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31.
This paper describes the problems encountered in developing environmental education in Federal protected areas in Brazil. Results of a survey on the current status of environmental education in four categories of Federal protected areas; namely national parks, biological reserves, ecological stations and environmental protection areas, are described and discussed. The study suggests that the development of environmental education in protected areas in the country has several limitations: financial resources, lack of training, material resources and a lack of policy on environmental education. It also identifies that some of these problems seem to be inter-related with those of the National System of Conservation Units of the country which may result in a retarding of the development of environmental education in such areas.  相似文献   
32.

Background, aim, and scope  

Climate changes are nowadays an important issue of concern, and it is expected that in the near future it will be intensified, leading to extreme environmental conditions. These changes are expected to originate additional sources of stress; therefore, the exposure of organisms to natural stressors is receiving an increased importance in risk assessment. Organisms tend to avoid extremely environmental conditions looking for optimum conditions. This work aimed to evaluate the effects of natural stressors on the energetic reserves of Daphnia magna using the quantification of lipids, proteins, and sugars.  相似文献   
33.
Abstract

The present study was undertaken to investigate the influence of biotic (snail size and presence of food during the test) and abiotic factors (temperature, water hardness and concentration of organic materials) on the molluscicidal activity of Euphorbia milii latex. Bioassays were conducted with B. glabrata (10 snails per concentration) and snail lethality was evaluated after 24 hr and 48 hr of exposure to lyophilized latex solutions. Neither the degree of water hardness, nor the presence of food during the test affected latex‐induced snail mortality. The snail size had a minor influence on E.milii‐induced snail lethality. Newly‐hatched (shell diameter ≤ 1mm) as well as young (3–8 mm) snails were slightly less susceptible than older (10–25 mm) mollusks. On the other hand, the molluscicidal effect of E.milii latex was modified by environmental factors such as temperature (i.e. LC50 and LC90 values were halved for every 10°C rise in temperature) and concentration of organic materials in the water (i.e. the higher the concentration of organic matter, the higher the LC50 value). The efficacy of E.milii latex as a molluscicide can be modified by factors such as water temperature and concentration of organic materials, and to a lesser extent by snail size.  相似文献   
34.
High infestations of alexandergrass (Brachiaria plantaginea) in experimental area have reduced seedbank of some weed species in soil at a greater degree compared to those obtained with the use of an efficient herbicide. Aconitic acid (AA) has been identified in those plants in high concentration. Thus, two experiments were carried out in the laboratory to determine the effects of pure AA on weed seed germination and on endophytic fungi in wild poinsettia (Euphorbia heterophylla) and morningglory (Ipomoea grandifolia) weed species. Doses of AA (0, 0.5, 1.0, and 2.0 mM) were introduced in agar-water 0.5% medium and weed seeds treated with and without external sterilization by sodium hypochloride. Four replications of fifty seeds of each species by treatment were sown in plastic boxes with cover and maintained in germination chamber for 12 days. Reduction in germination rate, root and stem growth were observed in both species, as well as reduction in root number in morningglory were also observed at 2.0 mM concentration of AA. An increase in number of seeds with presence of endophytic fungi was also observed in both species, independently of seed sterilization, mainly of a green type fungi coloration in wild poinsettia. Aconitic acid presents allelopathic activity and can stimulate endophytic fungi species growth in weed seeds.  相似文献   
35.
This paper describes a comparative study of four different cases on vulnerability, hazards and adaptive capacity to climate threats in coastal areas and communities in four developing countries: Bangladesh, Brazil, Cameroon and Uruguay. Coastal areas are vulnerable to sea-level rise (SLR), storm surges and flooding due to their (i) exposure, (ii) concentration of settlements, many of which occupied by less advantaged groups and (iii) the concentration of assets and services seen in these areas. The objective of the paper is twofold: (i) to evaluate current evidence of coastal vulnerability and adaptive capacity and (ii) to compare adaptation strategies being implemented in a sample of developing countries, focusing on successful ones. The followed approach for the case evaluation is based on (i) documenting observed threats and damages, (ii) using indicators of physical and socioeconomic vulnerability and adaptive capacity status and (iii) selecting examples of successful responses. Major conclusions based on cross-case comparison are (a) the studied countries show different vulnerability, adaptive capacity and implementation of responses, (b) innovative community-based (CBA) and ecosystem-based adaptation (EbA) and (c) early warning systems are key approaches and tools to foster climate resilience. A recommendation to foster the resilience of coastal communities and services is that efforts in innovative adaptation strategies to sea-level rise should be intensified and integrated with climate risk management within the national adaption plans (NAPAs) in order to reduce the impacts of hazards.  相似文献   
36.
37.
Petroliferous activities in Brazil have an accelerated development in the last years. As a consequence, the incidence of environmental accidents such as oil spills and contamination of soils has increased significantly. Therefore, it is extremely necessary to develop remediation techniques with lower costs, decontamination efficiency and impact minimisation. The aim of this work was to evaluate Sebastiania commersoniana phytoremediation potential in soil contaminated by petroleum. This species, which is a native tree, was selected due to its proven capacity for surviving in areas contaminated by petroleum. Experiments were carried out with soils that were vegetated but non-contaminated, soils that were freshly contaminated (25, 50 and 75 g kg?1) but non-vegetated, and soils that were vegetated and contaminated, samples were collected 60 and 424 days after contamination with the purpose of evaluating the percentage of petroleum degradation in relation to the time. The results obtained in the present study allow us to state that S. commersoniana proves to be tolerant to petroleum contamination with respect to plant’s growth. The degradation of petroleum hydrocarbons was evaluated by gas chromatography with a flame ionisation detector (GC-FID) equipped with a capillary column HP-5 (5% phenyl-methylpolysiloxane, 30 m; 0.25 mm; 0.25 μm). According to chromatographic analysis, samples in contact with S. commersoniana showed a significant area reduction of the hydrocarbon peaks. Analysis of the 60-day samples showed a reduction of petroleum hydrocarbons area higher than 60% and the 424-day samples showed a reduction higher than 94%, which demonstrates that a petroleum degradation process is occurring.  相似文献   
38.
Pereira Filho, Augusto J., Richard E. Carbone, John E. Janowiak, Phillip Arkin, Robert Joyce, Ricardo Hallak, and Camila G.M. Ramos, 2010. Satellite Rainfall Estimates Over South America – Possible Applicability to the Water Management of Large Watersheds. Journal of the American Water Resources Association (JAWRA) 46(2):344-360. DOI: 10.1111/j.1752-1688.2009.00406.x Abstract: This work analyzes high-resolution precipitation data from satellite-derived rainfall estimates over South America, especially over the Amazon Basin. The goal is to examine whether satellite-derived precipitation estimates can be used in hydrology and in the management of larger watersheds of South America. High spatial-temporal resolution precipitation estimates obtained with the CMORPH method serve this purpose while providing an additional hydrometeorological perspective on the convective regime over South America and its predictability. CMORPH rainfall estimates at 8-km spatial resolution for 2003 and 2004 were compared with available rain gauge measurements at daily, monthly, and yearly accumulation time scales. The results show the correlation between satellite-derived and gauge-measured precipitation increases with accumulation period from daily to monthly, especially during the rainy season. Time-longitude diagrams of CMORPH hourly rainfall show the genesis, strength, longevity, and phase speed of convective systems. Hourly rainfall analyses indicate that convection over the Amazon region is often more organized than previously thought, thus inferring that basin scale predictions of rainfall for hydrological and water management purposes have the potential to become more skillful. Flow estimates based on CMORPH and the rain gauge network are compared to long-term observed average flow. The results suggest this satellite-based rainfall estimation technique has considerable utility. Other statistics for monthly accumulations also suggest CMORPH can be an important source of rainfall information at smaller spatial scales where in situ observations are lacking.  相似文献   
39.
Journal of Polymers and the Environment - Nowadays, there is a need to obtain eco-friendly materials, especially plastics that are responsible for most of the environmental pollution. In this...  相似文献   
40.
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