Ecological land can provide people with ecological products and ecological services; and it plays an important role in maintaining the health and safety of the ecosystem. With China’s rapid urbanization development, ecological land has been invaded in large quantities, and damaged seriously, even resulting in loses of its ecological function. Based on land use data from 1995 to 2015, our study explores the spatial and temporal evolution of the damage or recovery of ecological land in the Yangtze River Economic Belt (YREB). Two spatial models, geographic detector and geographic weighted regression (GWR), were employed to assess the global effects and the local effects of the driving factors for ecological land change, respectively. Our study divided the ecological land change into five types based on the degree of change as severe damage, slight damage, unchanged, slight recovery, and obvious recovery. The results show that from 1995 to 2015, the total area of ecological land in the YREB increased initially and then decreased, but the overall trend was decreasing. The total damaged area was larger than the recovered area. Arable land and woodland both showed downward trends. In terms of ecological land change over the past 20 years, the type of unchanged had the largest area, followed by slight damage and slight recovery. Our study further revealed that ecological land change was the net result of the interaction of many factors, and the explanatory power between any two driving factors was greater than that of any individual driving factor. In addition, driving factors have different impacts on ecological land change in different geographical locations. This knowledge should help land managers and policymakers to be better informed when developing pertinent land use policies at the regional and local levels. The lessons can also be extended to other regions for better management of their ecological land for sustainable use.

Landscape morphology can reflect the spatial behavior of land use. Using the Poyang Lake area as an example, the landscape pattern characteristics in 1995, 2000, 2015, and 2018 are determined by calculating the fractal dimension, fractal stability, patch density, patch shape fragmentation, and landscape isolation, and fractal theory is used to analyze the spatial behavior of land use. The results show that building land was the land use type which consistently had the highest fractal dimension, but the fractal dimension of building land shows a downward trend, indicating that the spatial form of building land gradually developed in an orderly direction under the action of land use spatial behavior. Paddy, dryland, and forested land were the land use types which always had the lowest fractal dimension, and they are in unstable states. The calculation results of patch density, patch shape fragmentation index, and landscape isolation index supported the conclusions of the fractal analysis. One recommendation for realizing the rational layout of the land is to reduce the fractal dimension of building land through scientific and reasonable planning and to guide the orderly development of building land. For natural landscapes such as forested land, shrub forest land, high-coverage grassland, and water area, their fractal dimensions should be increased to reduce human interference and maintain their stability. Finally, the results of this study suggest that the fractal dimension should be introduced into the National Spatial Planning, and used as an index for evaluating the rationality of the regional land use pattern.

Environmental and social problems caused by overfertilization, excessive pesticides, and encroachment on farmland are increasingly serious in agricultural settings, especially in suburban agricultural areas and highly intensive agricultural areas. Hence, modern agriculture not only pursues economic benefits, but it also pays more attention to ecological functions and social stability. This paper proposes a set of methods which are designed to realize optimal agricultural benefits and sustainable development by scientifically adjusting the land use structure. Taking Changsha County in South Central China as a case study, this paper first built an index system and adopted the information entropy-TOPSIS method to assess the economic, social, and ecological benefits of agricultural land use. Next, a coupled coordination model and an obstacle model were chosen to diagnose those factors that remained as obstacles to achieving the sustainable and coordinated development of the benefits of agricultural land use. Finally, based on the analysis of the changes in the benefits and obstacles over time, socio-economic and ecological constraints were established, and the multi-objective linear programming method (MOLP) was used to determine the comprehensive benefits and optimal land use structure. The results indicate that: (1) The agricultural benefits were stably increasing from 0.20 in 1996 to 0.79 in 2016. (2) The economic benefit index is no longer the main obstacle, while the social benefit index, which includes components such as the food security index, has become the principal influencing factor. (3) The optimal land use structure and comprehensive benefits were presented by taking into consideration the economic development, environmental protection, and social needs. This study emphasizes economic development, but it also seeks coordinated development with comprehensive benefits. The results of the study could provide scientific recommendations for optimizing the agricultural land use spatial patterns and sustainable land use.

The rural homestead is a major part of the rural land system, which is an important carrier of various rural issues such as rural decline, rural hollowing and others. Great changes have occurred in China's rural areas, while the rural homestead has also undergone transformation. Based on summarizing the multi-functional classification of homesteads from previous research, this study divided and defined the population bearing function, assets, and residential function of homesteads from the perspective of functional improvement according to the results of a survey questionnaire. Using Poyang County as the case study, this paper analyzed the functional transformation of rural homesteads through the model of coordinated transformation degree. The results demonstrated the following trends. (1) From 2000 to 2017, the transformation degrees of rural homestead functions in Poyang County have obviously improved overall. (2) The high value areas of the transformation degrees were mainly distributed in the northern hilly region and around Poyang Lake, while most of the low value areas were distributed in the plain areas near the county town. (3) In the regions with better location conditions and resource endowments, the basic conditions and trend of non-agriculturalization of the population, capital and other factors are more significant. According to the differentiation of rural homestead transformations which occurred in different regions, the government could put forward targeted development suggestions for the future.

The configuration of a multifunctional rural landscape is critical for its protection. Although studies on multifunctional rural landscapes have been conducted, there is a lack of information regarding the spatiotemporal characteristics and tradeoff/synergy relationships of rural landscape functions in the time series on the administrative unit scale. The purposes of this study were to (1) analyze the spatial-temporal distribution characteristics of the tradeoff and synergy from the perspective of multifunctionality for efficient use of rural landscape resources and (2) formulate regional sustainable development policies to minimize the conflict between people and nature. Aiming at the scientific representation of landscape function and the quantification of landscape multifunctional relationships, and by taking Qingpu District of Shanghai as an example, six kinds of rural landscape functions were constructed according to the functional framework of “productive function, living function and ecological function”. Based on the data for 1980 to 2018, the characteristics of variations of multifunctional tradeoff and synergy relationships of the rural landscape in 184 administrative villages were studied by the methods of Spearman rank correlation coefficient analysis and bivariate spatial autocorrelation. The following results were obtained. 1) The fine division of rural landscape function types was realistic and necessary for analyzing the regional multi-function relationships in the regions with rapid development. In the process of rapid urbanization, the rural landscape functions of urban suburban areas changed under the combined action of natural resource endowment, social and economic conditions and other internal and external factors. As a result, the agricultural production function could not replace the economic development function and become the function of rural landscape production. The research results of Qingpu District showed that the agricultural production function was no longer the primary functional form, yet the economic development function became the dominant function in this area. 2) Temporal and spatial analysis methods of rural landscape functions can accurately and comprehensively reflect the evolution of the characteristics of multifunction tradeoffs and synergies. According to the Spearman rank correlation analysis of the multifunction value of the rural landscape in the time dimension, the results masked the differences of resource and environment carrying capacity caused by the differences of regional landscape resource endowment in the spatial dimension. 3) The spatial and temporal differences of the multi-functional tradeoffs and synergies of the rural landscape in Qingpu District from 1980 to 2018 were significant. There was significant heterogeneity of tradeoffs and synergies between functions in the spatial pattern, with clustering characteristics. Meanwhile, as for the temporal pattern, the tradeoffs and synergies of functions changed differently in terms of Moran's I and the correlation coefficient. The results of this study can provide scientific references for urban-suburban-rural space reconstruction and regional sustainable development.

As a global issue, farmland abandonment is considered to be one of the most crucial fields in the study of land use change. The clarification of its driving factors plays a vital role in improving the efficiency of rural cultivated land use and ensuring national food security. This paper aims to study the factors influencing farmland ab-andonment in 49 villages of Ganzhou City by adopting the Qualitative Comparative Analysis (QCA). The results show that: (1) Farmland abandonment is the outcome of synergism among many factors, among which the low–level of agricultural mechanization is definitely a necessary condition in Ganzhou, and it contributes a material effect to the abandonment. (2) The path leading to farmland abandonment is not unique to the study area, and can be attributed to five different combinations. These combinations can be enumerated as: A1 (a combination of convenient transportation, complete agricultural facilities, low-level agricultural mechanization, low-level land circulation, and no industrial policy support), A2 (a combination of complete agricultural facilities, low-level agricultural mechanization, low-level land circulation, sufficient agricultural labor, and no industrial policy support), A3 (a combination of convenient transportation, complete agricultural facilities, low-level agricultural mechanization, sufficient agricultural labor, and no industrial policy support), A4 (a combination of convenient transportation, low-level agricultural mechanization, low-level land circulation, sufficient agricultural labor, and industrial policy support), and A5 (a combination of inconvenient transportation, complete agricultural facilities, low-level agricultural mechanization, high-level land circulation, sufficient agricultural labor, and industrial policy support). (3) In the above-mentioned combinations, the core conditions and peripheral conditions conjointly impact on farmland abandonment. Finally, corresponding policy implications are proposed in order to further reveal the mechanism of farmland abandonment. These recommendations provide new ideas and methods for policy makers to use in making decisions and will promote the effective use of farmland.

Poaceae species such as silver grass or reed are commonly used in traditional mulch farming in Japan, where the Nishi-Awa area is a Globally Important Agricultural Heritage Systems (GIAHS) site. Farmers here have traditionally used silver grass for mulch farming; furthermore, local farmers have learned from long-standing experience that Japanese knotweed (Fallopia japonica, Polygonaceae) is better for cultivation of solanaceous crops in this area. However, it is unclear why Japanese knotweed mulching is beneficial for cultivation of solanaceous crops. Thus, in this study, we hypothesized that Japanese knotweed mulching may be effective in avoiding hazards associated with continuous potato cropping, as native potato used to be cultivated twice a year in the past. Therefore, we investigated the effects of Japanese knotweed mulching on continuous potato cropping and after tomato cropping, which is another solanaceous crop species. Field experiments were conducted in 2018. First, we compared Japanese knotweed mulching, silver grass mulching and no grass mulching (control) in a soil under continuous potato cultivation and in an uncultivated soil. As a result, the extent of the potato yield decrease was reduced by Japanese knotweed mulching. Secondly, we compared Japanese knotweed-mulching and no grass mulching in a soil after a tomato crop and in an uncultivated soil. The extent of decrease in potato growth and yield was also reduced by Japanese knotweed mulching. These findings indicate that mulching with Japanese knotweed helped to avoid the risks associated with continuous potato cropping.