Based on the present situation of the serious soil erosion, which is the consequence and a form of the comprehensive representation of ecological disturbance in Guizhou, and the basic principles and methodology of environmental economics, the amounts of N, P and K lost and amount of the soil detained and deposited as a result of soil erosion, were selected as the five major indexes for assessment of economic costs. Monetary values of the economic costs on-site and off-site were worked out. Comparison of the results with the main indexes of the economy construction in the province shows directly the extent of the economic costs resulting from the soil erosion there. The study has also clarified some concepts relevant to economic costs of soil erosion that were not fully understood before.

As the ecological environment is seriously degenerated in the arid area of northwest China,ecological environment construction plays an important role in implementation of the grand strategy of developing west China. Taking Xinier zone in Yuli County in the middle reach of the Kongque River as example, major ecological environment problems, status of the water resources and quantity of water available for the construction of the ecological environment were analyzed. Based on the analysis, a layout for ecological environment construction in that zone has been proposed.

The impact of land use on the agrolandscape at the village level between Baka and Daka, Xishuangbanna, Yunnan was explored. The results show that the intensity index of human disturbance ( HD ) is 3.196 5 in Baka, higher than that of Daka because of lack of a large area of natural forest of commonweal. Correspondingly, the fragmentation index of grain and cash crops landscapes of Baka ( R i 0.069 2 and 0.098 0 hm ^-2 ) is higher than that of Daka, respectively. On the other hand, the heterogeneity, evenness and dominance indexes of the landscape of Daka ( H 1.459 5, E 0.664 2 and D 0.737 7) are higher than those of Baka, respectively,due to additional commonweal forest, scenic forest and water in Daka. Hence, Daka can maintain sustainable development depending on the commonweal forest. Cash crop plantations and grain crop farmlands make up a large proportion of the total, indicating that cultivation of grain and cash crops is the key to development of the mountain regions there. However, expansion or maintenance of the acreage of paddy fields contributes greatly to the increase in population carrying capacity of the land. Under the impact of the market and techniques, the scales of the agrolandscapes fluctuate from year to year, but remain stable from a long-term point of view. Nationality cultural policy and market have great impact on land use and landscape patterns of the two villages.

Resources and environment are the heart and base of agricultural sustainable development. Eco-security of agricultural and rural development means the resources and environment in the area are balanced and the agro-ecosystem is healthy. Took Du′an Yao Autonomous County of Guangxi Zhuang Autonomous Region for case study and based on the set evaluation index system eco-security evaluation on agricultural sustainable development in Du′an was conducted, and the county was regionalized according to bio-security. On such a basis, strategies for land use and building-up of eco-security in different eco-security regions for agricultural sustainable development in Du′an have been proposed. 

Numerous in number, uninhabited islands represent about 94% of the total number of the islands in China,but only 2% in terms of area. As regard to future models of protective development, concepts of, principles for and approaches to habitats renewal are introduced. The future models may include the following optional strategies,such as nature reserve,ecological tourism, marine farm, harbor, etc. Based on the principles of protective development and ecological restoration, and rationales and methodology of habitat renewal, these islands can be sorted into four types, ecological, developmental, inhabitant-free, and defense-oriented, which facilitates effective respective management.

Distribution of light spectrum and primary production in the waterbody of Meiliang Inlet of Taihu Lake was studied. The results show that on the water surface, the intensity of UV-C was low (10 ^-5 μE·m ^-2 ·s ^-1 ), that of UV-B increased with wavelength and that of UV-A was much higher (10 ^-2 μE·m ^-2 ·s ^-1 ) but attenuated rapidly with maximum vertical diffuse attenuation coefficient ( K _d )value up to 12.5 m ^-1 . K _d of visible light could reach as high as 8.2 m ^-1 . In comparison with the value on the surface, the intensity of ultraviolet at 0.5 m was less than 1%, and of visible light around 20%. The primary production was relatively low in the surface, reached peak at the depth of 0.2 m and then decreased with the increase in depth. Direct measurement revealed that dissolved oxygen in the water was high at the depth of 0.2 m. Concentration of chlorophyll-a varied with light intensity in the water. These results show that the distribution of primary production was the result of the joint effect of ultraviolet and visible light.

A plot experiment was conducted in Rugao demonstration base in a region of highly sandy soil along the Changjiang River in Jiangsu Province to investigate effects of IFC-microelement fertilizer on yield and nitrate accumulation of Chinese cabbage. The plots in the experiment all received the same rate of phosphorus and potassium but different rate of nitrogen, combined with or without additional IFC-microelement fertilizer (30 kg·hm ^-2 ). The experiment shows that the application of IFC-microelement fertilizer at an appropriate rate increased yield and nitrogen accumulation of the crop but decreased nitrogen and nitrate contents in the crop, and nitrogen contamination of the soil and ground water as well.

A pot experiment was conducted to study effect of application of biogas slurry on nitrate content and nutrition quality in romaine lettuce and lettuce. The results show that the application of biogas slurry increased plant height and yield of the crops, which had lower nitrate contents but higher water and amino acid contents (in lettuce) and higher vitamin C content (in romaine lettuce). On the basis of N,P,K fertilization (N∶P∶K=120∶80∶100 mg·kg ^-1 ), additional application of biogas slurry at 500 ml·pot ^-1 improved nutrition quality of the vegetables by decreasing nitrate content in the leaves of lettuce and romaine lettuce by 53.5% and 45.5% respectively, and also increased yield by 51.0% and 56.7% , respectively.Under this experiment conditions, the fertilization recommendation is the best for the two crops.

Effects of different soil amendments (montmorillonite, rice straw and chicken manure) on the characters of mixed soil (copper mine tailing and garden soil) and on the growth of ryegrass on the soil were studied. The results show that montmorillonite had no significant effect on ryegrass at various growth stages, but rice straw and chicken manure, though inhibitive to ryegrass growth in terms of biomass of the first and second cuttings, increased the yield of the third and fourth cuttings significantly, showing enormous residual effect, which is mainly due to their slow decomposition in soils. Earthworms can only grow in soil with rice straw applied at a suitable rate. No obvious difference in soil phosphatase was observed between treatments except for the one, which was suitable for growth of earthworm. Rice straw and chicken manure increased urease activity. The treatments using rice straw decreased the quantity of available metals in soil, but the ones using chicken manure increased available metal concentration, suggesting that it must be careful in using chicken manure, containing large amounts of metals, as organic fertilizer. 

The photolysis of rich d -trans- allethrin , Es-biothrin , d -allethrin and hydrolysis of the three pyrethroids in water varying in temperature and pH were studied in the laboratory. Results of the test show that the photolysis of all the three pyrethroids in aqueous solutions under a 500 W xenon lamp fitted to the first order reaction dynamic equation, and the photolytic half-life values of rich d -trans- allethrin , Es-biothrin , d -allethrin in water were 1.84,1.37 and 1.51 h, respectively. The results also show that the hydrolytic rates of the three pyrethroids in the buffer solutions with pH being 5 and temperature at 25 ℃ were very low, with half-life longer than 162 d. With the temperature and the pH value rising, the hydrolytic rate was accelerated. The hydrolytic half-life values of rich d -trans- allethrin, Es-biothrin and d -allethrin in the buffer solutions with pH being 9 and temperature at 50 ℃ were 0.21,0.22 and 0.18 d, respectively. The experiment also shows that the three pyrethroids differed slightly in photolytic and hydrolytic rates in spite of their difference in isomer content.The mechanism of the hydrolysis was also discussed.

Screening of zymogens in lab for better fermentation of pig-dung and urban waste in composting shows that the effects of Streptomyces microflavus, Polystictus versicolor and Pseudomonas sp. were the highest in promoting decomposition of the materials,and the effects of Trichoderma viride, Penicillium sp.-1 and Streptomyces microflavus were the highest in deodorizing the compost.

Heavy-metal-tolerant bacteria in the agricultural soils around a lead-zinc smeltery were investigated. The results show that with increase in pollution, the number of culturable bacteria dropped drastically whereas the proportion of heavy-metal-tolerant bacteria rose. The adaptabilities of bacteria to Pb and Zn stresses vary. After a long time of screening, most strains of bacteria became able to stand low concentration of Pb ( < 2 mmol·L ^-1 ) and some grew dependent on low concentration of Pb (0.5 mmol·L ^-1 ). No strains, however, were found tolerant to concentration higher than 4 mmol·L ^-1 Pb. Zn contamination, when reaching 0.5 mmol·L ^-1 in concentration, began inhibiting bacteria activity. But in all the samples investigated, bacteria were found tolerant to Zn, ranging from 4 to 6 in mmol·L ^-1 concentration and some even to Zn of 8 mmol·L ^-1 in concentration. The number of strains tolerant to both Pb and Zn was very limited, so was their tolerance to 2 mmol·L ^-1 and below only.

The effects of transgenic Bt cotton on the parasitoid in tri-trophic system involving Sukang 310, Sylepta derogata and Apanteles ruficrus have been investigated. The negative effects of Bt cotton (Sukang 310) on the development of parasitoid ( Apanteles ruficrus ) were found in the fields. The population of Apanteles ruficrus descended significantly. The parasite ratio in the experiment is lower than that of the control. 

Ecological Footprint Analysis is a new method for measuring ecological sustainable development. The method is used to calculate ecological footprint and ecological carrying capacity of Nanjing in 1998. It is concluded that the ecological footprint demands did not pose any threat to sustainable development of the local ecosystem but has some negative impacts on sustainable development of the ecosystem of the country and the globe. 更多还原 AbstractFilter('EnChDivSummary','ChDivSummaryMore2','ChDivSummaryReset2');

With increase in release of GMP (genetically modified plants),it has become a very important ecological concern to assess GMP′s invasiveness.Exploration of characteristics of the potential invasiveness of GMP was made from the angle of ecology (seed,plant) and the angle of physio-biochemistry (enzyme expression,objective protein detection and photosynthetic ability) in an attempt to set up an index system for assessing invasiveness of GMP,which may be used as reference for evaluation of the security of GMP.