Seasonal variation of the radiocaesium transfer soil-to-Swiss chard (Beta vulgaris var. cicla L.) in allophanic soils from the Lake Region, Chile

The transfer factor (TF) of radiocaesium from soil-to-Swiss chard (Beta vulgaris var. cicla L.) was studied in two different characteristic allophanic soils (umbric andosol and dystric fluvisol) of the Lake Region, an important agricultural region situated in central-south Chile. To investigate especially the time dependence and the effect of K-fertilisation on the TF, field experiments were conducted. Plots of 7.6 m2 were labelled with 100 kBq 134Cs m(-2) at Santa Rosa Experiment Station close to the city of Valdivia characterised by a temperate climate and high precipitation rates. The variation in time of the radiocaesium TF soil-to-Swiss chard was observed during two consecutive years after soil contamination by sequential harvests and radiocaesium analyses of the plants. The TFs showed no significant ageing effect, but a pronounced seasonal decrease with effective half-lives of about 140 and 160 days for the umbric andosol without and with K-fertilisation, respectively, and of 50 and 60 days for the dystric fluvisol without and with K-fertilisation, respectively. The effect of K-fertilisation on the absolute values of the TF was determined by the ratio between the median TF values obtained for corresponding dates without and with use of K-fertiliser. A ratio of TF(without K)/TF(with K) = 1.8 for the umbric andosol and TF(without K)/TF(with K) = 2.9 for the dystric fluvisol was obtained, indicating a reduction of the TF by applying 90 kg K ha(-1). The maximal values of the TF to chard predicted by the equation characterising the seasonal decrease of the TF at the beginning of the harvest periods are 0.19 for the umbric andosol and 0.11 for the dystric fluvisol, both values for soil treated with common K-fertilisation.     

Integrating design thinking with sustainability science: a Research through Design approach

Design disciplines have a long history of creating well-integrated solutions to challenges which are complex, uncertain and contested by multiple stakeholders. Society faces similar challenges in implementing the Sustainable Development Goals, so design methods hold much potential. While principles of good design are well established, there has been limited integration of design thinking with sustainability science. To advance this integration, we examine the process of designing MetaMAP: an interactive graphic tool for collaborating to understand social–ecological systems and design well-integrated solutions. MetaMAP was created using Research through Design methods which integrate creative and scientific thinking. By applying design thinking, researchers and practitioners from different backgrounds undertook multiple cycles of problem framing, solution development, testing and reflection. The testing was highly collaborative involving over 150 people from diverse disciplines in workshops, case studies, interviews and critique. Reflecting on this process, we discuss design principles and opportunities for integrating design thinking with sustainability science to help achieve Sustainable Development Goals.     

Recent Invasions of the Gulf of Maine: Three Contrasting Ecological Histories

Introduced species are common members of estuarine communities where their role as competitors and predators is of concern, This paper examines the invasion of Gulf of Maine benthic habitats by the ecologically similar alien invertebrates Styela clava, Botrylloides diegensis , and Membranipora membranacea .
Styela clava increased slowly in abundance at study sites in Beverly, Massachusetts and Portsmouth, New Hampshire. We found no evidence of competitive dominance by S. clava , even though it is the competitive dominant in similar habitats elsewhere. Botrylloides diegensis rapidly became a dominant species after its arrival in the Great Bay Estuary, but this dominance was short-lived. B. diegensis persists in the estuary as an early colonist of primary space and as an epibiont on secondary substrates in established communities. Membranipora membranacea became the dominant epiphyte on laminarian kelps within two years. Although M. membranacea overgrew the native epiphytes Obelia geniculata and Electra pilosa in the overwhelming majority of encounters these native species are more common on other algal hosts. Therefore, competitive dominance is not likely a factor in the successful invasion of the Gulf of Maine by M. membranacea .
These species provide evidence for opposing views of the role of competition in mediating community invasion. We show that ecological similarity among species is not an accurate criterion to predict either the mechanism of invasion or the means of persistence. In addition, these data indicate that biological invasions must be examined on broad spatial and temporal scales; short-term or narrowly focused studies can lead to incorrect conclusions.     

Preferential incubation positions for different sized eggs and their influence on incubation period and hatching asynchrony in Snares crested (<Emphasis Type="Italic">Eudyptes robustus</Emphasis>) and yellow-eyed penguins (<Emphasis Type="Italic">Megadyptes antipodes</Emphasis>)

In crested penguins (Eudyptes spp.), second-laid eggs typically hatch before first eggs. Amongst a variety of factors that have been considered as mechanisms underlying this reversal, has been the idea that crested penguins can adjust the degree of hatching asynchrony by manipulating egg positions (i.e. placing the smaller first egg in the supposedly thermally disadvantaged anterior position) during incubation (termed Preferential Incubation Hypothesis). We tested this in the Snares crested penguin (Eudyptes robustus) and the closely related, but synchronously-hatching, yellow-eyed penguin (Megadyptes antipodes). Snares crested penguins were more likely to place their first eggs, which are smaller than second eggs, in the anterior incubation position than were yellow-eyed penguins, which have a clutch of two similar-sized eggs. But when yellow-eyed penguins, a non-brood reducing species, were provided with an artificial size-dimorphic clutch, they also placed smaller eggs more frequently in the anterior position, suggesting that a general preference exists among penguins to place smaller eggs in the anterior position. Egg temperatures of small first eggs of Snares crested penguins were higher in the anterior than in the posterior position. Large first eggs in lesser size-dimorphic clutches experienced high temperature differences in relation to position, while small first eggs in greater size-dimorphic clutches were incubated at similar temperatures. In yellow-eyed penguins, large eggs within clutches generally had higher egg temperatures than small eggs. Incubation periods of second eggs declined with increasing egg size. Egg-size variation, rather than egg positioning behaviour, influenced hatching patterns in Snares crested penguins. In lesser size-dimorphic clutches, second eggs were more likely to hatch first while in greater size-dimorphic clutches, small first eggs were more likely to hatch at the same time or before the second eggs. This was similar in yellow-eyed penguins, where second eggs hatched earlier in clutches with large first eggs. Our data contradicts the Preferential Incubation Hypothesis and we conclude that this hypothesis is unlikely to explain the reversed hatching asynchrony in crested penguins.Communicated by C. Brown     

Rodent sperm analysis in field-based ecological risk assessment: pilot study at Ravenna army ammunition plant,Ravenna, Ohio

Ecological risk assessment (ERA) guidance recommends that field-truthing efforts proceed when modeled hazard quotients (HQs) suggest that toxicological effects are occurring to site receptors. To date, no field methods have been proposed by the regulatory community that can lead to definitive determinations of acceptable or unacceptable risk for birds and mammals, the two terrestrial classes of receptors that are commonly assessed using the HQ method. This paper describes rodent sperm analysis (RSA) as a viable method to be applied in the field at sites with historical contamination. RSA is capable of detecting biological differences that bear on reproduction, a highly regarded toxicological endpoint of concern in USEPA Superfund-type ERAs. The results of RSA's first application at a study site are reported and discussed. The paper also provides the rationale for RSA's efficacy in the context of Superfund and other environmental cleanup programs, where limited time and money are available to determine and evaluate the field condition.     

Efficient Delineation of Nested Depression Hierarchy in Digital Elevation Models for Hydrological Analysis Using Level‐Set Method

In terrain analysis and hydrological modeling, surface depressions (or sinks) in a digital elevation model (DEM) are commonly treated as artifacts and thus filled and removed to create a depressionless DEM. Various algorithms have been developed to identify and fill depressions in DEMs during the past decades. However, few studies have attempted to delineate and quantify the nested hierarchy of actual depressions, which can provide crucial information for characterizing surface hydrologic connectivity and simulating the fill‐merge‐spill hydrological process. In this paper, we present an innovative and efficient algorithm for delineating and quantifying nested depressions in DEMs using the level‐set method based on graph theory. The proposed level‐set method emulates water level decreasing from the spill point along the depression boundary to the lowest point at the bottom of a depression. By tracing the dynamic topological changes (i.e., depression splitting/merging) within a compound depression, the level‐set method can construct topological graphs and derive geometric properties of the nested depressions. The experimental results of two fine‐resolution Light Detection and Ranging‐derived DEMs show that the raster‐based level‐set algorithm is much more efficient (~150 times faster) than the vector‐based contour tree method. The proposed level‐set algorithm has great potential for being applied to large‐scale ecohydrological analysis and watershed modeling.     

Databanks of data sources for environmental chemicals

There exist a vast variety of data sources, either manual sources or computerized databases in the field of environmental chemicals. To facilitate the access and to retrieve the information wanted efficiently, we built up two “databanks of data sources”, one called “Databank of Manual Sources (DMAS)” and the other named “Databank of Databases (DADB)”. The set‐up of these databanks is explained and the load status statistics are shown. DMAS has 164 and DADB 106 hits.