Effectiveness of vegetation‐based biodiversity offset metrics as surrogates for ants

Biodiversity offset schemes are globally popular policy tools for balancing the competing demands of conservation and development. Trading currencies for losses and gains in biodiversity value at development and credit sites are usually based on several vegetation attributes combined to yield a simple score (multimetric), but the score is rarely validated prior to implementation. Inaccurate biodiversity trading currencies are likely to accelerate global biodiversity loss through unrepresentative trades of losses and gains. We tested a model vegetation multimetric (i.e., vegetation structural and compositional attributes) typical of offset trading currencies to determine whether it represented measurable components of compositional and functional biodiversity. Study sites were located in remnant patches of a critically endangered ecological community in western Sydney, Australia, an area representative of global conflicts between conservation and expanding urban development. We sampled ant fauna composition with pitfall traps and enumerated removal by ants of native plant seeds from artificial seed containers (seed depots). Ants are an excellent model taxon because they are strongly associated with habitat complexity, respond rapidly to environmental change, and are functionally important at many trophic levels. The vegetation multimetric did not predict differences in ant community composition or seed removal, despite underlying assumptions that biodiversity trading currencies used in offset schemes represent all components of a site's biodiversity value. This suggests that vegetation multimetrics are inadequate surrogates for total biodiversity value. These findings highlight the urgent need to refine existing offsetting multimetrics to ensure they meet underlying assumptions of surrogacy. Despite the best intentions, offset schemes will never achieve their goal of no net loss of biodiversity values if trades are based on metrics unrepresentative of total biodiversity.     

Artificial radioactivity in environmental media (air, rainwater, soil, vegetation) in Austria after the Fukushima nuclear accident

Several environmental media in Austria were monitored for artificial radionuclides released during the Fukushima nuclear accident. Air (up to 1.2 mBq/m³ particulate ¹³¹I) and rainwater (up to 5.2 Bq/L ¹³¹I) proved to be the media best suited for the environmental monitoring, allowing also a temporal resolution of the activity levels. Significant regional differences in the wet deposition of ¹³¹I with rain could be observed within the city of Vienna during the arrival of the contaminated air masses. Forward-trajectory analysis supported the hypothesis that the contaminated air masses coming from the northwest changed direction to northeast over Northern Austria, leading to a strong activity concentration gradient over Vienna. In the course of the environmental monitoring of the Fukushima releases, this phenomenon—significant differences of ¹³¹I activity concentrations in rainwater on a narrow local scale (8.1 km)—appears to be unique. Vegetation (grass) was contaminated with ¹³¹I and/or ¹³⁷Cs at a low level. Soil (up to 22 Bq/kg ¹³⁷Cs) was only affected by previous releases (nuclear weapon tests, Chernobyl). Here, also significant local differences can be observed due to different deposition rates during the Chernobyl accident. The effective ecological half-lives of ¹³⁷Cs in soil were calculated for four locations in Austria. They range from 7 to 30 years. No Austrian sample investigated herein exceeded the detection limit for ¹³⁴Cs; hence, the Fukushima nuclear accident did not contribute significantly to the total radiocesium inventory in Austrian environmental media. The levels of detected radioactivity were of no concern for public health.     

Proactive limit values for responsible management of chemicals

Limit values (LVs) are legal concentration limits for constituents, residues and contaminants in consumer products or for emissions from production processes into environmental compartments. They are a traditional regulatory aid to manage chemicals in human environments. To make them proactive, LVs should become enforced by means of a transparent and informed decision process whose starting point is the Basic Rule of Environmental Hygiene, BREH:Avoid useless exposure as far as possible, minimize useful exposure in a reasonable manner, and prevent that exposure which is dangerous. The BREH calls upon minimizing exposure not only according toon site risk potentials and acceptance, but also tooff site avoidability and acceptability.     

Predictions for isomer distributions of toxic dioxins and furans in selected industrial combustion processes

Three thermodynamic databases of polychlorinated dibenzo-p-dioxins and dibenzo-furans (PCDD/Fs) have been used to simulate the PCDD/F isomer distribution in industrial combustion processes. The three databases had been derived using the Group Additivity approach and two computational molecular modelling methods, Modified Neglect of Diatomic Overlap (MNDO) and Parametrized Model 3 (PM3), respectively. The predictions of the toxic PCDD/F isomer distributions using the three different databases have been compared with measured values from industrial processes. An excellent agreement between the predictions using the MNDO method and the measured data has been obtained. It is concluded that the PCDD/F isomer distributions within each group observed in these combustion processes may be thermodynamically controlled.     

Correlation between PCDD/F, PCB and PCBz in coal/waste combustion. Influence of various inhibitors

In the flue gas of co-combustion of solid waste and coal in a laboratory scale furnace high concentrations of polychlorinated dibenzo-p-dioxin and furans (PCDD/F), polychlorinated biphenyls (PCB) and polychlorinated benzenes (PCBz) have been detected. These toxic emissions have been reduced by the help of various inhibitors added to fuel before incineration. Knowledge of the congener pattern and homologue profiles of PCDD/F, PCB and PCBz is important to elaborate the mechanism of formation and inhibition of the toxic compounds formed during co-combustion of solid waste and coal. Principle component analysis (PCA) is used in order to find the similarity between the samples and separate them according their toxicity. By the help of the component analysis (CA) the best correlated congeners are effectively detected. Using linear regression between the independent variables and the indicator parameters various good correlated pairs between PCDD/F, PCB and PCBz have been elaborated. Generally it was found that the samples with higher toxicity show a good correlation between tetra- and pentachlorinated benzenes and tetra- and pentachlorinated dibenzo-p-furans. The best indicator parameter for PCDD/F World Health Organization toxic equivalent (WHO-TEQ) among the PCBz congeners investigated is 1,2,4,5-TCBz. This isomer is also significantly correlated with PCDD/F WHO-TEQ and with the sum of PCDD/F WHO-TEQ and PCB WHO-TEQ. However for samples with higher percentage of inhibitors the above mentioned relationship between the surrogate and WHO-TEQ disappeared. The PCB homologues and congeners show no correlation with PCBz and PCDD/F homologues and congeners.     

Treatment of spent wash in anaerobic mesophilic suspended growth reactor (AMSGR)

Approximately 400 KL of spent wash or vinasse per annum is generated at an average COD concentration of 100,000 mg/l, by over 250 distilleries in India. There is an urgent need to develop, assess and use ecofriendly methods for the disposal of this high strength wastewater. Therefore, an attempt was made to investigate a few aspects of anaerobic digestion of spent wash collected from a distillery. The study was carried out in a 4 L laboratory scale anaerobic mesophilic suspended growth reactor. After the successful startup, the organic loading was increased stepwise to assess the performance of the reactor. During the study period, biogas generated was recorded and the maximum gas generated was found to be 16.9 L at an Organic Loading Rate (OLR) of 38 g COD/L. A 500% increase in the Volatile Fatty Acid (VFA) concentration (2150 mg/L) was observed, when the OLR was increased from 38 to 39 g COD/L. During the souring phase the removal of COD, Total Solids (TS) and Volatile Solids (VS) were in the order of 52%, 40% and 46% respectively. The methane content in the biogas varied from 65% to 75%.     

Prenatal diagnosis of a de novo supernumerary marker derived from chromosome 16

Marker chromosomes are supernumerary chromosomes of unknown origin and are seldom found in prenatal diagnosis. Application of fluorescent in situ hybridization (FISH) allows the identification of the chromosomal origin of markers. Estimation of the risk of an abnormal phenotype outcome can be enabled by collecting data on phenotypes associated with markers of the same chromosomal origin. So far only very few cases of prenatal diagnosis of de novo supernumerary markers derived from chromosome 16 have been reported. Here the prenatal diagnosis of a de novo supernumerary marker chromosome 16 is described and the relevant literature discussed. Copyright © 2001 John Wiley & Sons, Ltd.     

The evolution of worker–queen polymorphism in Cataglyphis ants: interplay between individual- and colony-level selections

In many ants, young queens disperse by flying away from their natal nest and found new colonies alone (independent colony founding, ICF). Alternatively, in some species, ICF was replaced by colony fission, in which young queens accompanied by workers found a new colony at walking distance from the mother nest. We compared the queen morphology of Cataglyphis floricola, which disperses by fission, with that of its most likely living ancestor, Cataglyphis emmae, which disperses by ICF. As in other species, the transition from ICF to fission is associated with queen miniaturization. Interestingly, C. floricola presents two types of small queens: brachypters (with short non-functional wings) and ergatoids (worker-like apterous queens). Ergatoids are, on average, 2.8 mg lighter and have half the number of ovarioles than brachypters, which limits the advantage for a colony to produce ergatoids instead of brachypters. Furthermore, more ergatoids are produced than brachypters, but their individual survival rate is lower. During colony fission, 96% of the cocoons containing brachypters but only 31% of those containing ergatoids are transferred to the daughter nests where, after emergence, they compete for becoming the next queen. The remaining queen cocoons, which stay in the mother queen's nest, are eliminated by workers upon emergence, probably to maintain monogyny. This waste of energy suggests that producing ergatoids instead of brachypters is unlikely to increase colony efficiency. We argue that the evolution of ergatoids could derive from a selfish larval strategy, developing into worker-like queens in spite of the colony interest.