Cyanide is a high-volume production chemical and the most commonly used leaching reagant for gold and silver extraction. Its environmental behavior and fate is of significant concern because of its high toxicity. This paper presents an investigation of the feasibility of phytoremediation as an in- situ technique to treat cyanide-contaminated soil. Corn(Zea mays L.)and soybean(Glycine max(L.)Merr.)were used. Results from this tests indicated that low dose of cyanide(≤45.5 CN detectable effects under room temperature(23.0～26.0℃). Significant reduction in the plant growth rates(≥10%)was found at high cyanide concentration in the irrigation water(≥91.0 CN mg·L-1)used. The potential of detached leaves to remove cyanide was also investigated. Excised plant leaves(1.5 g fresh weight)were kept in a glass vessel with with 100 mL spiked aqueous solution(deionized oxygen-saturated water)at 23.5℃ for 28 h. The disappearance of cyanide from the aqueous solution was tracked photometrically. More than 90% cyanide in the aqueous solution was removed by plant materials over a 28-h exposure period. The cyanide removal capacity was determined to be 4.43 and 3.42 mg CN·kg fresh weight-1·hour-1 for soybean and corn, respectively. Resutls from this investigation indicated that plants and plant materials were all found to be able to efficiently remove cyanide from the contaminated medium through their internal enzyme systems. In conclusion, cyanide elimination with plants seems to be a feasible option for cleaning soils contaminated with cyanide or gold and silver mine waste and wastewater.
In the paper, a simple dynamic numerical model of phytoplankton, zooplankton and nutrient is set up. Based on the continuous monthly observational data in autumn, the linear regression analyses method is used to calculate some major parameters in the dynamic numerical model, it is shown that, the input by precipitation and runoff is an important factor that brings about the increase of nutrient in this sea areas. The numerical simulation results based on the above calculated parameters agree with those observed ones basically, and it is also shown that, the input by precipitation and runoff has a larger effect on the distribution rule of phytoplankton and zooplankton in this sea areas.
The sub-acute toxicity test was conducted for PCB1254 upon the zebrafish(Brachydanio rerio). Results showed that the no observed effect concentration of PCB1254 is 0.40μg·L-1 and lowest observed effects concentration of PCB1254 is 2.0μg·L-1. The 30 d LD50 of PCB1254 on the zebrafish is 5.09μg·L-1. The morphology of gill and liver tissues were examined by transmission electron microscope. The results showed that the epithelium cells of gill tissue collapsed and top cell of secondary lamella of gill swelled when zebrafish were exposed to PCB1254( > 2.μg·L-1)for 30 d. Some hepatic cells showed the atrophy and deformation accompanying a lot of lipofuscin granules deposition in cytoplasm under high concentration PCB1254(50μg·L-1).
Effects of mangroves restored in different years on physical and chemical properties of coastal soils were studied. Results showed that the effects on deep soils(20-25cm)were more significant than surface soils(0-5cm). Eh values of 20-25cm soils under mangrove forests were higher than those of barren soils. Restored mangroves strongly assimilated nutrients from soils to accelerate their growth. The contents of NH4+-N were higher than those of NO2--N and NO3--N and NH4+-N was the main inorganic nitrogen assimilated by mangroves. Although its contents were nearly the same as the inorganic nitrogen, PO43--P was assimilated little. As mangroves grew, pH values at depth of 20-25cm decreased significantly and soil acidification was strengthened. There was no significant difference in SO42- contents among the surface soils but at depth of 20-25cm, the contents of the soils under mangrove forests was higher than those of barren soils.
On the londuse background of Shanghai city, the structure properties under different grains of regional landscape are studied by using the methods of landscape ecology, and meanwhile, the variogram make it available to analyze the structure properties under different extents. The paper concludes as follows:(1)The landscape indices differ greatly with different grains. According to this research area, the research area takes on the most typical urban landscape properties with the grain of 20m.(2)The special structure of the landscape indices are basically the same with different extents, yet smaller extent are more sensitive to the change of small scale, vice versa.(3)Different landscape indices have different responses to change of grains and extents. In this paper, LSI, SHDI, SHEI are more sensitive to the change of grain, yet CONTAG and PAFRAC is less sensitive. To the change of extents, SHDI and CONTAG are more sensitive, while PAFRAC is less.(4)Different proceeds have different influence on different landscape indices, so that the special structure of different landscape indices differs a lot.(5)Generally, it shows that the patches along the directions of E0°N45°W varies more.
The results from the investigations on the mangrove soils in the Futian Nature Reserve, Shenzhen show that the chemical characteristics of the soils vary widely along the transect approximately parallel to the coastline, while the variations in soil chemical parameters along the transect approximately perpendicular to the coastline are relatively insignificant. As a result of contamination by wastewaters discharging into the mangrove wetland from the surrounding urbanized areas, the bio-available concentrations of many heavy metals are much higher, compared to those in the mangrove soils occurring in the front part of the Pearl River Delta. Concentrations of total and available P were higher in the soils affected by wastewater than those not directly affected by wastewater. It appears that the accumulation of pyrite in the mangrove soils in Futian is not related the abundance of organic matter, indicating that organic matter has not been a limiting factor for pyrite accumulation in this site. Inorganic reduced S is somewhat related to EC and the HCl-extractable Fe, suggesting that increases in soluble sulfate and reactive iron may favor the accumulation of pyrite in the soils. However, because the correlation coefficients are not sufficiently great(R2<0.2), the controls of soluble sulfate and reactive iron on pyrite accumulation may be limited.
The photocatalytic degradation of trichlorfon in aqueous TiO2 dispersions was investigated. The result shows addition of NaOH can promote the photocatalytic degradation of trichlorfon and it can keep the pH value on the photocatalytic degradation of organic phosphorus pesticides. When the initial concentration of organic phosphorus of trichlorfon is between 3.1 mg·-1 and 31 mg·-1, the change of inorganic phosphor fit zero order kinetic law on the effect of 50 mg TiO2 within 90 minutes. It shows the linear relationship between the rate constants and the initial concentration of trichlorfon. Finally, this paper discusses the influence factors on the photocatalytic degradation of trichlorfon.
Based on the data of grassland investigation in 1981 and grassland distribution calculated from TM remote sensing image by means of GIS technology in 2000, the spatial and temporal dynamic of in MinXians grassland is monitored. Contrasting the grassland of 1981 with one of 2000, the spatial feature of degradation would be researched in the paper. To most spatial analysts, Moran'I is probably a known measure to test spatial autocorrelation, and the Z-value of Moran'I indicates positive spatial autocorrelation. The results of Moran'I and Z(Gi*)and the moving plots all shows that the center of grassland degradation is the XiJiang village which is at the northwest of MinXian. From 1981 to 2000, the quantities of grasslands in the east are more than in the west, and the qualities of grasslands in the south are better than in the north. And the spatial structure of grassland is more obviously than before in the MinXian. It shows that the grassland is centralized degenerated in the northwest and middle of the MinXian, but the grassland of the some villages would be increasing in the east. It is caused by the lagging of the economic and technology. In other words, little money and poor technology are used in the area. So the area is weak to the disturbance from the environments.
The Natural Mangrove Reserve in Zhangjiang Estuary is locates in Yunxiao. The total area is about 2360hm2. It is the only one of National Natural Mangrove Reserve in Fujian. There are all together 688 species of plants and animals in the Reserve. Among them 2 species animal of national first-grade, 19 species animal of national second-grade and 162 species animal of "three adsum" 77 species reserve resident birds of China-Japan and 41 species reserve resident birds of China-Australia. It is the largest Avicennia marina forest in China. This review summarized the status of biodiversity and put forward the strategy of biodiversity conservation.
endemic genera to China of Spermatophyte were found in Dabashan Nature Reserve of China. They are taking the proportion of 4.98 percent to all the Spermatophytic genera. They are divided into 22 monogenera and 23 minor-genera. And monogenera was proportion of 48.9 percent to the Spermatophytic genera.,and minor-genera was that of 51.1 percent respectively. Among these plants 22 woody plants and 23 herb plants could be defined, accounting for 48.9 and 51.1 percent to the overall genera in this area respectively. These endemic genera to China of Spermatophyte distributed over the lower and middle mountains. 6 genera in the lower mountain and 39 genera in the middle one, were taken the proportion of 13.3 and 87.6 percent to the overall genera plants respectively. They were taken as the numerous ancient endemic genera and obvious transitional nature and abundant threatened species, and were considered that many of them existed in Sichuan and Hubei provinces, and that were important characteristic plants in Chuandong and the west of Hubei endemic center.
Duzhong(Eucommia ulmoides)is important Chinese medicine, due to it's high price and short supply, many duplicates are found in market. As Traditional taxonomy is difficult to ensure correct identification genuine Eucommia ulmoides, to develop an ultimate and definitive means for origin identification of genuine, the chloroplast matK gene was amplified by PCR using a consensus primer set and its nucleotide sequence was determined by PCR direct sequencing. The characteristic analysis of Eucommia ulmoides matk sequence was generated using Clustal aligned matK sequences of Apocynaceae and some related taxa, Celastraceae, and some most closely related matK sequences. 1140 bp matK gene sequences of Eucommia ulmoides were determined. Among 67 matK sequences analyzed, 32bp were unique in Eucommia ulmoides, including a "GAC" indels. These characteristic nucleotide loci might be used to obtain species-specific RFLP pattern or to design species-specific primers to ultimate identify genuine Duzhong. Chloroplast matK gene sequences might be a good molecular marker to be used to identify traditional Chinese medical plants.
In this paper, the vegetation of Dapingzhang Forest Park, Dongguan,was divided into five types and eight subtypes based on the data obtained from route surveys in the filed. The result shows that the plant species is considerable, and also the plant resources. Forest is compose of secondary evergreen broad-leaved forest, Acacia mangium forest and Camellia oleifera forest. Other vegetation types are grass slopes, farm vegetation, manned grass and nursery. Discussion about the rehabilitation of vegetations of Dapingzhang Forest Park was made to meet the need for the construction of this park..
Rebuilding on Shazui ponds is one part of Environment Compensation strategy, which belongs to Managing Shenzhen River Project. Through two years monitoring from Dec. 2000 to Oct. 2002 around the ponds, we record 69 species of the bird, 5 of which are new reoosdal species in Futian, the total reoordal b:rd species in Futian has increased from 189 species to 194 species. Comparing with these in the period before reforming area, the average density, abundance, community diversity of the birds have increased clearly. It shows that the effect of the rebuilding was significantly positive and successful. It is suggested that all ponds around the mangrove of Futian should be improval directionally and need to enhanced ecological management.
nucleotides of the coding region have been sequenced in the mitochondrial cytochrome b gene from Mandarin fish S. chuatsi and the corresponding amino acid sequence has also been deduced. The contents of A+T and G+C are 53.4% and 46.6% respectively。While the first positions of the codons have more or less even usage in 4 nucleotides, the second positions of the codons in the gene have bias to higher T and lower G;and only 3.7% G were found in the third positions. In deduced amino acid sequences, the percentage of Leu used in cytb gene were over twice than any other amino acids, the usage of Cys accounted for only 0.79%. Further studies will determine whether the nucleotide usage in different positions of codons and composition of amino acids were characteristic of S. chuatsi or sinipercinae, and molecular phylogeny and phylogeography of Sinipercinid fishes.
Huizhou Xihu Lake is a shallow city lake. Using the previous research data and preset data, we calculated Carlson trophic state index(TSI)in Xihu Lake. Results of the study show that Xihu Lake was hypereuthrophic, but the present water quality is better than several years ago. Some countermeasure should be adopted such as enforcing non-point pollution control, Xihu Lake aquatic ecosystem restoration.
Fish culture is an important commercial practice in China. The rapid development of fish culture industry over last few decades has aroused the increasing concern about its impact on the marine and freshwater environments involved. Recent studies show that great changes in community structure of fish, plankton and aquatic macrophytes, as well as in water quality could take place in fish culture zones, and most fish culture systems have been threatened in some degree. Environmental effects and fisheries management of the fish culture zones have become the focus of growing concern. Fisheries management is no longer a question of maximizing the yield of commercially exploited resources. In order to achieve the sustainable aquaculture, practical steps should be defined to move from the traditional fisheries management framework to ecosystem-based management.
Total 93 red tides events were recorded from 1981 to 2002 in Shenzhen coastal waters. During the 22 years, there are four featwres of the red tides:1)The red tide events were caused more in Dapeng Bay, Daya Bay and Shenzhen Bay. 2)The frequency of red tide events increased, and the duration of them extended. 3)There were two seasons during which the red tide events take place more frequently the on was from March to May, another was from September to November. 4)The diversity of red tide causative species increased, about 36 species were recored. 5)It seemed that there抯 an obvious trend on the succession of red tide causative organisms, and there were frequently new species causing red tide events.
Guangdong is one of the provinces with the most mangrove resources in China. There are 31 species, 17 families of mangrove plants and 21 438.3hm2 of mangrove wetlands which mainly distribute in western Guangdong and Pear River Delta. Mangrove has important ecological functions of preventing or reducing natural disasters, purifying environment, moderating regional climate, conserving biodiversity and so on. Conservation and development of mangrove is one of the eight major forestry projects in the ecological construction of Guangdong Province. In this paper, the ecological functions of mangrove were analyzed; the mangroves importance for the construction of forestry ecological province and its present situation of conservation and development in Guangdong were discussed, and some threatening factors such as utilization of mangrove wetlands for cultivation or aquiculture, expansion of urban areas in coastal region and wastewater pollution were pointed out. In the end, some suggestions for conservation and development of mangrove were put forward.
Scales, as the critical issue in ecology, exist in any ecological process in forms of temporal and spatial scales, and play a important role in ecology. This can be due to two reasons:one is the demand of understanding pattern and process on larger scales when solving many global environmental problems, while past ecological research mainly on small scales, and another is the conclusion that an given ecological problem lies on the scale selected in the study. But there remain a lot of problems in the study of ecological scales, such as the confusion between scales and some related concepts, the lack of a set of systemic and perfect methods for scale identification, and for scaling as well. This paper clarified the exact meaning of scales firstly, and looked back to the development history and importance of ecological scale andlysis. Next it discussed the relations between scales and hierarchy theory, as well as scale and pattern. In addition, it also discussed the methods and the developing trend of identifying scales and scaling.
An increasing amount of information is being collected on the ecological and socio-economic value of goods and services provided by ecosystems。However, much of this information appears scattered, data on ecosystem goods and services often appears at incompatible scales of analysis, and therefore ecological economic analysis isnt comparative。In response to this challenge, this paper presents a conceptual framework and typology for describing,classifying and valuing ecosystem functions, goods and services in a clear and consistent manner, a classification is given for the fullest possible range of 23 ecosystem functions that provide a much larger number of goods and services。, and a checklist and matrix is provided, linking these ecosystem functions to the main ecological, sociocultural and economic valuation methods。
Photosynthetic bacteria release H2 during N2 fixation. H2 may be evolved either by nitrogenase or hydrogenase,and the activity of the two enzymes,in turn, is influenced by the various physiological conditions. Among those factors, organic carbon restrains the hydrogenase expression but promote the H2 production. On the other hand, ammonium restrains the nitrogenase activity but decreases the H2 production;the existance of oxygen makes both nitrgenase and hydrogenase inactive, which restrains H2 evolved reaction consequently.
To study the distributions and causes of antibiotic resistance bacteria in indigenous soil, the bacteria were investigated on tests for antibiotic resistance(Apr, Kmr and Cmr, respectively)from the different environment. The plasmids from antibiotic resistance bacteria were isolated and identified. The results showed that there is no significance difference between the control and living area in Apr and Kmr bacteria. No Cmr bacterium was detected from samples. The Apr and Kmr bacteria with plasmid were both 18.2% in control area. The Apr and Kmr bacteria with plasmid were 36.4% and 27.3%, respectively in living area. These results suggest that the distribution of antibiotic resistance bacteria is no significance increase in indigenous soil.
Combining the characteristics and the developing need of ecology speciality, the teaching contents, manners, effect and examining method of microbiology experiments were discussed. We thought that the experimental contents will be designed scientifically, the media and network techiques should be used optimally, the teaching time in experiment will be arranged positive effectively, and the interest of students in microbiology experiments must be encouraged. These are necessary for students to learn and improve the experimental skills, and for teachers to culture the excellent students for ecology science in the new century.
