Does carbon limitation reduce nitrogen retention in soil?

Environmental Chemistry Letters - Artificial soils made from waste materials offer an alternative to imported natural topsoils, notably in large-scale groundwork and reclamation projects. Benefits...     

Threshold to maturity in a long-lived reptile: interactions of age, size, and growth

Thresholds to sexual maturity—either age or size—are critical life history parameters. Usually investigated in short-lived organisms, these thresholds and interactions among age, size, and growth are poorly known for long-lived species. A 34-year study of captive green turtles (Chelonia mydas) that followed individuals from hatching to beyond maturity provided an opportunity to evaluate these parameters in a long-lived species with late maturity. Age and size at maturity are best predicted by linear growth rate and mass growth rate, respectively. At maturity, resource allocation shifts from growth to reproductive output, regardless of nutrient availability or size at maturity. Although captive turtles reach maturity at younger ages than wild turtles, the extensive variation in captive turtles under similar conditions provides important insights into the variation that would exist in wild populations experiencing stochastic conditions. Variation in age/size at maturity should be incorporated into population models for conservation and management planning.     

Effects of seawater temperature and pH on the boring rates of the sponge Cliona celata in scallop shells

Warmer, more acidic water resulting from greenhouse gas emissions could influence ecosystem processes like bioerosion of calcifying organisms. Based on summer-maxima values (temperature = 26 °C; pH = 8.1) at a collection site in New York (40°56″ N, 72°30″ W), explants of the boring sponge Cliona celata Grant, 1826 were grown for 133 days on scallop shells in seawater ranging from current values to one scenario predicted for the year 2100 (T = 31 °C; pH = 7.8). High water temperature had little effect on sponge growth, survival, or boring rates. Lower pH slightly reduced sponge survival, while greatly influencing shell boring. At pH = 7.8, sponges bored twice the number of papillar holes and removed two times more shell weight than at pH = 8.1. Greater erosion resulted in weaker scallop shells. This study suggests that lower seawater pH may increase boring rates of C. celata in shellfish, with potentially severe implications for wild and farmed shellfish populations.     

Societal change and the control of deforestation in Thailand

Thailand underwent a major shift in forest policy in the second half of the 1980s to promote sustainable management and control of deforestation. This paper puts this in the context of earlier changes in forest policy and analyses the underlying causes of the shift by analysing changes in the relative strength of different interest groups within the framework of a policy pressures model. Internal pressures had a stronger impact on Thai forest policy than external pressures. Protectionist groups became more numerous and more powerful in Thailand in the 1980s in relation to exploitative groups, and their rise in influence was facilitated by continuing progress in democratization and pluralization, linked to the consequences of economic development. Such political change could help to explain the apparent link between better environmental management and economic development shown in the Environmental Kuznets Curve.     

Creating local institutional arrangements for sustainable wetland socio-ecological systems: lessons from the ‘Striking a Balance’ project in Malawi

Wetland socio-ecological systems provide livelihood benefits for many poor people throughout the developing world, yet their sustainable development requires local utilisation strategies that balance both environmental and development outcomes. Community-based local institutional arrangements that mediate peoples’ relationships with their environment and facilitate adaptive co-management offer one means of achieving this, and increasingly many NGOs and development practitioners have sought to integrate local institutional capacity building into development projects. In the context of wider academic debates surrounding the long-term sustainability of externally facilitated local institutions, this article draws on the experiences of the three-year Striking a Balance (SAB) project in Malawi which sought to embed sustainable wetland management practices within community-based local institutional arrangements. Drawing on field data collected through participatory methods at three project sites some 5 years after the cessation of project activities, we examine the extent to which SAB’s local institutional capacity building has been successful, and from this draw some lessons for externally driven project interventions which seek win-win outcomes for people and the environment. With reference to Elinor Ostrom’s design principles for long-enduring common property resource institutions, we suggest that the observed declining effectiveness of SAB’s local institutions can be attributed to issues of stakeholder inclusiveness and representations; their sustainability was arguably compromised from their inception on account of them being nested within pre-existing, externally driven village ‘clubs’ whose membership and decision-making was not congruent with all the wetland stakeholders within the community.     

Processes of distribution of pharmaceuticals in surface freshwaters: implications for risk assessment

The global consumption and production of pharmaceuticals is increasing concomitantly with concern regarding their environmental fate and effects. Active pharmaceutical ingredients are mainly released into the aquatic environment through wastewater effluent discharge. Once in the environment, pharmaceuticals can undergo processes of natural attenuation, i.e. dilution, sorption, transformation, depending on physico-chemical properties of the compound, such as water solubility, lipophilicity, vapour pressure, and environmental conditions, such as pH, temperature and ionic strength. A major natural attenuation process is the sorption on dissolved organic matter, colloids, suspended solids and sediments, which in turn control pharmaceuticals distribution, residence time and persistence in aquatic systems. Here we review studies of sorption capacity of natural sorbents to pharmaceuticals. These report on the importance of several environmental and sorbent-specific properties, such as the composition, quality, and amount of the sorbent, and the environmental pH, which determines the speciation of both the sorbent and compound. The importance of accounting for distribution processes on freshwater sorbents for any determination of environmental concentrations of pharmaceuticals is apparent, while the reliability of surrogate standards for measuring dissolved organic matter (DOM) distribution is evaluated in the context of the need for robust environmental risk assessment protocols.     

An analytical model of an urban heat island circulation in calm conditions

Environmental Fluid Mechanics - We obtain an analytical model solution to an idealization of an urban heat island (UHI) circulation—the steady shallow convective flow of a viscous stably...     

Technological thinking: Its impact on environmental management

A style of thinking that is variously called technological, technocentric, and technocratic dominates environmental management. However, there is growing criticism of this style of thought, leading some to conclude that, if environmental management is to progress, technological thinking needs to be supplemented by radically different ways of thinking. The intent of this article is to examine the role of technological thinking in environmental management, seeking to establish some of its limitations. It is concluded that, while technological thinking is a satisfactorytactical strategy, it has serious deficiencies when problems requirestrategic thinking.     

Ideology and environmental risk management

Summary Although risk management is interdisciplinary in nature, in practice it is excessively compartmentalized. For instance, two quite different orientations to risk management are commonly seen, the relationship between them being one of suspicious rivalry rather than cooperation. Thus, anyone interested in developing a more integrated form of risk management is faced with the problem of trying to understand why these opposed factions have developed and what sustains their mutual antagonism. Hopefully, this paper makes a contribution in this regard by discussing the psychological and socio-political roots of environmental ideology.Dr Alan Miller is currently Professor of Psychology at the University of New Brunswick. He received his early training in biology (in England) and ecology (in Canada). He subsequently spent several years pursuing research at the Northwest Institute for Medical Research in Chicago, USA. A growing interest in the human aspects of environmental and medical problems led to a further graduate study in psychology, followed by teaching positions in Ireland and Canada. His current interests include: the education of environmental professionals; the psychosocial problems involved in environmental management, and the problems inherent in interdisciplinary project groups.