Taking the Yangtze River Economic Belt as the research object, this paper comprehensively valuated the carbon dioxide emissions efficiency of tourism in the Yangtze River Economic Belt from 2001 to 2016 based on DEA-SBM and Malmquist-Luenberger index, and explored its spatial and temporal differentiation characteristics from a static and dynamic perspective. On this basis, the influencing factors of its carbon dioxide emissions efficiency of tourism were discussed. Research showed that: (1) The average value of static carbon emissions efficiency of tourism in the Yangtze River Economic Belt from 2001 to 2016 was 0.672, and there was 32.8% improvement space from the production frontier. The average ML index of tourism carbon emissions efficiency during the study period was 1.092, indicating that the average annual growth rate of the carbon dioxide emissions efficiency of tourism in the Yangtze River Economic Belt was 9.2%. The change value of carbon dioxide emissions efficiency of tourism in different periods showed great volatility; (2) The spatial and temporal differentiation characteristics of tourism carbon emission efficiency in the Yangtze River Economic Belt are obvious. Specifically, the upstream basin showed the characteristics of low efficiency and low growth, the middle reaches of the river basin presented the characteristics of medium efficiency and high growth, while the downstream basin showed the characteristics of high efficiency and medium growth; (3) The growth of the carbon dioxide emissions efficiency of tourism in the Yangtze River Economic Belt was mainly due to the progress of technology, while the contribution of improvements in technical efficiency was relatively small. The impacts of these factors affecting the carbon dioxide emissions efficiency of tourism were quite different in different regions.

Based on the method of ecological footprint model, this paper makes a comparative study on the difference of ecological carrying capacity of urban agglomerations in the middle reaches of the Yangtze River from 2008 to 2017,it is found that:(1) the overall ecological footprint of urban agglomerations in the middle reaches of the Yangtze River, and Hubei, Hunan and Jiangxi provinces shows an inverted U-shaped feature. Among the three provinces, Hubei Province has the highest ecological footprint, while Hunan and Jiangxi are relatively close .(2) the overall per capita ecological carrying capacity of the urban agglomeration in the middle reaches of the Yangtze River and Hubei Province is increasing year by year, while the overall per capita ecological carrying capacity of Hunan Province and Jiangxi Province is decreasing slightly, the cities with the highest per capita ecological carrying capacity, the second highest in Hubei Province and the lowest in Hunan Province, the higher the level of social and economic development, the higher the proportion of biological resources projects;(3) the average ecological deficit level of each province is gradually expanding, with the highest in Hubei Province, the second in Hunan Province and the lowest in Jiangxi Province, and the cities in the first echelon are mainly distributed in Hubei Province, the cities of the fourth echelon are mainly distributed in Hunan Province and Jiangxi Province;(4) the developing trend of ecological pressure index of each province presents obvious “inverted u” type, Hubei Province is the largest, Hunan Province is the second, Jiangxi Province is the smallest;(5) the development trend of ecological pressure index of each province presents obvious “U” type characteristic, Jiangxi Province is the largest, Hunan Province is the second, Hubei Province is the smallest. In view of this, this paper from the optimization of energy consumption structure, intensive land use structure, differentiated use of land and other aspects of the relevant countermeasures and recommendations.

Urban land use is an important driving force of social and economic development as well as one of the important factors affecting carbon emission. Based on the analysis of 15 sub-provincial cities in China, the panel regression model was used to analyze the carbon emission efficiency of these cities from 2001 to 2017, the results indicate that:(1)From 2001 to 2017, the carbon emission efficiency of each sub-provincial city showed an overall upward trend, with an average growth rate of 6.823%. Chengdu had the most significant upward trend, whose average annual growth rate is 13.150%，Shenzhen had a slow average annual growth rate of only 5.232%.(2)The intensive use of industrial land (IILU) has a significant impact on the urban carbon emission efficiency. The per capita labor force, capital investment, science and education expenditure have a significant positive effect on carbon emission efficiency, while the per capita energy consumption has a negative effect. In the controlled variables, except that the influence of urbanization is insignificant, the proportion of industrial output value and per capita GDP have a significant promoting effect on carbon emission efficiency, while sulfur dioxide emission per unit of industrial output value has a significant inhibiting effect.(3) Different explanatory variables in the IILU index have different effects on the different areas with low, medium and high carbon emission efficiency. The regional differences are quite large. The factor of per capita labor force only has a positive effect on the area with high value, the factor of per capita energy consumption has a significant negative effect on the area with low, medium and high value, the factor of per capita capital has a significant promoting effect on the area with low, medium and high value, and the factor of per capita science and education has a significant promoting effect on the area with low, medium and high value. The research proposes countermeasures and suggestions from the aspects of improving land conversion rate, changing extensive economic development mode and advocating green development path of low-carbon civilization, so as to reduce urban carbon emission, environmental pollution and achieve the purpose of optimizing urban air quality.

Tourism attraction is the driving force for the development of tourism destinations. The evaluation of tourism attraction based on demand side has crucial guiding significance for the management and marketing of rural tourism. Taking Jiangxi Province as an example, this paper divides the rural tourism destination types, constructed the rural tourism attraction evaluation system based on network information. Meanwhile, it uses spatial autocorrelation and kernel density analysis to analyze the spatial distribution pattern of rural tourism destinations’ attraction. The finding shows that: (1) The rural tourism destinations in Jiangxi can be divided into six categories (ecological tourism, leisure and vacation, farming experience, agricultural science and technology, local culture and characteristic villages and towns) and 24 basic types. (2) The attractiveness index of single rural tourism destination in Jiangxi Province is quite different, and the attractiveness index of different types of rural tourism destinations also has significant difference. Specifically, the eco-tourism destinations’ attraction is the highest, while the categories of agricultural science and technology rural tourism destinations have the lowest attraction. (3) The rural tourism destinations have brought good leisure experience to tourists, and the overall satisfaction of tourists is relatively high, but the degrees of network attention and tourist sharing are quite low. (4) The attractiveness of rural tourism destinations is remarkably concentrated in the three major areas of “Nanchang-Jiujiang-Yichun”, “Pingxiang-Yichun” and “Shangrao-Jingdezhen”, and the spatial agglomeration pattern of various types of rural tourism destinations varies greatly. Based on the conclusions above, the study puts forward to four suggestions for improving the attractiveness of rural tourism in Jiangxi Province: (1) Excavate the characteristics of rural tourism resources and avoid the dilemma of homogenization and commercialization. (2) Enhance the development quality of less attractive rural tourism destinations based on resource advantages, and promote the coordinated development of different types of rural tourism destinations. (3) Strengthen the marketing and publicity of rural tourism sites, and enhance tourists’ network attention and sharing behavior. (4) Optimize the development pattern of rural tourism, and realize the balanced development of regional rural tourism in Jiangxi Province.

Based on mathematical statistics and barycenter model, we explored the spatial-temporal differentiation features of land consolidation at the county level of Hubei province from 1998 to 2017. By taking the core indicators of land consolidation implementation, such as consolidation intensity, consolidation potential and consolidation difficulty, we also evaluated the coordination of land consolidation implementation in Hubei province from 1998 to 2017 by using the coupling coordination degree model. The research results showed that:(1) From 1998 to 2017, the land consolidation in Hubei Province showed an overall upward trend. The scale of investment, the scale of construction, the scale of new cultivated land, and the number of projects all showed the characteristics of slowing down and stabilizing after rapid development. In the aspect of spatial distribution, it showed the characteristic of high distribution in central plain of Hubei Province, low in eastern and western Hubei Province.(2)The gravity centers of each implementation element for land consolidation projects were all located in the hinterland of Jianghan plain and present a fluctuating change in the area of Tianmen city-Zhongxiang city-Jingshan county.(3)The implementation coordination degree of land consolidation projects presented three states: low coupling coordination, moderate coupling coordination and high coupling coordination from 1998 to 2017 in Hubei province. The low coupling coordination state is mainly concentrated in the low hilly areas in the north and east of Hubei province, and the high coupling coordination state is mainly concentrated in the central plains of Hubei province. While the moderate coupling coordination state is widely distributed, covering the whole province. Finally, the analysis of spatial-temporal pattern characteristics and implementation coordination of regional land consolidation projects can provide decision-making basis to coordinate the development and implement differentiated control of regional land consolidation in the new era of China.

Understanding the changing laws of urban space production, life and ecological functions under the background of rapid urbanization is not only an important part of human-economic geography research, but also an intrinsic basis for urban land space development and its pattern optimization. This paper takes Changsha Metropolitan Area as the empirical area, takes remote sensing image and urban land use survey data as the main data sources, selects 2000, 2009 and 2016 as the research time nodes, and builds the “production-living-ecological” function evaluation system based on the differences of land main functions. Using spatial autocorrelation, cold hot spot analysis and sample band analysis, the characteristics of Changsha’s “production-living-ecological” function are explored and the regulatory path is proposed. The results show that: (1) The overall production and living functions of the Changsha metropolitan area continue to strengthen, but the ecological function has been weakened; (2) The strength of the “production-living-ecological” function within the Changsha metropolitan area has also changed, and the functional space has been reorganized. The balance of functions of students is improved; (3) The comprehensive function level of “production-living-ecological” in Changsha urban area continues to improve, and high-level areas gradually gather in urban centers, showing single-core agglomeration→single-core agglomeration-multi-core dispersion→network equalization Functional space structure development model, but the “production-living-ecological” functional space unit change mode is different; (4) The spatial pattern of the Changsha metropolitan area should be comprehensively regulated from the aspects of “uality” and “quantity” of the “production-living-ecological” functional land use structure.

The construction of regional land ecological network is an important content of land ecological construction. In the current research, the selection of multi-scale ecological source sites involves less research, and further research is needed. This paper takes Jiangsu Province as the research area and conducts evaluation of land ecological sensitivity and importance based on land use survey data. On this basis, sensitive, extremely sensitive, important, and extremely important vectors were selected and ecological source places were determined through threshold screening. Ecological corridors were then generated to form a multi-level land ecological network system plan in Jiangsu Province. Results of the research are: (1) The land ecological network system of Jiangsu province consisted of 31 primary sources, 175 secondary ones, 1313 third-level ones as well as 61 primary corridors, 345 secondary ones, 3882 third-level ones, and the area of those was 23 526.26 km2, accounting for 22.04% of the total area of Jiangsu. (2) The primary ecological sources were mainly composed of river, lake and wetland area, while the majority of the second and third ones were paddy field and woodland. Among these, the Yangtze River, Taihu, Nantong section of coastal wetlands, Hongze lake, Gaoyou lake, the southern section of Yancheng coastal wetlands, the northern section of Yancheng coastal wetlands, Luoma Lake, Ge Lake, Baima Lake were the most fundamental ecological sources, with the integral index of connectivity (dIIC) standing in the top 10 list among 1 519 ones, which made great contributions to the land ecological connectivity in general. (3) The results of evaluation of land ecological sensitivity and importance are key foundation and basis of the selection of ecological sources. In addition, a combination of ecological sources and corridors can better realize the planning of regional land ecological network.

In this paper, the daily precipitation dataset of grid points(0.5°×0.5°) of version 2 during 1961??2018 from China Meteorological Administration, daily reanalysis dataset from NCEP/NCAR and the tropical cyclone (TC) database that’s from the Shanghai Typhoon Institute of China Meteorological Administration(CMA-STI), were used to analyze long-term variation of the regional extreme precipitation and its possible cause in Jiangnan Area. The regional extreme precipitation events were determined by the percentile threshold method and classified according to their weather systems. Then, the linear trend analysis, M-K mutation test and Spearman correlation analysis methods were used for the analysis of the long-term variation of regional extreme precipitation events. The results are as follows: (1) There were 790 regional extreme precipitation events in Jiangnan Area from 1961 to 2018, including 436 frontal extreme precipitation events, 135 cyclonic extreme precipitation events and 219 other types of extreme precipitation events. (2) Frontal and cyclonic extreme precipitation events both show an upward trend, and the precipitation days and precipitation amount of them significantly increased. The intensity of all types of extreme precipitation events all had been an upward trend. However, the precipitation days and precipitation amount of other types of regional extreme precipitation events show an downward trend. The upward trend of precipitation days and precipitation amount of regional extreme precipitation events started later than those of frontal type,but the extreme precipitation days of them changed suddenly around in the 1990s, and the extreme precipitation amount of regional and cyclonic changed suddenly around in the 1980s. (3) The variation of regional extreme precipitation events may be caused by the variation of frontal and cyclonic extreme precipitation events, while the local meridional circulation and the number of tropic cyclone appearing in the Jiangnan Area are the possible reasons for the long-term variation of frontal and cyclonic extreme precipitation events respectively.

Urban heat islands are environmental problems caused by the combination of surface characteristics, socio-economic and meteorological factors, with significant seasonal differences. A large number of studies have analyzed the relationship between land cover types, land cover indices, landscape indices, and urban heat islands, ignoring the impact of meteorological factors and the interaction between meteorological factors, surface features and socio-economics on urban heat islands. Based on the analysis of the intensity and spatial autocorrelation analysis of heat islands in different seasons in Wuhan, this paper uses geo-detectors to study the driving factors and interactions of urban heat islands in different seasons and the detection of heat island risk areas. The results show that the intensity of heat islands in various seasons in Wuhan shows a strong agglomeration characteristics in space. According to the sequence of spring, summer, autumn and winter, the main driving factors of the four seasons heat island intensity in Wuhan are surface characteristics, socio-economic, socio-economic and meteorological factors. The main driving factors for the four seasons are land cover type, night light, night light and air pressure. . Among the interaction effects of the 11 driving factors, the most important interactions of the four-season heat island intensity are land cover type and night light, land cover type and NDVI, land cover type and night light, air pressure and land cover type or NDVI. The results of risk detection show that the highest average heat island intensity in spring, summer, autumn and winter is urban built-up area, urban built-up area, urban built-up area, bare land and low vegetation coverage area. The lowest are water body, water body, water body and vegetation; the average city of four seasons The intensity of the heat island increased with the increase of nighttime light; the average heat island intensity of the NDVI sub-region showed a trend of increasing first and then decreasing; the average heat island intensity of the gas pressure sub-region showed a gradual upward trend. These results reveal the seasonal variation characteristics of heat island intensity, which can provide a basis for the formulation of measures to alleviate urban heat island effect.

Due to the different spatial and temporal resolution of different sensors, the research period of NDVI dynamic change is relatively short. Based on EOT algorithm, taking Danjiangkou Water Source Area as an example, with the help of GIMMS NDVI and MODIS NDVI data in overlapping period, the 8 km resolution GIMMS NDVI data is resampled to 1 km, and the long-term NDVI data set of 1982-2018 is constructed. On this basis, the temporal and spatial dynamic changes of NDVI in Danjiangkou Water source area are analyzed. The results show that EOT algorithm has good applicability in spatial resampling. The fit between EOT NDVI and MODIS NDVI was higher (r=0.929, P<0.01, n=24), and there was a significant correlation between EOT NDVI and Landsat NDVI (r=0.702, P<0.01, n=200). In space, the EOT algorithm is affected by the mixed pixel in the area with complex land use types, the prediction accuracy is reduced, and higher in the area with continuous vegetation distribution. In space, the EOT algorithm is affected by the mixed pixel in the area with complex land use types, the prediction accuracy is reduced, and higher in the area with continuous vegetation distribution. Based on the analysis of time series NDVI data, the NDVI showed an upward trend of 0.002 9 year-1. Spatially, the NDVI in Danjiangkou Water source area increased significantly (P<0.05), and the annual average NDVI increased significantly in Hanzhong City, Ankang City, Shangzhou city in the north, Zhuxi County in the South and other regions. The areas with decreased annual NDVI are mainly distributed in Danjiangkou reservoir, Shiyan City, Nanyang City, Pingli County and other areas with rapid economic development. The Mann Kendall test showed that there was no mutation in the annual NDVI time series, but the NDVI in some regions was different at different times.

Monitoring of regional vegetation cover change is the basis of researching the carrying capacity of resources and environment, which is crucial for regional sustainable development. Based on the MODIS NDVI data, the fractional vegetation coverage of the Three Gorges reservoir area in 2001-2018 was calculated by using dimidiate pixel model. Combining the extraction model of fractional vegetation coverage change type and distribution index, the distribution characteristics of fractional vegetation cover change on different topographic factors in the reservoir area were revealed. The research shows that: (1) The fractional vegetation cover of the Three Gorges reservoir area is dominated by high and medium-high coverage, which accounted for 65.72% and 28.61% of the total area of the study area respectively. In the past 18 years, the annual coverage growth rate reached 0.14%. (2) The vegetation stability type accounted for 79.50% of the reservoir area, the vegetation improvement type accounted for 16.71%, and the vegetation degradation type accounted for 3.79%. In 26 distticts of the Three Gorges reservoir area, the vegetation improvement area in 7 districts, such as Changshou District and Jiangbei District, is less than the vegetation degradation area, which had high ecological degradation risk. (3) The vegetation degradation type in the area with elevation less than 500 m and slope less than 6° is significant; the improvement of vegetation in the elevation range of 500-1 100 m is the dominant type; the area with slope of 6°-15° has no obvious dominant distribution. Vegetation stability and vegetation improvement type with an elevation greater than 1 100 m and a slope greater than 15° are the dominant distributions. (4) In the study area, the vegetation degradation type on the flat slope is significant in different aspects. When the aspects changes from the shade to the sunny slope (west slope → south slope, north slope → east slope), the dominant distribution type of vegetation cover changes from vegetation degradation type to vegetation improvement type. The research results reveal the spatial distribution and change characteristics of vegetation cover in the Three Gorges reservoir area, which has certain reference significance for the ecological environment assessment and vegetation restoration and protection of the reservoir area.

The Yalong River Basin is one of the key regions for hydropower development in China. Exploring the temporal and spatial evolution characteristics of dry and wet condition of the basin in the context of global climate change is conducive to rational planning and full use of water resources, providing scientific guidance for agricultural production activities in the basin. Based on the monthly meteorological data of 16 meteorological stations in and around the Yalong River Basin from 1981 to 2017, the potential evapotranspiration ET0 of each station was calculated using the Penman-Monteith (PM) formula. The corrected CHIRPS satellite precipitation products with higher spatial resolution is used to calculate the standardized precipitation evapotranspiration index SPEI. The cloud model and Mann-Kendall (MK) trend test are used to analyze the spatial and temporal distribution characteristics and trends of the inter-decadal, annual and seasonal scales. The results show that: (1) The deviation correction of the CHIRPS satellite precipitation product not only improves the accuracy, but also obtains the precipitation with higher spatial resolution; (2) the spring is humidified in the basin, and the other time scales show a trend of drought. The rate of aridification is the fastest in winter. The stability of the wet and dry variation in the annual scale is the worst, and the stability in autumn is relatively best. The spatial distribution of SPEI in spring and winter is weaker than the time distribution. (3) The relative dry and wet areas of the watershed at the same time scale are approximately normal, and the spatial distribution of dry and wet changes in the basin is quite different; (4) There is no obvious regional distribution pattern in the drought and wetting high-incidence areas of all levels in the basin. The highest frequency of drought and wetting is about 20%, and the frequency change range is gradually reduced with the increase of dryness and wetness; (5) Frequency difference of wet and dry in different ages is more significant. The annual average drought frequency change shows decrease-increase-decrease trend, the wet frequency change shows increase-decrease-decrease trend, and wetting high-incidence areas transferred from downstream to upstream.

The construction of ecological network pattern is one of the important ways to ensure regional ecological security, to coordinate economic and social development and ecological system contradictions, and to enhance human well-being. This study takes Anqing City as an empirical area, identifies the regional ecological sources by evaluating the ecosystem service functions, and then uses the circuit theory to construct the ecological network pattern, demonstrates the regional ecological network structure characteristics according to the current density, and finally proposes the regional ecological network and Ecological security optimization strategies. The results of this study indicate that the ecological network structure of Anqing City is mainly composed of 24 source sites larger than 1 km2, 3 potential corridors, 23 pinch points and 3 important obstacles. The ecological sources are mainly composed of forest land and cultivated land. The areas with better ecological resources are mainly distributed along the Dalongshan Forest Park in the north of the city, the edge area of the eastern development zone and the western farm area. The ecological resource flow in the central urban area is blocked, the ecological corridor connectivity is poor, and the ecological network pattern is significantly heterogeneous. This study analyzes the ecological network security under different thresholds, proposes the ecosystem improvement and restoration strategies under different network patterns, and has positive practical guiding implication for improving the supply capacity of regional ecosystem services and the connectivity of ecological networks.

In the southeastern monsoon region of China, climatic studies based on tree-ring width have made great progress during the past decade. In terms of some tree-ring width chronologies without obvious growth limiting factors to meet the requirement for climatic reconstructions, reliable climatic signals have been successfully extracted by splitting tree-ring width into earlywood and latewood width and building corresponding width chronologies. However, how the corresponding earlywood and latewood of tree-ring width with clear limiting climatic factor respond to climate has not been investigated until now. The tree-ring width chronology of high-altitude Pinus taiwanensis was highly sensitive to prior April-July temperature in Sanqingshan, Jiangxi Province of China. In order to investigate the reason of the high sensitivity and the potential of its corresponding earlywood and latewood chronologies for climatic reconstructions, it was split into sub-annual chronologies, that is, the earlywood- and latewood-width chronologies. Both the sub-annual chronologies were found to have the same dominating climatic factor, i.e., prior April-July temperature, as the original chronology. The relationship stood for both high and low frequencies, which clearly explained why the high-latitude tree-ring width chronology was highly sensitive to climate. The study also demonstrated that the reconstruction quality using tree-ring width chronology could be influenced to some extent by whether the corresponding earlywood- and latewood-width chronologies contained similar climatic signals.

Huangpi District is Wuhan City’s largest town rich in mountain and water resources, and constructing its ecological security pattern is an important guarantee for the sustainable development of Wuhan City. Taking the land utilization alteration data and DEM elevation map of Huangpi District photographed in December 2017 as the main data source, and taking forest land, water area and wetland with high ecological sensitivity as source areas, the author establishes the minimum cumulative resistance model to identify ecological corridors and nodes, divide ecological function areas, construct and optimize the ecological security pattern of Huangpi District. The research results show that: (1) The identified ecological source areas in the area studied is 169.55 km2, accounting for 7.5% of the total area of the district, and showing the spatial distribution characteristics that“they are distributed at both ends, which are relatively independent, with poor connectivity”; (2) Extracting a total of 132 ecological corridors and 83 ecological nodes. From the perspective of spatial distribution, corridors are concentrated in mountains in the northern and waters in the south. It is the most difficult to connect the land between urban construction land and large-scale cultivation land. (3) According to the calculation results, the area studied is divided into ecological security-level areas with five different levels, and from south to the middle part and from north to the middle part, the ecological security level roughly shows a trend from low to high. Optimizing the ecological network connection plays an important protection role in safeguarding the ecological security of the region, maintaining the ecological stability of the region and alleviating the ecological pressure of the region.

Since the impoundment of the Three Gorges Reservoir, the hydrodynamics of the mainstreams and tributaries in the reservoir have changed significantly. It is very important to find out the reason of the density flow in the bay of the Three Gorges Reservoir. Based on the field observation data of 2018, the water flow velocity, water temperature and turbidity of Shennong Bay were analyzed. The results show that the water temperature in the Shennong Bay was not changed greatly in spring and winter, the sediment concentration was very low, and the difference of the mainstream and tributary was small, which leaded to the density flow in an irregular state. The water temperature in summer and autumn changed greatly, the sediment concentration increased greatly, and the water body most of them were submerged into the reservoir bay from the mainstream by means of medium and bottom inversion. In the flood season, the reservoir was affected by the high sediment concentration, which leaded to the increase of water density and the formation of density flow, and most of them appear in the middle and bottom of the reservoir bay. In other months, the density flow potential was formed by the temperature difference of the water body, and the temperature difference was the reverse irrigation. From June to August,the main cause of density flow was the sediment concentration of the difference between the mainstream and tributary increased, the contribution rate of sediment content to water density increased, up to 75%; the density of water in other months mainly affected by water temperature, the contribution of water temperature to water density exceeded 80% in each month, and the maximum contribution rate was 95%.

In order to characterize the heavy metal pollution in farmland and woodland (Koelreuteria integrifoliola plantation) around mining area in Tongling City, Anhui Province, the Tomlinson Pollution Load Index and Bio-concentration Factor were applied to evaluate the pollution level of soil heavy metals pollution levels of Cd and Cu, and the enrichment level of plant heavy metals in the research area.The results showed that the total contents of Cd and Cu of farmland in the study area were 2.34 and 161.25 mg/kg respectively, which are higher than 1.26 and 80.15 mg/kg respectively in woodland.Both exceeded risk screening value of agricultural land soil contamination(GB 15618-2018, pH≤5.5) and soil heavy metal background value in Tongling City. The soil pollution level of farmland and woodland were moderate pollution and slight pollution respectively.The content of Cd in brown rice (0.95 mg/kg) seriously exceeded limit for Cd in “National Standard for Food Safety” (GB 2762-2017). The enrichment factors of Cd and Cuin above-ground organs of K. integrifoliola were lower than those of rice. In sum, the pollution of Cd and Cu in the woodland (K. integrifoliola plantation) both are lower than those in farmland,and returning farmland to forest is a better land use option in the study area.

Based on the micro-survey data of farmers in the Loess Plateau, this paper empirically analyzes the main effect of the relationship between collective action and farmers' adoption of soil and water conservation technologies and the moderating effect of ecological compensation on the relationship between collective action and farmers' adoption of soil and water conservation technologies by using a multi-level nonlinear Tobit model. The results show that: (1) collective action has a significant positive impact on any type of soil and water conservation technology; (2) Ecological compensation can adjust the relationship between collective actions and farmers' adoption of soil and water conservation technologies. However, different types of soil and water conservation technologies have different adjustment directions, which have positive adjustment for labor-intensive soil and water conservation technologies and negative adjustment for capital-intensive soil and water conservation technologies. Based on this, the following policy suggestions are put forward: to enhance farmers’ ability and scale of collective action participation, to refine the standard of compensation amount and years, to formulate ecological compensation policies with differentiated technical attributes and so on.

Based on the data surveyed on 1 237 peasant households in Shanxi, Shaanxi and Gansu located on the Loess Plateau, this paper analyzes the spatial difference due to the soil and water conservation tillage technologies adopted by the farmers, with the assistance of the Heckman sample selection model, it studies farmers adoption behavior and the influencing factors in these three provinces. The result showed that: firstly, the regional difference is obvious in terms of farmers adopt the soil and water conservation tillage technology in the above provinces, farmers in Shanxi prefer to adopt straw ploughing and subsoiling, farmers in Shaanxi prefer to adopt moderate or non-tillage and groove ridge planting, while in Gansu, farmers prefer to adopt straw ploughing, stubble mulching, plastic film mulching and subsoiling. Secondly, family income has a significant positive effect on the adoption and adoption degree in these provinces. The proportion of non-agricultural income has a significant positive effect on the adoption of soil and water conservation tillage technology. The adoption degree is negatively affected by livestock. Thirdly, precipitation has a significant negative effect on the adoption behaviors in the three provinces. The parcels type has a significant negative impact on the adoption and adoption degree with this technology in Shanxi and Shaanxi, but no significant effect exists in Gansu province. Fourthly, social network has a significant positive impact on the adoption degree with the soil and water conservation tillage technology in the three provinces. The technology promotion has increased the adoption rate. The government subsidies have a significant positive effect on the adoption degree of soil and water conservation tillage technology in Shanxi and Gansu provinces, while no significant effect exists in Shaanxi province.

Based on the literature review and the research hypothesis of the relationship between capital endowment and farmer′s willingness to pay for the cultivated land protection,this paper used the survey data of 483 households from Wuhan“1+8”metropolitan area and employed the order logistic model to test empirically the impacts of capital endowment on the farmers′ willingness to pay for cultivated land protection.The results show that: (1)33.5% of the farmers are willing to pay around 20 Yuan to protect the cultivated land and the overall level is low; compared to suburban,the outer suburbs farmers have a stronger willingness than the farmers in suburban stronger cultivated land dependence.(2) As far as the significant variables are concerned in each model,except for the total annual household income of economic capital, the remaining capital endowments have a significant positive impact on the willingness to pay for cultivated land protection.(3)On the whole, compared with economic and cultural capital, social capital have a stronger influence on farmers′ willingness to pay for cultivated land protection.(4)There are significant differences in the impact of farmer capital endowments on the willingness to pay for cultivated land protection in suburban and outer suburbs:compared to outer suburbs,the influence of the remaining farmer capital on the willingness to pay for farmland protection is greater in suburban in addition to the relationship with relatives and friends;further analysis find that total annual household income and family laborers of economic capital and statements in mass meetings of social capital have a significant impact on the suburban farmer;while the degree of trust in village collectives of village-type and the degree of relationship with relatives and friends of neighborhood-type all have an important impact on the willingness of farmers to pay for cultivated land protection in suburban and outer suburbs,and only the degree of relationship with relatives and friends of neighborhood-type is valid in suburban.The major findings derived from the study can be summarized as follows:it is necessary to establish various rural cooperative economic organizations actively,improve the savings level of farmers;develop rural education vigorously,especially vocational education and continuing education;encourage farmers to participate in the organization of rural social collective activities actively to strengthen communication among farmers, farmers and village cadre; especially strengthen the construction of rural collective organizations in outer suburbs to improve the accumulation of capital endowment of farmers to enhance the willingness of farmers to pay for cultivated land protection,and promote cultivated land protection better.