The stress of scramble: sex differences in behavior and physiological stress response in a time-constrained mating system

Iteroparous species maximize lifetime reproductive fitness by balancing current and future reproductive investments. In order to maximize fitness in the face of social or environmental heterogeneity, individuals of the same species may vary in whether they prioritize current reproductive opportunity or sacrifice immediate reproduction in order to prioritize survival and future reproductive potential. Glucocorticoid (GC) secretion plays an important role in mediating this trade-off by promoting behavioral and physiological responses associated with survival, often at the expense of nonessential (e.g., reproductive) functions. We used wood frogs (Lithobates sylvaticus [Rana sylvatica]) to test whether males and females differed in their (a) physiological response (plasma corticosterone [CORT] concentration) to standardized handling stress—a proxy for predation threat—and (b) performance of reproductive behaviors that may enhance their conspicuousness to predators. We also tested whether levels of male competition influenced sex differences in these factors, as more intense competition may require males to devote more time to risky reproductive behaviors. We found that females had lower baseline CORT but exhibited a significantly greater CORT response to a stressor and spent less time performing potentially risky behavior (surface floating) than did males. These sex differences were consistent across different levels of male mating competition. Our results reveal that during breeding, males and females may differentially respond to stressors and perform risk-prone behaviors, despite facing the same extreme breeding constraints, providing new insight into the survival-reproduction trade-off of explosively breeding species.     

Contrasting nitrate adsorption in Andisols of two coffee plantations in Costa Rica

Fertilizer use in coffee plantations is a suspected cause of rising ground water nitrate concentrations in the ground water-dependent Central Valley of Costa Rica. Nitrate adsorption was evaluated beneath two coffee (Coffea arabica L.) plantations in the Central Valley. Previous work at one site had identified unsaturated zone nitrate retardation relative to a tritium tracer. Differences in nitrate adsorption were assessed in cores to 4 m depth in Andisols at this and one other plantation using differences in KCl- and water-extractable nitrate as an index. Significant adsorption was confirmed at the site of the previous tracer test, but not at the second site. Anion exchange capacity, X-ray diffraction data, extractable Al and Si, and soil pH in NaF corroborated that differences in adsorption characteristics were related to subtle differences in clay mineralogy. Soils at the site with significant nitrate adsorption showed an Al-rich allophane clay content compared with a more weathered, Si-rich allophane and halloysite clay mineral content at the site with negligible adsorption. At the site with significant nitrate adsorption, nitrate occupied less than 10% of the total anion adsorption capacity, suggesting that adsorption may provide long-term potential for mitigation or delay of nitrate leaching. Evaluation of nitrate sorption potential of soil at local and landscape scales would be useful in development of nitrogen management practices to reduce nitrate leaching to ground water.     

Pollution and Waste Production in Home-Based Enterprises in Developing Countries: Perceptions and Realities

Using mainly qualitative data from a four country case study, this paper describes the nature of home-based enterprises (HBEs) and the wastes that they produce. It finds that most only generate material similar to domestic wastes, but in greater quantities. While some are undoubtedly generating dangerous wastes, they are only a small proportion of all HBEs and tend to be aware of at least some of the problem and take mitigating steps. The paper argues that the encouragement of clean processes should replace the usual negative views about HBEs that are held by policy makers.     

Protection of biota on nonpark public lands: Examples from the US Department of Energy Oak Ridge Reservation

Security buffers of Department of Defense (DoD) and Department of Energy (DOE) reservations provide long-term habitat protection for many rare and endangered species. The importance of these government-owned reservations as nationally valuable resources has been relatively unrecognized. During the last 50 years, the DOE Oak Ridge Reservation (ORR) has been a relatively protected island in a region of rapidly expanding urbanization and land clearing. Consisting of the Oak Ridge National Environmental Research Park and associated lands surrounding DOE facilities at Oak Ridge Tennessee, the unique nature of the ORR in the surrounding landscape is clearly visible from the air and has been documented using remote sensing data. Although forests dominate much of other regions of eastern Tennessee, this 15,000-ha tract of mostly natural forest habitat is unique in the southern Ridge and Valley physiographic province, which is otherwise widely developed for pasture, marginal cropland, woodlot, and urban uses. Twenty state-listed and federal-candidate plant species are known to be present on the ORR. This richness of species, which are provided protection by state and federal laws, exceeds that of the Great Smoky Mountains National Park on a species area basis and is an index of the value of the ORR both regionally and nationally in conserving biodiversity. With the end of the Cold War, changing DoD and DOE missions combined with increasing development pressure contribute to uncertainty in the future management of security reservations.     

The classic environmental issue

Summary Environmental issues are rarely straightforward. The construction of the Tellico Dam not only proved to be an exceptionally complex environmental problem but also developed into a major political issue in its own right. Following the discovery of a previously unknown species of fish near the site of the nearly completed dam, environmentalists began a long legal battle to halt construction work and protect the habitat of the fish. The United States Supreme Court found in their favour, but local political interests, through a series of clever manoeuvres, succeeded in exempting the dam from all legislation to secure its completion. The blatant use of political expediency to resolve an environmental dilemma makes the Tellico Dam a classic case study for students of environmental policy and decision-making.Graham Bennett was born in London in 1948 and graduated from the School of Environmental Sciences at the University of East Anglia where he also completed his doctoral research. Since 1980 he has been working in The Netherlands as an Associate in the Department of Environmental Science at the Catholic University of Nijmegen. His research interests lie in the field of environmental management and he is currently involved in the study of environmental policy making in Britain and The Netherlands with particular reference to the control of pollution by local authorities.     

Evaluation of management effectiveness of protected areas in the Volta Basin,Ghana: perspectives on the methodology for evaluation,protected area financing and community participation

ABSTRACT

Protected areas are widely recognized as an important strategy for biodiversity conservation. Most of the sites are, however, poorly managed as resource exploitation by fringe communities and low government funding, among other things, threaten their management effectiveness. We used the World Commission on Protected Areas framework for designing management effectiveness evaluation systems, with the Rapid Assessment and Prioritization of Protected Areas Management (RAPPAM) methodology as a tool, to evaluate six components of the management cycle at six sites in Ghana for their management effectiveness. We examined the robustness of RAPPAM as an evaluation tool in the African context. The results showed that most of the sites evaluated are vulnerable and exposed to various degrees of pressure and threats, including poverty in the nearby communities, adjacent land-use and encroachment. On RAPPAM, we noted that apart from inconsistencies in some of the assessment scores due to the biases associated with the self-assessment approach of the methodology, the management effectiveness framework places little emphasis on financing and community participation, though both play major roles in the management process. We proposed a modification of the framework within the African context, to address effectively the underlying courses of pressure and threats facing Ghana’s protected areas.     

Implementing Sustainability: the Use of Natural Channel Design and Artificial Wetlands for Stormwater Management

Sustainability is a concept that has been widely embraced both politically and intellectually but has not been addressed in terms of practical application. In most resource sectors, the features of a sustainable future remain unclear and there are few examples that give practical expression to sustainability. This is especially true in the case of water resources management which has been conspicuous in its absence from the majority of the literature. This paper attempts to address this deficiency on two counts. First, it provides a discussion of sustainability and the application of the concept to the management of water resources. Second, the paper illustrates how the concept can be utilized for the management and planning of urban stormwater. The paper concludes by offering research opportunities to investigate the feasibility of adopting natural channel design and artificial wetlands for sustainable stormwater management.     

Environmental education in third world schools: Rhetoric or realism?

Summary Approaches to teaching about environmental concerns that have been successful either in Western schools or in non-formal Third World projects are unlikely to be effectively implemented in Third World schools. The perceptions of schooling in the Third World, together with the economic, political and social context in which it is conducted, present constraints that are very different. Unless these constraints are recognized, attempted reforms by environmental educators will, at best, remain only at the rhetorical level and, at worst, prove counter-productive. The paper discusses three broad categories of constraint: arising from the socio-political context of schooling, the educational system itself, and issues concerning school-village transfer. The argument is illustrated by reference to research in developing countries on similar educational reforms, such as community schooling, and with examples from the author's research in Papua New Guinea. The paper concludes with some positive lessons for those wishing to see a concern for environmental issues pervade the curriculum of schools in the Third World. The danger of making such reforms over-ambitious is stressed. To be successful, such work must be given high status in the eyes of students and teachers and examination reforms should be introduced to reinforce this.Dr Graham Vulliamy lectures in Sociology in the Department of Education at the University of York. Following field research trips to Papua New Guinea in 1979–1980, 1982 and 1986, he has a special interest in the implementation of educational reforms in developing countries. He is an executive editor of theBritish Journal of Sociology of Education and of theInternational Journal of Educational Development.     

The grand fiction of a personal odyssey

This paper describes a personal intellectual transformation that resulted from immersion within the Clark milieu of the early 1970s: a liberation from limitations of exclusive reliance upon a positivist quantitative paradigm in the study of human/environment transactions. The paper traces the genesis, nurturing, and subsequent evolution of a research program oriented toward developing a humanistic perspective on the environmental experience of the elderly. The parallel development of similar research on children (much of it also emanating from Clark) is noted. The paper concludes with advocacy for the development of a humanistic life-cycle perspective on environmental experience that will embrace the ‘hole in the middle’, the span of life between childhood and old age that, to date, has been subjected to limited study.     

Hydrologic Model Framework for Water Resources Planning in the Santa Cruz River,Southern Arizona1

Abstract: The authors develop a model framework that includes a set of hydrologic modules as a water resources management and planning tool for the upper Santa Cruz River near the Mexican border, Southern Arizona. The modules consist of: (1) stochastic generation of hourly precipitation scenarios that maintain the characteristics and variability of a 45‐year hourly precipitation record from a nearby rain gauge; (2) conceptual transformation of generated precipitation into daily streamflow using varied infiltration rates and estimates of the basin antecedent moisture conditions; and (3) surface‐water to ground‐water interaction for four downstream microbasins that accounts for alluvial ground‐water recharge, and ET and pumping losses. To maintain the large inter‐annual variability of streamflow as prevails in Southern Arizona, the model framework is constructed to produce three types of seasonal winter and summer categories of streamflow (i.e., wet, medium, or dry). Long‐term (i.e., 100 years) realizations (ensembles) are generated by the above described model framework that reflects two different regimes of inter annual variability. The first regime is that of the historic streamflow gauge record. The second regime is that of the tree ring reconstructed precipitation, which was derived for the study location. Generated flow ensembles for these two regimes are used to evaluate the risk that the regional four ground‐water microbasins decline below a preset storage threshold under different operational water utilization scenarios.