Regensburger Beiträge zur Bodenkunde, Landschaftsökologie und Quartärforschung; Band 10: Standortvariabilität von Radiocäsium in Böden

Die Bedeutung von Humusauflagen in Waldökosystemen im Rahmen der Schadstofffilterung und in ihrer Funktion als Senken- und Quellen für Schadstoffe, ist besonders eindrucksvoll über die Einträge mit langlebigen Radionukliden aus dem Tschernobyl-Fallout des Jahres 1986 klar geworden. Bei einer Halbwertzeit von 31,17 Jahren ist auch in weiten Teilen Mitteleuropas das Radionuklid Cäsium 137 (Cs137) radioökologisch relevant. Besonders betroffen sind die Nordalpen sowie die südostbayerischen Mittelgebirge, vor allem der Bayerische Wald. Zwar nimmt die Ortsdosisleistung ab, aber das dem Kalium chemisch analoge Cäsium wird vom Forstökosystem einerseits in den humosen Auflagen fixiert und ist dort andererseits in hohem Maße bioverfügbar. Infolge seiner Analogie zum Kalium wird es von Pilzen und Pflanzen in Kraut-, Strauch- und Baumschicht als den ersten Gliedern in der Nahrungskette bevorzugt als vermeintliches Makronährelement aufgenommen. Je mächtiger die organischen Auflagehorizonte entwickelt sind, um so nachhaltiger wird das Radionuklid als Kontaminante der gesamten Nahrungskette in bioverfügbarer Form in den Humusauflagen der Forstökosysteme gespeichert. Das ist der Grund dafür, warum sich Radionuklide wie Cs137, das bei allen kerntechnischen Prozessen im Störungsfall in die Umwelt gelangt, über Generationen hinweg in den Forstökosystemen halten wird. Die organischen Auflagen steuern seine Verweildauer und Präsenz. Die Kenntnis ihrer Mächtigkeiten ist sowohl für Fragen des radioökologischen Gebietsmonitorings als auch der Modellierung von herausragendender Bedeutung. Die Ermittlung der Humusmächtigkeiten ist in der Regel mit zeitaufwendigen Kartierungsarbeiten verbunden. In der vorliegenden Studie werden Möglichkeiten aufgezeigt mittels geophysikalischer Methoden (hier Bodenradar / Ground Penetrating Radar) die Mächtigkeiten der Humusauflagen und der liegenden Ah-Horizonte zu ermitteln, ohne direkte Eingriffe in den Boden zu tätigen. Damit sind auch nachfolgende Untersuchungen an ungestörten Flächen durchführbar, was den großen Vorteil der hier erstmals umgesetzten Methodik darstellt. Die vorgestellte Studie wurde vom Bayerischen Staatsministerium für Umwelt, Gesundheit und Verbraucherschutz (BayStMUGV, München) in Auftrag gegeben

A Novel Approach to Monitoring the Cs-137 Contamination of Forest Soils in Bavaria, Germany

Regarding the radioactive fission product Cs-137, particularly forest soils are hot spots of long-term contamination. Previous studies have indicated that monitoring should take account of the exceptional role of humus for Cs-137 mobility and bioavailability to effectively evaluate contamination patterns and to enhance future protection strategies in forests. As official programmes in Bavaria lack such considerations, a new monitoring project has been established together with the Bavarian State Ministry of the Environment and Public Health, focussing on humus-controlling landscape parameters (relief, vegetation etc.) as crucial core criteria. Comprising a total of 48 sites, the project provides a solid base for future research. Both the site selection process and first results are presented here

Soil Mapping Using Electromagnetic Induction to Assess the Suitability of Land for Growing Leptospermum nitens in Western Australia

Leptospermum sp. with dihydroxyacetone in their nectar are a source of high-value medicinal honey production and can provide income from agriculturally marginal lands. The current study was from two newly planted Leptospermum nitens sites, one with duplex soil and the other in deep sandy soil, in the low rainfall areas of the south-west of Western Australia, with the aim of identifying key soil parameters influencing the plantation’s survival and growth. Electromagnetic induction (EMI) at different depths was used to investigate the possible impact of soil variability on the Leptospermum nitens plantations. Two EMI surveys were conducted at each site, at different times of the year, to account for soil moisture variability (relatively dry and wet conditions). A least-square inversion algorithm was used to determine true electrical conductivities at three different soil depths (0–0.5, 0.5–0.8, and 0.8–1.6 m) to produce quasi-3D maps of soil inverted electrical conductivity. Corresponding soil samples from each depth were used for the physico-chemical analysis of soil parameters and to develop laboratory-based electrical resistivity to soil volumetric moisture calibrations with R2 values between 0.95 and 0.99. Shrub survival and growth (canopy diameter) were estimated using unmanned aerial vehicle (UAV) images and machine learning. Comparing EMI soil mapping with UAV imagery results showed significantly greater shrub survival and growth (p < 0.001) in areas with higher ECa ranges of 12–24 mS m−1 at the variable textured site and 6–9 mS m−1 at the uniformly sandy site. Overall, the variable textured site, with an 82% survival rate, had a significantly higher shrub count and larger plants than the uniformly sandy site, with a 75% survival rate. A principal component analysis (PCA) identified inverted EC to be strongly correlated with soil moisture > pH > soil texture. Such soil mapping may be a robust and effective method for risk assessment of new shrub plantations

Vacuum drying soil samples is a low-temperature alternative to conventional oven drying when determining soil water repellence

Here we investigated a low-temperature (20˚C) soil drying technique to generate soil water contents equivalent to those achieved by conventional oven drying (105˚C). The effect of drying temperature, plus aeration status (oxic or anoxic), on SWR was also investigated

Geomorphic and sedimentary signatures of catastrophic glacier detachments: A first assessment from Flat Creek, Alaska

Large-volume detachments of low-angle mountain glaciers involve the sudden mobilization of large amounts of glacier ice and lithic material in long-runout mass flows. Scientific investigations of these events have only recently brought to light their global occurrence and the similarities in the conditions under which they occur. While this recent research suggests that glacier detachments may become more frequent in a warming climate, a long-term record is largely lacking. Knowledge of the geomorphic signatures of glacier detachments could help establish such a record. Here, we present the first geomorphic and sedimentary assessment of a glacier detachment deposit. We investigate the landscape impacts of the Flat Creek glacier detachments in Alaska's St. Elias mountains through a combination of remote sensing analyses, field observations, Electrical Resistivity Tomography, and grain size and grain orientation analyses. From these data, we outline a land-system model that may help identify past glacier detachments elsewhere. Some of the most distinguishing features we documented were large bodies of buried ice-conglomerates, a rapid response of the remnant glacier ice, clusters of small-scale thermokarst ponds, countless molards, parallel striations etched into the hillslope and individual clasts, and a very long runout distance. We assess these features in terms of their longevity in the landscape and compare them to what has been described at glacier detachment sites elsewhere. Finally, we discuss to what extent glacier detachment deposits can be distinguished from deposits left by rock(−ice) avalanches, debris flows, and surging glaciers, and show that a differentiation is possible if detailed field investigations are undertaken

Projektifizierung durch EU-Förderung: Konturen und Tätigkeitsbereiche der EU-Projektwelt

Dieser Beitrag nimmt die Durchsetzung und die Verbreitung der »Projektlogik« in der EU-Förderpolitik in den Blick und skizziert die vielfältigen Arbeits- und Tätigkeitsbereiche, die in den vergangenen Jahren rund um die EU-Förderpolitik entstanden sind. Ausgehend von der Diskussion um einen generellen Trend zur "Projektifizierung" von Arbeit und Leben in der Gegenwartsgesellschaft werden zunächst die grundlegenden Merkmale der Projektorganisation und die Etablierung des Projektmanagements als Managementmodell dargestellt. Daraufhin werden die wichtigsten Prinzipien, Praktiken und Tätigkeitsbereiche der Projektwelt der EU-Förderpolitik sowie einige Merkmale der »Professionalisierung« des EU-Projektmanagements skizziert. Dabei soll deutlich werden, wie stark die Logik des Projektmanagements die Umsetzung der EU-Förderpolitik heute durchdringt und inwiefern davon vor allem solche Akteur/-innen profitieren, die die Spielregeln der Projektwelt der EU-Förderung beherrschen und geschickt anzuwenden wissen.

Extended Trochanteric Osteotomy with Intermediate Resection Arthroplasty Is Safe for Use in Two-Stage Revision Total Hip Arthroplasty for Infection

Background: This study sought to compare the results of two-stage revision total hip arthroplasty (THA) for periprosthetic infection (PJI) in patients with and without the use of an extended trochanteric osteotomy (ETO) for removal of a well-fixed femoral stem or cement. Methods: Thirty-two patients who had undergone an ETO as part of a two-stage revision without spacer placement were matched 1:2 with a cohort of sixty-four patients of the same sex and age who had stem removal without any osteotomy. Clinical outcomes including interim revision, reinfection and aseptic failure rates were evaluated. Modified Harris hip scores (mHHS) were calculated. Minimum follow-up was two years. Results: Patients undergoing ETO had a significantly lower rate of interim re-debridement compared to non-ETO patients (0% vs. 14.1%, p = 0.026). Reinfection following reimplantation was similar in both groups (12.5% in ETO patients vs. 9.4% in non-ETO patients, p = 0.365). Revision for aseptic reason was necessary in 12.5% in the ETO group and 14.1% in the non-ETO group (p = 0.833). Periprosthetic femoral fractures were seen in three patients (3.1%), of which all occurred in non-ETO patients. Dislocation was the most common complication, which was equally distributed in both groups (12.5%). The mean mHHS was 37.7 in the ETO group and 37.3 in the non-ETO group, and these scores improved significantly in both groups following reimplantation (p < 0.01). Conclusion: ETO without the use of spacer is a safe and effective method to manage patients with well-fixed femoral stems and for thorough cement removal in two-stage revision THA for PJI. While it might reduce the rate of repeated debridement in the interim period, the use of ETO appears to lead to similar reinfection rates following reimplantation

Effects of three intravitreal injections of aflibercept on the ocular circulation in eyes with age-related maculopathy

Aims: To investigate changes in ocular perfusion following three consecutive intravitreal injections with aflibercept for treatment of neovascular age-related macular degeneration (nAMD). Methods The study included 20 eyes from 20 Caucasian patients with unilateral nAMD and 20 fellow eyes. All nAMD eyes were treated with standard intravitreal injection of aflibercept (IVA;2 mg). Measurements of ocular perfusion at the optic nerve head (ONH) and the choroid were performed with laser speckle flowgraphy (LSFG). Measurements were conducted at baseline, 1 week after the first injection, at the time point of the second and third injection as well as 1 month after the third injection. Results In treated eyes, mean blur rate (the main output parameter of LSFG) in the ONH microvasculature and in the choroid was significantly reduced 1 week after the first IVA treatment. The effect persisted throughout the entire follow-up period (p<0.001). No change in ocular perfusion was observed in fellow eyes. Conclusions: IVA for treatment of nAMD leads to a reduction in perfusion of the ONH and the choroid in the treated eye with no apparent effect on the fellow eye