Background of the emergence of ecological residence and eco-residential area is elaborated,with its concept being defined as"Ecological residence and residential environment is designed and constructed in line with the principle of ecology with fairly sound ecological metabolism process,ecological service functions,harmony and reciprocity between nature and human beings,and sustainable development".Eco-residence and eco-residential environment is systemized in four views,that are,the systems view of harmony between nature and human beings;the nature view of obeying the nature law;the economic view of saving natural resources;the humane view of regarding human as the center.Five principal themes of ecological residence and eco-residential area are shown in a tree diagram.They are health(physical and mental health and environmental health),nature and environment protection,benign eco-circulation, Fengshui(the geographical and ecological relationship between location of a residential area and natural environment),and ecological civilization.So construction of eco-residence and eco-residential area is a kind of ecological engineering composed of many components and techniques that are inter-linked,interacted,interdependent,interpromoting,interrestricting,and interdetermined.

China has a total of33 nature reserves intended for the conservation of red-crowned cranes,covering a land area of 3.099 million hm².The habitats of red-crowned cranes are now faced with severe security problems due to economic development,human activities and lack of an overall design for nature reserves.According to the principle of maintaining regional ecological integrity of ecosystems,iterative methods and integer linear programming were employed to study designing of nature reserve network for red-crowned cranes with the target of conserving 70% and 60% of the highly suitable wetlands and moderately suitable wetlands in the country,respectively.A design scheme was worked out.

Lake restoration is an important step of rehabilitating ecological function of the Yangtze River.Whether the step as a program could be successful or not depends on how the farmers,who have lost their original benefits and contributed to the ecosystem recovery,are compensated.In the Dongting Lake area,an important commercial agriculture base of the country with a high population density,practical implementation of the program has come across a number of challenges.One of them is the tough task of population relocation.The Dongting Lake area is an ideal site for a case study to explore basic issues in eco-compensation,that are,who should pay,who should get paid,how much is the payment and how payment is done,etc.

Investigations were carried out of dynamic changes in soil moisture content under the farmland shelter belt system in different phenological phases of wheat.The results demonstrated that the law of the change in mean soil water content of farmland in different phenological phases of wheat is seedling stage>regreening phase>jointing stage>milking stage;Shelter belts have little influence on wheat during the seedling stage and regreening stage,but drastically competition for water occurs between the shelter belts and the wheat during the milking stage;Young forests can effectively increase soil water content in farmland,which is favorable to the growth of wheat.In terms of ability of competing for moisture with crops,mature forests are stronger than young forests.The competition is concentrated within the range of 0.2 times of the height of the tree.

Distributions of roots and rhizosphere nutrients were evaluated for wheat and maize intercropping system.The effects of intercropping on exudate of organic acid in the roots were discussed.Pot experiments and solution cultivation experiments were carried out.The results showed that intercropping increased growth of roots and their exudate of organic acid.It also made N content increase and P,K contents decrease in the rhizosphere soil of maize.On the contrary,the N content decreased and P,K contents increased in the rhizosphere soil of wheat.The effects of intercropping on the roots of wheat and maize were found quite distinct.

Integrated benefits of rice-duck complex ecosystem,including reduction of methane emission and other eco-economic benefits,were studied by adopting plot experiments.The results showed that compared with conventional paddy fields,the pattern of rice-duck ecological planting and breeding significantly reduced the total amount of methane emission from paddy fields,by 44.2% for early rice and 40.7% for late rice.Methane emission was higher from late rice fields than from early rice fields,in all treatments.At the same time,soil fertility and physical characteristics of the soil in the rice-duck complex ecosystem were both improved,and redox status of the soil was also markedly meliorated.What′s more,the direct economic benefit of the rice-duck complex ecosystem was higher than that of the conventional paddy fields. 

On the bases of the investigation and analyses on shoaly land resource and its exploitation,the strategic countermeasures on rational exploitation of shoaly land resource have been proposed.

Law of changes in nitrate under different soil moisture and supply of different forms and quantities of N fertilizer in Yinchuan alluvial plain were studied by means of field experiments and indoor cultivation.The results showed that nitrification process is directly related with soil moisture content and forms of N fertilizer.Nitrate obviously appeared 9 days after the application of N fertilizer.Nitrification process was restrained under dry or saturated soil water conditions.Granulation of urea can slow down nitrification process and form less nitrate than other forms of N fertilizer.Therefore,applying large-sized urea granules can reduce nitrate loss and increase N availability to plants.Nitrate increases in soil profile with the increasing of application rate of N fertilizer.Nitrate in the cultivated layer increases due to application of more N fertilizer,especially large-sized urea granules.However,granulated urea only provides the lowest amount of nitrate in the whole soil profile compared with the other forms of N fertilizer applied.The Nitrate content would not get up to a harmful level if N fertilizer is applied reasonably,but nitrate is accumulated in the 60 cm-deep soil profile under traditional N fertilizer application,easily causing nitrate leaching due to high aeration of Guanyu soil.

Maturity indices of vermicomposted cattle manure were studied in an optimal moisture condition at 20℃ and with inoculation of Eisenia foetida in laboratory.The variations of biological and chemical parameters of cattle manure during vermicomposting and their correlation coefficients indicated that GI,URE,NH₄⁺-N and NO₃^--N/NH₄⁺-N were the priority selected maturity indices for vermicomposted cattle manure,NO₃^--N and APH common ones,and INV,WSC,WSN and VS unsuitable maturity ones.

Rice paddy soil has oxic-anoxic interfaces where methane consumption and ammonia oxidation might happen simultaneously.Due to similarity of enzyme-catalyzing methane consumption to ammonia oxidation,methane produced within paddy soil could affect ammonia oxidation while methane oxidation will probably be significantly influenced by variation of ammonia concentration induced by the application of ammonia-based fertilizers.The relationship of methane consumption to ammonia oxidation in rice paddy soils is reviewed here.

A quantitative evaluation index system for agricultural eco-environment,which is composed of 17 indexes in three aspects,such as ecological resources,impact of human activities,and system response,is established.And the agricultural eco-environment in Liucheng,Guangxi was evaluated with the model of fuzzy comprehensive evaluation.The results show that the eco-environment of Liucheng is in a common level,the natural eco-environment is a good state,and the ecosystem operates normally though it has been significantly affected by human activities.The results are in agreement with the actual situation in Liucheng which shows that the index system is reliable and practical.Suggestions and countermeasures for improving the agricultural eco-environment quality of Liucheng are raised. 

Early patterns of community composition and structure under 10-year-old tree plantations on the wasteland of Geheyan hydroelectric project were evaluated.Undamaged natural secondary forests and unmanaged wasteland near the project were also investigated in order to provide contrasts for further analysis.There were 75 species invaded and established on the wasteland other than the two planted,including 26 species of shrubs and 50 species of herbs under 35 families and 68 genera.Different planted species brought about diverse preliminary forest community under the plantation.61 species appeared under the plantation of Sabina chinensis,a native species,including 30 herbaceous species and 16 woody species and 14 vine species,whereas only 42 species under the plantation of Pinus elliottii,an exotic species,by contrast,including 34 herbaceous species,3 vein species and 5 woody species.The species diversity under Sabina chinensis increased more quickly than that under Pinus elliottii,especially on the shrub layer.The difference in species composition resulted in different community structure.It is necessary for us to get more information on tree species to be planted,not only their biological features but also their ecological characteristics before making plantation scenarios.

A field survey and sampling for chemical analysis was carried out to investigate copper contents in Artemisia argyi and Artemisia scoparia.A.argyi grew dominantly on copper mining spoils at Jiguanshan,Yunnan Province and A.scoparia widely distributed at Tonglüshan,Hubei Province.Both species were found to grow vigorously on the copper mining spoils with comparatively large biomass.The rooting zone soils supporting both species containing high concentrations of copper.Study results showed that A.argyi accumulated a large amount of copper in roots and leaves,ranging from 41 to 156 mg·kg^-1 or averaging 83±29 mg·kg^-1,and from 58 to 464 mg·kg^-1 or 216±96 mg·kg^-1 in average,respectively.A.scoparia accumulated higher copper in roots than in shoots in most cases ranging from 58 to 513 mg·kg^-1 or averaging 183±101 mg·kg^-1 with the former and from 42 to 259 mg·kg^-1 or 97±52 mg·kg^-1 in average with the latter.It was also found that A.argyi had higher leaf/root ratios（leaf/root>1）than A.scoparia（shoot/root<1）in terms of copper concentration.These results may suggest that both species could survive on soils contaminated with copper by different mechanisms.It was suggested that A.argyi possessed potential for phytoextraction and A.scoparia for phytostabilization,and that both had the potential to serve as pioneer species for phytoremediation of copper-contaminated soils.

Emission of ammonia during composting of dairy cattle waste and effects of organic materials added to adjust moisture content of the compost on loss of ammonia were studied.Results indicated that the emission of ammonia concentrated mainly in the early stage of composting,especially in the first 2 weeks,and the total N loss during the composting period was about 17%～50% of the total N in the dairy cattle waste.Addition of moisture regulating materials could reduce the N loss in varying degrees during composting.Sawdust showed the best restraining effect on ammonia emission,followed by rice hull and rice straw.Therefore,some steps should be taken to prevent the N lose.

Conception of ecological province, targets of the construction of an ecological province, ecological principles related to the construction, relationship between mankind and nature, criteria for evaluation of ecological provinces, evaluation index systems and some other theoretic issues are discussed and explored.