Possible involvement of plant ABC transporters in cadmium detoxification: a cDNA sub-microarray approach

As a nontolerant plant to a large number of toxic compounds, Arabidopsis thaliana is a suitable model to study regulation of genes involved in response to heavy metals. Using a cDNA-microarray approach, we identified some ABC transporters that are differentially regulated after cadmium treatments, making them putative candidates for being involved in Cd sequestration and redistribution in plants. Regarding yeast and fission yeast, in which Cd is able to form complexes either with glutathione (GSH) or phytochelatins (PC) subsequently transported into vacuoles via ABC transporters, it is also very likely that some plant ABC transporters are able to transport GS(2)-Cd or PC-Cd complexes into subcellular compartments or outside of the cell. The characterization of such transporters is of great interest for developing molecular biology approaches in phytoremediation.     

Testing the evolution of increased competitive ability (EICA) hypothesis in a novel framework

The "evolution of increased competitive ability" (EICA) hypothesis proposes that escape from natural enemies, e.g., after transcontinental introductions, alters the selection regime because costly defenses no longer enhance fitness. Such an evolutionary loss of defenses enables resources to be directed toward growth or other traits improving performance. We tested the EICA hypothesis in a novel framework in which the natural enemy is the traveler that follows its widespread host by accidental or deliberate (biocontrol) introductions. In a greenhouse experiment we used populations of Senecio vulgaris from North America, Europe, and Australia that differ in the history of exposure to the rust fungus Puccinia lagenophorae. Contrary to what is predicted by EICA, we found no evidence for increased levels of resistance to the rust fungus in plant populations with a longer history of rust exposure (Australia). Similarly, there was no evidence for reduced fecundity in these populations, although vegetative vigor, measured as secondary branching and growth rate, was lower. The maintenance of high rust resistance in populations with no (North America) or only a short history (Europe) of rust exposure is surprising given that resistance seems to incur considerable fitness costs, as indicated by the negative association between family mean resistance and fitness in the absence of disease observed for all three continents. The comparison of population differentiation in quantitative traits with estimates of differentiation in amplified fragment length polymorphic (AFLP) markers suggests that a number of fitness-related traits are under divergent selection among the studied populations. The proposed framework to test changes in the evolutionary trajectory underlying EICA can be employed in an expanded range of systems. These may include investigations on a cosmopolitan weed or crop when an antagonist is expanding its geographic range (such as our study), studies along a chronosequence of introduction time with expected increasing accumulation of natural enemies over time, or comparisons between introduced plant populations that differ in exposure time to biocontrol organisms.     

Increasing development in the surroundings of U.S. National Park Service holdings jeopardizes park effectiveness

Protected areas are cornerstones of biodiversity conservation, but they are in danger of becoming islands in a sea of human dominated landscapes. Our question was if protected areas may even foster development in their surroundings because they provide amenities that attract development, thus causing the isolation of the ecosystems they were designed to protect. Our study analyzed historic aerial photographs and topographical maps to reconstruct road development and building growth within and around Indiana Dunes and Pictured Rocks National Lakeshores in the U.S. Great Lakes region from 1938 to 2005, and to estimate the effects of park creation in 1966 on changes in landscape patterns. Historic U.S. census housing density data were used as a baseline to compare observed changes to. Our results showed that park establishment was effective in reducing and stopping the fragmenting impact of development within park boundaries. However, increased amenity levels following park establishment led to enhanced development in the surroundings of both parks. In the extreme case of Indiana Dunes, building density outside the park increased from 45 to 200 buildings/km² and road density almost doubled from 3.6 to 6.6 km/km² from 1938 to 2005. Development rates of change were much higher than in the broader landscape, particularly after park establishment. The potential amenity effect was up to 9500 new buildings in the 3.2-km zone around Indiana Dunes between 1966 and 2005. For Pictured Rocks the absolute effect was smaller but up to 70% of the observed building growth was potentially due to amenity effects. Our findings highlight the need for conservation planning at broader scales, incorporating areas beyond the boundaries of protected areas.     

Plant invasions, generalist herbivores, and novel defense weapons

One commonly accepted mechanism for biological invasions is that species, after introduction to a new region, leave behind their natural enemies and therefore increase in distribution and abundance. However, which enemies are escaped remains unclear. Escape from specialist invertebrate herbivores has been examined in detail, but despite the profound effects of generalist herbivores in natural communities their potential to control invasive species is poorly understood. We carried out parallel laboratory feeding bioassays with generalist invertebrate herbivores from the native (Europe) and from the introduced (North America) range using native and nonnative tetraploid populations of the invasive spotted knapweed, Centaurea stoebe. We found that the growth of North American generalist herbivores was far lower when feeding on C. stoebe than the growth of European generalists. In contrast, North American and European generalists grew equally well on European and North American tetraploid C. stoebe plants, lending no support for an evolutionary change in resistance of North American tetraploid C. stoebe populations against generalist herbivores. These results suggest that biogeographical differences in the response of generalist herbivores to novel plant species have the potential to affect plant invasions.     

Simulation der aeroben und anaeroben Abwasserreinigung mit einfachen Mitteln

Before waste-water-relevant organic materials are to be found in large quantities, their specific behavior in sewage treatment plants must be known. With the aid of the OECD simulation test #303 A, an estimation of their elimination in biological clarification stages can be made. In this work, an economical and continuous testing system is presented, which consists of a polyester flies bound to an activated biosludge with a high inoculum density, allowing one to measure no only the elimination of individual substances, but also the specific degree of mineralization. The toxicity of the activated biosludge and the nitrifying substances can also be examined. With the described testing procedure, it is possible to determine the rate of degradation within only a few hours. Finally, it can also be seen that it is possible to reliably and continuously determine the rate of anaerobic, biological degradability through the use of such a modified testing procedure.     

Oekopsychologie: Some general implications from a particular literature

One goal of this paper is to present a perspective on psychological research in which the relationship between person and environment is the central point of interest. The german term Oekopsychologie is introduced as a higher level framework that subsumes both, the theory-oriented ecological perspective (the Oekologische Psychologie in German), and problem-oriented and environmental psychology (the Umweltpsychologie in German) with its more applied character. It is argued that the ecological perspective should be based on 10 tenets which stem from an emphasis on the fundamental importance of the man-environment relationship. The paper is also an attempt to stimulate bridge-building activities between German-speaking and English-speaking environmental psychologists.     

Organic certification for shrimp value chains in Ca Mau,Vietnam: a means for improvement or an end in itself?

Eco-certification has been used as a tool to mitigate adverse effects of aquaculture production and might thus be understood as a private approach to sustainable ecosystem management. In production forests in Ca Mau, Vietnam, where mangrove have suffered degradation despite legal protection, different projects have targeted reversing this trend by means of private certification using the ‘Naturland’ organic standard as a reference. So far the outcomes have, however, been proven unsatisfactory. With the aim to better understand the reasons for these poor outcomes, a survey of forty households was conducted in a production forest in Rach Goc commune, Ngoc Hien District. We evaluated farmers’ perceptions on mangrove management, the drivers guiding shrimp farming, and whether there was a difference between participants and non-participants in a former ‘Naturland’ organic project. To complement the survey, a range of stakeholders involved in shrimp value chains were interviewed to better understand the terms and benefits of certification. The results of this survey suggested that, when applied to shrimp–mangrove farming systems in production forests in Ca Mau, ‘eco-certification’ and associated benefits are not very satisfactory. The survey results revealed that certified farms do not show significant differences to non-certified farms in terms of social and environmental benefits. As far as the implementation process was concerned, the survey results showed that a failure to integrate local farmers as participants consequently resulted in households becoming ‘objects’ for certification and not project partners with equal weight and power. It appears that rather than being a tool for improvement, ‘Naturland’ certification for shrimp–mangrove farming systems in Ca Mau’s production forests has become an end in itself.     

Quantifying disturbance effects on vegetation carbon pools in mountain forests based on historical data

Although the terrestrial carbon budget is of key importance for atmospheric CO₂ concentrations, little is known on the effects of management and natural disturbances on historical carbon stocks at the regional scale. We reconstruct the dynamics of vegetation carbon stocks and flows in forests across the past 100 years for a valley in the eastern Swiss Prealps using quantitative and qualitative information from forest management plans. The excellent quality of the historical information makes it possible to link dynamics in growing stocks with high-resolution time series for natural and anthropogenic disturbances. The results of the historical reconstruction are compared with modelled potential natural vegetation. Forest carbon stock at the beginning of the twentieth century was substantially reduced compared to natural conditions as a result of large scale clearcutting lasting until the late nineteenth century. Recovery of the forests from this unsustainable exploitation and systematic forest management were the main drivers of a strong carbon accumulation during almost the entire twentieth century. In the 1990s two major storm events and subsequent bark beetle infestations significantly reduced stocks back to the levels of the mid-twentieth century. The future potential for further carbon accumulation was found to be strongly limited, as the potential for further forest expansion in this valley is low and forest properties seem to approach equilibrium with the natural disturbance regime. We conclude that consistent long-term observations of carbon stocks and their changes provide rich information on the historical range of variability of forest ecosystems. Such historical information improves our ability to assess future changes in carbon stocks. Further, the information is vital for better parameterization and initialization of dynamic regional scale vegetation models and it provides important background for appropriate management decisions.     

Selective uptake,distribution, and redistribution of 109Cd, 57Co, 65Zn, 63Ni,and 134Cs via xylem and phloem in the heavy metal hyperaccumulator Solanum nigrum L

The focus of this article was to explore the translocation of ¹⁰⁹Cd, ⁵⁷Co, ⁶⁵Zn, ⁶³Ni, and ¹³⁴Cs via xylem and phloem in the newly found hyperaccumulator Solanum nigrum L. Two experiments with the uptake via the roots and transport of ¹⁰⁹Cd, ⁵⁷Co, and ⁶⁵Zn labeled by roots, and the redistribution of ¹⁰⁹Cd, ⁶⁵Zn, ⁵⁷Co, ⁶³Ni, and ¹³⁴Cs using flap label in S. nigrum in a hydroponic culture with a standard nutrient solution were conducted. The results showed that ¹⁰⁹Cd added for 24 h to the nutrient medium of young plants was rapidly taken up, transferred to the shoot, and accumulated in the cotyledons and the oldest leaves but was not efficiently redistributed within the shoot afterward leading to a rather low content in the fruits. In contrast, ⁵⁷Co was more slowly taken up and released to the shoot, but afterward, this element was redistributed from older leaves to younger leaves and maturing fruits. ⁶⁵Zn was rapidly taken up and transferred to the shoot (mainly to the youngest leaves and not to the cotyledons). Afterward, this radionuclide was redistributed within the shoot to the youngest organs and finally accumulated in the maturing fruits. After flap labeling, all five heavy metals tested (¹⁰⁹Cd, ⁵⁷Co, ⁶⁵Zn, ⁶³Ni, ¹³⁴Cs) were exported from the labeled leaf and redistributed within the plant. The accumulation in the fruits was most pronounced for ⁶³Ni and ⁶⁵Zn, while a relatively high percentage of ⁵⁷Co was finally found in the roots. ¹³⁴Cs was roughly in the middle of them. The transport of ¹⁰⁹Cd differed from that previously reported for wheat or lupin and might be important for the potential of S. nigrum to hyperaccumulate cadmium.     

Air pollution and diseases of the respiratory tracts in pre-school children: A transfer function model

The purpose of the present statistical analysis was the assessment of the relation between time series of environmental factors and of frequencies of diseases of the respiratory system in pre-school children. During about one year, daily measurements of air pollutants and climatic variables were taken. During the same period of time two series of medical data were collected: (i) The daily relative number of pre-school children, exhibiting diseases of the respiratory tracts who either came to the outpatients' clinic of the children's hospital or were reported by paediatricians in Basle (ENTRIES). (ii) The daily relative frequency of symptoms of the respiratory tracts observed in a group of randomly selected pre-school children (SYMPTOMS).By means of transfer function models the relation between the two target variables and the explaining variables was analysed. Several practical problems did arise: Choice of the appropriate transformation of the different series, interpretation of the crosscorrelation function using different methods of prewhitening, time splitting and nonstationarity of the crosscorrelation structure. In particular, it was found that after prewhitening the crosscorrelation function between the explanatory series SO₂ and the response series SYMPTOMS changes with time. While during the winter period an instantaneous relation between these two series (and to a lesser extent between NO₂ and SYMPTOMS) was identified, no such relation was found for the other seasons.