Strike-induced chemosensory searching is absent in the cordylid lizard,Cordylus cordylus,a scleroglossan ambush forager

Summary Strike-induced chemosensory searching (SICS) was not detected experimentally in the cordylid lizard,Cordylus cordylus. Both components of SICS, a post-strike elevation in tongue-flick rate (PETF) and searching movements for attacked and released prey, were absent. The findings are consistent with previous data showing that PETF and/or SICS are lacking in all lizard families yet studied that forage primarily by ambush, but are present in actively foraging scleroglossan families and the herbivorous iguanian family Iguanidae. It is suggested that foraging behavior is a primary determinant of the presence or absence of SICS in lizards. Nevertheless, in most families in the two major clades, Iguania and Scleroglossa, the plesiomorphic foraging mode is retained. The findings agree with the prediction that SICS is absent in families lacking lingually mediated prey chemical discrimination (PCD), presumably due to selection against movement by ambush foragers that avoid being detected by either prey or predators because they remain motionless. Although PETF and SICS were absent, labial-licking and lingual movements similar to those observed after swallowing increased after biting prey, suggesting that the functions of these lingual movements may have been related to grooming. Locomotory movements did not increase following biting and appeared to represent avoidance of the experimenter.     

Exploratory Analysis and a Stochastic Model for Humusdisintegration

Ulrich (1981) supposes in the hypothesis of humusdisintegrationthat the balance between polymerisation and breakdown of organicmaterial may be disturbed in chemically well buffered Europeanforest soils. This new aspect of aluminium toxicity may causenitrogen exceedance in forest ecosystems and subsequent seasonalnitrate output (Eichhorn and Hütterman, 1999).In a research program the substances in the seepage water aremonitored in a small woodland in central Germany. We explorethese multivariate data for examining possible influences on theprocess of humusdisintegration and its temporal evolution. As aresult, a regression model for carbon is developed, whichincludes covariables, i.e., other substances, as well as spatialand temporal terms describing systematic variability. Especiallyiron and aluminium turn out to be very influential in the model.So far our work is a basic step for monitoring the seepage waterdata by means of stochastic modelling.     

The analysis of free chlorine in the presence of nitrogenous organic compounds

Comparative analyses for aqueous chlorine using Standard Methods indicated that in chlorinated solutions containing nitrogenous organic compounds, none of these methods gave a reliable measurement of free available chlorine. Examination of the cyanuric acid-aqueous chlorine system showed that combined chlorine reacted as if it were free chlorine in all the Standard Methods. The implication of these studies for water and wastewater chlorination is that in waters containing nitrogenous organic compounds, N-Chloro compounds form which may result in an overestimation of the disinfecting potential of the added chlorine, when free chlorine is measured by Standard Methods.     

Increased lipid accumulation but not reduced metabolism explains improved starvation tolerance in cold-acclimated arthropod predators

Predatory arthropods are used for biological control in greenhouses, but there is increasing interest to extend their use to the outdoor environment where temperatures are typically lower. Acclimation at low temperature increases the ability of ectotherms to cope with subsequent more extreme cold, but may involve costs or benefits to other performance traits. A recent study in mesostigmatid mites (Gaeolaelaps aculeifer) showed that starvation tolerance was improved following a period of cold exposure. However, the physiological mechanisms that underlie improved starvation tolerance following cold exposure were not investigated. To examine whether cold acclimation would also improve starvation tolerance in an insect, we repeated the starvation study in another arthropod predator, the pirate bug Orius majusculus, as well as in G. aculeifer. Before tests, the two species were acclimated at 10, 15, or 20 °C for 7 (G. aculeifer) or 16 (O. majusculus) days. We then analyzed the effects of thermal exposure on body composition, consumption, and basal metabolic rate in both species. Our results confirmed that exposure to low temperature improves starvation tolerance in these arthropod predators. Body composition analyses revealed that both species had accumulated larger lipid stores during exposure to colder temperature, which at least in part can explain the larger starvation tolerance following cold exposure. In contrast, consumption and basal metabolic rate were not changed by thermal acclimation. Our study indicates that predatory arthropods exposed to cold increase their physiological robustness and ability to endure environmental challenges, including low temperature and low prey availability.     

Intraspecific competition and high food availability are associated with insular gigantism in a lizard

Resource availability, competition, and predation commonly drive body size evolution. We assess the impact of high food availability and the consequent increased intraspecific competition, as expressed by tail injuries and cannibalism, on body size in Skyros wall lizards (Podarcis gaigeae). Lizard populations on islets surrounding Skyros (Aegean Sea) all have fewer predators and competitors than on Skyros but differ in the numbers of nesting seabirds. We predicted the following: (1) the presence of breeding seabirds (providing nutrients) will increase lizard population densities; (2) dense lizard populations will experience stronger intraspecific competition; and (3) such aggression, will be associated with larger average body size. We found a positive correlation between seabird and lizard densities. Cannibalism and tail injuries were considerably higher in dense populations. Increases in cannibalism and tail loss were associated with large body sizes. Adult cannibalism on juveniles may select for rapid growth, fuelled by high food abundance, setting thus the stage for the evolution of gigantism.     

Influence of various emission scenarios on ozone in Europe

In this study, we investigated the effect of numerous regulations enforced since 1985 to improve air quality on ozone in Europe with the focus on Switzerland, using the Comprehensive Air Quality Model with Extensions (CAMx) for a specific summer period. Several emission scenarios for the year 2010 were also considered. The model results suggest that the emission reductions of ozone precursors should have been effective to reduce ozone production between 1985 and 2000 in northern Switzerland. However, observations do not indicate any significant change in surface ozone levels since early 1990s, except in the region of Zurich where there is a small negative trend. On the other hand, the model predictions match very well the spatial variability of the trends but the calculated trends are around 0.5 ppb year⁻¹ lower than those observed. This difference is similar to the background ozone increase as suggested by the long-term observations at the high Alpine station Jungfraujoch. These results support the hypothesis that the decrease in local ozone production due to emission reductions might have been partly or completely compensated by the simultaneous increase in the background ozone. In 2010, a strict application of the Gothenburg Protocol in Europe would lead to a decrease in peak ozone concentrations by about 5% in Switzerland under the meteorological conditions applied. Our calculations also indicated that emission controls only in Switzerland would not be very effective to improve the air quality in the future. The further development of the background ozone will in any case be very important for the tropospheric ozone levels.     

Estimation of no effect concentrations from exposure experiments when values scatter among individuals

The parameters that are most commonly used in risk assessment, LC_x values or no observed effect concentrations, both have serious drawbacks. As an alternative, No effect concentrations (NEC) as a parameter in a process-based model, offer great potential in risk assessment.     

Multidimensional risk analysis of antifouling biocides

In order to improve the orientation about the long-term sustainability of the use of the antifouling biocides tributyltin (TBT), copper, Irgarol® 1051, Sea-Nine? 211 and zinc pyrithione, used for the protection of fouling in sea-going ships, the risks posed to the marine biosphere due to their use are evaluated. The newly presented method of risk analysis uses release rate, spatiotemporal range, bioaccumulation, bioactivity and uncertainty as 5 dimensions of ecotoxicological risk. For each dimension, a scoring procedure is briefly described. The resulting risk profiles of the antifouling biocides show characteristics of the different substances, but also indicate where further information is required. Application of the method is proposed as a decision support in the integrated development of products, informed purchasing and for regulatory purposes.     

Contribution of Ecosystem Services to Air Quality and Climate Change Mitigation Policies: The Case of Urban Forests in Barcelona,Spain

Mounting research highlights the contribution of ecosystem services provided by urban forests to quality of life in cities, yet these services are rarely explicitly considered in environmental policy targets. We quantify regulating services provided by urban forests and evaluate their contribution to comply with policy targets of air quality and climate change mitigation in the municipality of Barcelona, Spain. We apply the i-Tree Eco model to quantify in biophysical and monetary terms the ecosystem services “air purification,” “global climate regulation,” and the ecosystem disservice “air pollution” associated with biogenic emissions. Our results show that the contribution of urban forests regulating services to abate pollution is substantial in absolute terms, yet modest when compared to overall city levels of air pollution and GHG emissions. We conclude that in order to be effective, green infrastructure-based efforts to offset urban pollution at the municipal level have to be coordinated with territorial policies at broader spatial scales.     

Ecosystem services in mountain regions: experts’ perceptions and research intensity

Facing the challenges of global and regional changes, society urgently needs applicable and broadly accepted tools to effectively manage and protect ecosystem services (ES). This requires knowing which ES are perceived as important. We asked decision-makers from different thematic backgrounds to rank 25 ES on the basis of their importance for society. To test whether perceptions are varying across regions, we surveyed three Alpine regions in Austria and Italy. The ranking of importance showed a high variability amongst experts but was not influenced by region or thematic background. ES that satisfy physiological needs (‘fresh water’, ‘food’, ‘air quality regulation’) were indicated as most important. ES that relate to safety and security needs were ranked in the middle field, whereas cultural ES were perceived as less important. We used principal component analysis (PCA) to identify ES bundles based on perception of importance. In order to investigate whether research intensity follows the perceived importance, we related the interviews with a comprehensive literature review. ‘Global climate regulation’, ‘food’, ‘biodiversity’, ‘fresh water’ and ‘water quality’ were studied most often. Although ‘habitat’, ‘energy’, ‘primary production’, ‘tourism’, ‘water cycle’, and ‘local climate regulation’ were ranked as important by decision-makers, they did not receive corresponding research attention. We conclude that more interaction between research and stakeholders is needed to promote a broader application and understanding of the ES concept in practice. The use of ES bundles could help to manage its inherent complexity and facilitate its application.