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121.
Dynamics of local governance in natural resource conservation in the Okavango Delta,Botswana
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There has been a shift in natural resource management worldwide. This paper describes how modern institutions and policies influence management and shape access to and utilization of resources by rural communities in the Okavango Delta, Botswana. It is rooted in the framework of adaptive co‐governance within social‐ecological systems, and employs a critical literature review to analyse access to and use of natural resources in rural Botswana. Prior to the establishment of community‐based natural resource management (CBNRM) in Botswana in 1989, resource governance was dominated by strong traditional institutions that were responsible for natural resource management and decision‐making. Contemporary natural resource governance is characterized by a bureaucratic system that invariably undermines the role of traditional institutions in natural resource governance. Findings indicate that policies and regulatory instruments deny rural communities adequate access to and utilization of resources available within their immediate environment. In spite of an orientation towards an anthropocentric approach to natural resource management (as in the case of CBNRM), the current governance system continues to undermine the inclusion of local resource users as legitimate stakeholders in the decision‐making process. 相似文献
122.
Recent Changes in Stream Flashiness and Flooding,and Effects of Flood Management in North Carolina and Virginia
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Beatriz Mogollón Emmanuel A. Frimpong Andrew B. Hoegh Paul L. Angermeier 《Journal of the American Water Resources Association》2016,52(3):561-577
The southeastern United States has undergone anthropogenic changes in landscape structure, with the potential to increase (e.g., urbanization) and decrease (e.g., reservoir construction) stream flashiness and flooding. Assessment of the outcome of such change can provide insight into the efficacy of current strategies and policies to manage water resources. We (1) examined trends in precipitation, floods, and stream flashiness and (2) assessed the relative influence of land cover and flow‐regulating features (e.g., best management practices and artificial water bodies) on stream flashiness from 1991 to 2013. We found mean annual precipitation decreased, which coincided with decreasing trends in floods. In contrast, stream flashiness, overall, showed an increasing trend during the period of study. However, upon closer examination, 20 watersheds showed stable stream flashiness, whereas 5 increased and 6 decreased in flashiness. Urban watersheds were among those that increased or decreased in flashiness. Watersheds that increased in stream flashiness gained more urban cover, lost more forested cover and had fewer best management practices installed than urban watersheds that decreased in stream flashiness. We found best management practices are more effective than artificial water bodies in regulating flashy floods. Flashiness index is a valuable and straightforward metric to characterize changes in streamflow and help to assess the efficacy of management interventions. 相似文献
123.
Kumar Gaurav Richa Srivastava Jai Gopal Sharma Ram Singh Vishrut Singh 《International Journal of Green Energy》2016,13(3):320-327
Biodiesel provides a feasible solution to the twin crisis of energy security and environmental concerns prevalent today, and it can be extracted from conventional oil crops as well as microalgae. However, lipid productivity in case of microalgae is much higher and has several advantages as compared with crop plants, so it is a better feedstock for biodiesel. In case of Chlorella pyrenoidosa, the heterotrophic cultured cells were found to be better in terms of lipid production, and ultimately biodiesel production, but the bottleneck is that in this mode glucose is used to feed the cells, which amounts to almost 80% of the total cost of biodiesel production. The purpose of this study is to evaluate and highlight the feasibility of using the industrially cheap cane molasses as a carbon source in place of glucose for a large-scale, low-cost lipid production of Chlorella pyrenoidosa. When treated molasses was used as a carbon source instead of glucose, the biomass sharply increases from 0.89 to 1.22 g L–1. On the other hand, the total lipid content increases from 0.27 to 0.66 g g–1. The specific growth rate and yield was higher in treated molasses as compared with that in glucose-supplemented. A mathematical model was also developed based on logistic, Luedeking–Piret, and Luedeking-Piret-like equations. Model predictions were in satisfactory agreement with the measured data, and the mode of lipid production was growth-associated. 相似文献
124.
125.
Miroslava Císarová Dana Tančinová Juraj Medo Miroslava Kačániová 《Journal of environmental science and health. Part. B》2016,51(10):668-674
The aim of the present study was to assess the antifungal and anti-toxinogenic activity of 15 essential oils (EOs) against three fungi of the genus Aspergillus (A. parasiticus KMi-227-LR, A. parasiticus KMi-220-LR and A. flavus KMi-202-LR). The minimum inhibitory doses (MIDs) of the tested essential oils and their antifungal activity were determined using the micro-atmosphere method. The original commercial essential oil samples of Jasminum officinale L., Thymus vulgaris L., Syzygium aromaticum (L.) Merrill &; Perry, Rosmarinus officinalis L., Ocimum basilicum L., Eucalyptus globulus Labill., Salvia officinalis L., Citrus limon (L.) Burm, Origanum vulgare L., Lavandula angustifolia Mill., Carum carvi L., Citrus sinensis (L.) Osbeck., Zingiber officinalis Rosc., Mentha piperita L. and Cinnamomum zeylanicum Nees. (C. verum J.S.Presl.) were produced in Slovakia (Calendula a.s., Nová ?ubovňa, Slovakia). All essential oils exhibited activity against all tested strains of fungi. After 14 days of incubation, A. flavus (KMi-202-LR) showed the highest susceptibility with a growth inhibition percentage (GIP) of 18.70% to C. limon and 5.92% to C. sinensis, while A. parasiticus (KMi-220-LR) exhibited a GIP of 20.56% to J. officinale. The minimum inhibitory doses (MIDs) of EOs with the most significant activity were recorded. The best antifungal activity, using the micro-atmosphere method was found in S. aromaticum with an MID of 62.5 μL L?1 air, T. vulgaris (MID of 62.5 μL L?1 air) and O. vulgare (MID of 31.5 μL L?1 air) against all tested strains. Mycotoxin production of the tested strains was evaluated by the thin layer chromatography (TLC) method. Mycotoxin production of AFB1 and AFG1 was inhibited following all treatments with C. carvi, R. officinale and S. officinale, Eucalyptus globulus L. and O. basilicum L. Essential oils exhibited a potential inhibition activity against toxic fungi, although, these affected only the production of AFB1. 相似文献
126.
M. J. Patiño Ropero N. Rodríguez Fariñas R. Mateo J. J. Berzas Nevado R. C. Rodríguez Martín-Doimeadios 《Environmental science and pollution research international》2016,23(7):6074-6081
The impact of mercury (Hg) pollution in the terrestrial environments and the terrestrial food chains including the impact on human food consumption is still greatly under-investigated. In particular, studies including Hg speciation and detoxification strategies in terrestrial animals are almost non-existing, but these are key information with important implications for human beings. Therefore, in this work, we report on Hg species (inorganic mercury, iHg, and monomethylmercury, MeHg) distribution among terrestrial animal tissues obtained from a real-world Hg exposure scenario (Almadén mining district, Spain). Thus, we studied Hg species (iHg and MeHg) and total selenium (Se) content in liver and kidney of red deer (Cervus elaphus; n?=?41) and wild boar (Sus scrofa; n?=?16). Similar mercury species distribution was found for both red deer and wild boar. Major differences were found between tissues; thus, in kidney, iHg was clearly the predominant species (more than 81 %), while in liver, the species distribution was less homogeneous with a percentage of MeHg up to 46 % in some cases. Therefore, Hg accumulation and MeHg transfer were evident in terrestrial ecosystems. The interaction between total Se and Hg species has been evaluated by tissue and by animal species. Similar relationships were found in kidney for both Hg species in red deer and wild boar. However, in liver, there were differences between animals. The possible underlying mechanisms are discussed. 相似文献
127.
Efrén García-Ordiales José María Esbrí Stefano Covelli Miguel Angel López-Berdonces Pablo L. Higueras Jorge Loredo 《Environmental science and pollution research international》2016,23(7):6024-6038
Sediments from the Castilseras reservoir, located downstream on the Valdeazogues River in the Almadén mercury district, were collected to assess the potential contamination status related to metals(oids) associated with river sediment inputs from several decommissioned mines. Metals(oids) concentrations in the reservoir sediments were investigated using different physical and chemical techniques. The results were analyzed by principal component analysis (PCA) to explain the correlations between the sets of variables. The degree of contamination was evaluated using the enrichment factor (EF) and the geoaccumulation index (Igeo). PCA revealed that the silty fraction is the main metals(oids) carrier in the sediments. Among the potentially harmful elements, there is a group (Al, Cr, Cu, Fe, Mn, Ni, and Zn) that cannot be strictly correlated to the mining activity since their concentrations depend on the lithological and edaphological characteristics of the materials. In contrast, As, Co, Hg, Pb, and S showed significant enrichment and contamination, thus suggesting relevant contributions from the decommissioned mines through fluvial sediment inputs. As far as Hg and S are concerned, the high enrichment levels pose a question concerning the potential environmental risk of transfer of the organic forms of Hg (mainly methylmercury) from the bottom sediments to the aquatic food chain. 相似文献
128.
Patrícia Gomes Teresa Valente M. Amália Sequeira Braga J. A. Grande M. L. de la Torre 《Environmental science and pollution research international》2016,23(7):6039-6045
Reactive waste dumps with sulfide minerals promote acid mine drainage (AMD), which results in water and soil contamination by metals and metalloids. In these systems, contamination is regulated by many factors, such as mineralogical composition of soil and the presence of sorption sites on specific mineral phases. So, the present study dedicates itself to understanding the distribution of trace elements in different size fractions (<2-mm and <2-μm fractions) of mining soils and to evaluate the relationship between chemical and mineralogical composition. Cerdeirinha and Penedono, located in Portugal, were the waste dumps under study. The results revealed that the two waste dumps have high degree of contamination by metals and arsenic and that these elements are concentrated in the clay size fraction. Hence, the higher degree of contamination by toxic elements, especially arsenic in Penedono as well as the role of clay minerals, jarosite, and goethite in retaining trace elements has management implications. Such information must be carefully thought in the rehabilitation projects to be planned for both waste dumps. 相似文献
129.
H. Pizarro M. S. Vera A. Vinocur G. Pérez M. Ferraro R. J. Menéndez Helman M. dos Santos Afonso 《Environmental science and pollution research international》2016,23(6):5143-5153
Since it was commercially introduced in 1974, glyphosate has been one of the most commonly used herbicides in agriculture worldwide, and there is growing concern about its adverse effects on the environment. Assuming that glyphosate may increase the organic turbidity of water bodies, we evaluated the effect of a single application of 2.4?±?0.1 mg l?1 of glyphosate (technical grade) on freshwater bacterioplankton and phytoplankton (pico, micro, and nanophytoplankton) and on the physical and chemical properties of the water. We used outdoor experimental mesocosms under clear and oligotrophic (phytoplanktonic chlorophyll a?=?2.04 μg l?1; turbidity?=?2.0 NTU) and organic turbid and eutrophic (phytoplanktonic chlorophyll a?=?50.3 μg l?1; turbidity?=?16.0 NTU) scenarios. Samplings were conducted at the beginning of the experiment and at 1, 8, 19, and 33 days after glyphosate addition. For both typologies, the herbicide affected the abiotic water properties (with a marked increase in total phosphorus), but it did not affect the structure of micro and nanophytoplankton. In clear waters, glyphosate treatment induced a trend toward higher bacteria and picoeukaryotes abundances, while there was a 2 to 2.5-fold increase in picocyanobacteria number. In turbid waters, without picoeukaryotes at the beginning of the experiment, glyphosate decreased bacteria abundance but increased the number of picocyanobacteria, suggesting a direct favorable effect. Moreover, our results show that the impact of the herbicide was observed in microorganisms from both oligo and eutrophic conditions, indicating that the impact would be independent of the trophic status of the water body. 相似文献
130.
Sara García-Salgado M. Ángeles Quijano 《Environmental science and pollution research international》2016,23(24):24567-24577
Ultrasonic probe sonication (UPS) and microwave-assisted extraction (MAE) were used for rapid single extraction of Cd, Cr, Cu, Ni, Pb, and Zn from soils polluted by former mining activities (Mónica Mine, Bustarviejo, NW Madrid, Spain), using 0.01 mol L?1 calcium chloride (CaCl2), 0.43 mol L?1 acetic acid (CH3COOH), and 0.05 mol L?1 ethylenediaminetetraacetic acid (EDTA) at pH 7 as extracting agents. The optimum extraction conditions by UPS consisted of an extraction time of 2 min for both CaCl2 and EDTA extractions and 15 min for CH3COOH extraction, at 30% ultrasound (US) amplitude, whereas in the case of MAE, they consisted of 5 min at 50 °C for both CaCl2 and EDTA extractions and 15 min at 120 °C for CH3COOH extraction. Extractable concentrations were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The proposed methods were compared with a reduced version of the corresponding single extraction procedures proposed by the Standards, Measurements and Testing Programme (SM&T). The results obtained showed a great variability on extraction percentages, depending on the metal, the total concentration level and the soil sample, reaching high values in some areas. However, the correlation analysis showed that total concentration is the most relevant factor for element extractability in these soil samples. From the results obtained, the application of the accelerated extraction procedures, such as MAE and UPS, could be considered a useful approach to evaluate rapidly the extractability of the metals studied. 相似文献