Shengjin Lake wetland is located in the middle and lower reaches of the Yangtze River in China. It is a typical lake-type wetland and is also an ideal place for rare cranes to overwintering. The changes of wetland landscape are closely related to the habitat quality of wintering cranes. It is of great significance to study the habitat change of wintering cranes in wetland for wetland ecological restoration and restoration. In this paper, we analyze four kinds of winter cranes and wetland landscape pattern types from the years 1986 to 2015. Also, we adopted the Pearson correlation analysis method to analyze the relationship between wetland landscape types and crane population, and the main landscape types of cranes habitat were obtained. We selected disturbance degree, food richness, vegetation cover, and hydrological condition as the main factors affecting wintering habitat of cranes. We established a habitat suitability index model for wintering cranes and generated habitat suitability assessment maps by ArcGIS. The results show that the change of landscape pattern in Shengjin Lake protected area was obvious, the number of wetland patches increased, the fragmentation degree of landscape increased, the landscape patch difference became smaller, and the diversity index and evenness index increased gradually. From 1986 to 2015, the number of wintering cranes decreased and the habitat suitability index of wintering cranes decreased from 0.845 to 0.465, and the habitat suitability of wintering cranes fell from 13,577.11 to 7424.42 ha, which showed the overall habitat deteriorated significantly and had a positive correlation between the crane population and habitat suitability.
Environmental Chemistry Letters - Nanosilver (nAg) is increasingly being used in a wide array of fields, and its toxicity has been extensively studied. Here we present a review of environmental nAg... 相似文献
Oil gelling agents are widely used in emergency response of marine oil spills. However, the biological toxicity of oil gelling agents is not well understood. This research aimed to evaluate the environmental safety of oil gelling agents used for rapid removal and cleanup of marine oil spills. We used luminescent bacteria (Acinetobacter sp. Tox2 and Acinetobacter sp. RecA) combined with exposure experiment using marine medaka (Oryzias melastigma) juveniles to detect the acute toxicity and genotoxicity of 10 oil gelling agents. As a result, a certain level of acute toxicity was detected from the oil gelling agent FOA and GMN-01 (the toxicity equivalent to 0.067 mg/L and 0.084 mg/L of HgCl2, respectively), and a certain level of genotoxicity was detected from the oil gelling agent NORSOREX (the toxicity equivalent to 0.307 mg/L of MMC) by the luminescent bacteria test. However, no obvious acute toxicity or genotoxicity was detected from the above three oil gelling agents in fish-exposure experiments. Our results suggest that the 10 oil gelling agents have no obvious acute toxicity or genotoxicity to higher organisms (including marine medaka). The luminescent bacteria test is more sensitive in detecting biological toxicity of oil gelling agents. This study provides a reference for environmental safety evaluation of the oil gelling agents used in the cleaning up of the marine oil spills. 相似文献
The oxidation of soil organic matter (SOM) and total petroleum hydrocarbon were investigated in two soils at eight different hydrogen peroxide (H2O2) concentrations to determine the optimal H2O2 dosage for the efficient remediation of soils contaminated by crude oil with minimal SOM removal. In our study, H2O2 concentrations up to 1100 mM increased the SOM destruction up to 10%–15% in the two soils while no improvement of the crude oil removal efficiencies was observed. The results indicate that the destruction of SOM significantly limits the oxidation of crude oil because SOM might consume H2O2 more effectively than crude oil at H2O2 concentrations above 1100 mM. In addition, H2O2 concentrations higher than 1100 mM were not expected for both soils because of the extremely rapid H2O2 decomposition, and low H2O2 utilization, of both soils. 相似文献
Volatile organic compounds (VOCs) are crucial to control air pollution in major Chinese cities since VOCs are the dominant factor influencing ambient ozone level, and also an important precursor of secondary organic aerosols. Vehicular evaporative emissions have become a major and growing source of VOC emissions in China. This study consists of lab tests, technology evaluation, emissions modeling, policy projections and cost-benefit analysis to draw a roadmap for China for controlling vehicular evaporative emissions. The analysis suggests that evaporative VOC emissions from China's light-duty gasoline vehicles were approximately 185,000 ton in 2010 and would peak at 1,200,000 ton in 2040 without control. The current control strategy implemented in China, as shown in business as usual (BAU) scenario, will barely reduce the long-term growth in emissions. Even if Stage II gasoline station vapor control policies were extended national wide (BAU + extended Stage II), there would still be over 400,000 ton fuel loss in 2050. In contrast, the implementation of on-board refueling vapor recovery (ORVR) on new cars could reduce 97.5% of evaporative VOCs by 2050 (BAU + ORVR/BAU + delayed ORVR). According to the results, a combined Stage II and ORVR program is a comprehensive solution that provides both short-term and long-term benefits. The net cost to achieve the optimal total evaporative VOC control is approximately 62 billion CNY in 2025 and 149 billion CNY in 2050. 相似文献