purpose, we developed a national Swiss soil spectral library (SSL; nCombining double low line4374) in the mid-infrared (mid-IR), calibrating 16 properties from legacy measurements on soils from the Swiss Biodiversity Monitoring program (BDM; nCombining double low line3778; 1094 sites) and the Swiss long-term Soil Monitoring Network (NABO; nCombining double low line596; 71 sites). General models were trained with the interpretable rule-based learner CUBIST, testing combinations of {5,10,20,50, and 100} ensembles of rules (committees) and {2, 5, 7, and 9} nearest neighbors used for local averaging with repeated 10-fold cross-validation grouped by location. To evaluate the information in spectra to facilitate long-term soil monitoring at a plot level, we conducted 71 model transfers for the NABO sites to induce locally relevant information from the SSL, using the data-driven sample selection method RS-LOCAL. In total, 10 soil properties were estimated with discrimination capacity suitable for screening (R2≥0.72; ratio of performance to interquartile distance (RPIQ) ≥ 2.0), out of which total carbon (C), organic C (OC), total nitrogen (N), pH and clay showed accuracy eligible for accurate diagnostics (R2>0.8; RPIQ ≥ 3.0). CUBIST and the spectra estimated total C accurately with the root mean square error (RMSE) Combining double low line 8.4 gkg-1 and the RPIQ Combining double low line 4.3, while the measured range was 1-583 gkg-1 and OC with RMSE Combining double low line 9.3 gkg-1 and RPIQ Combining double low line 3.4 (measured range 0-583 gkg-1). Compared to the general statistical learning approach, the local transfer approach - using two respective training samples - on average reduced the RMSE of total C per site fourfold. We found that the selected SSL subsets were highly dissimilar compared to validation samples, in terms of both their spectral input space and the measured values. This suggests that data-driven selection with RS-LOCAL leverages chemical diversity in composition rather than similarity. Our results suggest that mid-IR soil estimates were sufficiently accurate to support many soil applications that require a large volume of input data, such as precision agriculture, soil C accounting and monitoring and digital soil mapping. This SSL can be updated continuously, for example, with samples from deeper profiles and organic soils, so that the measurement of key soil properties becomes even more accurate and efficient in the near future

GEOCHEMISTRY OF EUROPEAN BOTTLED WATER

In Europe, ca. 1900 "mineral water" brands are officially registered and bottled for drinking. Bottled waters is groundwater and is in large parts of the continent rapidly developing into the main supply of drinking water for the general population. This book is the first state of the art overview of the chemistry of groundwaters from 40 European countries from Portugal to Russia, measured on 1785 bottled water samples, equivalent to 1189 distinct bottled water brands from 1247 wells in 884 locations plus an additional 500 tap water samples acquired in 2008 by the network of EuroGeoSurveys experts all across Europe. In contrast to previously available compilations, all chemical data (contained on the enclosed CD) were measured in a single laboratory, under strict quality control with high internal and external reproducibility, affording a single high quality, internally consistent dataset. More than 70 parameters were determined on every sample using state of the art analytical ..

URBAN GEOCHEMICAL STUDIES IN EUROPE

Urban soil is generally contaminated to a variable degree depending on its proximity to contamination sources. Traffic is one of the main sources of urban contamination; lead (Pb) from the use of leaded petrol, zinc (Zn) and cadmium (Cd) from tyre wear, antimony (Sb) from break pads, and the platinum group elements (PGEs) from the wear of catalytic converters, are some typical elements that often reach high concentrations in the urban environment. Lead was also a key ingredient in white paint, and in towns with a high proportion of white wooden houses very high concentrations were found in soil. Crematoria can or have emitted mercury (Hg). Coal and heavy oil fired municipal power and heating stations emit sulphur (S), silver (Ag), vanadium (V), bromine (Br) and barium (Ba). The use of impregnated wood may have resulted in high concentrations of arsenic (As), especially in kindergartens (nursery schools) and playgrounds. Building materials (plaster and paint) may also contain high concentrations of organic contaminants, especially polychlorinated biphenyls (PCBs), which again end up in urban soil. Coal and wood burning, the use of diesel fuel, and the production of coke, all lead to the emission of polycyclic aromatic hydrocarbons (PAHs). There exist countless other sources of local contamination in towns, and there is thus every reason to be concerned about the quality of the urban environment, and the suitability of soil for sensitive land uses, such as schools, playgrounds, parks and vegetable gardens. Contaminated urban soil may contaminate indoor dust and, therefore, to an increased human exposure to toxic chemicals. Consequently, the distribution of toxic contaminants in urban soil needs to be documented and known by city administration to avoid costly mistakes in land use planning, and further spreading of highly contaminated materials. The EuroGeoSurveys \u2018Geochemistry\u2019 Expert Group during the compilation of a proposal to the Directors for a European wide urban geochemistry project, using a harmonised sampling and analytical methodology, it discovered that many urban geochemical studies have been performed in Europe by National Geological Surveys, which are not known to the wider geoscientific community. Since, the results of these studies are directly related to our quality of life, the EuroGeoSurveys \u2018Geo chemistry\u2019 Expert Group decided to publish at least one case study from each country in a book,which will be available in the second half of 2010. A concise description of some of these studies will be given in this paper

Geochemical atlases of Europe produced by the EuroGeoSurveys Geochemistry Expert Group: state of progress and potential uses.

An ‘Atlas’is a collection of maps usually published in a book form. A ‘Geochemical Atlas’is a thematic special purpose atlas with maps describing the geographical distribution of chemical elements and other physico-chemical parameters in different natural sample media, such as stream sediment, overbank or floodplain sediment, stream water, ground water, soil, plants, etc. Because our standard of living and health depend closely on the chemistry of near-surface materials, such atlases that provide data on the state of our environment are important for policy and decision makers, but also for researchers and citizens alike. The EuroGeoSurveys Geochemistry Expert Group is dedicated to provide harmonised multi-purpose geochemical data bases, and has already published the Geochemical Atlas of Europe, and is in the process of preparing the Atlas of Ground water eochemistry of Europe, and the Atlas of Agricultural and Grazing Land Soils. An important aspect is that all raw data, quality control information, statistics, maps and interpretation texts are freely available for downloading through the internet