Driven by intensive planting and economic benefits, continuous cropping, planting a single crop in the field year after year, has become a common planting mode in China. Long-term continuous cropping has caused many problems, including serious pests and diseases, low yields, and deteriorating soil health. Crop rotation is one of the effective solutions to continuous cropping obstacles and plays a crucial role in the implementation of national strategies such as food security, ecological environment development, and rural revitalization. The paper expounded on the economic and ecological benefits of crop rotation compared with continuous cropping through literature review, and provided suggestions for developing China’s crop rotation based on the comparison of domestic and foreign crop rotation systems. The results show that compared with continuous cropping, crop rotation has higher economic and ecological benefits. Also, it is found that China’s current crop rotation system differs from foreign countries in terms of guidance, promotion mechanisms, subsidy methods, and regulatory measures, and there are still many problems in the development process of crop rotation in China. Combining with the experiences of foreign crop rotation, this paper proposes that we should formulate scientific crop rotation plans, develop crop rotation techniques (conservation tillage, cover crops, water-saving irrigation, and etc.), strengthen the promotion of crop rotation, accurately implement the crop rotation policy, and timely carry out reasonable evaluation and policy adjustments, which have a guiding significance for the large-scale development of crop rotation in China.

The paper aims to analyze research progresses of soil enzymes in China and abroad, and summarize the role of soil enzymes in carbon and nitrogen cycle in agricultural ecosystem, in order to provide reference for agricultural production. Soil enzyme is a kind of protein that could catalyze biochemical reactions. It plays an active role in catalyzing non-exclusive organic substances, organic substances and certain mineral compounds into a variety of nutrient substances and some useful elements that could promote the growth of vegetation, and has an active effect on the development of agricultural ecosystem. At present, soil enzymes have been used as important indicators of soil carbon and nitrogen cycle, and the process of nutrient cycle in soil could be reflected by the change of enzyme activities.

Phragmites australis is a typical perennial gramineous plant with superior reproductive capacity, This study was based on the summary of the ecological habit characteristics of P. australis, the effects of water and salt on the physiological morphology of P. australis were analyzed, and the ecological function of reed in coastal wetlands was clarified from the aspects of anti-wind and wave elimination, purification of water quality and adsorption of heavy metals. And the research progress of reed breeding technology was summarized, the aim is to provide scientific basis for making full use of the application of reed community in coastal wetland vegetation restoration and ecological construction.

The degradation of lake ecosystem due to pollution is a long- term problem faced by China. Therefore, the ecological restoration technology of lakes is very important. To explore the main direction of lake ecological restoration technology in the future, the existing lake ecological restoration technologies at home and abroad were comprehensively analyzed. The three most common and most problematic forms of degradation, such as lake eutrophication, lakeside degradation and reduced biodiversity, were summarized and discussed by analyzing the mechanisms and forms of lake ecosystem degradation. Different ecological restoration techniques were discussed for these three types of degradation, the principles and guidelines of ecological restoration were summarized, and the advantages and disadvantages of different ecological restoration techniques were discussed. Finally, we put forward suggestions on the structure of the lake ecological restoration project and matters needing attention, which can provide a basis for the future ecological restoration of lakes.

In view of the shortage of water and heat resources in different ecological areas, and the frequent occurrence of wind disaster, lodging, low yield, poor quality and other problems in maize production, a new maize variety ‘MC278’ was bred by taking ‘Jing X005’ as female parent and ‘Jing 27’ as male parent. The inoculation tests of the variety in Jilin, Hebei and other places showed that it had strong resistance to small spot disease, Curvularia, dwarf mosaic, silk smut and stem rot, and was easy to infect large leaf spot, and it was moderately resistant to corn borer in Jilin. In the regional trials in Beijing, Inner Mongolia and other regions in different years, the kernel yield of ‘MC278’ was significantly higher than that of ‘Zhengdan 958’ (CK), the highest yield was 16166 kg/hm², and the average yield was increased by 8.3%. The content of crude protein, crude starch and lysine of ‘MC278’ were significantly higher than those of ‘Zhengdan 958’. In 2019, the production in Hebei, Shanxi, Inner Mongolia and other regions showed that the yield of ‘MC278’ was all more than 12804 kg/hm², and the maximum yield was 14283 kg/hm². ‘MC278’ was equipped with field management measures and harvest techniques, such as suitable sowing date, density and water and fertilizer management, and prevention and control measures of diseases and insect pests. The variety passed the national examination and approval in 2019 (National Approved Maize Variety No.20190030), and its planting area now includes 15 provincial regions, such as Anhui, Shanxi, Shandong and etc.

To sort out the application research of ecological value assessment by using the choice experiment method in China, 59 related documents are analyzed. The results show that the domestic research on ecological value assessment can be roughly divided into the research on the ecological value of scenic spots and the study of regional value. The tourism cost in the study of ecological value of scenic spots is 265.51-1381.38 per visit, and the estimated value by ticket is 7.78-127.12 yuan per visit; the regional ecological value is mainly paid by personal willingness and family willingness, among which, the environmental value of individual willingness payment is 23.77-1066.99 yuan per year, while the household willingness payment is 21.77-769.42 yuan per year. The results show that the ecological value calculated by travel cost is higher in scenic spots valuation study, and the value measured by individual willingness payment is more different in the estimation of regional ecological value. Therefore, attention should be paid to the difference between different accounting methods.

The grain aphid Sitobion miscanthi (Takahashi), considered as S. avenae (Fab.) in China, is one of the most widely distributed aphid species which needs chemical control annually in northern China at wheat grain filling stage. The spatial-temporal population dynamics of the grain aphid is affected by geographical area, meteorological factors, natural enemies, agricultural practices, biodiversity, and resistance characteristics of wheat varieties to aphid at different growth stages in field. In general years, the dynamics of aphid population develop with the wheat growing and temperature rise in field. The aphid number has sporadic occurrence at the jointing stage of wheat seedling and cluster occurrence at booting stage, increases rapidly after head sprouting, and reaches the peak at mid-late stage of grain filling, and decreases sharply at milking stage. The aphid spatial distribution pattern follows random distribution - contagious distribution - aggregated distribution (mosaic distribution) - uniform distribution - aggregated distribution (mosaic distribution)- disappearance. The wheat grain number is affected weakly by aphids before wheat head sprouting because the population of aphids is very small in field. But the 1000-grain weight is significantly affected by the aphid as its population increases rapidly during grain filling stage in field. In this paper, an ecological control strategy is proposed for grain aphid. We suggest that the dynamic control index of this pest should be established according to the resistance/tolerance characteristics of wheat varieties to aphid during different growth stages. The priority should be given to the biological control before wheat head sprouting, and the dynamic control index should be strict; the chemical control should be carried out after head sprouting, and the dynamic control index could be loosened. The utilization of plant protection UAV combined with artificial intelligence is also suggested to automatically discover the occurrence center of aphid and other pests/diseases, and to spray pesticides precisely on the occurrence center in wheat field simultaneously.

The purposes are to enrich the variety of comprehensive rice-fishery cultivation, make full use of paddy resources, expand market supply and provide an important basis for the steady development of rice fishery comprehensive farming industry in mountainous areas. The comparative analysis on ecological comprehensive rice-fishery cultivation of Allogynogenetic gibel carp ‘CAS Ⅲ’ and Cipangopaludina cahayensis was conducted in Wuyishan City. The results showed that after 139 days of cultivation, the total yield of ‘rice+crucian carp+snail’ model reached 9937.5 kg/hm², 7.72% higher than ‘rice+crucian carp’ model, but 7.67% lower than ‘rice+snail’ model. The total profit of ‘rice+crucian carp+snail’ was higher than that of ‘rice+crucian carp’ and ‘rice+snail’ model by 25.83% and 77.91% respectively; the comparative benefits of output-input ratio, cost profit and sales profit rate were significantly higher than those of the ‘rice+snail’ model. The ecological farming model of ‘rice+crucian carp+snail’ could effectively improve the comprehensive farming effect of paddy field, but it is also necessary to optimize the key technologies and the mixed proportion of aquatic animal stocking in order to further improve the comparative benefits of rice-fishery cultivation in paddy field.

Spermophilus dauricus is a common species of wild rodents in China, which mainly inhabits prairie, forest, meadow and farmland habitats with the characteristics of mall size, big population, strong adaptability and wide distributions. S. dauricus is the most important vector of plague bacillus and harmful for crops, forests and pasture. This paper made a general review on taxonomic status, morphological features, all ecological aspects, experimental animal development and its pest control. Possible research directions and research gaps were proposed to provide reference for the effective monitoring, control and management in future.

The traditional aquaculture pattern can easily cause water pollution and waste of water resources. In order to reach the goal of healthy aquaculture, pond recirculating aquaculture system (PRAS) takes measures to purify water by using power flow purification and bioremediation techniques under the guidance of circular economy, such as establishing artificial wetland to form a sustainable development model. In this study, we summarized the construction of the three main models of PRAS and their effects on water purification, and analyzed the main problems in the operation of the system. The existing studies showed that the average removal rates of TN, TP, NH4+-N, CODMn, and NO2--N were basically maintained at 60%. Besides, we analyzed the factors such as the ratio of purification area to pond area as well as the effects of the substrate, plant, pH and temperature in the purification unit. This study can provide a reference for further in-depth research on PRAS.

Production of plant secondary metabolite is the result of long-term interaction between plants and environment, and the alkaloid plays an important role in the process of growth and development of plants as one of the secondary metabolites with higher medicinal value. This paper summarizes the eco-physiological function of alkaloid in terms of regulating of plant growth, responding to environmental stress and defending plant diseases and insect pests, as well as the ecological factors and genetic factors that affecting the formation of alkaloids in plants, and further discusses the interaction between plants and environment. It may provide new approaches for completely and deeply comprehending correlations between plants and environment, and producing high quality traditional Chinese medicine.

Yuanjiang dry-hot valley is a poorly vegetated and fragile arid ecosystem in low land. Although it was lushly forested before the middle of the 17^th century, it became a tropical montane savannah after the end of the 17^th century. This study focuses on the diversity and distribution patterns of plants in this representative xerophytic flora, aiming to explain the impact of main environmental factors such as temperature, precipitation and underground water supply on species and populations, so as to explore the adaptation of plants. Furthermore, dry-hot environment indications corresponding to species and species assemblage were considered. Therefore, alpha and beta indices were employed to cope with biodiversity differences in plant species and its environment, respectively. Selected indices were subscribed to the relationship among species, population size, and their living circumstances in terms of Species_estimated, Singletons, Uniques, ACE, ICE, and Chao2. The results show that: (1) alpha diversity is higher in the transects and plots closing to the river channel (< 25 m), and decreases away from the riverway; (2) beta diversity increases from upper to lower stream in L-transect (Bray-Curtis < 0.500), however, it is reversed in P-transect, the homoplasy is obvious (Bray-Curtis > 0.500); (3) in the lowland of dry-hot valley, indices of Species_estimated, Singletons, Uniques, ACE, ICE, and Chao2 are significantly high beside river especially in the tidal range, which indicates a strong reliance on water supply. Conclusively, species composition and distribution patterns in the lowland of Yuanjiang dry-hot valley are deeply affected by heterogenity of water and temperature allocation. Plant species and their diversity are closely correlated to the microhabitat along river channel, and this correlation could be an approach for environmental monitoring potentially.

Picking orchard is an important type of leisure agriculture. It has obvious advantages in reducing the circulation links of agricultural products, exploiting the marketing channels, building brands, integrating the primary, second and tertiary industry, and improving agricultural economic benefits. Taking Laoyou Ecological Farm in Yangzhong Town of Youxi County as an example, this paper analyzed the problems in the development of picking orchard, such as lack of overall planning, inadequate service concept, insufficient varieties for picking, fierce homogenization competition, high labor cost, as well as less fine management, brand building and marketing promotion. Based on the analysis, we put forward management suggestions, including accurate positioning of the picking orchard, adopting high standard green planting technology, improving service facilities, implementing functional zoning, using new media for marketing promotion, establishing brands and so on, in order to promote the transformation and upgrading of traditional orchard and realize rural industry revitalization.

To understand the development and application of meta-analysis in agroecology research and provide reference for relevant research, 718 valid literature was obtained with ‘meta’ as the keyword, and quantified by CiteSpace visualization software and Web of Science (WOS) literature analysis tool. The results show that the total number of international publications in agro-ecological meta-analysis has increased significantly. University of California, Davis (UC Davis), China Agricultural University, Chinese Academy of Sciences, Chinese Academy of Agricultural Sciences and Wageningen University have high international influence in the field of agro-ecological meta-analysis. The research topics of agroecology meta-analysis are diverse. The assessment of ecological and environmental effects of farmland management measures, land use change, climate change on biodiversity and greenhouse gases, the dynamics of carbon and nitrogen nutrient cycling, and the changes and interaction difference of different ecosystems are the main application fields at the present stage. As an important tool for agro-ecological research, meta-analysis provides a new way to verify hypotheses and develop new theories for large-scale comprehensive research, but it is still difficult to fully meet the needs of practical work by simple meta-analysis. A comprehensive meta-analysis based on big data fusion, machine learning model algorithms and expert knowledge assessment will be the focus of future research.

The problem of land resource ecology security has become one of the hot topics in the field of sustainable utilization of land resource now. Based on the summary of concept and features of ecological security, the authors expounded the connotation, driven factors, framework and methods of land resource ecological security. The land resource ecological security mainly included two aspects, which were (1) land ecological system structure and function in healthy and balanced status; (2) providing stable, balanced and adequate supply for human society sustainable development. The achievement of land resource ecological security required the coordinated promotion and development of nature, economy and society, the impact of economy and society factors on land resource is far more than that of nature. On the assessment framework, the authors summarized the source and application of four kinds of assessment frameworks, which were the PSR framework system, the DPSIR framework system, the DPSER framework system and the framework system of “nature-economy-society”. About the evaluation method, the authors compared the advantages and disadvantages of four kinds of methods respectively. They were the method of mathematical model, ecological model, landscape ecological model and digital terrain model. At the same time, some new evaluation methods about the ecological security of land resource in recent years were put forward. At last, a prospect for the developing trend of ecological security of land resource was proposed: (1) based on ecological function zoning, the assessment indicator system of land resource ecological security which reflected pertinence and otherness should be established, the best threshold value of ecological security should be confirmed; (2) more researches on land resource ecology security and dynamic early warning of the typical areas, such as arid area, sand area, karst region, water and soil loss region, alpine plateau area and so on should be developed; (3) the evaluation method should be better combined with geographic information technology; (4) in order to control the ecological security of land resource better and realize the sustainable use of land resource, new evaluation method should be explored. Only in this way, it can ensure sustainable utilization of land resource.

To systematically understand the carbon dynamics of farmland ecosystem in arid area and its response to climate change, the authors simulated the spatio-temporal changes of net primary productivity (NPP) of farmland ecosystem in Xinjiang during 1979-2009 by using a new process-based dynamic global vegetation model (Agro-IBIS), and revealed the response of farmland NPP to the changes of different climatic factors and CO2 concentration through the correlation analysis. The results showed that: the average NPP of farmland in Xinjiang was 723.78 g C/(m2·a), while the average total carbon storage was 237.15 Tg C, the average annual net exchange of carbon in agroecosystem (NEE) was -63.36 g C/(m2·a), overall playing as carbon sink during 1979-2009. In terms of the spatial variation of farmland NPP in Xinjiang, the overall change showed a gradual increasing trend except for a slight decrease of NPP in oasis farmland of the Tianshan Mountains. In past 31 years, the correlation between total annual NPP and the average annual temperature was higher than that between it and the average annual precipitation in Xinjiang farmland, indicating that irrigation had much more effects than natural precipitation on oasis agricultural productivity in arid areas of Xinjiang. It was verified that the results of Agro-IBIS model were reasonable in simulation of the carbon budget of farmland ecosystem in Xinjiang, which could provide scientific basis for the simulation and prediction of potential carbon sequestration of farmland ecosystem in the arid area of northwestern China and the scientific formulation of regional carbon management policies.

The author reviewed recent progress to understand the impacts of drought on agricultural ecosystems. The impacts of drought on accumulation and distribution of dry matter could be mainly well analyzed from cell to individual crop based on field experiments. Drought could significantly reduce the efficiency of photosynthesis through decreasing the stomatal conductance and the activity of enzyme. In the early stages of crop growing season, drought could properly increase the dry matter that transferred to root and improve water use efficiency, while in the middle and late stages, drought could directly affect above-ground biomass synthesis and reduce the crop yield. However, drought was a regional disaster which could last for a long time and affect various types of crop. The field observation was costly in time and resource, and the remote sensing could not reflect the impacts of drought on different types of crop. Along with the development of simulation technology, crop growth model based on the field observation could be effectively used for regional analysis. It could also accurately reflect the impacts of drought on different crops through different crop parameters. Crop growth model has become an important tool to carry out the impacts of drought on agricultural ecosystems.

Agro-ecosystem service value is related to people’s welfare and lays a solid foundation for the rural ecological revitalization. The research on the agro-ecosystem service value assessment is to provide a basis for strengthening the protection of agro-ecological environment. Taking agro-ecosystem service value of Sichuan Province as a research object, this paper calculated the coefficient of social development stage by combining Peal growth curve model and Engel coefficient based on the equivalent factor method of unit area value, and calculated the value of agro-ecosystem service of Sichuan from 2000 to 2017. The results showed: (1) the agricultural land in Sichuan was dominated by forest land and grass land from 2000 to 2017, the change of agricultural land showed that the area of cultivated land, grass land and water decreased, while the area of garden land and forest land increased; (2) the value of agro-ecosystem service changed significantly from 2000 to 2017 in Sichuan with an increase of 2.79 times, of which the increment of ecological service value of forest land accounted for 73.64% of the total increment; (3) each agro-ecosystem service value sorting remained unchanged from 2000 to 2017 in Sichuan, the values of soil conservation, hydrological regulation and biodiversity maintenance were obviously higher than other functions, accounting for nearly 50% of the total value. By calculating the coefficient of social development stage, the theoretical evaluation value of agro-ecosystem service value was modified, so that the evaluation result can better reflect agro-ecosystem service value in different social development stages.

Cadmium is one of the most important toxicity elements and it can transfer easily in soil and from soil to plant. Calcium is one of the essential elements for plant growth and it plays an important role in plant growth and signal transduction.[Objective][Method] In order to understand more clearly the ecological effects of cadmium-calcium interactions on plants, explore the interaction mechanism of Cd and Ca coexistence and make the best of the relationship between the Cd and Ca, it is possible to provide scientific foundation for preventing and controlling heavy metals contamination.[Result]This paper reviewed the ecological effects of cadmium-calcium interactions on plants, including: (1) In the process of plant uptake, cadmium and calcium were antagonistic relationship. On the one hand, Cd could inhibit the absorption of Ca by plants to limit the growth of plants; On the other hand, Ca could inhibit the absorption of Cd by plants to relieve cadmium toxicity. (2)The application of exogenous Ca could promote the growth of photosynthetic pigments and the synthesis of photosynthetic pigments under Cd toxicity. (3) In the process of regulating the activities of antioxidant enzymes, the application of exogenous Ca could enhance antioxidant enzyme activities to reduce oxidative damage.[Conclusion]Thus, the effects of cadmium and calcium on plant growth, photosynthetic pigments and antioxidant enzyme activities were antagonistic.

Pig breeding wastewater has the characteristics of complex components and limited treatment capacity. Therefore, bio-ecological technology becomes the key and basic technology for treatment of breeding wastewater from small pig farms. In this study, based on the dry feces process popularized at present, a bio-ecological technology-based combined system with source separation, oxidation pond, three-dimensional bio-filter and constructed wetlands was designed for a small pig farm in Jiangxi Province, and the effect of the system was evaluated. Our results indicated that this system had a high rate of contaminant removal efficiency, and could meet the Discharge Standard of Pollutants for Livestock and Poultry Breeding (GB 18596-2001).

Ecosystem services is the resource and environment foundation of human survival and development, of which related researches have become hot-spots in geography, ecology, environmental science and economics and other disciplines. Meanwhile, a great research achievements have made at domestic and abroad. This paper used the citation analysis as an argument to support and comment on the research progress of the core issues of Ecosystem services during the past 20 years. It suggested that the hot-spots and frontiers of ecosystem services focus on society and culture, trade-offs and management, evaluation and modeling, payment for ecosystem services (PES), landscape pattern, and sustainable development. Analysis of the key issues in the study of ecosystem services, from the basic problems of ecosystem services, formation mechanisms, the diversity of ecosystem services, the temporal heterogeneity and scale characteristics of ecosystem services, the coupling between ecosystem services and human welfare Relationship between the five aspects described separately. It also summarized the development trend of ecosystem services and analyzes the key areas for future development, and pointed out the reasons why Ecosystem services needs multidisciplinary and interdisciplinary research paradigm. Finally, it evaluated the problems existing in research of Ecosystem services in China.

This study focuses on the ecological habits of four species of owls in Wucheng of Shanxi in order to accumulate the ecological base material of owls in this area. The study used the line transect method to record the migration time, collect data about the characteristics of habitat, nests and eggs. The study also analyzed thediets with food content analysis method. The results showed that the migration characteristics among Otusscops, Asio otus and Asio flammeus were similar in different years, the duration of northward migration was short but the interval was long and the duration of southward migration was long but the interval was short. There were differences between Otus scops and Athene noctua in the nest-site selection and breeding behavior. The propagating success rate of Athene noctua, whose nest-site was near the residential area, was higher. The main diets of four species of owls were small mammals and birds; meanwhile, they also fed on a few insects, somelivestock and fowls. The overlap of needs between different species may increase the competition. Owls are worth the attention and need to be protected because of their important role in the ecosystem and their low population quantity.

It is an important way to realize green development of agriculture in Sichuan hilly areas by selecting a reasonable ecological circular agriculture model according to local climate resources and agricultural types and carrying out nutrient balance management. This paper took Pengxi County of Sichuan as an example to conduct the empirical analysis, aiming to provide a scientific basis for the development of ecological circular agriculture in the hilly areas of eastern Sichuan. The results show that, based on the target yields and target nitrogen (N) application rates of crops and orchards, the application amount of organic fertilizer (biogas slurry) is calculated. The livestock and poultry manure and biogas slurry, which are produced in the project area, could be recycled within the crop fields and orchards, and the replacement rate of chemical fertilizer N could reach 31%-62%. Based on the calculation of the manure and organic fertilizer replacement in crop fields and orchards, the carrying capacity of livestock in the project area still has a certain potential. The model combines the local leading and advantageous agricultural industries, uses local planting and breeding wastes scientifically and rationally, and reduces the risk of agricultural non-point source pollution. Finally, the analysis of the management mechanism and development path of ecological circular agriculture in this study could provide an example for the development of circular agriculture in the hilly areas of eastern Sichuan.

Rice-duck farming ecological technology is to leave the ducklings in the paddies all day long, to stimulate the growth of rice, promote the material circulation and improve paddy environment by using ducks’ continuous activities. As a result, a new farming mode was built, which combined planting and feeding together, reduced cost and increased efficiency and promoted the matter cycle. The authors reviewed the impacts of integrated rice-duck farming technology on matter accumulation of rice, strong stem effect, root activity, injurious insects and weeds controlling, biological diversity, soil physical-chemical properties, methane emission and controlling nitrogen loss, and elaborated the successful planting and feeding mode practices of the integrated rice-duck farming ecological implementation such as the release of duckweed, rice-duck farming system with two-batch-duck raising, the release of ducks aged zero day, methane-rice-duck cycling, insect-proof screen mulching and so on. The authors also pointed out the problems that to be solved in integrated rice-duck farming ecological agricultural development, and the study could provide references for the technological theories and practice development of integrated duck-rice farming system.

Oil tree peony, which has greatness of fruiting quantity,is used as peony groups that produce seeds and process edible oil or peony plants in the oil yield of more than or equal to 22% of species collectively. Oil tree peony, as the development of woody oil crops in China, has high economic value, ecological value and social benefits. In addition, Peony seed oil,with remarkable economic value,is rich in unsaturated fatty acids and α-linolenic acid.The peony flower is large in size, the single flower is large, which has high ornamental value; Oil tree peony has the features such as cold, drought and barren resistance,and is the economic tree of greening.This paper mainly introduces the research and utilization of oil tree peony,economic value, landscape ecological value and development prospects, and provides reference for our country to promote the scale of oil tree peony and build an industrial system.

Based on the review of the country’s support for rural revitalization and the construction of beautiful countryside in recent years, the authors emphatically analyzed the problems and difficulties faced by the construction of beautiful countryside, and pointed out that the main problems are serious pollution of rural garbage and sewage, excessive use of pesticides and fertilizers, and the lack of rural civilization. By summarizing the typical cases of the construction of beautiful countryside in Huzhou, Zhejiang, the authors believe that the construction of beautiful countryside needs to pay attention to several key issues, such as combining the reality of the countryside, adhering to the market orientation and giving full play to the advantages of rural talents, so as to provide reference for the construction of beautiful countryside in various places.

In order to better evaluate the health of the wetland ecosystem in the Yellow River Delta Nature Reserve, according to its characteristics and the connotation of wetland ecosystem health, we used the Euclidean distance theory and selected 13 indicators from four aspects of water, soil, biology and society, to construct the assessment system of the wetland ecosystem and evaluate the ecosystem health. Then, we analyzed the existing problems of the reserve based on the index diagnosis method. The results showed that the ecosystem health index (A value) was 0.656. The water guarantee rate, soil pH, dynamic balance of plant community, dynamic balance of animal community, population density, ratio of water extraction to water storage, ratio of wetland output value to input capital contributed positively to A value. The contribution of soil available phosphorus, wetland capital input capacity and supply function type to A value was negative. The evaluation method adopted by this study on wetland ecosystem health based on Euclidean distance could accurately reflect the ecosystem health, the existing problems were analyzed, and some suggestions on further improvement of the natural reserve were put forward.

The study of land use change and ecosystem service value (ESV) is of great significance to the sustainable development and utilization of land resources. Taking Harbin as the study area, the characteristics of land use changes were analyzed by using the comprehensive evaluation and sensitivity analysis method of ecosystem service value based on equivalent factor. By improving and adjusting the unit area corresponding to different land use types and the service value and coefficient table of ecosystem in Harbin, this paper made a comprehensive, systematic and in-depth analysis on the temporal and spatial distribution pattern of ecosystem service value in Harbin from 2005 to 2020. The results showed that (1) from 2005 to 2020, the area of cropland and construction land increased slightly, while the area of forest land decreased gradually; the changes of the other three land use types were relatively small; (2) the overall ESV of Harbin showed a downward trend, forest, cropland and water area were the main contributors to the value of ecosystem services in Harbin, and the ecological service value of Harbin was mainly reflected in water conservation, soil protection and waste treatment. Therefore, when formulating the land use plan for the study area, it is necessary to focus on protecting the land use types with higher ecosystem service value coefficient, such as forest, cropland and water area, and carry out more scientific and rational planning, so as to realize the sustainable development of the land use types in each region in Harbin.

Ecological stoichiometry has become the hotspot research of ecology, which can be used to unify all ecological processes based on multiple chemical elements. To better understand the ecological stoichiometry characteristics respond to terrestrial and aquatic ecosystem, this study first focused on these ratios in different environment at large scale. Second, using ecological stoichiometric to clarify the effect of growing environment change on ecosystem structure, function and stability, which varied with the change of nutrient availability, fertilization, species and growth rate.

The intensive agriculture and urbanizion have caused important habitat alterations in agricultural landscapes and the decline of farmland wildlife. Field margin, one of the most important parts in rural landscape, is characterized by high biodiversity which fulfils not only important ecological but also landscape functions. In this research, plant diversity of field margins was explained with species diversity, ecosystem diversity, time sequence/spatial layout diversity, original and functional diversity. Then, the relationship between plant diversity and field margin structure, factors related to adjacent land use and landscape structure was summarized and discussed. Furthermore, the ecosystem functions and services of field margins were summarized, including agronomic, environmental, wildlife and recreational functions. And the methods employed for biodiversity conservation of field margins were reviewed. At last, future constraints and opportunities in field margin research were discussed for promoting their role in conservation of biodiversity and cultural landscape heritage.

The eco-enviromental carrying capacity is a critical part of regional sustainable development.In consideration of the social, economic and environmental status of Hainan Province, this paper selects 27 indexes to construct a pressure-state-response (P-S-R) model and mainly uses GIS spatial analysis and fuzzy comprehensive evaluation to study the spatial and temporal difference of eco-enviromental carrying capacity in 18 cities and counties of Hainan Province.The research mainly indicates in three points.First,the eco-enviromental carrying capacity in Hainan Province is better than other provinces and the overall level of which is high.Second,with the development of social and economic, the membership value of the vast majority of cities and counties is increasing, and the carrying capacity of eco- environmental is increasing continuously.Third,The eco-enviromental carrying capacity of cities and counties in Hainan Province shows an decreasing trend in the eastern-midwest-northern regions.

Ecological livability is a key link in the implementation of the rural revitalization strategy, and an important foundation and guarantee for improving the ecological well-being of farmers. It requires continuous enrichment and development on the basis of past practices. This article summarizes the practices and innovations achieved in the implementation of the Global Environment Facility project-"Market Transformation of Energy Efficient Bricks and Rural Buildings", and combined with the vision and expected results of the "China Zero Carbon Village and Town Construction Promotion" project, puts forward suggestions on the construction of zero-carbon villages and distributed energy system in rural areas under the rural ecological livable construction, including strengthening policy planning and guidance to improve the design of rural clean energy development system; strengthening infrastructure construction to build a rural distributed renewable energy system; strengthening urban and rural coordination to enhance the interconnection of urban and rural energy; strengthening the development of industrial integration to coordinately solve environmental problems in the rural ecologically livable construction; strengthening innovation support to promote the high-quality development of rural energy. These measures will accelerate the sustainable development of rural ecological livability and build a beautiful new countryside.

The purpose is to provide theoretical reference and data support for optimizing the allocation of land resources and promoting the sustainable development of regional ecology, society and economy. Based on the construction of the evaluation index system of land use benefit, using the models of coupling coordination degree, relative development degree and obstacle degree, the spatial-temporal evolution characteristics and major influencing factors of the coupling coordination degree of land use ecology-society-economy system in 17 cities of the Shandong Province were explored. The results are as follows. Land use ecology-society-economy system of Shandong was in the primary coordination state of running-in stage and showed a continuous rising trend in 2008-2017. The coupling coordination degree increased steadily from 0.54 to 0.70, and its annual average was 0.63. The equilibrium level of coupling coordination degree among cities was gradually improved in 2008-2017. Its variation coefficient of coupling coordination degree decreased from 0.126 to 0.072, but the coupling coordination degree of land use ecology-society-economy system in different cities still showed an obvious gradient distribution difference from the east to the west of the province. There was a significant difference in the relative development degree among the ecological, social and economic subsystems of land use in different cities. The southern sides of central Shandong and its northern area, together with Weihai City, had constituted an obvious half-circle ecological lag region by 2017. Social and economic barriers affecting the coupling coordinated development of land use ecology, society and economy were dominant throughout, but the ecological impact increased since 2013. During the study period, the coupling coordination level of land use ecology-society-economy system in different cities in Shandong was continuously improved, but the differences among different regions were still obvious, and there was still more space for improvement. Therefore, it is suggested that different cities should consider the main obstacle factors of their own and implement differentiated development strategies according to local conditions.

Lianping is a county located in the nine mountain area, northeast of Guangdong province. It is an upstream county of Xinfeng River and water supply resources of Dongjiang River, as well as an important ecological barrier of northern Guangdong province. Because of its mountain area location and backward economic development, Lianping was on the list of key counties for poverty alleviation and development of Guangdong province in 2015. In order to develop local agricultural economy on the basis of environment and water resources protection, the best and only way for them to choose is sustainable development. Ecological agriculture is an important part of sustainable development, and Lianping has significant advantages and unique conditions in ecological resources. In this study, the natural resources, social resources and agricultural production in recent years of Lianping county were analyzed in depth. The advantages vs disadvantages, opportunities vs challenges of the development of ecological agriculture in the county were clarified. In refer to some successful cases of ecological agricultural development at home and abroad, we have made an overall planning of ecological agricultural development for Lianping county and put forward some related policy recommendations. Our planning may provide some decision-making advices and strategic guidance for the ecological agricultural development of this county.

This study mainly summarizes the characters of biochar and its functions in improvement different soil property, crop growth and development, restoration of ecological environment, greenhouse gas emission reduction, etc, to provide new information for biochar in agricultural production and ecological environment protection. So, in order to indicate the impact of biochar on improve different soil and ecological environment, we analyze domestic and foreign research documents before 2017. Biochar, as a soil amendment, slow-release fertilizer carrier, and new environment functional material, has increasingly become a research focus point in agricultural and environmental sciences and other fields. However, the research on biochar is basically still in the stage of academic mechanisms exploration, and just infancy in application and promotion. Further exploration should be needed by scientific researchers in the future, and we elaborated some of the viewpoints in this field at the end.

In order to explore the way of water spinach planting in floating bed affecting the water micro-ecological environment of tilapia aquaculture ponds, water spinach floating beds were set up in the ponds under the 10% coverage. These ponds served as the treatment group, while the other ponds without floating beds served as the control group. After the vigorous growth of water spinach, the samples of water from treatment ponds, control ponds, and the samples of water spinach roots were collected respectively. The DNA of the samples was extracted, part of them was used to amplify the 16S rRNA genes and carry out the high-throughput sequencing, to investigate the effect of water spinach planting on the bacterial community structure in water, and analyze the relationship between the root system of water spinach and the bacterial community structure of surrounding water. Another part of DNA was used to conduct the fluorescent quantitative PCR to determine the copy number of nitrogenase gene, and analyze the effect of water spinach planting on the nitrogenase genes in tilapia aquaculture pond ecosystems. The results showed that the direct effect of water spinach planting on the community structure of planktonic bacteria in the water was not significant; however, the root biofilm of water spinach played an important role as a key part of the pond micro-environment. At the same time, water spinach root biofilm also increased the number of nitrogen-fixing microorganisms per unit volume in pond water.

The problem of coordinated development of urbanization and ecological environment is becoming more and more important. On the basis of reviewing the domestic and foreign literature on the coordinated development of urbanization and ecological environment, the connotation of urbanization and ecological environment was sorted out. The economic theory and the interaction mechanism of its development was explored. From the empirical study to understand the current domestic and international urbanization and ecological environment coordinated development of the status quo and the difference between time and space, the new urbanization and ecological environment coordinated development of the future direction and implementation of the summary. It was found that the current research on urbanization and ecological environment had focused on the application of environmental Kuznets curve and coupled coordination model. Due to the different angles and emphases of the analysis, there were some differences in domestic and foreign research. There were some shortcomings in the current domestic research. For example, breaking the data constraints, ignoring the ecological environment on the role of urbanization feedback, being difficult to in-depth problem root.

Combined with the soil animal research at home and abroad in recent years, and based on the predecessors’ research results, this paper introduces in detail the ecological functions of different kinds and representative soil animals, such as earthworms, ants, soil nematode and collembolan and so on, according to soil animal diversity, as well as how the soil animals generate interaction relationship with various environmental factors. Although many scholars at home and abroad have had a lot of research on soil animal diversity, there are rarely report on soil animals’ ecological function and their interaction with different environmental factors, and how to function. Therefore, we summarize the interaction mechanism between soil animal diversity, ecological function and natural environmental factors (such as atmospheric N deposition, vegetation type, soil environment, etc.) and human disturbance (such as reclamation, fire, etc.), and discuss the ecological function of soil animals and future research hotspots, so as to provide the basis for better understanding the role of soil animals in underground in terrestrial ecosystem.

The Ecological Conservation Area (ECA) of Beijing is not only an important protective screen for the ecological safety of Beijing, but a significant foundation for local social-economic development. Its development requires balancing the relationship of ecological protection and economic development. Miyun District, located in the northeast of Beijing as an ECA, was taken for case study. In this study, farmers’ income data change from 2006 to 2018 was analyzed, and indicators of agroforestry water expenditure, the regional GDP, cultivated land area, etc., were selected to construct the evaluating system for correlation analysis and multiple linear regression analysis, aiming to explore the indicators’ impacts on farmers’ income. The results showed that the per capita income of farmers had an upward trend and was positively correlated with five indicators such as agroforestry water expenditure and regional GDP, and was negatively correlated with total agricultural machinery power consumption and other indicators. To promote the coordinated development of ecological economy in ecological conservation areas, the study puts forward some adaptive income increasing strategies, such as strengthening the infrastructure construction, increasing the investment in human capital, promoting industrial transformation and upgrading and improving the ecological compensation mechanism.

In order to evaluate the suitability of the eco-climate resources for the growth and development of blueberry, the evaluation index system of eco-climate suitability of blueberry was established based on the scientific, systematic, practical and dynamic principles, 12 indexes from 3 aspects (the ecological environment, the climate condition in growth period and field management level) were selected. The membership functions of the soil, temperature and other factors on the eco-climate suitability of blueberry were established by the fuzzy mathematics theory, meanwhile, a two-level hierarchy evaluation model was constructed combined with the expert scoring method of the weight of each factor. The eco-climate suitability degree of blueberry in the specific cultivation land and time period could be determined by the evaluation model. This study filled up the blank of the fuzzy evaluation of the eco-climate suitability of blueberry in China, provided a scientific basis forintroduction, garden establishment, yield and quality prediction, and meteorological disaster assessment.