Stoffflussanalyse von quartären Ammoniumverbindungen für die Schweiz

Background, aim, and scope Compared to other micropollutants such as pesticides or pharmaceuticals, less attention has been paid to biocides so far. A prioritisation of the biocides currently used in Switzerland in terms of pollution of waters revealed that quaternary ammonium compounds (QAC), the isothiazolinones chloromethylisothiazolinone and benzisothiazolinone as well as Irgarol exhibit the highest risk potential. The QAC benzalkoniumchloride (BAC) and didecyldimethylammoniumchloride (DDAC-C10) are used in considerable amounts and have a high biological activity. Materials and methods The emissions of selected QAC in waters and soil and the predicted environmental concentrations (PECs) were estimated by means of a substance flow analysis (SFA). The study was based on data from the Swiss products register, on literature, contacts to producers and users as well as on own assumptions. Results and discussion The consumption of BAC (four homologues) and DDAC-C10 in biocidal applications in Switzerland amounts to 90 and 30 tons annually. The most important applications are disinfectants for public health areas, food and feed areas as well as wood preservatives. The total emissions to the environment of all five substances account for approximately 11?t/a. The PECs in surface waters and sediments vary from values slightly lower than the predicted no-effect concentration (PNEC) to roughly three orders of magnitude below the PNEC. However, concentrations above the PNEC are possible at certain locations, particularly downstream of wastewater treatment plants (WWTP) effluents and sewer overflows. Effects on aquatic organisms can therefore not be excluded. Three BAC homologues could not be assessed, as there were no PNEC values available. Conclusions The contribution of emissions from WWTP (punctual emissions) to the environment is only about one tenth and relatively low compared to diffuse emissions. This means that measures for the emission reduction focussing only on end-of-pipe solutions in WWTP will not reduce the emissions significantly. Moreover, for the evaluation of measures, attention has to be paid to the fact that biocides such as the selected QAC are often also applied in non-biocidal applications (e.?g. three times higher volumes in the case of BAC). Recommendations and perspectives SFA serves as a useful tool for early recognition of environmental problems caused by chemicals. This allows recommending appropriate risk reduction measures in the production, the use and the end-of-life phase. It is advisable to use the SFA already in the development stage of chemicals and later on as a quality control tool. The relevant sources of chemicals and sinks in the environment can thus be determined in complex systems, even in absence of extensive measurements or product registers with consumption figures by means of estimations and scenarios.     

Bayesian Small Area Models for Assessing Wildlife Conservation Risk in Patchy Populations

Abstract:  Species conservation risk assessments require accurate, probabilistic, and biologically meaningful maps of population distribution. In patchy populations, the reasons for discontinuities are not often well understood. We tested a novel approach to habitat modeling in which methods of small area estimation were used within a hierarchical Bayesian framework. Amphibian occurrence was modeled with logistic regression that included third-order drainages as hierarchical effects to account for patchy populations. Models including the random drainage effects adequately represented species occurrences in patchy populations of 4 amphibian species in the Oregon Coast Range (U.S.A.). Amphibian surveys from other locations within the same drainage were used to calibrate local drainage-scale effects. Cross-validation showed that prediction errors for calibrated models were 77% to 86% lower than comparable regionally constructed models, depending on species. When calibration data were unavailable, small area and regional models performed similarly, although poorly. Small area estimation models complement wildlife ecology and habitat studies, and can help managers develop a regional picture of the conservation status for relatively rare species.     

Factors of Dynamics of Plankton Crustacean Communities under Eutrophic Conditions

Russian Journal of Ecology - It has been shown that the main drivers of the dynamics of cladoceran and copepod abundances can be predators (fish), the quantity and/or quality of food in terms of...     

The Effect of Vaccinium vitis-idaea on Properties of Mountain-Meadow Soil under Alpine Lichen Heath

Russian Journal of Ecology - Abstract—The study of the effect of mycorrhiza symbiosis on the transformation of carbon and nitrogen compounds in soils is important in view of the necessity to...     

Temporal and Spatial Variations of Phytoplankton Community Structure in Lake Erhai,a Chinese Plateau Lake,with Reference to Environmental Factors

Russian Journal of Ecology - Temporal and spatial variations of phytoplankton community in Lake Erhai were investigated from May 2010 to April 2011. A total of 124 species belonging to 8 phyla and...     

Origin of major ions in monthly rainfall events at the Bamenda Highlands, North West Cameroon

Rainwater characteristics can reveal emissions from various anthropogenic and natural sources into the atmosphere. The physico-chemical characteristics of 44 monthly rainfall events （collected between January and December 2012） from 4 weather stations （Bamenda, Ndop plain, Ndawara and Kumbo） in the Bamenda Highlands （BH） were investigated. The purpose was to determine the sources of chemical species, their seasonal inputs and suitability of the rainwater for drinking. The mean pH of 5 indicated the slightly acidic nature of the rainwater. Average total dissolved solids （TDS） were low （6.7 mg/L）, characteristic of unpolluted atmospheric moisture/air. Major ion concentrations （mg/L） were low and in the order K＋ 〉 Ca2＋ 〉 Mg2~ 〉 Na＋ for cations and NO3 〉〉 HCO3 〉 SO] 〉 CI- 〉 PO3- 〉 F- for anions. The average rainwater in the area was mixed Ca-Mg-SO4-CI water type. The CI-/Na＋ ratio （1.04） was comparable to that of seawater （1.16）, an indication that N a＋ and CI originated mainly from marine （Atlantic Ocean） aerosols. High enrichments of Ca2＋, Mg2＋ and SO2- to Na＋ ratios relative to seawater ratios （constituting 44% of the total ions） demonstrated their terrigenous origin, mainly from Saharan and Sahelian arid dusts. The K＋/Na＋ ratio （2.24）, which was similar to tropical vegetation ash （2.38）, and NO3 was essentially from biomass burning. Light （〈 100 mm） pre-monsoon and post-monsoon convective rains were enriched in major ions than the heavy （〉 100 mm） monsoon rains, indicating a high contribution of major ions during the low convective showers. Despite the acidic nature, the TDS and major ion concentrations classified the rainwater as potable based on the WHO guidelines.     

Empirical Trials of Plant Field Guides

We designed 3 image‐based field guides to tropical forest plant species in Ghana, Grenada, and Cameroon and tested them with 1095 local residents and 20 botanists in the United Kingdom. We compared users’ identification accuracy with different image formats, including drawings, specimen photos, living plant photos, and paintings. We compared users’ accuracy with the guides to their accuracy with only their prior knowledge of the flora. We asked respondents to score each format for usability, beauty, and how much they would pay for it. Prior knowledge of plant names was generally low (<22%). With a few exceptions, identification accuracy did not differ significantly among image formats. In Cameroon, users identifying sterile Cola species achieved 46–56% accuracy across formats; identification was most accurate with living plant photos. Botanists in the United Kingdom accurately identified 82–93% of the same Cameroonian species; identification was most accurate with specimens. In Grenada, users accurately identified 74–82% of plants; drawings yielded significantly less accurate identifications than paintings and photos of living plants. In Ghana, users accurately identified 85% of plants. Digital color photos of living plants ranked high for beauty, usability, and what users would pay. Black and white drawings ranked low. Our results show the potential and limitations of the use of field guides and nonspecialists to identify plants, for example, in conservation applications. We recommend authors of plant field guides use the cheapest or easiest illustration format because image type had limited bearing on accuracy; match the type of illustration to the most likely use of the guide for slight improvements in accuracy; avoid black and white formats unless the audience is experienced at interpreting illustrations or keeping costs low is imperative; discourage false‐positive identifications, which were common; and encourage users to ask an expert or use a herbarium for groups that are difficult to identify. Pruebas Empíricas de Guías de Campo de Plantas Hawthorne, Cable & Marshall     

Characterizing the Width of Amphibian Movements During Postbreeding Migration

Habitat linkages can help maintain connectivity of animal populations in developed landscapes. However, the lack of empirical data on the width of lateral movements (i.e., the zigzagging of individuals as they move from one point to point another) makes determining the width of such linkages challenging. We used radiotracking data from wood frogs (Lithobates sylvaticus) and spotted salamanders (Ambystoma maculatum) in a managed forest in Maine (U.S.A.) to characterize movement patterns of populations and thus inform planning for the width of wildlife corridors. For each individual, we calculated the polar coordinates of all locations, estimated the vector sum of the polar coordinates, and measured the distance from each location to the vector sum. By fitting a Gaussian distribution over a histogram of these distances, we created a population‐level probability density function and estimated the 50th and 95th percentiles to determine the width of lateral movement as individuals progressed from the pond to upland habitat. For spotted salamanders 50% of lateral movements were ≤13 m wide and 95% of movements were ≤39 m wide. For wood frogs, 50% of lateral movements were ≤17 m wide and 95% of movements were ≤ 51 m wide. For both species, those individuals that traveled the farthest from the pond also displayed the greatest lateral movement. Our results serve as a foundation for spatially explicit conservation planning for pond‐breeding amphibians in areas undergoing development. Our technique can also be applied to movement data from other taxa to aid in designing habitat linkages. Caracterización de la Amplitud de Movimiento de Anfibios durante la Migración Pos‐Reproducción