A study was carried out on permeability of soils under some typical forest vegetations,such as Chinese pine,larch,Korean pine,oak,weed trees,and filbert bushes in Eastern Liaoning mountain region with the method of temporary sampling plot.The results indicated that the soils under all the six forest vegetations showed good permeability,with the initial rate of infiltration(f ₀/mm·min ^-1)ranging 12.8～61.1,and averaging 38.7 for A horizon,16.8～41.7 and 27.0 for B horizon,29.3～38.2 and 24.4 for C horizon and the stable rate of infiltration(f _c/mm·min ^-1)ranging 2.6～4.2 and averaging 3.5 for A horizon,2.2～4.1 and 2.9 for B horizon,1.1～3.3 and 2.2 for C horizon.The saturated hydraulic conductivity ranged 1.53～2.23,averaged 1.86 for A horizon,0.77～2.05 and 1.27 for B horizon,0.50～1.28 and 0.79 for C horizon.Soil permeability varied significantly among vegetation types and soil horizons.Generally speaking,soil permeability under broadleaf forest was better than under coniferous forest,and the soil under filbert bushes also showed good permeability.A horizon is better than B horizon and B horizon is better than C horizon in permeability.When the difference in forest age was beyond two age grades,the older the forest,the higher the initial soil permeability under it.When the Horton equation was used to model soil saturated penetration course,the result was quite similar to what was determined in the field.

By combining aerial remote sensing images with field investigations,two agricultural land use maps of the studied region in 1979 and 1999 were obtained.Comparison and analysis of the two maps showed changes in land use during that period of time.Through visits to farmers,causes of the changes were explored.The result showed that technology and input were the major contributors to higher yield of the farmland,and to increase the economic benefit of the farmland was the direct driving force of the changes in land use structure of upland fields.

Bashang region is a typical agriculture-pasture-interlacing zone,whose eco-environment is fairly vulnerable and hence it is very sensitive to environmental changes.Located only about 200 km away from Beijing and Tianjin,the region is a water-source and an ecological protection barrier for Beijing and Tianjin.Thus,study on the area is of great significance.Since 1950s,land use and land cover have undergone several changes.Before 1980s,large areas of grassland were turned into upland fields and some into woodland.And in early 1990s,the farmland was gradually changed back into grassland and some into woodland or paddy fields.The alteration of land use and land cover caused changes in soil nutrients,such as organic matter,total N,total P,total K,alkali-hydrolyzable N,and readily available K,readily available B,Mn,Zn,Cu,and Fe,though regularly.When grassland was turned into woodland or upland fields into woodland or paddy fields,total soil nutrients increased.This was only a general trend.Exceptions did exist,especially with alkali-hydrolyzable N,readily available P,readily available K,and micro-elements,which sometimes altered inconsistently with the above-said patterns. 

Through a long-term stationary experiment combined with the adoption of quantitative and qualitative methods,the ecological effects of planting Eulaliopsis binata on soil physical and chemical properties,micrometeorological environment of grassland,water losses and soil erosion were studied.The results showed that compared with barren land,the land grown with Eulaliopsis binata decreased in soil bulk density,increased in total soil porosity,non-capillary porosity and capillary porosity,improved in water permeability,soil aeration,soil fertility,and soil water-holding capacity,decreased in soil temperature and soil erosion rate.Therefore,planting Eulaliopsis binata in slope wasteland in the purple soil areas can yield favorable ecological benefits.

Preparation of compost of pig manure and sawdust mixture was studied.The mixture was designed to have three ratios.For the primary fermentation,a static aerobic composting system with temperature-based feedback controlling aeration rate was used and lasted for 15 days.And for the secondary fermentation,windrow composting was adopted,with the pile turned up periodically.This stage lasted for 30 days.Changes in temperature,moisture,organic matter and pH were monitored during the entire process.Analysis of decomposability and nutrient contents of the composts of three different ratios showed that end-products of the composting were bio-stable and abundant in nutrients and that the higher the nutrient content of pig manure,the higher the nutrient content in compost.This shows that composting of mixture of pig manure and sawdust can produce high quality compost by optimizing the composting process for 45 days.

Acute toxicity tests of four new pesticides were conducted in the lab with Scenedesmus obliquus,Daphnia magna and Brachydanio rerio as subject to evaluate the safety of pesticides in the aquatic ecosystem.Results showed that acetamiprid as pesticide was extremely toxic to Daphnia magna,highly toxic to Brachydanio rerio and low toxic to Scenedesmus obliquus;pymetrozine as pesticide was low toxic to Daphnia magna and Brachydanio rerio,but moderately toxic to Scenedesmus obliquus;oxadiazon as herbicide is highly toxic to Scenedesmus obliquus,but moderately toxic to Daphnia magna and Brachydanio rerio;quizalofop-p-ethyl as herbicide was highly toxic to Scenedesmus obliquus and Brachydanio rerio,but moderately toxic to Daphnia magna.

Through on-the-spot investigation and laboratory analysis,a study on the effects of soil physical and chemical properties of cinder yard of Wuhu Thermal Power Station on vegetation was carried out.The results showed that there were 30 species of naturally colonized plants in the cinder yard.Most of them relied on wind to spread and propagate.It was related to the propagula resource in the surroundings of the cinder yard. The poor physical properties,unbalanced soil fertility or infertility and excessive concentration of heavy metals are the main limiting factors for vegetation growth. 

Two strains of bacteria(W1 and W2)feeding only on 2-chlorobenzoic acid were isolated.The degradation enzyme system of W1 is inducible,with rate constant being -0.134 h ^-1,whereas the degradation enzyme system of W2 constructive with rate constant being -0.038 8 h ^-1 while degrading 2-chlorobenzoic acid.Besides,W1 can also degrade 4-chlorobenzoic acid,benzene,toluene and 2-hydroxphenol,but not 3-chlorobenzoic acid,1,4-dichlorobenzoic acid,ethylbenzene,propylbenzene and naphthalene. Plasmid and chromosome extraction experiments indicate that the degradation genes of W1 are on chromosome. 

Through comparative study on toxic effect of Cr ⁶⁺ and Cr ³⁺ on some biochemical and physiological characters of leaves and roots of A.philoxeroides,it has been found that A.philoxeroides was injured by the pollution of Cr ⁶⁺ and Cr ³⁺.When polluted,the five major biochemical and physiological indexes of the plant,including the content of chlorophyll,SOD,POD, CAT activity and the content of soluble protein all changed,rising first and then falling,or keeping on rising or keeping on falling.The toxic effect of Cr ⁶⁺ was much stronger than that of Cr ³⁺ and the damage was greater to roots than to leaves.

The forms,contents and distribution of Cu,Zn in some orchard soils in Shandong Province were studied.The results showed that the contents of total Cu,Zn in orchard soils were higher than in other agricultural soils.Distribution of the elements varied with soil and form.For Cu,the distributions of different forms of the element showed a similar trend:residual>organically bound>precipitate>exchangeable in brown soil and cinnamon soil and residual>precipitate>organically bound>exchangeable in Chao soil and Shajiang black soil.But the distribution of different forms of Zn element was in the trend of residual>precipitate>organically bound>exchangeable in the four soils.Based on the physical and chemical properties of soils and the contents of total Cu,Zn in the soils studied,it is learned that the distribution of different forms of Cu,Zn elements in some soils is related to the properties of soils.With pH increasing,the contents of exchangeable Cu,Zn decreased in some orchard soils.And the contents of some forms of Cu,Zn are related to the contents of total Cu,Zn.Significant positive correlation existed between precipitate Cu and total Cu with correlation coefficient being 0.824.And so was the relationship between residual Zn and total Zn and its correlation coefficient was 0.993.

Based on the analysis of the relationship between hazard-free food production and Chinese ecological agriculture,it is held that Chinese ecological agriculture is an effective approach to the production of hazard-free food.For production of hazard-free food,discussion is also devoted to related technological and management systems.

It is of high strategic significance to pursue sustainable development in Nujiang Valley of Yunnan Province.To that end,the characteristics of the eco-economic pattern and resources environment were analyzed and on such a basis,strategies for sustainable development in the valley were put forward. 

The environmental behaviour,bioconcentration of rare earth elements and their effects on animal gonad were studied by means of radioisotope tracer.The results indicated:(1)The ¹⁴⁷ Pm ¹⁴¹Ce and ¹⁴⁷ Nd had strong adsorptivity in soil.So,they were hard to transfer and accumulate easily in soil.When in water body,they accumulated in sediment.(2)All the organisms under study showed apparent ¹⁴⁷ Pm concentrating capabilities.(3)The residues of ¹⁴⁷ Pm ¹⁴¹Ce and ¹⁴⁷ Nd were unevenly distributed in the animal′s viscera and tissues.But,higher residues were found in bone,marrow,eye,brain,heart,adipose and testis,and their concentration increases with dosage and time,which shows selective accumulation.There were much higher concentration of RE in bone than in other viscera and tissues,and ¹⁴¹ Ce is the highest in eye.(4)With intraperitioneal dosing of Nd or Ce being 200 mg·kg ^-1,the gonadial hormone(testosterone or progesterone) concentration in the serum decreased significantly as compared with the control,showing apparent inhibition on gonadial hormone secretion in mice.However,with different dosages of Ce,200 and 800 mg·(kg·d) ^-1 added in feed,the testosterone concentration in serum made no significant difference,but the malformation rate of spermatozoon proves higher,and increased with feeding time and dosage.Based on the primary exploration on safety of agricultural use of RE for eco-environment,some suggestions are brought forth.

Since photochemical degradation of pesticides on the soil surface is an important transformation pathway in the environment,the study on photodegradation of pesticides plays a key role in assessment of their ecological risks.The studies on photodegradation of pesticides in soil,including methodology,important affecting factors and other critical research points were reviewed.Types of major photochemical reactions,prospects and some cases of application of photodegradation of pesticides in soil were also discussed.

With the development of eco-tourism along the east coastal region of Xiamen Island as a case for study, a cooperative shares system is put forward for development of eco-tourism as a mechanism to guarantee effective community participation,to improve the living standard of the local residents and to protect the ecology in the processes of exploiting and managing the ecological resources.On such a basis,exploration is made on an operational framework of the cooperative shares system for development of eco-tourism in the east coastal region of Xiamen Island.