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551.
Coastal deforestation in the Ayeyarwady Delta, Myanmar (formerly Burma) is addressed through the promotion of native-species mangrove plantations on cleared land formerly sustaining natural mangrove forests. To date there are no attempts to determine the optimal mangrove plantation strategy to maximize economic returns for private or communal plantation owners. We integrated empirical biological and economic data to suggest optimal mangrove plantation strategies in the region. We censused 4-yr oldAvicennia officinalis mangrove plantations in two townships to calculate survival and growth rates of mangroves planted using different techniques across an inundation gradient. We used the calculated rates to forecast the production of fuelwood, poles and posts at 10, 13 and 15 yr after establishment. We calculated the compound rate of growth for the three commodities over a 7-yr period, and then forecast commodity price for the same harvest intervals. Integration of those parameters in our model led us to conclude that both profit and the internal rate of return would be greatest for plantations of seedlings raised in polyethylene bags as opposed to bare-root or direct propagule planting. Therefore, the use of potted seedlings should be promoted, despite higher initial costs. The optimal rotation period varies according to ground level and planting technique. Optimizing economic returns for coastal plantations does not necessarily require a sacrifice of ecological benefits. Due to a discrepancy between official conversion quotes and local real value no conversion estimate in USD is given.  相似文献   
552.
ABSTRACT: The nonlinear least squares (NLS) method was applied to pumping and recovery aquifer test data in confined and unconfined aquifers with finite diameter and partially penetrating pumping wells, and with partially penetrating piezometers or observation wells. It was demonstrated that noiseless and moderately noisy drawdown data from observation points located less than two saturated thicknesses of the aquifer from the pumping well produced an exact or acceptable set of parameters when the diameter of the pumping well was included in the analysis. The accuracy of the estimated parameters, particularly that of specific storage, decreased with increases in the noise level in the observed drawdown data. With consideration of the well radii, the noiseless drawdown data from the pumping well in an unconfined aquifer produced good estimates of horizontal and vertical hydraulic conductivities and specific yield, but the estimated specific storage was unacceptable. When noisy data from the pumping well were used, an acceptable set of parameters was not obtained. Further experiments with noisy drawdown data in an unconfined aquifer revealed that when the well diameter was included in the analysis, hydraulic conductivity, specific yield and vertical hydraulic conductivity may be estimated rather effectively from piezometers located over a range of distances from the pumping well. Estimation of specific storage became less reliable for piezometers located at distances greater than the initial saturated thickness of the aquifer. Application of the NLS to field pumping and recovery data from a confined aquifer showed that the estimated parameters from the two tests were in good agreement only when the well diameter was included in the analysis. Without consideration of well radii, the estimated values of hydraulic conductivity from the pumping and recovery tests were off by a factor of four.  相似文献   
553.
Summary. The European plant Thlaspi caerulescens hyperaccumulates zinc in its leaves to concentrations exceeding 2 %. This may represent a defense against herbivory, as shown by reduced feeding on plants grown in high-zinc versus low-zinc substrates. However, the more evolutionarily relevant comparison involves plants whose metal content differs due to genetic rather than environmental causes. In our study, plants were grown in a uniform hydroponic solution containing 10 mg/l Zn. Foliar Zn concentrations were measured, and plants of contrasting Zn concentration were chosen for feeding trials using Pieris napi oleracea larvae. Comparisons revealed no statistically significant preferences when young larvae were used, but highly significant avoidance of high-Zn leaves by later-instar caterpillars, suggesting that hyperaccumulation could evolve in response to the selective pressures of herbivory.  相似文献   
554.
The number of indoor air quality (IAQ)-related health complaints in commercial buildings, and the frequency of litigation over the effects of poor IAQ is increasing. These increases have ramifications for insurance carriers, which pay for many of the costs of health care and general commercial liability. However, little is known about the actual costs to insurance companies from poor IAQ in buildings. This paper reports on the results of a literature search of buildings-related, business and legal databases, and interviews with insurance and risk management representatives aimed at finding information on the direct costs to the insurance industry of poor building IAQ, as well as the costs of litigation. The literature search turned up little specific cost information, but indicated that there is a strong awareness and growing concern over the “silent crisis” of IAQ and its potential to cause large industry losses. The source of these losses includes both direct costs to insurers from paying health insurance and professional liability claims, as well as the cost of litigation. In spite of the lack of data on how IAQ-related health problems affect their business, the insurance industry has taken the anecdotal evidence about their reality seriously enough to alter their policies in ways that have lessened their exposure.  相似文献   
555.
Rackley EB 《Disasters》2006,30(4):418-432
This paper draws on two periods of field research, conducted in 2004, to consider the state of governance in the Democratic Republic of the Congo (DRC). The first measures the paralysing impact of illegal taxation on riverine trade in the western provinces; the second documents civilian attempts to seek safety from violence in the troubled east, and evaluates third-party efforts to provide protection and security. Analysis of study findings suggests that the DRC's current governance crisis is neither historically novel nor driven exclusively by mineral resources, extraction rights or trafficking. Rather, government by predation is an endemic and systematic feature of the civil and military administration, ensuring the daily economic survival of soldiers and officials, who are able to wield their authority in a 'riskfree' environment, without oversight or accountability. The paper's conclusion tries to make sense of the persistence of corruption in social and political life, and assess the capacity of ordinary citizens to reverse their predicament.  相似文献   
556.
India has a long coastline of about 7,517 km. with 20% occupying the coastal area. Due to increase in population; people have been exploring the possibility of developmental opportunities in the coastal areas. Tsunami in 2004 was another unexpected natural catastrophe which badly affected many South Indian coastal states especially the state of Tamil Nadu. Coastal communities here are increasingly at risk from many chronic and episodic coastal hazards which threaten the health and stability of coastal ecosystems and communities. The degradation of the coastal environment from chronic human-induced actions threaten food security, livelihoods, the overall economic development and well being of coastal communities. Disasters big or small affecting the coastal communities are reminders that, coastal communities are not resilient to normally recurring hazards. This fact has raised the question of developing community resilience since the most effective approach to reducing the long-term impact of coastal hazards would be to enhance capacities of coastal communities through initiatives which are aimed at ensuring a sustainable recovery in the aftermath of a disaster as well as reducing people’s vulnerability to these disasters. Eight elements of resilience i.e., Governance, Coastal Resource Management, Land Use and Structural Design, Society and Economy, Risk Knowledge, Warning and Evacuation, Emergency Response and Disaster Recovery have been identified which are considered essential to reduce risk from coastal hazards, accelerate recovery from disaster events, and adapt to changing conditions by the affected community. In this paper, all the eight resilience elements have been examined with respect to vulnerability and capacity assessment in selected Tsunami (2004) affected districts in the state of Tamil Nadu, India in order to identify the extent of resilience.  相似文献   
557.
Storm surge often is the most destructive consequence of hurricanes and tropical storms, causing significant economic damage and loss of life. Many coastal communities that are located in high‐risk areas vis‐à‐vis hurricanes and tropical storms are prepared for moderate (between six and eight feet) storm surges. Such preparation, though, is not commensurate with more severe, but less frequent, storm surges (greater than eight feet). These gaps in preparedness have serious implications for community resilience. This paper explores elements of the vulnerability and resilience of coastal communities during major storm surge events, drawing on Volusia County, Florida, United States, as a case study. It simulates the impacts of five hurricanes (Categories I–V) and their associated storm surges on local infrastructure systems, populations, and access to resources. The results suggest that Volusia County is subject to a ‘tipping point’ , where surge damage from Category IV storms is significantly greater than that from Category III and lower hurricanes.  相似文献   
558.
Socioecological models provide a framework for predicting how animals respond competitively to the abundance and distribution of food resources. Testing predictions of socioecological models requires analysis of relationships among food resource characteristics, competitive behaviors, and measures of rank-related skew in energy balance or reproductive success. A positive relationship between dominance rank and energy balance has been observed among female mountain gorillas in Bwindi Impenetrable National Park, Uganda. This study examines the proximate mechanisms underlying feeding competition among those females. To assess the contestability of food resources, we measured the time a female spent feeding at a food site (food site residence time). We also examined the relationship between dominance rank and the access to resources, as well as the rate, context, and direction of aggression, and the number of neighbors in close proximity. As predicted, females had longer food site residence times and higher aggression rates with fruit and decaying wood than with herbaceous vegetation, suggesting that those resources may be contestable. Aggression was predominantly directed down the dominance hierarchy, although against expectation, rank was not significantly correlated with aggression rates or the time spent feeding on contestable foods. Higher-ranking females had significantly fewer neighbors, suggesting that lower-ranking females avoid higher-ranking ones. This study provides additional support for the claim that there is variability in how primates respond to the quality and distribution of food resources and that avoidance as a strategy to cope with feeding competition may result in similar skew in energy balance as rank-related aggression.  相似文献   
559.
Pomacea insularum were collected from polluted and unpolluted freshwater ecosystems in Malaysia. Besides the shells, the soft tissues were dissected and pooled into cephalic tentacle, foot, mantle, operculum, digestive tract, penial sac, lung sac, and remainder. These tissues were analyzed for the concentrations of Cu, Cd, Fe, Ni, and Zn. The present work resulted in three interesting findings. First, the concentrations of Cu, Cd, Fe, and Zn found in most of the different parts of P. insularum collected from the polluted Juru River were significantly (P < 0.05) higher than those found in the snails from the other four sites. Second, positive and significant correlation coefficients were found for sediment-lung sac for Cd, Fe, and Zn while sediment-digestive tract for Cu. These correlation results indicated that lung sacs could reflect the environmental concentrations of Cd, Fe, and Zn, while the digestive tract could do the same for Cu. Third, the different concentrations of heavy metals found in the different parts indicated different metal regulation and binding sites in these organs. The significant correlation coefficients between different tissues indicated that they might be caused by similar metal regulation and sequestration. Based on the above findings, P. insularum are a potential biomonitor of Cd, Cu, Fe, and Zn pollution in freshwater ecosystems.  相似文献   
560.
The data presented in this study indicate the feasibility of utilizing modified forms of peat as a cation exchanger, anion exchanger, and oil coalescer. The‐modification processes require relatively inexpensive chemicals in small amounts and only simple procedures are involved. This factor in conjunction with the availability of peat makes these modified systems well suited for large scale applications.  相似文献   
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