Why Do People Continue to Live Near Polluted Sites? Empirical Evidence from Southwestern Europe

Environmental Modeling & Assessment - Poverty is a major determinant for pollution exposure, according to the US location choice literature. In this paper, we assess the impact of...     

Development of a Cropland Management Dataset to Support U.S. Swat Assessments

The Soil and Water Assessment Tool (SWAT) is widely used in the United States (U.S.) to simulate hydrology and water quality simulation. Process‐based models like SWAT require a great deal of data to accurately represent the natural world, including topography, land use, soils, weather, and management. With the exception of management, all these data are available nationally from multiple sources. To date, credible SWAT studies in the U.S. have assembled suitable management data (operation scheduling, fertilization application rates, and plant growth parameterization). In this research, we develop a national management database for SWAT using existing U.S. Department of Agriculture data sources. These data are compatible with existing SWAT interfaces and are relatively easy to use. Although management data from local sources is preferred, these data are not always available. This work is intended to fill this void with more reasonable management data than the existing defaults. This national database covers all major cultivated crops and should facilitate improved SWAT applications in the U.S. These data were tested in two case studies and found to produce satisfactory SWAT predictions. The database developed in this research is freely available on the web.     

Do the size and age of mating plugs alter their efficacy in protecting paternity?

An obvious means to secure paternity is the production of a mating plug that blocks the female genital opening after mating. Although the mechanical efficacy and persistence of plugs on/in the female genital openings are key traits that determine the degree of paternity protection, these factors have hardly been explored. We therefore investigated the influence of the size of the amorphous plug material (experimentally terminated mating duration as a proxy) and age of the mating plug (time interval between copulations with two successive males) on the efficacy of the plug by analysing the mating success of subsequent males in the dwarf spider Oedothorax retusus (Linyphiidae: Erigoninae). Overall, subsequent males attempted to mate in 82 % of trials but only 32.5 % of these resulted in copulation, demonstrating that the plugs are effective safeguards against remating. Remating probability was significantly higher after previous short copulations (~small plug size) compared to long copulations (~large plug size). In the small plug group, fresh plugs (short remating intervals) were significantly less effective compared to older plugs. In the large plug group, remating probability was similarly low over all remating intervals. The observed copulations, however, do not necessarily result in sperm transfer, since sperm masses were found on the plugged female genital area. Our study on O. retusus shows that mating plugs are a powerful mechanical safeguard whose efficacy varies with plug size and age. We discuss these findings in the light of theoretical considerations on the evolution of effective mating plugs.     

SWATMOD‐Prep: Graphical User Interface for Preparing Coupled SWAT‐MODFLOW Simulations

This article presents SWATMOD‐Prep, a graphical user interface that couples a SWAT watershed model with a MODFLOW groundwater flow model. The interface is based on a recently published SWAT‐MODFLOW code that couples the models via mapping schemes. The spatial layout of SWATMOD‐Prep guides the user through the process of importing shape files (sub‐basins, hydrologic response units [HRUs], river network) from an existing SWAT model, creating a grid, performing necessary geo‐processing operations to link the models, writing out SWAT‐MODFLOW files, and running the simulation. The option of creating a new single‐layer MODFLOW model for near‐surface alluvial aquifers is available, with the user prompted to provide groundwater surface elevation (through a digital elevation model), aquifer thickness, and necessary aquifer parameter values. The option of simulating nitrate transport in the aquifer also is available, using the reactive transport model RT3D. The interface is in the public domain. It is programmed in Python, with various software packages used for geo‐processing operations (e.g., selection, intersection of rasters) and inputting/outputting data, and is written for Windows. The use of SWATMOD‐Prep is demonstrated for the Little River Experimental Watershed, Georgia. SWATMOD‐Prep and SWAT‐MODFLOW executables are available with an accompanying user's manual at: http://swat.tamu.edu/software/swat-modflow/ . The user's manual also accompanies this article as Supporting Information.     

Enzymatische Umsetzung von Arsenkampfstoffen durch das Pilzenzym Mangan-Peroxidase

Das Pilzenzym Mangan-Peroxidase wurde eingesetzt, um verschiedene Arsenkampfstoffe in zellfreien Reaktionsans?tzen (in vitro) abzubauen. Die Konzentrationsabnahme der Arsenkampfstoffe wurde nach Thiol-Derivatisierung mittels Gaschromatographie geprüft. Alle untersuchten arsenorganischen Verbindungen wurden von der Mangan-Pero-xidase bei Raumtemperatur zu mehr als 90% umgesetzt. Aliphatische Arsenkampfstoffe wurden schneller angegriffen als aromatische Derivate.     

Assessment of Ecological Integrity from Environmental Variables in an Impacted Oligotrophic,Alpine Lake: Whole Lake Approach Using 3d-Spatial Heterogeneity

The ecological integrity of a lake as a whole can only beassessed through an adequate sampling strategy. Spatialheterogeneity of phytoplankton as well as vertical andhorizontal variability of physical and chemical variables wereestimated from 57 stations at four seasons differing in theirhydrological regime. Resolution of grid positions, located byGPS, was 250 m near the impact site, 500 m for the southernpart of the lake, and 1000 m in the northern part. Data areanalysed by conventional gridding methods as well as in threedimensions with a novel GIS-technique. Horizontal large scaledifferences in several variables are associated withhydrological situations. Local variability in the southern baywas due to input of industrial tailings at times. Spatialvariation of phytoplankton biomass estimated as chlorophyll-aand relevant associated environmental variables were analysedusing a graphical multimetric approach. With this technique,the directly impacted area can be evaluated relative to theremaining part of the lake. The lake is then compared with tworeference lakes, one within the same catchement, the other ina different water-shed. An index of ecological integrity wasdeveloped describing multimetric intra- and interspecific lakevariability. The final index was used to describe the statusof lake water quality relative to a `undisturbed' referencelake. Results showed that Traunsee is ecologically intactalthough its chemistry differs substantially from an`external' reference.     

Influence of global change on phytoplankton and nutrient cycling in the Elbe River

The effects of changing climatic and socioeconomic conditions on the water quality of the Elbe River were investigated using the deterministic model QSim. Since the impact of global change on river water quality marks the endpoint of various processes in the catchment and in the atmosphere, this study was performed within a network of interacting models that determined input parameters for water quality simulations. The development of phytoplankton and nutrient concentrations under conditions of global change was modeled along a 700 km stretch of the river. The simulations revealed a strong, scale-dependent effect of climate change on phytoplankton biomass, leading to a longitudinal shift of the dominating processes (primary productivity vs. respiration) along the river continuum. Under reduced flow, combined with increasing temperature and global radiation, phytoplankton biomass increased and phytoplankton maxima shifted in upstream direction, followed by higher system respiration rates in the adjacent downstream sections. In contrast, higher flow shifted the phytoplankton maximum toward the downstream sections. Even a drastic reduction of phosphorus inputs from anthropogenic sources had only limited influence on algal biomass, due to the ability of algal cells to store phosphorus. A strong reduction in P-inputs especially in the headwaters would be necessary to counterbalance the possible climate-induced effects on algal biomass.