Cyanide is the most widely used leaching reagent for gold extraction. Its environmental behaviour and fate is of significant environmental concern. β-cyanoalanine synthase(CAS) was found to be able to catalyse the conversion of cyanide to the ammino acid asparagine. This paper presents an investigation on the potential use of plant tissues to degrade cyanide. Excised plant tissues (1.0g fresh weight) from 3 woody plant speices out of the Salicaceae family were kept in a glass vessel with 100 mL spiked aqueous solution (oxygen-saturated deionized water) at room temperature of 20～23℃ for 28h. Samples were taken directly from the solution and determined photometrically at a wavelength of 638 nm. The cyanide removal rate was determined experimentally between 22.13% and 67.04% over a 28 h exposure period and varied with plant tissues and species. The maximum metabolic velocity, vmax, was 0.4934～1.9449 mg CN·kg^-1 (fresh weight)·h^-1. The highest removal velocity was 1.9449 mg CN·kg^-1(fresh weight)·h^-1 with the leaves from Poplar trees (Populus deltoides), followed by 1.7259 mg CN·kg^-1 (fresh weight)·h^-1 with the leaves of hybrid willow trees (Salix matssudana Koidz×Salix alba L). The lowest removal velocity was 0.4934 mg CN·kg^-1 (fresh weight)·h^-1 with the new stem from hybrid willow trees. Results of this investigation indicated that the plant tissues were able to metabolize cyanide. The maximum removal capacity was found in plant leaves of the three groups tested. In conclusion, using excised plant tissues seems to be a feasible option for the characterization of the degradation pathways of cyanide.

Investigations were made on plant diversity, earthworm diversity, and soil organic matter in different directions of natural secondary forest in Dawuling Mountains. Four slopes,east-facing slope (EFS),south-facing slope (SFS),west-facing slope (WFS), and north-lacing slope (NFS) of Datianding Hill and Qieding Hill,were sampled. In the Dawuling Mountain, 1)the number of tree was lower on SFS that other directions, the densities of on SFS of Datianding Hill and Qieding Hill being 0 Ind·m^-2 and 0.06 Ind·m^-2, respectively, but there was no difference of tree diversity among directions, Shannon-Weaver index of tree ranging from 0 to 2.24, Margalef index from 0 to 3.15; 2) the number of shrub was not dominant in any directions, but SFS had the lowest shrub diversity, Shannon-Weaver index and Margalef index of SFS of Datianding Hill being 1.52 and 1.70, respectively, those of Qieding Hill being 2.05 and 2.33, respectively; 3) the number of herb on SFS was the highest among those or all directions, the densities of herb on SFS of Datianding Hill and Qieding Hill being 87 Ind·m^-2, and 44 Ind·m^-2,respectively, and SFS also had the highest herb diversity, Shannon-Weaver index and Margalef index of herb on SFS of Datianding Hill being 2.46 and 3.36, respectively; 4) the number of earthworm was low on SFS. the densities of earthworm on SFS of Datianding Hill and Qieding Hill being 7 Ind·m^-2 and 0 Ind·m^-2, respectively, but the earthworm diversities was insignificantly influenced by direction, Shannon-Weaver index of earthworm ranging from 0 to 1.63. Margalef index from 0 to 2.20; and 5) direction had no influence on the content of soil organic matter, and the soil within 50 cm from the surface had 11.2～40.6% of organic matter, that between 50 cm and 100 cm from the surface having 5.6～17.5% of organic matter. Because of direction effects on biological sources, different methods should be used to manage natural secondary forest according to slope-exposure.

Basing on the previous research, we develop the niche-fitness theory of urban system and modify the model. First,we select 21 indexes such as GDP growing rate, average income etc. to establish the niche-index system. Then, taking 35 cities of China for example, we calculate five kinds of niche-fitness values from 1996—2000, namely niche-fitness of economic development and income, environmental niche-fitness, niche-fitness of foundational establishment, niche-fitness of education and health, and average niche-fitness. Analyzing the result, we draw the following conclusions: (1)Niche-fitness values of urban ecosystem not only are different in space in time, but change when ecological factors given different weights. (2) Five kinds of niche-fitness of 35 Chinese cities have different rules in space. (3) Five kinds of niche-fitness of 35 cities have different rules with time. (4) Of the five kinds of niche-fitness, that of foundational establishment of 32 cities is the lowest; environmental niche-fitness of 27 cities is the highest. Among all the cities, Shenzhen has the highest values of the five kinds of niche-fitness. Shijiazhuang has the lowest environmental niche; Yinchuan has the lowest niche-fitness of foundational establishment; as for as the other three kinds of niche-fitness, Guiyang has the lowest values.

Se stress in S. maxima and S. platensis at different growing phases was studied. Adding Se started from the 1^st day to the 5^st day and Se concentration increased every day. The cumulating Se concentration at the 7^st day was 1000mg·L^-1(stress of Se Ⅰ～Ⅴ). The growth of Spirulina, the absorption and bio-organization of Se were also discussed. It was indicated that the stress of Se Ⅰ～Ⅳ showed no significant effect; and the stress of Se Ⅴ showed obvious promotion. The total Se content and bio-organization rate of Se increased from Ⅰ to Ⅴ, The results were first explained by the stress intensity of Se.

Nanjiang Industrial Estate is located near North River, there are some metals machining, plating factories. To investigate the present environmental condition of water area around Nanjiang Industrial Estate and then to assess the impact to water area from the industrial estate, we sampled and analyzed the aquatic around Nanjiang Industrial Estate. The result showed that the aquatic around Nanjiang Industrial Estate wasn't polluted by heavy metals, but was polluted by organic compounds.

Ecosystems of coastal waters in China, including salt marshs, mangroves, coral reefs, estuarines, and some shallow seas, have been severely influenced by human activities, and more or less degradation has been resulted. It has been paid great attention to the increasingly severe situation of this degradation phenomenon. Based on long-term data, the characteristics of degraded ecosystem of Daya Bay waters mainly reflected the structure and function of species composition, community structure, succession and productivity etc., as well as habitat deterioration. Analysis of long-term data revealed that some anthropic disturbances, such as the coastline changes caused by the large construction projects, decrease of plowlands and wetlands, a great deal of pollutants input from terrestrial, eutrophication of water body caused by mariculture, over-fishing, etc. have accelerated the degradation of Daya Bay ecosystem. The results might be provided to the restoration, reconstruction and sustainable utilization of damaged coastal ecosystem.

A case study for the structure and effects of "pig-biogas-tea" eco-agriculture was carded out in Fenghuang town,Chao'an County, Guangdong Province. In such eco-agricuiture, animal husbandry, biogas production and tea farming were combined and developed into a cycling ecosystem. The investigation and analysis results showed that this farming system could decrease the inputs and costs, and increase the quality of tea. Meanwhile, the application of wastes of biogas production could also reduce and replace the use of chemical fertilizers and pesticide, by doing so, it could improve soil fertility and environment quality. It was indicated that this kind of eco-agriculture model had good ecological, economical and social benefits, so it would be extended in the hilly areas of south China.

The paper briefly dealt with the toxic effects of Cr⁶⁺, Cr³⁺ and their combined pollution on the physiology of roots and leaves of high aquatic plant—Myriopllum verticillatum. The results show that Cr³⁺ could stimulate the growth of root when the treated concentration below 1 mg·L^-1, while Cr⁶⁺ and the combination treatment show significant inhibition to the growth of root. The highest concentration of chlorophyll gained when treated with Cr³⁺ at concentration of 1 mg·L^-1. The concentration of chlorophyll decreased as the increase of Cr⁶⁺ concentration. The concentration of soluble protein increased at first and decreased finally as the promotion of concentration of Cr⁶⁺, Cr³⁺ and their combined treatment. The same effects also took place on the activities of SOD, POD and CAT. The peak of concentration of protein occurred at the combination treatment of 1 mg·L^-1. The results suggest Cr⁶⁺ and Cr³⁺ have corroborative pollution effect to the M. verticillatum, and Cr⁶⁺ is more poisonous than the Cr³⁺.

Mikania micrantha H.B.K. is distributed mainly in Delta of the Pearl River and the eastern coastal areas in Guangdong Province. It is transmitted gradually from Shengzhen to the east, north and west of Guangdong Province. M. micrantha often establishes in open areas and the humid soil that has rich organic matter. It is the distribution center of the invasive M. micrantha that in organic domestic rubbish, the heap of sludge beside drainage ditches and abandoned fields. It spreads and extends far away from established fields by means of plenty of seeds and fast vegetative reproduction. Anthropic factor such as long-distance transport is the major reason that M.micrantha is transmitted in long range, Shrubs were damaged hard by M. micrantha and distributed secondary forests were damaged to a certain degree. Fruit trees were damaged larger because of weeding and fertilization.

Imposex of marine temale gastropods is induced by the pollution of organotin compounds. The present study reported the histological characters of male sex organs from male and imposex individuals of prosobranchs Mauritia arabica, Chicoreus brunneus and Conus betulinus. There were two types of vas deferens and penis found among the species, one is open,and another is closed. Based on the present and previous studies, the closed type evolves from the open. Although no significant differences were histologically observed in male sex organs between male and irnposex individuals, imposex individuals do not have male reproductive function because of its incomplete male genital system, e.g., lack of testis and prostate. Since endocrine disrupting chemicals have more or less similar effects on human and animals, we should attach great importance to imposex of marine gastropods.

Investigation and monitoring on phosphorus pollution and eutrophication status of the large and medium reservoirs for water supply in Guangdong province were carried out in flood season and dry season of 2000. Among the 20 investigated reservoirs, half have been contaminated by phosphorus. So phosphorus pollution was one of the important causes that involved in eutrophication. The concentration of TP was consistent with the trophic state of the reservoirs. Phosphorus limitation phenomenon was common in the reservoirs, and it was more obvious in the dry season. Under low temperature and phosphorus limitation diatoms had more advantage than green algae.

Based on the pot experiments in sand culture, both the removal of pollutant Cadmium by Kandelia candel and the toxicity of Cadmium to seedlings Kandelia candel were determined in the absence and presence of Methamidophos, respectively. The results showed that, although 100 mg·L^-1 Methamidophos had no effect on the removal of pollutant Cadmium by soil-culture Kandelia candel, there was a synergistic toxicity effect between Cadmium and 100 mg·L^-1 Methamidophos to seedlings Kandelia cande. It assumed that this synergistic toxicity effect might result from the membrane-lipid pemxidation of Cadmium vs. seedlings Kandelia candel: this peroxication would no doubt enhance the ability of Kandelia candel to be penetrated, then facilitate the transfer of Methamidophos from water into Kandelia candel, thus lead to the synergistic toxicity between Cadmium and Methamidophos. Therefore, it is suggested that the mixture toxicity between Cadmium and other pollutants should be considered to determine the tolerance concentration of Cadmium to Kandelia candel.

The toxic algae phaeocystis is one of key taxa in redtide-caused marine algae,due to its complex heteromorphic life cycle,great geograPhic differences,and minuteness of Polymorphic motile cells,the identification of Phaeocystis species is difficult and controversial.In 1997 and 1999,Pltaeocystis bloomed in southern China coastal waters,its taxonomic status is unresolved yet.The Partial sequence of 18S rDNA from the strain P₂ collected In Hong Kong coastal waters were determined in this study.The sequences were then used as molecular criteria to investigate the algae identities.The result shows that the strain is Phaeocystis globosa.

Chemical pollution of the environment has become a major source of concern because of human activities. There is more and more aluminum wastes which is discharged into the environment at a high increasingly rate. In particular, many studies have investigated the impact of aluminum on biota in the environment. This review discusses the relationships between aluminum toxicity and ecological risk, especially health risk of human beings, focusing on toxicological ecology and molecular ecology. In this paper we demonstrated the impact of aluminum on environmental safety in relation to the ecological risk and health risk. In addition, the development of the techniques in treating and minimizing aluminum toxicity were discussed.

This paper discussed the present progress of algae species and genetic, the relationship between habitat diversity and species diversity, and the main problems which faced Chinese algal biodiversity. Some suggestions of conservation and utilization of algal biodiversity were put forward.

Annual net primary productivity (NPP) of terrestrial vegetation is the net amount of carbon fixed by plant photosynthesis. NPP is an important index in global change ecology. The history of NPP research is reviewed in this paper, and the applications of RS and GIS technology for measuring NPP in larger scale is discussed. This review also concludes about the characteristics and tendency of NPP research in recent.

In this paper, the application of the research and development directions in the field of drought monitoring is revealed. The principles and methods of soil moisture monitoring are simply summarized. Some methods have been discussed, such as statistical analysis, physics model based on soil moisture dynamics, soil moisture balance model, artificial neural network model and remote sensing model. Finally, the review points out the problems in this research field.

Eutrophication of water body is a problem of global concern. The potential for nutrient loss in runoff has been increased by the continued application of fertilizer and the excrement from livestock and poultry culturing industry. That has created a nitrogen and phosphorus imbalance. So the agricultural non-point source pollution has been considered as the main pollution source of eutrophication. This paper provides a brief overview of the management of agricultural non-point source pollution including source control strategies and transport control strategies. The conclusion is that the key strategy is to set up stable, harmonious and benefic cycling ecosystems.