Plants grow better if seeds see green

We report on the response of dry plant seeds to their irradiation with intense green light applied at biostimulatory doses. Red and near-infrared light delivered by lasers or arrays of light emitting diodes applied at such doses have been shown previously by us to have effects on mammalian cells. Effects include cell proliferation and elevation of cell vitality, and have practical applications in various biomedical fields. Growth processes induced by photoreceptor stimulation (phytochromes and cryptochromes) in plant seeds with green light were described so far only for imbibed seeds. In this paper, we show that irradiation of dry cress, radish and carrot seeds with intense green light (laser or arrays of light emitting diodes), applied at biostimulatory doses, resulted in a significant increase in biomass—14, 26, and 71 days after seeding, respectively. In the case of radish and carrot, the irradiation led to important changes in the root-to-foliage surface ratio. Seeds with a potential to grant growth acceleration could be of special interest in agricultural applications, and could even compensate for shorter growth seasons caused by climate change.     

Documenting lemming population change in the Arctic: Can we detect trends?

Lemmings are a key component of tundra food webs and changes in their dynamics can affect the whole ecosystem. We present a comprehensive overview of lemming monitoring and research activities, and assess recent trends in lemming abundance across the circumpolar Arctic. Since 2000, lemmings have been monitored at 49 sites of which 38 are still active. The sites were not evenly distributed with notably Russia and high Arctic Canada underrepresented. Abundance was monitored at all sites, but methods and levels of precision varied greatly. Other important attributes such as health, genetic diversity and potential drivers of population change, were often not monitored. There was no evidence that lemming populations were decreasing in general, although a negative trend was detected for low arctic populations sympatric with voles. To keep the pace of arctic change, we recommend maintaining long-term programmes while harmonizing methods, improving spatial coverage and integrating an ecosystem perspective.     

Correction to: Status and trends of circumpolar peregrine falcon and gyrfalcon populations

While collating contributions and comments from 36 researchers, the coordinating authors accidentally omitted Dr. Suzanne Carrière from the list of contributing co-authors. Dr. Carrière’s data are described in Tables 1 and 3, Figure 2 and several places in the narrative. The new author list is thus updated in this article.     

Röntgenkristallographische Daten der Tetrathiomolybdate und Tetrathiowolframate vom Typ Me2BX4

The Science of Nature -     

The DNA damage activity (DDA) assay and its application to river waters and diesel exhausts

An extremely sensitive assay has been developed for DNA-damaging chemicals using a DNA repair-deficient strain of Escherichia coli. Considerable DNA-damaging activity has been demonstrated by this assay in natural surface-water samples and in diesel-exhaust particulate extracts.     

The occurrence of chlorinated bis-(propyl)ethers in the Elbe River and tributaries

Dedicated to Prof Dr. Dr. E. h. H. Sinn on the occasion of his 65th birthda     

O2 and H2S coexistence in stromatolites

The coexistence of O₂ and H₂S in recent microbial mats is demonstrated. Oxygen and H₂S are not only coexisting in considerable concentrations within recent stromatolites but high concentrations of the respective gases occur in alternating laminae. This “sandwich structure” is produced by alternating populations of oxygenic and anoxygenic photosynthetic bacteria and cyanobaeteria. The finding of such conditions may explain the alternation of oxidized and reduced iron minerals in Precambrian stromatolites and possibly also in the banded iron formations (BIFs).     

Flexible habitat selection and interactive habitat segregation in the marine congeners <Emphasis Type="Italic">Idotea baltica</Emphasis> and <Emphasis Type="Italic">Idotea emarginata</Emphasis> (Crustacea,Isopoda)

Habitat segregation among competing species is widespread yet very little is know how this is achieved in practice. In a case study, we examined short-term effects of conspecific and congeneric density on habitat selection in two competing marine isopod species, Idotea emarginata and Idotea baltica. Under semi-natural conditions in large outdoor cylindrical tanks (4 m high; volume 5.5 m³), animal groups of different size and composition had the choice between a set of relevant habitat samples (surface-floating seaweed, the water column, seaweed on the bottom). Habitat selection in both I. baltica and I. emarginata proved to be largely independent of conspecific density (level of intraspecific competition). In single-species treatments, both species showed a similar and stable pattern of distribution, with a clear preference for seaweed on the bottom. In mixed-species treatments (MST), however, the species were largely separated by habitat. While the distribution of I. emarginata was completely unaffected by the mere presence of interspecific competitors, habitat selection of I. baltica changed notably when I. emarginata was present. The habitat use patterns observed in MST conformed to those realized in geographical areas where the two species overlap in distribution: I. emarginata is dominant among decaying seaweed on the sea floor, and I. baltica is the dominant species among surface-floating seaweed. Our findings suggest that habitat segregation between the two species is essentially interactive, resulting from rapid decision-making of I. baltica with respect to habitat selection. The underlying mechanism is discussed. I. emarginata is highly superior to I. baltica in interference competition and rapidly eliminates the latter from one-habitat systems which do not allow I. baltica to escape from this interaction. In more natural, heterogeneous environments, however, I. baltica seems to be able to coexist with the superior competitor due to its broader habitat niche, flexibility in habitat selection, and a behavioural disposition to avoid normally preferred habitats when these are occupied by I. emarginata.     

Trade-offs and synergies in joint knowledge creation for coastal management: insights from ecology-oriented sand nourishment in the Netherlands

In order to successfully inform environmental management, environmental research needs to balance legitimacy, credibility, and salience. This paper aims to identify trade-offs and synergies between these three attributes in collaborative research for environmental management, and draws lessons for organizing such research. Empirically, it draws on a study of a research program on the ecological effects of coastal protection through sand nourishment. Our findings suggest that the legitimacy and salience of knowledge creation, particularly in an interactive governance context, are complementary. At the same time, we found trade-offs between practical relevance and fundamental knowledge creation, as well as between issue diversity and the depth and quality of scientific inquiry. Balancing the legitimacy, credibility, and salience of knowledge may be enabled by interactive knowledge creation involving policy-makers, experts and stakeholders. We conclude that successful management-oriented environmental research, particularly in the case of wicked problems, requires both a careful design of arrangements for stakeholder engagement, and well- established linkages to broader regulatory and institutional contexts.