Does low soil base saturation affect fine root properties of European beech ( Fagus sylvatica L.)?

It is generally believed that high soil solution Al3+ in acidic soils with low base saturation (BS), negatively influences the properties of fine roots. Fine roots from European beech (Fagus sylvatica L.) trees growing in highly acidic soils with very low BS and potentially high Al3+ concentration in the soil solution were analysed and the dependency of fine root properties on soil BS was measured. The fine roots were sampled down to 1m depth at seven forest sites located on the Swiss Plateau. These sites varied in their BS from 1.4 to 11.4% in the mineral layers. We evaluated relationships between the BS of these mineral layers and fine root properties, such as ratio between bio- and necromass (live/dead ratio), specific root length (SRL), root tip abundance (RTA), root branching abundance (RBA), O2-consumption, and the Ca/Al molar ratio in the fine root tissue. The fine root properties were compared not only with the BS of the soil, but also with the Ca/Al molar ratio in the fine root tissues. Significant relations of fine root properties occurred when the soils of the seven sites were grouped into two BS groups (<5 and 5-10%). The live/dead ratio, the RTA, the RBA, the O2-consumption, and Ca/Al molar ratio were lower in the group of BS <5% than in the group 5-10%. Decreases in the morphological properties and in the O2-consumption were related to decrease in the Ca/Al molar ratio of the fine root tissues. There is evidence that the fine root properties are negatively influenced, nevertheless, fine root systems of mature European beech in their natural ecological environment seem to be able to compensate adverse effects of low B

Machine learning based soil maps for a wide range of soil properties for the forested area of Switzerland

Spatial soil information in forests is crucial to assess ecosystem services such as carbon storage, water purification or biodiversity. However, spatially continuous information on soil properties at adequate resolution is rare in forested areas, especially in mountain regions. Therefore, we aimed to build high-resolution soil property maps for pH, soil organic carbon, clay, sand, gravel and soil density for six depth intervals as well as for soil thickness for the entire forested area of Switzerland. We used legacy data from 2071 soil profiles and evaluated six different modelling approaches of digital soil mapping, namely lasso, robust external-drift kriging, geoadditive modelling, quantile regression forest (QRF), cubist and support vector machines. Moreover, we combined the predictions of the individual models by applying a weighted model averaging approach. All models were built from a large set of potential covariates which included e.g. multi-scale terrain attributes and remote sensing data characterizing vegetation cover. Model performances, evaluated against an independent dataset were similar for all methods. However, QRF achieved the best prediction performance in most cases (18 out of 37 models), while model averaging outperformed the individual models in five cases. For the final soil property maps we therefore used the QRF predictions. Prediction performance showed large differences for the individual soil properties. While for fine earth density the R2 of QRF varied between 0.51 and 0.64 across all depth intervals, soil organic carbon content was more difficult to predict (R2 = 0.19–0.32). Since QRF was used for map prediction, we assessed the 90% prediction intervals from which we derived uncertainty maps. The latter are valuable to better interpret the predictions and provide guidance for future mapping campaigns to improve the soil maps

Religion als religiös-ethnische Gemeinschaft. Das Beispiel der Parsi Zoroastrier in Indien

Zusammenfassung: Dieser Beitrag widmet sich der Charakterisierung einer Sozialform von Religion, die durch die Verknüpfung ethnischer und religiöser Grenzziehung gekennzeichnet ist. Dabei wird insbesondere auch die Frage nach ihrem Bestehen unter den Bedingungen moderner Gesellschaft gestellt. Als Fallbeispiel dienen die Parsi Zoroastrier Mumbais, die eine wichtige Rolle in der Modernisierung Indiens spielten und deren religiös-ethnische Tradition nun mit den Bedingungen der Moderne konfrontiert ist. In einem Modus erhöhter gemeinschaftlicher Konflikte und Reflexivität zeigen sich "zentripetale" Tendenzen der Bestätigung der bestehenden ethnischen und religiös-rituellen Praxis. Deren Analyse weist auf die Spezifität der hier untersuchten Sozialform hin: Zugehörigkeit ist von individuellen Entscheidungen weitgehend entkoppelt, kollektive Akteure fehlen, die die Gemeinschaft durch Entscheidungen verändern könnten und der bestätigende Bezug auf die gemeinschaftliche Tradition stellt in einer symbolisch deregulierten Situation den erfolgreichsten Weg zu gemeinschaftlichem Einfluss dar. Gekoppelt an Ethnizität ist religiöse Gemeinschaft unempfindlich gegenüber Entscheidungen individueller und kollektiver Akteure und kann ihre traditionelle Praxis bei gleichzeitiger Öffnung für Dissens wahre

Benefits of hierarchical predictions for digital soil mapping—An approach to map bimodal soil pH

Maps of soil pH are an important tool for making decisions in sustainable forest management. Accurate pH mapping, therefore, is crucial to support decisions by authorities or forest companies. Soil pH values typically exhibit a distinct distribution characterized by two frequently encountered pH ranges, wherein aluminium oxides (Al2O3) and carbonates (CaCO3) act as the primary buffer agents. Soil samples with moderately acid pH values (pH CaCl2 of 4.5-6) are less commonly observed due to their weaker buffering capacity. The different strength of buffer agents results in a distinct bimodal distribution of soil pH values with peaks at pH of around 4 and 7.5. Commonly used approaches for spatial mapping neglect this often observed characteristic of soil pH and predict unimodal distributions with too many moderately acid pH values. For ecological map applications this might result in misleading interpretations. This article presents a novel approach to produce pH maps that are able to reproduce pedogenic processes. The procedure is suitable for bimodal responses where the response distribution is naturally inherent and needs to be reproduced for the predictions. It is model-agnostic, namely independent from the used statistical prediction method. Calibration data is optimally split into two parts corresponding each to a data culmination, i.e. for soil pH values belonging to the ranges of the two principal buffer agents (Al2O3 and CaCO3). For each subset a separate model is then built. In addition, a binary model is fitted to assign every new prediction location a probability to belong either to Al2O3 or CaCO3 buffer range. Predictions are combined by weighted mean. Weights are derived from probabilities predicted by the binary model. Degree of smoothness is chosen by sigmoid transform which allows for optimal continuous transition of the pH values between Al2O3 and CaCO3 buffer ranges. For each location uncertainty distributions may be combined by using the same weights. We illustrated application of the new approach to a medium and strong bimodal distributed response (1) pH in 0–5 cm and (2) pH in 60–100 cm of forest soils in Switzerland (2 530 calibration sites). While model performance measured at 354 validation sites slightly dropped compared to a common modelling approach (drop of R2 of 0.02–0.03) distributional properties of the predictions are much more meaningful from a pedogenic point of view. We were able to demonstrate the benefits of considering specific distributional properties of responses within the prediction process and expanded model assessment by comparing observed and predicted distributions

A decade of monitoring at Swiss Long-Term Forest Ecosystem Research (LWF) sites: can we observe trends in atmospheric acid deposition and in soil solution acidity?

Trends in atmospheric acid deposition and in soil solution acidity from 1995 or later until 2007 were investigated at several forest sites throughout Switzerland to assess the effects of air pollution abatements on deposition and the response of the soil solution chemistry. Deposition of the major elements was estimated from throughfall and bulk deposition measurements at nine sites of the Swiss Long-Term Forest Ecosystem Research network (LWF) since 1995 or later. Soil solution was measured at seven plots at four soil depths since 1998 or later. Trends in the molar ratio of base cations to aluminum (BC/Al) in soil solutions and in concentrations and fluxes of inorganic N (NO3-N + NH4-N), sulfate (SO4-S), and base cations (BC) were used to detect changes in soil solution chemistry. Acid deposition significantly decreased at three out of the nine study sites due to a decrease in total N deposition. Total SO4-S deposition decreased at the nine sites, but due to the relatively low amount of SO4-S load compared to N deposition, it did not contribute to decrease acid deposition significantly. No trend in total BC deposition was detected. In the soil solution, no trend in concentrations and fluxes of BC, SO4-S, and inorganic N were found at most soil depths at five out of the seven sites. This suggests that the soil solution reacted very little to the changes in atmospheric deposition. A stronger reduction in base cations compared to aluminum was detected at two sites, which might indicate that acidification of the soil solution was proceeding faster at these site

Religiöse Rituale und soziale Ordnung

In diesem Open-Access-Buch wird die Bedeutung von religiösen Ritualen für die soziale Ordnung systematisch untersucht. Dazu werden Konzepte des Zusammenhangs von Ritualen mit verschiedenen Ebenen des Sozialen erarbeitet: Interaktion, Gemeinschaft und Gesellschaft.; In diesem Open-Access-Buch wird die Bedeutung von religiösen Ritualen für die soziale Ordnung systematisch untersucht. Dazu werden Konzepte des Zusammenhangs von Ritualen mit verschiedenen Ebenen des Sozialen erarbeitet: Interaktion, Gemeinschaft und Gesellschaft

Drought response and changing mean sensitivity of European beech close to the dry distribution limit

European beech (Fagus sylvatica L.) covers a large area mainly in the colline and montane ranges in Europe, and a drier and warmer climate, as expected for the coming decades, is likely to alter its distribution. So far, an altitudinal shift has been projected using a variety of modelling approaches. However, we lack knowledge about the climatic and edaphic factors that control the growth and competitive behaviour of beech at its dry distribution limit. We applied and further developed dendroecological methods to study the drought response and sensitivity pattern of beech at sites with different moisture regimes. We compared three pairs of sites from different geographical regions near the dry distribution limit of beech in Switzerland, consisting of a dry and mesic site each. Radial growth differed between mesic and dry sites, in that average ring-width at mesic sites was around double the width at dry sites. For the whole study period (1930-2006), the sites with the lowest available soil water capacity (AWC) were found to respond most sensitively to drought. However, in recent years, sites with higher AWC have shown increasing drought sensitivity, i.e. they have responded even more strongly to drought than the dry sites. This change in sensitivity corresponds to a seasonal shift in drought response at mesic sites, with a change in the months showing significant drought response in all three studied regions compared with the past. Even though dry sites generally displayed a larger number of negative pointer years than mesic sites, it appears that the frequency of pointer years has increased at mesic sites, i.e. they have become more sensitive particularly in the last quarter of the twentieth century. Yet, the frequency of pointer years at the dry sites has remained fairly constant. These results indicate that beech trees near their dry distribution limit are adapted to extreme conditions already, while changes in the growth patterns of beech under mesic conditions have to be expecte