Carbon dioxide flux across a forest-field ecotone

CO₂ flux of a deciduous forest and an old-field surface, and the ecotone between these two typical southern U.S. ecological communities, was studied in July, 1989. Rates of CO₂ flux were greatest in the old field and least in the forest plots. The ecotone showed the greatest variation in CO₂ flux. These differences appear to be due to differences in soil surface temperature, the old field being more exposed to direct solar radiation. The ecotonal community represents a landscape property which should be considered in studies of the transfer of carbon across the soil-atmosphere boundary.     

Mercury contamination-what we have learned since Minamata

Atmospheric cycling of mercury and other pollutants has become a major concern as industrialized countries have eliminated point discharges, sometimes by relocating the industries to underdeveloped and developing countries where point sources have become problems. Such circumventions may be to no avail in the long run as pollution continues to elevate levels of methylmercury in fish in waterways that are remote from direct contamination as well as where the source can be readily identified. Much has been learned about the cycling of mercury in the environment since human disabilities and deaths at Minamata, Japan, initially drew attention to the problem of methylmercury poisoning from the consumption of contaminated seafood in the 1950s. In that instance, methylmercury produced industrially concentrated to toxic levels in fish. As this manufacturing process was not used outside Japan, concern did not become immediate in other developed nations until the 1960s when it was established that mercury was not only biomethylated by microorganisms but also biomagnified through the food chain. Point sources to the waterways may have been eliminated too late to return the levels in fish to background because of the geochemical cycling of mercury through the environment. Despite decreases in domestic, industrial and agricultural point source releases over the last two decades, large quantities from non-point sources such as fossil fuel combustion, smelters, and incinerators are still being released. Much of this mercury is transported from the atmosphere to aquatic ecosystems and stored in sediments until it is again released to the water and atmosphere.     

The use of simple kinetic models to help design environmental monitoring systems

This paper describes the application of simple linear models to help design environmental monitoring systems. This process involves five steps: (1) The derivation of a schematic of the identified pollutant's transport and fate. (2) The derivation of the equation in the schematic. (3) Estimation of input data and numerical solution. (4) Comparison with initial field data. (5) Design of a monitoring system.Two examples of how this system was applied under field conditions are given. Advantages of this approach are: (1) It forces a consideration of the system as a whole rather than a series of distinct environmental components. (2) It forces a consideration of the physical-chemical and biological factors effecting pollutant transport in the system. (3) It sets up an analytical procedure for data analysis at the time the monitoring system is designed. (4) It helps show the functional relationship between pollutant levels in different environmental media. (5) It identifies points where sampling design could be changed to provide for a more efficient monitoring system. (6) It identifies gaps in our knowledge base.     

A pilot study on the determination of perfluorooctanesulfonate and other perfluorinated compounds in blood of Canadians

A pilot study was conducted to provide preliminary data on the concentrations of perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorooctanesulfonamide (PFOSA) in the blood of Canadians. A set of 56 human serum samples was collected from non-occupationally exposed Canadians and analyzed by microbore HPLC-negative ion electrospray tandem mass spectrometry. PFOS was the main component of perfluorinated organic compounds (PFCs) and was detected in all 56 blood specimens at an average concentration of 28.8 ng mL(-1) and a range from 3.7 to 65.1 ng mL(-1). The concentration of PFOA was an order of magnitude lower than that of PFOS and was found only in 16 samples (29%) at concentrations above the limit of quantification (LOQ). PFOSA was not detected at levels above the method detection limit (MDL) in any of the samples. The levels of PFCs observed in the sample group of non-occupationally exposed humans in Canada were similar to the levels reported in a previous US study with a similar sample pool size. Two distinct PFOS isomers in human serum were identified by accurate mass determination.     

On the origins of informal hierarchy: The interactive role of formal leadership and task complexity

Informal hierarchies are a common and important feature of many groups, yet we know little about the antecedent conditions that determine the strength of such hierarchies. Building on theory that has depicted hierarchy as a mechanism for reducing uncertainty and creating structure, we posit that informal hierarchies emerge most strongly in situations that are ambiguous, ill‐defined, and unstructured. Three independent studies confirm this notion, demonstrating that groups develop particularly strong informal hierarchies in situations characterized by both a lack of strong formal leadership and high task complexity. These findings support the theoretical notion that formal and informal hierarchies are closely related, but only under conditions of high task complexity in which the structuring functions of hierarchies are most crucial.     

Why did I say sorry? Apology motives and transgressor perceptions of reconciliation

Despite the importance of apology in reconciling interpersonal transgressions, little research has focused on the people engaging in the behavior. Why do transgressors apologize in the workplace, and do apology motives shape transgressor perceptions of reconciliation? We conducted three field studies using qualitative and quantitative methodologies to examine these questions. In Studies 1 and 2 (total N = 781), we identified four distinct apology motives—self‐blame, relational value, personal expedience, and fear of sanctions—and developed self‐report scales to measure the motives. In Study 3 (N = 420), we examined relations between apology motives and transgressor perceptions of victim forgiveness and relationship reconciliation through the lens of motivated cognition. We found that apologizing due to self‐blame, relational value, and personal expedience increases perceptions of victim forgiveness, whereas apologizing due to fear of sanctions decreases perceived forgiveness. Moreover, mediation analyses revealed that motives indirectly influence transgressor perceptions of relationship reconciliation through perceived forgiveness. Taken together, our research presents a novel multidimensional perspective on apology‐giving in the workplace, suggesting that why transgressors apologize can affect their perceptions of reconciliation. Overall, our research highlights the need to incorporate transgressor cognitive and motivational processes into reconciliation research.     

Not seeing is not believing: volunteer beliefs about Burmese pythons in Florida and implications for public participation in invasive species removal

Public engagement is important to invasive species management, and recreational harvest programs are one way agencies seek to involve the public and raise awareness. We surveyed participants (n = 660) and non-participants (n = 77) in the 2013 Python Challenge^TM to understand whether this event achieved its primary goal of raising awareness of the ecological impact of Burmese pythons (Python molurus bivittatus) in south Florida. Respondents indicated a high level of ‘concern’ about the seriousness of the python problem and the need for management actions. Concern was affected positively by environmental motivations, experience of seeing pythons in the wild, older age, and female sex, but negatively by level of Python Challenge involvement. Results suggest that ‘proximate’ experience of not seeing a python may reduce concern, whereas ‘ongoing’ experience may temper concern without diminishing involvement. This research highlights the role of experience in shaping beliefs and advises diligence in public participation programs.     

Development of new dunes in the Dutch Delta: nature compensation and ‘building with nature’

A new dune area was constructed by beach and foreshore nourishments along the Delfland Coast in the southwestern Netherlands. The new area is intended to be a compensation for losses of existing high quality dunes in nearby areas, due to the use/construction of Maasvlakte 2, the new harbour extension of Rotterdam opening in 2013. The target habitats for compensation include dry grey dunes and moist dune valley grassland. Due to the habitat type, the nourished material had to have a special character. The nourishment was carried out according to a special design and initial development of the new area had to follow certain pathways. In order to meet the compensation requirements in time. Careful monitoring is done to assess whether development of the new habitat is taking place in the direction of the desired target habitats. This paper reports on the construction of the new area and on the first years of development and monitoring. The monitoring mainly concerns development of the abiotic landscape elements, geomorphology, groundwater and soils. The lessons learned from this area are discussed in the light of the development of other recent young nature areas in the sandy Dutch delta coast. This gives new insights for coastal management in general in the context of building with nature.     

The dynamics of industrial symbiosis: a proposal for a conceptual framework based upon a comprehensive literature review

There is increasing evidence that throughout the world, firms, governmental agencies and NGOs are seeking to stimulate industrial symbiosis. This concept and its application have also been the topic of extensive research. Up till now, this work lacks a more comprehensive theoretical framework, and this paper fills this gap. We provide a theoretical basis for understanding the dynamics through which regional industrial systems change their connectiveness in an attempt to reduce their ecological impact. We position our framework within the field of industrial symbiosis based on a comprehensive literature search in the ISI Web of Science database for publications that listed ‘industrial symbiosis’, ‘eco-industrial park’, or a combination of ‘industrial-ecology’ and ‘regional’ as a topic.The framework conceptualizes industrial symbiosis as a process at two levels: (1) the level of the regional industrial system (RIS), and (2) the societal level where the concept and routines of industrial symbiosis diffuse. We link the dynamics at these levels to changes in ecological impact and increase in institutional capacity. We conclude with a research agenda based on the variables and their basic relationships specified in our framework. The main line of research we propose is to systematically investigate how institutional capacity evolves over time in regional industrial systems and how it affects the ecological impact of such systems. We also propose to investigate how insights from existing literature about stimulating and impeding factors to industrial symbiosis can be understood in terms of mechanisms of transmission and how these mechanisms interact to create nationally distinct patterns of diffusion of industrial symbiosis.     

Water quality status of dugouts from five districts in Northern Ghana: implications for sustainable water resources management in a water stressed tropical savannah environment

This study was primarily aimed at investigating the physicochemical and microbial quality of water in 14 such dugouts from five districts in the northern region of Ghana. Results obtained suggest that except for colour, turbidity, total iron and manganese, many physicochemical parameters were either within or close to the World Health Organisation’s acceptable limits for drinking water. Generally, colour ranged from 5 to 750 Hz (mean 175 Hz), turbidity from 0.65 to 568 nephelometric turbidity units (NTU; mean 87.9 NTU), total iron from 0.07 to 7.85 mg/L (mean 1.0 mg/L) and manganese from 0.03 to 1.59 mg/L (mean 0.50 mg/L). Coliform counts in water from all the dugouts in both wet and dry seasons were, however, above the recommended limits for drinking water. Total and faecal coliforms ranged from 125 to 68,000 colony forming units (cfu)/100 mL (mean 10,623 cfu/100 mL) and <?1 to 19,000 cfu/100 mL (mean 1,310 cfu /100 mL), respectively. The poor microbial quality, as indicated by the analytically significant presence of coliform bacteria in all samples of dugout water, strongly suggests susceptibility and exposure to waterborne diseases of, and consequent health implications on, the many people who continuously patronise these vital water resources throughout the year. In particular, more proactive sustainable water management options, such as introduction to communities of simple but cost-effective purification techniques for water drawn from dugouts for drinking purposes, education and information dissemination to the water users to ensure environmentally hygienic practices around dugouts, may be needed.