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991.
The consensus is that both ecological and social factors are essential dimensions of conservation research and practice. However, much of the literature on multiple disciplinary collaboration focuses on the difficulties of undertaking it. This review of the challenges of conducting multiple disciplinary collaboration offers a framework for thinking about the diversity and complexity of this endeavor. We focused on conceptual challenges, of which 5 main categories emerged: methodological challenges, value judgments, theories of knowledge, disciplinary prejudices, and interdisciplinary communication. The major problems identified in these areas have proved remarkably persistent in the literature surveyed (c.1960–2012). Reasons for these failures to learn from past experience include the pressure to produce positive outcomes and gloss over disagreements, the ephemeral nature of many such projects and resulting lack of institutional memory, and the apparent complexity and incoherence of the endeavor. We suggest that multiple disciplinary collaboration requires conceptual integration among carefully selected multiple disciplinary team members united in investigating a shared problem or question. We outline a 9‐point sequence of steps for setting up a successful multiple disciplinary project. This encompasses points on recruitment, involving stakeholders, developing research questions, negotiating power dynamics and hidden values and conceptual differences, explaining and choosing appropriate methods, developing a shared language, facilitating on‐going communications, and discussing data integration and project outcomes. Although numerous solutions to the challenges of multiple disciplinary research have been proposed, lessons learned are often lost when projects end or experienced individuals move on. We urge multiple disciplinary teams to capture the challenges recognized, and solutions proposed, by their researchers while projects are in process. A database of well‐documented case studies would showcase theories and methods from a variety of disciplines and their interactions, enable better comparative study and evaluation, and provide a useful resource for developing future projects and training multiple disciplinary researchers. Cazando la Quimera de la Multidisciplina en la Ciencia de la Conservación 相似文献
992.
Offsets are a novel conservation tool, yet using them to achieve no net loss of biodiversity is challenging. This is especially true when using conservation offsets (i.e., protected areas) because achieving no net loss requires avoiding equivalent loss. Our objective was to determine if offsetting the impacts of mining achieves no net loss of native vegetation in Brazil's largest iron mining region. We used a land‐use change model to simulate deforestation by mining to 2020; developed a model to allocate conservation offsets to the landscape under 3 scenarios (baseline, no new offsets; current practice, like‐for‐like [by vegetation type] conservation offsetting near the impact site; and threat scenario, like‐for‐like conservation offsetting of highly threatened vegetation); and simulated nonmining deforestation to 2020 for each scenario to quantify avoided deforestation achieved with offsets. Mines cleared 3570 ha of native vegetation by 2020. Under a 1:4 offset ratio, mining companies would be required to conserve >14,200 ha of native vegetation, doubling the current extent of protected areas in the region. Allocating offsets under current practice avoided deforestation equivalent to 3% of that caused by mining, whereas allocating under the threat scenario avoided 9%. Current practice failed to achieve no net loss because offsets did not conserve threatened vegetation. Explicit allocation of offsets to threatened vegetation also failed because the most threatened vegetation was widely dispersed across the landscape, making conservation logistically difficult. To achieve no net loss with conservation offsets requires information on regional deforestation trajectories and the distribution of threatened vegetation. However, in some regions achieving no net loss through conservation may be impossible. In these cases, other offsetting activities, such as revegetation, will be required. Compensación de los Impactos de la Minería para Obtener Ninguna Pérdida Neta de la Vegetación Nativa 相似文献
993.
994.
The River Avoca is severely polluted by discharges of acid mine drainage (AMD) from the abandoned sulphur and copper mines at Avoca. The riverine sediments were studied during a low flow period to establish the degree of contamination and to identify the major processes affecting sediment metal concentrations. pH plays a major role in the regulation of zinc adsorption and desorption in sediments, showing a significant correlation (p&0.001). The zinc concentration in the sediment falls below background levels after the input of AMD. However, the metal precipitated when the pH increased downstream of a fertiliser factory (pH8.0), some 7 km below the mine. In contrast Cu and Fe significantly increased (p0.001) both in the sediment (0--30 mm depth) and the surface ochre immediately below the mixing zone. Copper removal appears to be primarily by co-precipitation. Higher sediment enrichment factors for all metals were obtained in the surface sediment layer (ochre) deposited on larger stones and in floc material collected in sediment traps, compared with the subsurface sediment. Cadmium was not recorded in any of the sediment collected at the detection limit used (0.01 g g-1). Metal deposition in the sediments was found to be spacially variable, so sub-sampling is required, although replicates show little variation. Results indicate that short term variation in metal inputs is identified by sampling the surface layer only, whereas sampling of the subsurface layer (<63 m fraction) is more suitable for identifying long-term trends in sediment quality. The implication of sediment analysis in assessing environmental impact is discussed. 相似文献
995.
996.
To ensure proper development of young, mothers should react to offspring signals of need. Studies of such parent-offspring interaction often manipulated litter size to measure effects of changed offspring food demand. We used the extreme precociality of guinea pig (Cavia porcellus) pups to increase offspring demand without changing any other litter characteristic. As pups contribute to their own energy demands from birth by independent feeding, their food demand can be increased by withholding solid food early in lactation. We studied whether mothers reacted to increased food demand of offspring by enhanced parental care, especially by changes in the pattern of milk production and nursing. Pups deprived of solid food early in lactation grew more slowly and were in poorer body condition than pups in control litters, even after the former had access to solid food in late lactation. Mothers of deprived young reacted to offspring long-term need by maintaining nursing behaviour for longer than control mothers. However, this change in behaviour did not occur early in lactation when pup short-term need was greatest nor did it result in increased milk transfer at any time. Energy allocation of mothers measured by changes in their food intake, maternal body reserves, and milk production stayed the same whether offspring had early access to solid food or not. Thus mothers did not increase energy allocation to pups even though they apparently had information about the pups' poor state. 相似文献
997.
Summary Acoustical signals emitted by dancing bees have recently been shown to transmit information about the location of food sources in the western honeybee, Apis mellifera. Towne (1985) reported that in the Asian honeybee species Apis dorsata, which builds a single comb in the open under overhanging rocks or tree branches, sound signals were not emitted by the dancers. This led to the conclusion that acoustical communication is restricted to bees that nest in the dark, like A. mellifera. Here we show that in fact A. dorsata produces dance sounds similar to those emitted by A. mellifera, and that these acoustical signals contain information about distance, direction and profitability of food sources. The acoustical transfer of information has thus evolved independently of nesting in dark cavities. The significance of nocturnal activity in Apis dorsata for the evolution of sound communication is discussed.
Correspondence to: W.H. Kirchner 相似文献
998.
Fischer A Oehm C Selle M Werner P 《Environmental science and pollution research international》2005,12(6):381-386
Background Methyl tertiary butyl ether (MTBE) is a fuel additive which is used all over the world. In recent years it has often been
found in groundwater, mainly in the USA, but also in Europe. Although MTBE seems to be a minor toxic, it affects the taste
and odour of water at concentrations of < 30 μg/L. Although MTBE is often a recalcitrant compound, it is known that many ethers
can be degraded by abiotic means. The aim of this study was to examine biotic and abiotic transformations of MTBE with respect
to the particular conditions of a contaminated site (former refinery) in Leuna, Germany.
Methods Groundwater samples from wells of a contaminated site were used for aerobic and anaerobic degradation experiments. The abiotic
degradation experiment (hydrolysis) was conducted employing an ion-exchange resin and MTBE solutions in distilled water. MTBE,
tertiary butyl formate (TBF) and tertiary butyl alcohol (TBA) were measured by a gas chromatograph with flame ionisation detector
(FID). Aldehydes and organic acids were respectively analysed by a gas chromatograph with electron capture detector (ECD)
and high-performance ion chromatography (HPIC).
Results and Discussion Under aerobic conditions, MTBE was degraded in laboratory experiments. Only 4 of a total of 30 anaerobic experiments exhibited
degradation, and the process was very slow. In no cases were metabolites detected, but a few degradation products (TBF, TBA
and formic acid) were found on the site, possibly due to the lower temperatures in groundwater. The abiotic degradation of
MTBE with an ion-exchange resin as a catalyst at pH 3.5 was much faster than hydrolysis in diluted hydrochloric acid (pH 1.0).
Conclusion Although the aerobic degradation of MTBE in the environment seems to be possible, the specific conditions responsible are
widely unknown. Successful aerobic degradation only seems to take place if there is a lack of other utilisable compounds.
However, MTBE is often accompanied by other fuel compounds on contaminated sites and anaerobic conditions prevail. MTBE is
often recalcitrant under anaerobic conditions, at least in the presence of other carbon sources. The abiotic hydrolysis of
MTBE seems to be of secondary importance (on site), but it might be possible to enhance it with catalysts.
Recommendation and Outlook MTBE only seems to be recalcitrant under particular conditions. In some cases, the degradation of MTBE on contaminated sites
could be supported by oxygen. Enhanced hydrolysis could also be an alternative.
- * The basis of this peer-reviewed paper is a presentation at the 9th FECS Conference on 'Chemistry and Environment', 29 August
to 1 September 2004, Bordeaux, France. 相似文献
999.
Polak M Kroeger DE Cartwright IL Ponce deLeon C 《Environmental pollution (Barking, Essex : 1987)》2004,127(1):145-155
Although fluctuating asymmetry (FA) increases with exposure to certain types of environmental stressors such as temperature extremes, relatively little is known about the effects of interaction (e.g., synergism) between known sources of environmental stress on FA. Knowledge of such interaction effects, and of the magnitude of genotype-by-environment interaction, are of fundamental importance toward predicting the usefulness of FA as a bioindicator of environmental pollution. We tested for synergistic effects on FA between elevated temperature and exposure to lead, and examined FA responses simultaneously in four genetic strains of Drosophila melanogaster known to differ in their degree of developmental instability, and presumably in their buffering capacity. In the absence of heavy metal, bristle FA increased with temperature, but in the presence of lead, FA at high temperature (30 (degrees)C) was reduced to levels similar, or below, that at lower temperature (25 (degrees)C). This temperature by lead interaction was statistically significant, but paradoxical in that the disruptive effects of temperature appeared to be attenuated in the presence of the heavy metal. In no case was there a significant effect of lead on bristle FAs, despite documented assimilation of heavy metal by flies, and in no case was the genotype by environment interaction significant. Whereas lead treatment did not influence survival, survival was reduced at the high temperature, but significantly so only in one genetic strain (Oregon-R). There was no relationship between survival and FA across stress treatments within lines. Thus, any disproportionate stress-induced mortality in developmentally unstable classes (developmental selection) was unlikely to bias the FA results. Our results underscore the need for independent replication of significant findings before FA-based biomonitoring can be responsibly and effectively implemented. The results call for caution in using FA as a biomarker of stress, because stress factors may interact in complex and unpredictable ways, which could result in erroneous conclusions about real levels of stress present in field populations, under the unduly simplistic assumption that stress factors will act additively to increase FA. 相似文献
1000.
Enjie Li Joanna Endter‐Wada Shujuan Li 《Journal of the American Water Resources Association》2015,51(3):589-613
We characterize and compare water challenges confronting the 28 megacities of the world in 2014. Relying on existing literature and diverse primary data sources, we present a unique portrait at a global scale of the water implications of the rapid growth in megacities. We find that differentiating and analyzing the complexity of megacities' water problems based on geographic contexts, historical development trajectories, urban population growth rates, and forms of urban expansion helps explain the nature of the various water management problems they confront. Two governance features also shed light on megacity water challenges: fragmentation resulting from forms of megacity urban expansion; and, urban dualism resulting from contradictions between historical and cultural legacies and the rise of global engineering and technological norms for water management. The increasing vulnerability of megacities to climate change poses risks as well as opportunities for a more collective response to address this global phenomenon. Our analysis raises important questions and offers guidance about the future trajectories of many more large cities around the world that are on their way to becoming megacities. 相似文献