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381.
The integration of carbon sequestration value of forest ecosystems into forest management planning models has become increasingly important in sustainable forest management. This study analyses the economic effects of different minimum cutting ages on timber and carbon sequestration values for a Scots pine forest clumped mainly in older age classes in northeast Turkey. The analysis is performed by formulating three optimisation models. The objective of each model is to maximise net present value (NPV) of harvested timber, net present value of carbon sequestration and the total net present value of timber production and carbon sequestration, respectively. Results showed that increasing the minimum cutting ages by 10 years increased the NPV of timber by 10.5%. However, the current minimum cutting ages were optimal for maximizing the NPV of carbon and the sum of the NPV of timber and carbon benefits. In addition, the model outputs were found to be quite sensitive to unit carbon prices.  相似文献   
382.
This paper presents data on the concentrations of 5 metals, copper (Cu), cadmium (Cd), iron (Fe), zinc (Zn) and lead (Pb) in Blue Whiting sampled from the Eastern Black Sea coast of Turkey. The highest metal concentrations of Cu, Cd, Fe, Zn and Pb were recorded in Blue Whiting with the values of 2.71, 0.601, 14.137, 15.322 and 1.078 μg g‐1 dry weight, respectively. On average the metal concentrations in Blue Whiting followed the order of Zn > Fe > Cu > Pb > Cd. Temporal differences of concentrations of these metals were significant (p < 0.05). Spatial fluctuations of Cu, Cd, Fe, Zn and Pb concentrations in Blue Whiting were also significant (p < 0.01). It was found that the concentrations of Cu, Cd, Fe, Zn and Pb in the muscle in Blue Whiting were below the limit of Public Health Regulation in Turkey.  相似文献   
383.
The aim of this study is to determine the contents of aluminum, iron, manganese, nickel, copper, zinc, chromium, cadmium, lead, and mercury in sediments at 1–30?m depths of the Band?rma and Erdek Gulfs in the Southern Inner Shelf of the Marmara Sea. Sediment samples were collected from different depths (1?m, 5?m, 10?m, 20?m, 30?m) at each region in February 2008. Primary hydrographic conditions, such as temperature (6.6–14.5°C), salinity (22.6–26.875 psu), percentage of dissolved oxygen saturation (35–83 %), and pH (8.0–8.4) were recorded for each sampling point. Moreover the total organic carbon (0.5–2.9%) and the total calcium carbonate contents (0.8–60%) of sediment samples were determined. In surface sediments of both gulfs, Pb (21–62?mg?kg?1) and Cd (0.52–0.86?mg?kg?1) contents were determined to be higher than the shale average (Pb 20?mg?kg?1, Cd 0.2?mg?kg?1) while the other metal contents were measured to be lower in general. On the other hand, generally Hg (0.06–1.1?mg?kg?1) contents were higher than the shale average (0.3?mg?kg?1)at all of the examined stations in the Band?rma Gulf and lower than the shale average in the Erdek Gulf.  相似文献   
384.
Plastics are present in a lot of aspects of everyday life. They are very versatile and resistant to microbial attack. Polyurethanes are used in several industries and are divided in polyester and polyether polyurethanes and there are different types among them. Despite their microbial resistance, they are susceptible to the attack of fungi and bacteria but the mechanism to elucidate its biodegradation are unknown. There are reports from bacteria and fungi that are capable of degrading polyurethane but the studies about the enzymes that attack the plastic are focused on bacterial enzymes only. The enzymes reported are of type esterase and protease mainly since these enzymes are very unspecific and can recognize some regions in the polyurethane molecule and hydrolyze it. Fungal enzymes have been studied prior the 1990s decade but recently, some authors report the use of filamentous fungi to degrade polyurethane and also report some characteristics of the enzymes involved in it. This review approaches polyurethane biodegradation by focusing on the enzymes reported to date.  相似文献   
385.
The recent increased availability of information about the micro-geographic positions of population units in environmental surveys has led to important developments in spatial sampling methodologies and, as a result, has improved the estimation accuracy. In real data, however, information about the location of units is often affected by inaccuracy about their exact spatial positions, and these non-sampling errors can affect the estimation procedure. This paper aims to investigate the effects of positional errors on total estimation through a Monte-Carlo simulation study based on real populations of trees. Starting from perfect positioning, we examine two typical types of coarsening that frequently impact two different species of trees. The simulation results show that the exploitation of spatial information to estimate population totals continues to be relevant in the context of environmental surveys, even in the presence of inaccuracies.  相似文献   
386.
The sustainable development agenda 2030 calls for achievement of certain targets to ensure access to water and sanitation for all. Multi-stakeholder partnerships and the use of data and modelling tools are conditioning elements for their achievement. In this article, we demonstrate that participatory modelling supports informed and participatory decision making in complex river basins. An adapted companion modelling approach is presented to support collective action by reducing disputes and enhancing collaboration among stakeholders. The co-development and use of empirical models for understanding the complexity of the physical system is combined with the use of role-playing games to ensure the active involvement of stakeholders. The approach is implemented in a top-down water quality planning process in Turkey. Results show its suitability for managing water quality in complex river basins in an inclusive manner and its substantial benefits in developing stakeholders’ capacities and creating a cooperative environment.  相似文献   
387.
388.
This paper is a review of the community legislation of the European Union (acquis communautaire) with regard to the mineral extractive industry. It highlights the existing inconsistencies of the acquis, which require correction. Historically, the mining industry has received privileged treatment within the European Community. The treaties declare the promotion of a policy of using natural resources prudently and rationally to avoid their unconsidered exhaustion. However, mining is excluded from the scope of major environmental directives or reserves a certain freedom for interpretation. This has led to an increasing number of related cases at the European Court of Justice.The regulatory tools of the environmental acquis are rather diverse in controlling the emission sources, the pollution pathways, and the impacted receptor media through administrative measures or assigning environmental quality targets. A combined approach is needed for controlling the environmental impacts of the extractive industries. The amendment of the Seveso II Directive, the elaboration of a reference document on best available techniques and the preparation of a wide-scope directive on mining waste management might provide a frame for the elimination of the above discrepancies. In addition, a coherent European Community policy based on the balanced consideration of economic, environmental, and social aspects could ensure a sustainable development of the mining industry. National expert detached from the Hungarian Geological Survey, H-1143 Budapest, Stefánia út 14.  相似文献   
389.
Vital fluorescent probes have routinely been used to distinguish viable from non-viable embryos in various veterinary and aquaculture studies. Here, we present new protocols to rapidly detect embryo viability in the copepod Calanus helgolandicus using three of these probes, fluorescein diacetate (FDA), SYTOX green and 7-aminoactinomycin D (7-AAD), and the confocal laser scanning microscope. The percentage of fluorescent-FDA embryos and non-fluorescent SYTOX green and 7-AAD embryos were compared with the percentage of hatched unstained embryos and with the percentage of embryos that had been stained, washed, and allowed to hatch. Results showed that all three dyes accurately predicted embryo viability and could be used to rapidly calculate C. helgolandicus egg-hatching success. We also tested the possible applications of SYTOX green in egg-production/egg-hatching assays in which the dinoflagellate Prorocentrum minimum or the diatom Skeletonema costatum are used to investigate for the possible negative impact of diatoms on embryo viability. Other possible applications for fluorescence methods in studies on the reproductive biology of zooplankton, and in particular of copepods, are discussed.Communicated by R. Cattaneo-Vietti, Genova  相似文献   
390.
We studied the transformation of phenol in the presence of nitrous acid in the dark. The main detected intermediates were 2-nitrophenol, 4-nitrophenol and 4-nitrosophenol. For the first time a kinetic analysis of the reaction in a pH interval relevant to environmental chemistry has been carried out. The kinetic data are consistent with phenol transformation being initiated by HNO2. The results are relevant to the chemistry of the atmosphere, where HNO2 forms upon heterogeneous conversion of ·NO2, and to water treatment techniques.  相似文献   
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