Temporal and spatial variation of a winter soundscape in south-central Alaska

Context

Winter soundscapes are likely different from soundscapes in other seasons considering wildlife vocalizations (biophony) decrease, wind events (geophony) increase, and winter vehicle noise (technophony) occurs. The temporal variation and spatial relationships of soundscape components to the landscape in winter have not been quantified and described until now.

Objectives

Our objectives were to determine the temporal and spatial variation and acoustic–environmental relationships of a winter soundscape in south-central Alaska.

Methods

We recorded ambient sounds at 62 locations throughout Kenai National Wildlife Refuge (December 2011–April 2012). We calculated the normalized power spectral density in 59,597 recordings and used machine learning to determine acoustic–environmental relationships and produce spatial models of soundscape components.

Results

Geophony was the most prevalent component (84 %) followed by technophony (15 %), and biophony (1 %). Geophony occurred primarily at night, varied little by month, and was strongly associated with lakes. Technophony and biophony had similar temporal variation, peaking in April. Technophony occurred closer to urban areas and at locations with high snowmobile activity. Biophony occurred closer to rivers and was inversely related to snowmobile activity. Over 75 % of sample sites had >1 recordings of airplane or snowmobile noise, mainly in remote areas.

Conclusions

The soundscape displayed distinct patterns across 24-h and monthly timeframes. These patterns were strongly associated with land cover variables which demonstrate discrete acoustic–environmental relationships exhibiting distinct spatial patterns in the landscape. Despite the predominance of geophony, the presence of technophony in this winter soundscape may have significant negative effects to wildlife and wilderness quality.

     

Resistance to powdery mildew in a doubled haploid barley population and its association with marker loci

The genetic basis of resistance to powdery mildew (Erysiphe graminis DC. f.sp. hordei Marchal) was analyzed using doubled haploid barley (Hordeum vulgare L.) lines from the cross Harrington/TR306. Based on infection types observed after inoculation with defined single-conidium isolates, the lines were classified into four groups. The observed phenotypic ratio fit a two-locus model. The two putative loci were mapped relative to molecular markers. One coincided with the previously mapped dMlg locus on chromosome 4. Based on the observed infection types, Harrington carries the Mlg resistance allele, and TR306 carries a second locus on chromosome 7 (5H); this was tentatively designated Ml(TR). It is the first reported race-specific powdery mildew resistance gene located on that chromosome. These two loci were also detected by simple interval mapping of disease severity data from naturally infected field plots. Composite interval mapping with the first two resistance loci as co-factors detected an additional locus on chromosome 6, with a minor effect on resistance. Finally, superimposing the race-specific classification onto the field data provided evidence for a minor-effect locus on chromosome 7 (5H). The Mlg locus had the largest effect, the Ml(TR) locus had an intermediate effect and the other two loci had very small effects. This study demonstrates the effectiveness of an integrated approach to identifying and mapping resistance loci using classification data from inoculated experiments and quantitative data from field experiments. This revised version was published online in July 2006 with corrections to the Cover Date.     

Habitat Selection and Breeding Success in a Forest-nesting Alcid, the Marbled Murrelet, in Two Landscapes with Different Degrees of Forest Fragmentation

We studied habitat selection and breeding success in marked populations of a protected seabird (family Alcidae), the marbled murrelet (Brachyramphus marmoratus), in a relatively intact and a heavily logged old-growth forest landscape in south-western Canada. Murrelets used old-growth fragments either proportionately to their size frequency distribution (intact) or they tended to nest in disproportionately smaller fragments (logged). Multiple regression modelling showed that murrelet distribution could be explained by proximity of nests to landscape features producing biotic and abiotic edge effects. Streams, steeper slopes and lower elevations were selected in both landscapes, probably due to good nesting habitat conditions and easier access to nest sites. In the logged landscape, the murrelets nested closer to recent clearcuts than would be expected. Proximity to the ocean was favoured in the intact area. The models of habitat selection had satisfactory discriminatory ability in both landscapes. Breeding success (probability of nest survival to the middle of the chick rearing period), inferred from nest attendance patterns by radio-tagged parents, was modelled in the logged landscape. Survivorship was greater in areas with recent clearcuts and lower in areas with much regrowth, i.e. it was positively correlated with recent habitat fragmentation. We conclude that marbled murrelets can successfully breed in old-growth forests fragmented by logging.     

FraxForFuture—research on European ash dieback in Germany

Journal of Plant Diseases and Protection - European ash dieback caused by the alien, invasive ascomycete species Hymenoscyphus fraxineus currently represents, along with its side effects, the...     

Comparison of a DNA probe, complement-fixation and indirect immunofluorescence tests for diagnosing Anaplasma marginale in suspected carrier cattle

Most estimates of the prevalence of anaplasmosis have been based on serologic data using the complement-fixation (CF) and/or card agglutination tests. Since these tests are considered to be only about 50 percent reliable for detecting carrier cattle in enzootically stable herds, the need for more sensitive diagnostic tests is widely recognized. The objective in the present study was to compare the sensitivity of the CF test with that of the indirect immunofluorescence (IIF) test and a recently developed DNA probe in determining the prevalence of Anaplasma marginale infection in cattle from an enzootic area. The study herd consisted of 52 8-month-old steers and 13 3-year-old cows of mixed beef breed. All cattle were initially tested for this comparative purpose. All but one animal (one that was a positive reactor as assessed by all three tests, and served as a positive control), were treated with long-acting oxytetracycline in an attempt to clear any carrier infections. Each animal was then retested at 1 month and 2 months post-treatment (PT), in an effort to determine if the DNA probe could be used to evaluate the effectiveness of the drug. Six of the 65 (9.2%) initial serum samples were CF positive. In contrast, 60 (92.3%) and 64 (98.5%) of the samples were positive as assessed with the IIF test and the DNA probe, respectively. The DNA hybridization reactions varied in intensity within the sample population indicating different individual levels of infection. The DNA probe hybridized with two samples taken at 1 month PT, and with two different samples taken at 2 months PT. The mean IIF titers were reduced at both the 1 month and 2 month sampling times. These results suggest that the drug did not eliminate infections in all cattle. Some may have been cleared, but, in any event, the drug did reduce the level of infections below the sensitivity of the DNA probe and interrupted continuity of stimulation of antibody. Therefore, the DNA probe and the IIF test appear to be considerably more sensitive in detecting carrier infections than the CF test, and should be considered in future epidemiologic studies.     

Ability of different soil extraction methods to predict potassium release from soil in ley over three consecutive years

To avoid over‐fertilization of potassium (K) and thereby a mineral composition in the grass crop not optimal for animal health, estimation of K release from soil is important. The analytical methods should therefore predict the total K release. Furthermore, to minimize costs for the farmers they should provide information which remains valid over a period of several years. The relationship between different soil extraction procedures for K and K uptake in ley for three subsequent years after soil sampling was studied in 19 field experiments on a range of mineral soil types in Norway. Potassium determined with solutions that extracted exchangeable K or parts of exchangeable K (0.01 M CaCl₂, 0.5 M NaHCO₃, 1 M NH₄oAc, or ammonium acetate lactate) was significantly (p < 0.05) related to the K yield only in the 1st yr after soil sampling. Potassium extracted with boiling in 1 M or 2 M HNO₃ was significantly related to the K yield only in the 2nd and 3rd yr. Potassium extracted with cold 2 M HCl, boiling 0.1 M HNO₃ or 0.5 M HNO₃ was significantly related to the K yield in all 3 yr after soil sampling. Among these extractants, 0.1 M and 0.5 M HNO₃‐extractable K were better predictors of K uptake than 2 M HCl‐extractable K. These three extractants release some non‐exchangeable K in addition to exchangeable K. The fraction of 1 M HNO₃‐K extractable with 0.1 M HNO₃ varied from 4% to 45%, whereas from 15% to 78% of 1 M HNO₃‐K was extractable with 0.5 M HNO₃. Consequently, the more easily releasable fraction of K extracted by boiling with 1 M HNO₃ varied considerably between different sites.     

Modeling and mapping forest diversity in the boreal forest of interior Alaska

Context

Patterns of forest diversity are less well known in the boreal forest of interior Alaska than in most ecosystems of North America. Proactive forest planning requires spatially accurate information about forest diversity. Modeling is a cost-efficient way of predicting key forest diversity measures as a function of human and environmental factors.

Objectives

Investigate and predict the patterns and processes in tree species and tree size-class diversity within the boreal forest of Alaska for a first mapped quantitative baseline.

Methods

For the boreal forest of Alaska, USA, we employed Random Forest Analysis (machine learning) and the Boruta algorithm in R to predict tree species and tree size-class diversity for the entire region using a combination of forest inventory data and a suite of 30 predictors from public open-access data archives that included climatic, distance, and topographic variables. We developed prediction maps in a GIS for the current levels (Year 2012) of tree size-class and species diversity.

Results

The method employed here yielded good accuracy for the huge Alaskan landscape despite the exclusion of spectral reflectance data. It’s the first quantified GIS prediction baseline. The results indicate that the geographic pattern of tree species diversity differs from the pattern of tree size-class diversity across this forest type.

Conclusions

The results suggest that human factors combined with topographical factors had a large impact on predicting the patterns of diversity in the boreal forest of interior Alaska.

     

Comparative genotoxicity testing of rhine river sediment extracts using the comet assay with permanent fish cell lines (rtg-2 and rtl-w1) and the ames test*

Goals, Scope and Background

Improved quality of surface waters and sediments requires advanced strategies for ecotoxicological assessment. Whilst at least in Germany assessment strategies on the basis of chemical analysis and acute toxicity data dominated the last decades, the development of more specific biological endpoints and biomarkers in ecotoxicology is required in order to arrive at a good ecological potential and good chemical status of surface waters in the European river basins until the year 2015, as required by the European Water Framework Directive. Since sediments have for long been known to function both as a sink and as a source of pollutants in aquatic systems, and since part of the particle-associated substances have frequently been demonstrated to cause mutagenic and carcinogenic effects in aquatic organisms, particularly in fish, there is, among other requirements, an urgent need to develop, standardize and implement integrated vertebrate-based test systems addressing genotoxicity into recent sediment investigation strategies. Thus, the present study was designed to compare the suitability of two commonly used test systems, the comet assay and the Ames test, for the evaluation of the ecotoxicological burden of surface and core sediment samples from the river Rhine.

Methods (or Main Features)

In order to determine the importance of inherent enzymatic activities, two permanent fish cell lines with different biotransformation capacities, RTL-W1 and RTG-2, were compared with respect to their capability of detecting genotoxic effects in 18 surface and core sediment samples from 9 locations along the River Rhine in the comet assay with and without exogenous bioactivation. For further comparison, as a prokaryotic mutagenicity assay, theSalmonella plate incorporation assay (Ames test) with the test strains TA98 and TA 100 with and without exogenous metabolic activation was used.

Results and Discussion

Whereas all sediment extracts induced genotoxic effects in the comet assay with RTL-W1 cells, only 12 out of 18 sediment extracts revealed significant genotoxicity in the tests with the less biotransformation-competent RTG-2 cells. Exogenous bioactivation by addition of ß-naphthoflavone /phenobarbital-induced S9 from rat liver resulted in both reduction or increase of genotoxicity in samples from different sites, however, without consistent reaction patterns. In general, the responses of RTL-W1 cells indicated higher biotransformation capacity than in RTG-2 cells without S9 complementation. In Ames tests using TA98 with S9, 16 out of 18 extracts induced significant mutagenicity with induction factors up to 4. Compared to TA98, the strain TA100 proved less sensitive, with maximum induction factors of 1.3, indicating the potential presence of substances inducing frarneshift mutations, which can only be detected in the strain TA98. Chemical analyses revealed particularly high levels of hexachlorbenzene (up to 860 µg/kg) and priority PAHs (up to 4.8 mg/kg); so far, however, no correlation could be found between compounds analyzed and the corresponding biotests.

Conclusions

Results document that both comet assay and Ames test are capable of detecting xenobiotic interaction with DNA in consequence of exposure to complex environmental samples. Whereas the alkaline version of the comet assay detects a broad range of interactions with the DNA, however without information about their eventual importance, the Ames test only reveals established mutations, but fails to detect transient (reparable) DNA alterations. However, even transient primary changes in the DNA structure might result in carcinogenic processes and, eventually, in implications at the population level. As a consequence, for hazard assessment purposes, a combination of both assays is required to avoid false negatives in genotoxicity evaluation. Poor correlation between data obtained by chemical analysis and results in bioassays is indicative of our limited understanding of the sources of genotoxicity. In fact, numerous studies combining chemical and biological approaches for hazard assessment of complex environmental mixtures indicate that priority pollutant concentrations are a poor indicator of toxicity.If compared to the cell line RTG-2, RTL-W1 proved more effective in detecting genotoxicity in surface sediment samples and, thus, indicated the importance of bioactivation of at least part of the compounds in superficial layers of sediments. Results further document that the common assumption may be wrong that, in comparison to deeper strata, surface layers carry a lower toxic burden in consequence of the current decrease in water pollution. This might at least in part be due to remobilization of more heavily polluted sediments from deeper layers during severe flood events followed by re-sedimentation in flood plains or upstream weirs, where they might cover less polluted younger sediment layers.

Recommendations and Perspectives

For a comprehensive assessment of genotoxicity in surface and core sediments, a combination of eukaryotic (comet assay) and prokaryotic assays (Ames test) with and without exogenous bioactivation is recommended. Since studies with organic sediments extracts simulate a worst-case scenario and fail to take into account bioavailability, there is broad consensus that whole-sediment exposure protocols represent the most realistic scenarios. Whereas more realistic solid phase exposure has frequently been applied in both microbial and invertebrate acute toxicity testing, there is an urgent need to develop corresponding whole sediment fish-based genotoxicity tests.

     

Kennwerte und Eigenschaften der auf Braunkohlenbasis durch oxidative Ammonolyse hergestellten Humusdüngestoffe

Der auf Braunkohlenbasis durch oxidative Ammonolyse hergestellte Humusdüngestoff wird anhand seiner Standardparameter, Elementgehalte und chemischen Eigenschaften beschrieben. Hiernach ist die N-modifizierte Braunkohle ein schadstoffarmes, N-reiches, dauerhumusähnliches Bodenverbesserungsmittel, das als Granulat sehr lagerungsbeständig ist. Der neue Humusdüngestoff enthält stabil 5,78 ± 0,38% Gesamtstickstoff, der chemisch unterschiedlich gebunden ist. Aufgrund seiner vergleichsweise geringen N_min-Gehalte kann er in größeren Mengen zur nachhaltigen Verbesserung der KAK_pot und N_t-Bodenvorräte humusfreier und kolloidarmer Kippenböden eingesetzt werden.