Flood-risk management strategies for an uncertain future: living with Rhine River floods in The Netherlands?

Social pressure on alluvial plains and deltas is large, both from an economic point of view and from a nature conservation point of view. Gradually, flood risks increase with economic development, because the expected damage increases, and with higher dikes, because the flooding depth increases. Global change, changing social desires, but also changing views, require a revision of flood-risk management strategies for the long term. These should be based on resilience as opposed to the resistence strategy of heightening dikes. Resilience strategies for flood-risk management imply that the river is allowed to temporarily flood large areas, whereas the flood damage is minimized by adapting land use. Such strategies are thus based on risk management and 'living with floods' instead of on hazard control. For The Netherlands, one of the most densely populated deltas in the world, alternative resilience strategies have been elaborated and assessed for their hydraulic functioning and 'sustainability criteria'.     

Male fighting and “territoriality” within colonies of the ant Cardiocondyla venustula

The ant genus Cardiocondyla is characterized by a bizarre male polymorphism with wingless fighter males and winged disperser males. Winged males have been lost convergently in several clades, and in at least one of them, wingless males have evolved mutual tolerance. To better understand the evolutionary pathways of reproductive tactics, we investigated Cardiocondyla venustula, a species, which in a phylogenetic analysis clusters with species with fighting and species with mutually tolerant, wingless males. Wingless males of C. venustula use their strong mandibles to kill freshly eclosed rival males and also engage in short fights with other adult males, but in addition show a novel behavior hitherto not reported from social insect males: they spread out in the natal nest and defend “territories” against other males. Ant males therefore show a much larger variety of reproductive tactics than previously assumed.     

Workaholism and daily recovery: A day reconstruction study of leisure activities

This study among 85 individuals used a day reconstruction approach to examine whether workaholism moderates the relationship between daily activities during non‐work time and daily well‐being in the evening (evening happiness, momentary vigor before bedtime, and momentary recovery before bedtime). Specifically, it was hypothesized that daily work‐related activities during the evening have a stronger negative relationship with daily well‐being for employees high (versus low) in workaholism and that daily physical and social activities have a stronger positive relationship with well‐being for employees high (versus low) in workaholism. The results of multilevel analyses largely supported the hypotheses for daily physical and work‐related activities but not for social activities during non‐work time. These findings imply that organizations should not encourage their employees and particularly those who score high on workaholism to work during non‐work time and instead promote physical exercise. Copyright © 2012 John Wiley & Sons, Ltd.     

Chemical evaluation of odor reduction by soil injection of animal manure

Field application of animal manure is a major cause of odor nuisance in the local environment. Therefore, there is a need for methods for measuring the effect of technologies for reducing odor after manure application. In this work, chemical methods were used to identify key odorants from field application of pig manure based on experiments with surface application by trailing hoses and soil injection. Results from three consecutive years of field trials with full-scale equipment are reported. Methods applied were: membrane inlet mass spectrometry (MIMS), proton-transfer-reaction mass spectrometry (PTR-MS), gold-film hydrogen sulfide (H?S) detection, all performed on site, and thermal desorption gas chromatography with mass spectrometry (TD-GC/MS) based on laboratory analyses of field samples. Samples were collected from a static flux chamber often used for obtaining samples for dynamic olfactometry. While all methods were capable of detecting relevant odorants, PTR-MS gave the most comprehensive results. Based on odor threshold values, 4-methylphenol, H?S, and methanethiol are suggested as key odorants. Significant odorant reductions by soil injection were consistently observed in all trials. The flux chamber technique was demonstrated to be associated with critical errors due to compound instabilities in the chamber. This was most apparent for H?S, on a time scale of a few minutes, and on a longer time scale for methanethiol.     

Molecular taxonomy confirms morphological classification of deep-sea hydrothermal vent copepods (Dirivultidae) and suggests broad physiological tolerance of species and frequent dispersal along ridges

Dirivultid copepods are among the most successful organisms at deep-sea hydrothermal vents, as this family includes 50 morphologically described species. We studied COI diversity of some species in various geographical areas and vent fluid regimes, in order to gain a better understanding of true species diversity, dispersal strategies, and evolution. DNA taxonomy revealed the same entities as described with morphological characters. No cryptic species were detected. With the help of COI analyses, it was possible to identify a new species and match the dimorphic sexes of another species. The geographical distance between vents, as well as the extreme physico-chemical environment, are thought to affect the gene flow of fauna. We could not detect any sequence differences within species among different geographical scales (up to 2,000 km) or different vent fluid regimes. We suggest that Dirivultidae have relatively high gene flow between vents and are able to disperse relatively easy along ridges. Further, they have a broad physiological tolerance and thus might not have undergone speciation in response to heterogeneity caused by vent fluids.     

Spatial distributions and eco-partitioning of soil biogeochemical properties in the Everglades National Park

Large-scale ecosystem restoration efforts, such as those in the Florida Everglades, can be long-term and resource intensive. To gauge success, restoration efforts must have a means to evaluate positive or negative results of instituted activities. Edaphic properties across the Everglades landscape have been determined to be a valuable metric for such evaluation, and as such, a baseline condition from which to make future comparisons and track ecosystem response is necessary. The objectives of this work were to document this baseline condition in the southern most hydrologic unit of the Everglades, Everglades National Park (ENP), and to determine if significant eco-partitioning of soil attributes exists that would suggest the need to focus monitoring efforts in particular eco-types within the ENP landscape. A total of 342 sites were sampled via soil coring and parameters such as total phosphorus (TP), total nitrogen (TN), total carbon (TC), total calcium, total magnesium, and bulk density were measured at three depth increments in the soil profile (floc, 0-10 cm, and 10-20 cm). Geostatistical analysis and GIS applications were employed to interpolate site-specific biogeochemical properties of soils across the entire extent of the ENP. Spatial patterns and eco-type comparisons suggest TC and TN to be highest in Shark River Slough (SRS) and the mangrove interface (MI), following trends of greatest organic soil accumulation. However, TP patterns suggest greatest storages in MI, SRS, and western marl and wet prairies. Eco-partitioning of soil constituents suggest local drivers of geology and hydrology are significant in determining potential areas to focus monitoring for future change detection.     

Feeling interrupted—Being responsive: How online messages relate to affect at work

Being constantly connected to others via e‐mail and other online messages is increasingly typical for many employees. In this paper, we develop and test a model that specifies how interruptions by online messages relate to negative and positive affect. We hypothesize that perceived interruptions by online messages predict state negative affect via time pressure and that perceived interruptions predict state positive affect via responsiveness to these online messages and perceived task accomplishment. A daily survey study with 174 employees (a total of 811 day‐level observations) provided support for our hypotheses at the between‐person and within‐person level. In addition, perceived interruptions showed a negative direct association with perceived task accomplishment. Our study highlights the importance of being responsive to online messages and shows that addressing only the negative effects of perceived interruptions does not suffice to understand the full impact of interruptions by online messages in modern jobs.     

Interaction of soil pH and phosphorus efficacy: Long-term effects of P fertilizer and lime applications on wheat,barley, and sugar beet

Phosphorus (P), a plant macronutrient, must be adequately supplied for crop growth. In Germany, many soils are high in plant-available P; specifically in arable farming, P fertilizer application has been reduced or even omitted in the last decade. Therefore, it is important to understand how long these soils can support sustainable crop production, and what concentrations of soil P are required for it. We analyzed a 36-year long-term field experiment regarding the effects of different P application and liming rates on plant growth and soil P concentrations with a crop rotation of sugar beet, wheat, and barley. Sugar beet reacted to low soil P and low soil pH levels more sensitively than wheat, which was not significantly affected by the long-term omitted P application. All three crop species showed adequate growth at soil P levels lower than the currently recommended levels, if low soil pH was optimized by liming. The increase in efficacy of soil and fertilizer P by reduced P application rates therefore requires the adaptation of the soil pH to a soil type-specific optimal level.     

Field-scale modelling of carbon and nitrogen dynamics in soils amended with urban waste composts

Composting has emerged as a valuable route for the disposal of urban waste, with the prospect of applying composts on arable fields as organic amendments. Proper management of urban waste composts (UWC) requires a capacity to predict their impacts on carbon and nitrogen dynamics in the field, an issue in which simulation models are expected to play a prominent role.Here, we used a deterministic soil-crop model to simulate C–N dynamics in an arable field amended with three types of UWC (green waste and sludge, biodegradable waste, and solid waste), and a reference amendment (farmyard manure). The model is a version of CERES in which the soil C–N module was substituted with the NCSOIL model, whose microbiological parameters were determined from either laboratory incubation data or biochemical fractionation in a previous paper. CERES was tested against data from a field trial set up in 1998 in the Paris area, and managed as a maize (Zea mays L.)–wheat (Triticum aestivum L.) rotation. Comparison of observed and simulated data over the first 4 years of the field trial showed that CERES predicted the soil moisture and inorganic N dynamics reasonably well, as well as the variations in soil organic C. In particular, the parameterization of UWC organic matter from biochemical fractions achieved a similar fit as the parameterization based on incubation data. Wheat yields were also correctly predicted, but a systematic under-estimation of maize yields pointed at an under-estimation of spring and summer mineralization of N by CERES.Simulated N fluxes showed that the organic amendments induced an additional leaching ranging from 1 to 8 kg N ha⁻¹ yr⁻¹, which can be related to the initial mineral N content of the amendments. After 4 years, the composts had mineralized 3–8% of their initial organic N content, depending on their stability. Composts with slower N release had higher N availability for the crops. CERES could thus be used to aid in selecting the timing of compost application, in relation to its stability, based on both environmental and agronomical criteria.