Organochlorine compounds in a three-step terrestrial food chain

The concentrations of 15 organochlorine chemicals (PCBs and pesticides) were studied in a Central European oak wood food chain system: Great tit (Parus major), caterpillars (Tortrix viridana, Operophtera brumata, Erannis defoliaria), and oak-leaves (Quercus robur). Juvenile tits receive organochlorines from the mother via egg transfer and, eventually to a greater extent, from the caterpillar food source during nestling period. The concentrations of PCB 153 (2,2′,4,4′,5,5′-hexachlorobiphenyl, the most abundant in this study) was found in leaf material at ca. 1 ng/g, in caterpillars 10 ng/g, and in bird eggs 170 ng/g on an average and on a dry mass basis.     

Cd and Zn Concentration in Hybrid Poplar Foliage and Leaf Beetles Grown on Polluted Sediment-Derived Soils

Foliar Cd and Zn concentrations of hybrid poplars commonlyplanted on sediment-derived soils were assessed in field circumstances. Selected sites covered a range of soil types andplantation characteristics. Reference data for foliar concentrations were established from samples taken in a tree-nursery. Even in the reference situation a large variationin foliar Cd and Zn concentrations was observed, with relative standard deviations in the order of 15%. Foliar concentrations of Cd and Zn in poplars growing on sediment-derived soils increased during the growing season. The accumulation rate was markedly higher on polluted sediment-derived soils than in thereference situation. Poplars grown on polluted sedimentderived soils showed elevated and deviating foliar Cd and Znconcentrations (>7.5 mg Cd kg^-1 DW and 320 mg Zn kg^-1 DW). A thin unpolluted covering layer did not influence foliarconcentrations. Regardless of site characteristics, poplarage, species or clone, a significant positive relation wasfound between soil and foliar concentration for Zn and to alesser extent for Cd. Bioconcentration factors for Cd and Znwere higher than one in baseline situations, but mostly lowerthan one on polluted sediment-derived soils. Cd:Zn ratio wason the average twice as high as in the soil. Leaf beetlesshowed normal body concentrations for Zn, but higher Cdconcentrations than in reference situations. BCFs were lowerthan one on sediment-derived soils. Foliar results indicateda possible threat in long-term habitat development of poplarplantations. This conclusion was confirmed by the significanthigher Cd concentrations in leaf beetles grown on poplarswith deviant foliar concentrations. However, litterdecomposition rates were generally evaluated as normal.     

Manure and adoption of modern seeds in cereal‐based systems in West African drylands: linkages and (non)complementarities

Using a stepwise approach that combines several econometric methods, we assessed whether or not the adoption of modern seeds and the use of manure in cereal‐based systems are linked and, if so, what are the driving forces of the linkages between these two agricultural technologies under dry‐climate conditions in West Africa. We found complementary and substitutability linkages arising from jointness and endogeneity between the two technologies. Specifically, our findings reveal positive joint determination along with negative endogeneity between the two technologies indicating that, controlling for observable variables, both technologies are positively linked, but unobserved factors that affect one adoption decision are negatively correlated with the other. After controlling for jointness and endogeneity, we found significant complementarity linkages showing a significant positive effect of manure use on the adoption of modern seeds, which is also significantly and positively affected by the number of cash crops grown and remittances. The two technologies are reversely affected by schooling and the incidence of soil fertility problems within the farm, whereas the amount of healthy land has a positive effect on both. The study suggests that organic fertilizer can serve as an enabling factor for greater adoption of modern seeds, especially in less favourable climate areas, and strongly supports the argument behind the need to breed seeds suitable for the use of organic fertilizers. These findings provide avenues for re‐orientation of policies that promote the use of modern seeds in dryland areas in sub‐Saharan Africa, with a possibility of breeding and promoting them in packages with organic fertilizers to upscale their adoption.     

Performance Assessment of a 3D Hydrodynamic Model Using High Temporal Resolution Measurements in a Shallow Urban Lake

Urban lakes provide many ecosystem services, e.g., flood control, nature protection, coolness island, recreation. Hydrodynamic models will increasingly be used to enhance these benefits. We present the first validation of a three-dimensional (3D) hydrodynamic model on a small shallow lake with high resolution and high frequency measurements. Lake Créteil, France (area 0.4 km², mean depth 4.5 m, and catchment area 1 km²) is a former gravel pit and now part of a regional park. The model Delft3D-FLOW was calibrated on a one-month period, with continuous measurements of temperature at five depths at the center of the lake and at three depths at two other stations, and with current speed profiles at the centre of the lake. The model was then verified on 18 1-month periods with similar temperature measurements. The model reproduced very well the temperature dynamics, including the alternation between mixing and stratification periods and internal wave patterns. The mean absolute errors over the five depths at the central point remained below 0.55^°C in spring and summer, the most favorable seasons for phytoplankton growth. Horizontal temperature differences, which rose up to 3^°C at the beginning of stratification periods, were also well reproduced, as well as current speeds. These results are very promising for assessing nutrient and pollutant diffusion, settling and resuspension, as well as for understanding how phytoplankton blooms start in small shallow lakes.     

The importance of scientific literacy in fostering education for sustainability: Theoretical considerations and preliminary findings from a Brazilian experience

Scientific literacy can be considered as a new demand of post-industrial society. It seems necessary in order to foster education for sustainability throughout students' academic careers. Universities striving to teach sustainability are being challenged to integrate a holistic perspective into a traditional undergraduate curriculum, which aims at specialization. This new integrative, inter- and transdisciplinary epistemological approach is necessary to cultivate autonomous citizenship, i.e., that each citizen be prepared to understand and participate in discussions about the complex contemporary issues posed by post-industrial society. This paper presents an epistemological framework to show the role of scientific literacy in fostering education for sustainability. We present a set of 26 collaborative concept maps (CCmaps) in order to illustrate an instance of theory becoming practice. During a required course for first-year undergraduate students (ACH 0011, Natural Sciences), climate change was presented and discussed in broad perspective by using CCmaps. We present students' CCmaps to show how they use concepts from quantitative and literacy disciplines to deal with the challenges posed by the need of achieving a sustainable development.     

Ecosystem-based adaptation to climate change: what role for policy-makers, society and scientists?

In developing countries where economies and livelihoods depend largely on ecosystem services, policies for adaptation to climate change should take into account the role of these services in increasing the resilience of society. This ecosystem-based approach to adaptation was the focus of an international workshop on “Adaptation to Climate Change: the role of Ecosystem Services” held in November 2008 in Costa Rica. This article presents the key messages from the workshop.     

Finite population properties of individual predictors based on spatial patterns

In this study a conceptual framework for assessing the statistical properties of a non-stochastic spatial interpolator is developed through the use of design-based finite population inference tools. By considering the observed locations as the result of a probabilistic sampling design, we propose a standardized weighted predictor for spatial data starting from a deterministic interpolator that usually does not provide uncertainty measures. The information regarding the coordinates of the spatial locations is known at the population level and is directly used in constructing the weighting system. Our procedure captures the spatial pattern by means of the Euclidean distances between locations, which are fixed and do not require any further assessment after the sample has been drawn. The predictor for any individual value turns in a ratio of design-based random quantities. We illustrate the predictor design-based statistical properties, i.e. asymptotically p-unbiasedness and p-consistency, for simple random sampling without replacement. An application to a couple of environmental datasets is presented, for assessing predictor performances in correspondence of different population characteristics. A comparison with the equivalent non-spatial predictor is presented.     

Coastal management, climate change adaptation and sustainability in small coastal communities: leatherback turtles and beach loss

Beaches are frequently subjected to erosion and accretion that are influenced by coastal development interventions and natural variations due to storms and changes in river flow. Climate change may also exacerbate beach erosion and accretion. Natural scientists are concerned with the sustainability of species dependent on the beach ecosystem. Policymakers are pre-occupied with the economic sustainability of coastal communities should species decline and prolonged beach loss occur. The aim of this paper is to explore the linkage between science and policy by reporting the findings of a study of coastal change impacts on leatherback turtle nesting and analysing the socio-economic and adaptation implications of these changes for coastal communities. Grande Riviere, Trinidad, was used as a case study. Primary fieldwork investigated unsustainable coastal management practices. A questionnaire was administered to examine livelihoods, including ecotourism based on leatherback turtle nesting, and knowledge and awareness of climate change. One key finding of the study was that the community’s livelihoods were natural resources dependent, and that natural beach dynamics and unsustainable coastal management practices posed major threats to natural resource and economic sustainability. Another key finding was that, despite these impacts, community knowledge and awareness of climate change in general was low, and there was a perception of state responsibility for climate change adaptation. The research findings have global applicability for coastal communities at risk of exposure and that are highly vulnerable to natural resources damage arising from anthropogenic stress and potential climate change. These communities require policy reforms to strengthen current coastal management practices and adaptation responses aimed at ensuring long-term sustainability.