By using the Landsat TM data of 1995 and 2000,changes in land cover in the Three-Gorges Reservoir region during the 5 years are analyzed.It is shown that the changes in land cover in this region during this period were mainly displayed as conversion of forestland into grassland and cultivated land and of cultivated land into construction land,and secondarily as conversion of forestland into construction land,of forestland into shrubs and of grassland into forestland.Such changes indicate that,in recent years,the ecological environment in the Three Gorges Reservoir region was worsening on the whole,except some local areas.Therefore,it is essential to enhance protection of the ecological environment with emphases on conservation and rehabilitation of forestland and control of alienation of cultivated land.

Growth and contents of chemical elements of 6 r are and endangered species of plants from limestone regions were studied and com pared between different substrates limestone soil and acid red soil.Results show ed that:(1) there was no big difference between the two groups of plants in phen ological characteristics;(2)The growth of Heteroplexis microcephala and Pt eroceltis tatarinowii in limestone soil were higher than in acid soil,but that of Hainania trichosperma was lower;(3) The contents of Ca and B in these 6 species in limestone soil were higher than in acid soil,but the contents of Al i n the plants,except Hainania trichosperma,which was in reverse,were higher i n acid soil;(4)The biological absorption coefficients of K,Zn and B by the plant s in limestone soil were higher than in acid soil,while those of other elements such as N,P,Ca,Mg,Fe,Al and Mn were just on the contrary.

Characteristics of Four Herons living in Yuant ouzhu of Wuxi in the Taihu Lake region were studied in 2000.Results showed that there were 36 400 nests of Four Herons in Yuantouzhu,averaging about 0.52 nest/m ²,and 3.36 nests per tree in the habitat.Earlier settlers often built their ne sts in relatively better locations,far away from villages and highways.Tall tree s,especially Pinus massoniana,were their favorite nesting ground,often with larger birds on top or in the middle of the canopy and the smaller in the lower part.The average size of a clutch was 3 for Nycticorax nycticorax and Bubu lcus ibis,and 5 for Egretta garzetta and Ardeola bacchus. 

Functional regionalization of tourist forest r esorts is believed to be an effective means and a management tool to harmonize n atural preservation and exploitation of the resources.Based on elaborate analysi s of the resources,environment and social-economic characteristics of all fores ts that might be opened to tourism in China,fundamental objectives of,principles and methods for functional regionalization of tourist forest resorts are discus sed. 

Analysis of phosphorus concentrations in urban domestic sewage,in-flowing rivers and water bodies of Taihu Lake as well as var iation of the eutrophication index therein before and after the banning of phosp hate in detergents adopted in Taihu region demonstrated that the phosphorus conc entration decreased by about 24% in urban domestic sewage,by 16.07% in river wat er,and by 3.29% in eutrophication index of the lake water body.The phosphate ba n showed a significant effect on phosphorus concentration in the domestic sewage ,but no obvious effect on that in the in-flowing rivers or the eutrophication i ndex of the lake water body.Consequently,control of eutrophication of Taihu Lake calls for integrated management including other pollution control measures in t he region.

Experiment using HF-fumigation was conducted t o study effect of hydrogen fluoride on rubber tree saplings.Results showed that rubber tree saplings displayed typical symptoms of suffering.The higher the conc entration of hydrogen fluoride was,the more serious the symptoms were,and the hi gher the accumulation of fluoride in leaves.Young leaves were more vulnerable th an old ones,and the fluoride accumulation in old leaves was higher than in young ones.With rise in exposed concentration,electro-conductance of the plants incr eased significantly.Stomas deformed after HF-fumigation,and the higher the conc entration was,the more serious the deformity was.As the extent of damage deepene d,chlorosis of leaves occurred and chlorophyll contents gradually decreased.

Studies were carried out on degradation pattern s of chlorsulfuron in soils of wheat fields in Jiangsu and Hebei.The results sho wed that the degradation of chlorsulfuron in soils was very slow,with half-life being 22.82 days and 32.98 days in Jiangsu and Hebei,respectively.Rice is highl y sensitive to chlorsulfuron residue in the soil left from the preceding wheat c rop.The concentration of chlorsulfuron residue of 0.1 μg/kg is high enough to i nhibit root growth of the following rice crop.

Dynamic changes in enzyme activity in fluvo-aq uic soil under application of lanthanum (La) was studied through simulation expe riments.The activities of soil dehydrogenase,alkaline phosphatase, urease and su crase decreased with the time of incubation.La inhibited strongly the activity o f soil dehydrogenase,and to a significant level (P<0.05) with a maximum inh ibition ratio reaching up to 39% when its concentration was over 30 mg/kg.La als o showed an inhibitory effect on the activity of soil alkaline phosphatase and a maximum inhibition ratio of 15%.But its effect on soil urease was not as signif icant.It stimulated the activity of soil sucrase to a varying degree,with the ma ximum stimulation ratio being 15%.Consequently,the soil activity of dehydrogenas e can be taken as a sensitive index for assessing environmental effect of rare e arth elements. 

The experiment on quick composting of rice stra w through chemical pretreatment and combined chemical-biological treatment was conducted in lab.IR crystalline index, which indicates structure of the material ,of the straw samples treated by chemical agent A or B declined after 24 hours.T he straw was found obviously decomposed within 14 days after combined chemical- biological treatment.The average yield of the rice crops using the manure was in creased by 10% in pot experiment. 

In the countryside,there are abundant renewable resources of lignocelluloses,especially crop stalks and straws, which can be hy drolyzed with the aid of cellulose enzymes.The resultant solution is then used a s medium with addition of some supplements to culture Bacillus phosphaticum. Under favorable fermentation conditions,the cultured solution can have 5.1×10 ⁸/ml Bacillus phosphaticum.Mashed crop stalks and straws or organic residues from urban waste are mixed with the solution as absorbent and then the bacteriu m manure is ready for agricultural use.

Based on the development of and changes in rura l landscape introduced herein, contents and principles of ecological programs fo r rural landscape is elaborated with five typical types of ecological landscape construction cited as model.

The use of allelopathy and allelochemicals of pla nts to agriculture production depends on the understanding of allelopathy of pla nts.The results of previous studies showed that,as a message molecule,allelochem ical acts on target sites of plant cells,and then the target sites in turn conve y the message to inner cells,thus influencing membrane permeability,cell differ entiation,phytohormone generation,ions uptake, protein synthesis and gene statem ent,and so on,and eventually inhibiting plant growth.But action modes and sites of allelochemicals need to be further studied.

Distributional characteristics of metal hyperac cumulators at time and space as well as in family and genus and two basic condi tions that trigger emergence of nickel hyperaccumulators out of normal plants ar e discussed.Meanwhile,two ways commonly used in other countries for searching of hyperaccumulators are also introduced. 

It is of tremendous significance to build up ec ological courtyards in the rural areas.Generally there are three modes,that is,i ntensive facility plantation mode,on-scale facility animal rearing mode and comprehensive mode.Fairly detailed information is provided for planning and designi ng ecological courtyards and solar-energy-powered family houses.Based on the o peration and progress of the construction of ecological courtyards in Zaozhuang region,Shandong Province,costs and benefits of the construction of ecological co urtyards are briefly described.