Context Of Environmental Change Research Articles

River management under transformation: The emergence of strategic adaptive management of river systems in the Kruger National Park

Protected areas such as the Kruger National Park (KNP) face many management challenges, of which ensuring a healthy flow of rivers into the park is one of the most important. Although previous management policies isolated the KNP from its neighbours, this position has changed as the KNP seeks to negotiate a respected ‘place’ for water and conservation in a competitive environment. A major catalyst for this re-orientation has been the response from the KNP to the growing water crisis where its position needed to be seen within the wider catchment and policy context in South Africa. This paper presents an overview of the transforming management practices of the KNP in a changing political, socio-economic and environmental context, through the lens of water resources. We show that the KNP management model moved beyond inward-looking, isolationist policies to adopt responsivity to major change factors. The new approach was applied first in the sphere of river management in the KNP after which it spread to other domains such as fire and game management. It explicitly incorporates an experimental–reflexive orientation and considers management as a process of learningby- doing. This paper strives to review the transformation since the onset of explicit adaptive management of these rivers. The development of a new stewardship, based on a stakeholdercentred vision and on learning-focused management, has been a main achievement for the KNP. A closer partnership between researchers, managers and field staff, supported with buyin and co-learning, has led to a management framework based on a clear vision informed by stakeholder involvement, an objectives hierarchy, a scoping of management options, a monitoring system and a reflective evaluation process with feedback loops. Although developed through a focus on rivers, the framework can be embraced for the management of ecosystems as a whole.Conservation implications: The explicit adoption of strategic adaptive management for the rivers entering the KNP has had considerable implications not only with regard to management practice within the park, but also for the relationships with neighbours. This has also meant setting and implementing new goals and priorities with managers and staff.

Mechanistic modeling of turkey growth response to genotype and nutrition

Along with the fast genetic improvement, nutritional and environmental effects on poultry growth performance have made it necessary to develop growth models that have the flexibility to adapt to different genotypes and growing conditions. A mechanistic simulation model of energy and nutrient utilization in growing turkeys is presented herein. The model consists of simulating the average homeorhetic and homeostatic regulations associated with the utilization of circulating glucose, fatty acid, AA, and acetyl-CoA for protein and lipid retention in carcass, viscera, and feathers in a turkey population. Homeorhesis plays a major role in the control of protein and lipid turnover for the definition of genetic potential and feed intake, whereas homeostasis adjusts growth rate through protein and lipid turnover rates and, therefore, BW gain and feed intake to the growing conditions. Also, homeostasis enables the maintenance of a dynamic balance state during all the growing period through the control of circulating nutrient concentration. The model was developed and calibrated with experimental data that described energy utilization in male and female growing turkeys. Then, the ability of the model to adapt to genotypes and to predict the average response of a turkey population to dietary energy was evaluated. Model calibration showed simulations of energy and nutrient utilization that fitted well with the experimental data because ME was satisfyingly partitioned into heat production and energy retention as protein and lipid, and nutrient intake accurately partitioned BW gain into carcass, viscera, and feathers. The evaluation of the model was also satisfactory because BW gain and feed-to-gain ratio were globally in accordance with the observations in different male and female genotypes, in spite of an overestimation of the feed-to-gain ratio during the first weeks of age. Model evaluation showed that the BW gain and feed intake response of growing turkeys to dietary energy was accurately predicted. The model can therefore be used in different growing conditions as it is capable of simulating the growth of different turkey genotypes fed under changing environmental and nutritional contexts.

Ventral tegmental area disruption selectively affects CA1/CA2 but not CA3 place fields during a differential reward working memory task.

Hippocampus (HPC) receives dopaminergic (DA) projections from the ventral tegmental area (VTA) and substantia nigra. These inputs appear to provide a modulatory signal that influences HPC dependent behaviors and place fields. We examined how efferent projections from VTA to HPC influence spatial working memory and place fields when the reward context changes. CA1 and CA3 process environmental context changes differently and VTA preferentially innervates CA1. Given these anatomical data and electrophysiological evidence that implicate DA in reward processing, we predicted that CA1 place fields would respond more strongly to both VTA disruption and changes in the reward context than CA3 place fields. Rats (N = 9) were implanted with infusion cannula targeting VTA and recording tetrodes aimed at HPC. Then they were tested on a differential reward, win-shift working memory task. One recording session consisted of 5 baseline and 5 manipulation trials during which place cells in CA1/CA2 (N = 167) and CA3 (N = 94) were recorded. Prior to manipulation trials rats were infused with either baclofen or saline and then subjected to control or reward conditions during which the learned locations of large and small reward quantities were reversed. VTA disruption resulted in an increase in errors, and in CA1/CA2 place field reorganization. There were no changes in any measures of CA3 place field stability during VTA disruption. Reward manipulations did not affect performance or place field stability in CA1/CA2 or CA3; however, changes in the reward locations "rescued" performance and place field stability in CA1/CA2 when VTA activity was compromised, perhaps by trigging compensatory mechanisms. These data support the hypothesis that VTA contributes to spatial working memory performance perhaps by maintaining place field stability selectively in CA1/CA2.

Conceptual implicit memory and environmental context

Changes in environmental context between encoding and retrieval often affect explicit memory but research on implicit memory is equivocal. One proposal is that conceptual but not perceptual priming is influenced by context manipulations. However, findings with conceptual priming may be compromised by explicit contamination. The present study examined the effects of environmental context on conceptual explicit (category-cued recall) and implicit memory (category production). Explicit recall was reduced by context change. The implicit test results depended on test awareness (assessed with a post-test questionnaire). Among test-unaware participants, priming was equivalent for same-context and different-context groups, whereas for the test-aware, the same-context group produced more priming. Thus, when explicit contamination is controlled, changes in environmental context do not impair conceptual priming. Context dependency appears to be a general difference between implicit and explicit memory rather than a difference between conceptual and perceptual implicit memory. Finally, measures of mood indicated no changes in affect across contexts, arguing against mood mediation for the context effects in explicit recall.

The Memphis Girls' health Enrichment Multi-site Studies (GEMS)

To determine the efficacy of a 2-year obesity prevention program in African American girls. Memphis GEMS (Girls' health Enrichment Multi-site Studies) was a controlled trial in which girls were randomly assigned to an obesity prevention program or alternative intervention. Local community centers and YWCAs (Young Women's Christian Associations) in Memphis, Tennessee. Girls aged 8 to 10 years (N = 303) who were identified by a parent or guardian as African American and who had a body mass index (BMI) at or higher than the 25th percentile for age or 1 parent with a BMI of 25 or higher. Group behavioral counseling to promote healthy eating and increased physical activity (obesity prevention program) or self-esteem and social efficacy (alternative intervention). The BMI at 2 years. The BMI increased in all girls with no treatment effect (obesity prevention minus alternative intervention) at 2 years (mean, 0.09; 95% confidence interval [CI], -0.40 to 0.58). Two-year treatment effects in the expected direction were observed for servings per day of sweetened beverages (mean, -0.19; 95% CI, -0.39 to 0.09), water (mean, 0.21; 95% CI, 0.03 to 0.40), and vegetables (mean, 0.15; 95% CI,-0.02 to 0.30), but there were no effects on physical activity. Post hoc analyses suggested a treatment effect in younger girls (P for interaction = .08). The mean BMI difference at 2 years was -2.41 (95% CI, -4.83 to 0.02) in girls initially aged 8 years and -1.02 (95% CI, -2.31 to 0.27) in those initially aged 10 years. The lack of significant BMI change at 2 years indicates that this intervention alone is insufficient for obesity prevention. Effectiveness may require more explicit behavior change goals and a stronger physical activity component as well as supportive changes in environmental contexts.

Collective Action for Smallholder Market Access: Evidence and Implications for Africa

It is widely acknowledged that the involvement of small farmers into markets can contribute to higher productivity and income growth, which in turn can enhance food security, poverty reduction efforts, and overall economic growth. In Africa, as in other parts of the developing world, agricultural production systems and their participants face significant challenges as a result of changing economic, environmental, and sociopolitical context. New dynamics in the global agricultural economy, such as the growth of supermarkets, are providing smallholders with both the new opportunities and new constraints to participate in and benefit from market exchanges. Collective action in the form of producer groups can enable African smallholders to take advantage of the new value chains and deal with existing market imperfections. However, certain conditions must be in place to create and sustain incentives for farmers to organize around marketing. Experiences from collective action in natural resource management (NRM) have shown that the types of markets and products, characteristics of user groups, institutional arrangements, and external environment need to be considered in order to determine the effectiveness and sustainability of collective marketing for smallholders. This paper applies the lessons from collective action in NRM to marketing, using existing case studies of producer groups in Africa, and offers policy recommendations on the factors that contribute to the success of collective marketing efforts.

Phenotypic plasticity and population viability: the importance of environmental predictability

Phenotypic plasticity plays a key role in modulating how environmental variation influences population dynamics, but we have only rudimentary understanding of how plasticity interacts with the magnitude and predictability of environmental variation to affect population dynamics and persistence. We developed a stochastic individual-based model, in which phenotypes could respond to a temporally fluctuating environmental cue and fitness depended on the match between the phenotype and a randomly fluctuating trait optimum, to assess the absolute fitness and population dynamic consequences of plasticity under different levels of environmental stochasticity and cue reliability. When cue and optimum were tightly correlated, plasticity buffered absolute fitness from environmental variability, and population size remained high and relatively invariant. In contrast, when this correlation weakened and environmental variability was high, strong plasticity reduced population size, and populations with excessively strong plasticity had substantially greater extinction probability. Given that environments might become more variable and unpredictable in the future owing to anthropogenic influences, reaction norms that evolved under historic selective regimes could imperil populations in novel or changing environmental contexts. We suggest that demographic models (e.g. population viability analyses) would benefit from a more explicit consideration of how phenotypic plasticity influences population responses to environmental change.

Aerial alarm calling by male fowl ( Gallus gallus) reveals subtle new mechanisms of risk management

Alarm calling is a classic problem in evolutionary biology. Although a signaller may increase the likelihood of survival for group members, which typically include kin and mates, there are inherent risks associated with any behaviour that increases conspicuousness to predators. Callers can increase their indirect benefits by calling only in the presence of an appropriate audience and manage concomitant costs by judicious investment. Possible tactics for controlling costs include facultative variation in call structure and timing, as well as sensitivity to the environmental and social factors that predict personal vulnerability. We examined individual variation in the alarm-calling behaviour of male fowl in naturalistic social groups. Previous studies of cost management have focused on variation at the level of alarm call rate. We took advantage of recent advances in wireless sound recording and remote video monitoring to test for more subtle variation in signal structure and timing. These were then mapped onto individual mating success and moment-to-moment changes in environmental and social context. Results replicate the previous finding that alarm calling is sensitive to both social rank and recent mating success. In addition, we detected systematic variation in call structure as a function of personal vulnerability and proximity to a rival male. The frequency bandwidth of alarms was reliably influenced by degree of vigilance prior to calling, suggesting that this acoustic dimension reflects motivational state. Taken together, these results reveal several novel tactics for risk management, complementing those previously described at the level of gross variation in alarm-calling behaviour.

Environmental context change affects memory for performed actions

The current study investigated the effect of environmental context change between the study and test on the recall of action phrases that either were performed during encoding (subject-performed tasks, SPTs) or were verbally encoded (verbal tasks, VTs). Both SPTs and VTs showed the same magnitude of impaired recall when the study and test contexts mismatched. Furthermore, changing the context between the two study lists reduced cross-list intrusion errors compared to encoding the lists in the same context. Both SPTs and VTs benefited from studying the lists in different contexts as evidenced by reduced intrusions. Taken together, the results suggest that SPTs are integrated with their context because they suffered when context changed between the study and test, and they also benefited when they were performed in two environments versus the same environment.

Memorial Consequences of Environmental Context Change in Children and Adults

Changing environmental context during encoding can influence episodic memory. This study examined the memorial consequences of environmental context change in children. Kindergartners, first and fourth graders, and young adults studied two lists of items, either in the same room (no context change) or in two different rooms (context change), and subsequently were tested on the two lists in the room in which the second list was encoded. As expected, in adults, the context change impaired recall of the first list and improved recall of the second. Whereas fourth graders showed the same pattern of results as adults, in both kindergartners and first graders no memorial effects of the context change arose. The results indicate that the two effects of environmental context change develop contemporaneously over middle childhood and reach maturity at the end of the elementary school days. The findings are discussed in light of both retrieval-based and encoding-based accounts of context-dependent memory.

Biodiversity in microbial communities: system scale patterns and mechanisms

The relationship between anthropogenic impact and the maintenance of biodiversity is a fundamental question in ecology. The emphasis on the organizational level of biodiversity responsible for ecosystem processes is shifting from a species-centred focus to include genotypic diversity. The relationship between biodiversity measures at these two scales remains largely unknown. By stratifying anthropogenic effects between scales of biodiversity of bacterial communities, we show a statistically significant difference in diversity based on taxonomic scale. Communities with intermediate species richness show high genotypic diversity while speciose and species-poor communities do not. We propose that in species-poor communities, generally comprising stable yet harsh conditions, physiological tolerance and competitive trade-offs limit both the number of species that occur and the loss of genotypes due to decreases in already constrained fitness. In species-rich communities, natural environmental conditions result in well-defined community structure and resource partitioning. Disturbance of these communities disrupts niche space, resulting in lower genotypic diversity despite the maintenance of species diversity. Our work provides a model to inform future research about relationships between species and genotypic biodiversity based on determining the biodiversity consequences of changing environmental context.

Occupational risks, safety and masculinity: Newfoundland fish harvesters' experiences and understandings of fishery risks

There is no single, objective place from which to assess risk, and the best way to assess and minimise risk is through seeking input from a variety of different knowledge agents focusing on different sources and dimensions of risk and using multiple methodologies. This paper draws on Wynne's work on constructivist-realism and on the feminist literature on masculinity to examine fish harvesters' understandings and experiences of risk and safety in the province of Newfoundland and Labrador on Canada's east coast. Using data drawn from focus groups, phone interviews and from individual boat tours with Newfoundland fish harvesters, it is argued that their understandings and practices of risk and safety are dynamic and that this dynamism reflects the intersection of everyday requirements to get the job done in what are often uncertain and constrained circumstances associated with the interacting and changing regulatory, industrial and environmental contexts in which this work is done. From this perspective, while quantifying fisheries risks in terms of fatality, accident or Search and Rescue incident rates is important, the inclusion of fish harvesters' experiences and related safety knowledge in research and policy-development designed to reduce risk is imperative. The view from the deck of the vessel and fish harvesters' experiences on the water not only informs their observations and interpretations of risk but offer potential insights into risk and into expert claims about risk that should be taken into account when trying to understand fishing risk and improve safety.

Changes to open field surfaces typically used to elicit hippocampal remapping elicit graded exploratory responses

Studies show that changes in environmental context alter the spatial firing patterns (‘remapping’) and increase immediate early gene activation in hippocampal but not subicular neurons. However, such studies rarely report co-occurring behavioural responses. We examined the behavioural effects of habituating rats to a walled open field, and then of changing the environmental context by altering wall patterns and floor colour. These kinds of cue change are known to elicit spatial remapping in hippocampal regions, but not the subiculum. Relative to controls (no cue alterations), alteration of wall patterns elicited significant increases in exploratory locomotion through the open field, while combined alterations of floor colour and wall patterns elicited an even higher increase in exploratory locomotion. In addition, combined alterations (floor colour and wall patterns) significantly increased rearing frequency, and significantly decreased the time the rats spent immobile. These findings are relevant to how changes in environmental context affect neuronal responses in the hippocampal formation, and may aid in the development of novelty-response tasks where novelty resides in open field surfaces.

Human—environment interactions in Australia and New Guinea during the Holocene

During the long history of human occupation in Australia and New Guinea, any interaction between people and their environment has been played out against changing sociocultural and environmental contexts. Although archaeologists have used palaeoenvironmental data to better characterize the relationships between humans and their environment, and palaeoecologists and geomorphologists have likewise used archaeological and historical information to augment their interpretations, it is our contention that few Australian and New Guinean studies have truly integrated these perspectives. Often archaeologists and palaeoenvironmentalists use each other's information in a one-dimensional manner, tendencies that have yielded simplistic interpretations of the past that overemphasize intentional or unintentional human causation on the one hand, and climatic and environmental causation on the other. We discuss three issues relevant to a more integrated understanding of the past: conceptualizing human—environment interactions, issues of scale and perspective, and multidisciplinary research integration in Australia and New Guinea.

‘You think that I’m smoking and they’re not’: Why mothers still smoke in the home

Past research into smoking and motherhood has explained how smoking enables mothers to care in conditions of hardship and poverty. However, much of this research was conducted before the risks to the health of non-smokers of inhaling tobacco smoke were widely known, and so mothers’ attitudes towards passive smoking and caring remain under explored. Children living with smokers are at risk of developing serious acute and chronic conditions during childhood and later life. Despite increased awareness of health messages among parents, young children are still exposed to environmental tobacco smoke (ETS) in the home, with maternal smoking identified as the primary source of exposure. In this paper, we present the findings from a project set up to explore the changing social and environmental context of smoking and motherhood. Using focus groups, 54 mothers of children aged under five years from the Merseyside area of England, who smoked, discussed their beliefs about smoking, passive smoking and the health of their children. Although mothers were aware of the messages linking ETS exposure to childhood illnesses they appeared to rely more on their own explanations for any ill health experienced by their children, discounting smoking as a primary cause and preferring alternative explanations including ‘genetics’ and ‘pollution’. These alternative explanations were common both within and between groups, suggesting that they form part of a wider resistant dialogue constructed within families and communities, where information about smoking and child health is received, challenged, and reconciled with existing knowledge, before being either accepted or rejected. Crucially, this alternative dialogue supports the mothers’ continued smoking, and is inevitably linked to their personal need to smoke while caring. These findings have implications for the development of future strategies for promoting the health of children with mothers who are reluctant, or feel unable, to accept that smoking can affect the health of their children.

Environmental context effects in conceptual explicit and implicit memory

Previous research has found environmental context effects for both conceptual explicit and conceptual implicit memory (Parker, Gellatly, & Waterman, 1999). The research presented here challenges these findings on methodological grounds. Experiment 1 assessed the effects of context change on category-exemplar generation (conceptual implicit memory test) and category-cued recall (conceptual explicit memory test). Experiment 2 assessed the effects of context change on word association (conceptual implicit memory test) and word associate cued recall (conceptual explicit memory test). In both experiments, study–test changes in environmental context were found to influence performance only on tests of explicit memory. It is concluded that when retrieval cues across explicit and implicit tests are matched, and the probability of explicit contamination is reduced, then only conceptual explicit test performance is reduced by study–test changes in environmental context.

Health and climatic hazards: Framing social research on vulnerability, response and adaptation

Floods, windstorms, drought and wildfires have major implications for human health. To date, conceptual advances in analysis of vulnerability and adaptation to climatic hazards from the environmental and social sciences have not been widely applied in terms of health, though key progress is being made particularly in relation to climate change. This paper seeks to take this conceptual grounding further, examining how key themes relate to health concerns, exploring connections with existing health literatures, and developing an organising framework to aid analysis of how vulnerability to health impacts varies within society and how actors make decisions and take action in relation to climatic hazards and health. Social science research on this theme is challenging in part because of the complex mechanisms that link hazard events to health outcomes, and the many-layered factors that shape differential vulnerability and response within changing societal and environmental contexts (including the dual effect of hazards on human health and health systems, and the combination of ‘external’, ‘personal’ and ‘internal’ elements of vulnerability). Tracing a ‘health impact pathway’ from hazard event through health risk effects to health outcomes can provide a research tool with which to map out where the different factors that contribute to vulnerability/coping capacity come into effect.

Induced Biases in Emotional Interpretation Influence Stress Vulnerability and Endure Despite Changes in Context

Previous research has shown that interpretation biases can be experimentally induced and endure for 24 hours. In two experiments, we show that induced biases not only persist but survive changes in environmental context, including transferring to different rooms with different experimenters. In one experiment, training and testing materials were also presented in different sensory modalities without significantly reducing the magnitude of the induced bias. Furthermore, we found evidence of changes in emotional vulnerability, congruent with the direction of induced bias, which also persisted for 24 hours. Together with earlier results, these findings show that induced biases generalize over contexts and have persisting emotional consequences, suggesting that appropriately adapted training methods may contribute to developing therapeutic techniques within clinical settings.

Local soil classification and comparison of indigenous and technical soil maps in a Mesoamerican community using spatial analysis

The soil classification system developed by a Purhépecha community in central Mexico was formalized, incorporating symbolic, cognitive and practical components. The soil is recognized by farmers as a three-dimensional living body, composed of earth material, air and fluids, organic matter, and living organisms including plants and animals, and organized in layers. The indigenous soil taxonomy is hierarchical, with four categorical levels, and soil classification is flexible enough to adapt to a changing social and environmental context. The local soil map units were compared to those provided by a technical soil classification of general scope (USDA soil taxonomy), using spatial analysis within a GIS environment to determine levels of cartographic correlation. The average spatial correlation at high taxonomic level, computed taking into account only the dominant soils in each map unit, is 74% for the technical–local comparison and 75% for local–technical comparison. At low taxonomic level, the average spatial correlation based on dominant soils only is 62% for the technical–local comparison and 61% for the local–technical comparison. The variable levels of spatial correlation between technical and local soil map units reflect differences in the ways both systems classify soils. However, similarities and discrepancies between making technical and local soil maps reveal complementarities. Critical is the evaluation of topsoil characteristics, as the understanding and monitoring of topsoil dynamics are fundamental for land use decision-making by farmers. Spatial correlation analysis of topsoil properties provides a good basis for collaboration between farmers and soil surveyors. Merging technical and local thinking is indispensable to formulate sustainable land management schemes.

Concreteness and item-to-list context associations in the free recall of items differing in context variability.

Context variability can be defined as the number of preexperimental contexts in which a given concept appears. Following M. Steyvers and K. J. Malmberg's (2003) work, the authors have shown that concepts that are experienced in fewer preexperimental contexts generally are better remembered in episodic memory tasks than concepts that are experienced in a greater number of preexperimental contexts. The purpose of this article is to demonstrate that low context variability confers its memorial advantage because of stronger item-to-list context associations as compared with high context variability. Three experiments that use environmental context changes from study to test demonstrate that the low context variability advantage is eliminated when item-to-list context associations are not available because of environmental changes at test. In addition, the low context variability advantage is eliminated when inward processing at study prevents the formation of item-to-list context associations.