Based on a literature review and analysis of the statistics of the World Bank, this study investigated the rural transformation process of the world from the aspects of rural population, employment, grain production, and public services. It revealed that the world has transformed from rural society to urban society and from agriculture-based economy to nonagricultural economy. In this process, the development efficiency and public service quality were improved. The article points out that accompanying the globalization, industrialization, and urbanization processes, rapid rural depopulation exacerbated rural instability and vulnerability and led to rural decline that endangers rural sustainability. It highlights the importance of rural vitalization and calls for ruralization to form the urban-rural regional pattern with urbanization. Scientific planning, relocation, and local stakeholders' bottom-up initiatives must be encouraged. It is also necessary to scientifically govern the world's rural transformation process, identify and develop the rural vitalization growth point, and improve rural resilience.

Population aging is an important demographic phenomenon for the development of human society. At present, it brings both challenges and opportunities for rural development, thusly calls for systematic studies on its impact on rural development in order to explore appropriate strategies to cope with aging. In this article, the impacts of population aging are analyzed with respect to the changes of rural land use, ecological space, agricultural production, consumption structure, rural governance, and social security, from the ecological, production, and living aspects. On this ground, we propose that rural population aging impact and adaptation research should focus on the environment, economic development, and social development dimensions, combined with the general aims of the national strategy on rural vitalization, including thriving businesses, pleasant living environments, social etiquette and civility, effective governance, and prosperity. In addition, three research fields that are in urgent need of breakthrough are summarized: (1) the impacts of rural population aging on the valuation of ecosystem services and economic benefits from the perspective of population mobility; (2) spatial differentiation of rural population aging and its impacts on agricultural modernization; and (3) rural vitalization pathways to cope with population aging.

Since the reform and opening up in 1978, human geography in China has experienced important developments. As a branch of human geography, rural geography has carried out a series of research on the rural regional system of human-environment relations. Taking the geography research articles published in the past 40 years in major Chinese journals of geography as the analysis object and using bibliometrics and literature summarization methods assisted by Citespace tools, this study identified the key research areas, divided the themes into stages, and summarized progress in the major research areas. The results show that under the background of globalization, urbanization, modernization, and informationization, as well as rural industrial structure adjustment and rural development policy change, great changes have taken place. From 1978 to 2000, rural geography mainly focused on the research themes of rural urbanization, urban-rural relations, village clusters, agricultural development, and rural economy. The academic community showed greater interest in urban than rural research, which has made fundamental and strategic contributions to the agricultural and rural development of the country and regions From 2000 to 2008, rural geography began to shift to topics such as rural tourism, rural settlements, new rural construction, village planning, and hollow village, and the development of the discipline gradually progressed. Since 2008, rural geography has shifted to more diverse topics, mainly including rural transformation, rural restructuring, rurality, rural governance, rural community, and spatial restructuring, which converge with rural geography research internationally. In the future, the research of rural geography in China should be based on the construction of theories and methods of rural geography and serve the rural vitalization strategy. More attention should be paid to the development, transformation, differentiation, restructuring, and governance of rural areas, deepening theoretical research on the value of diversified space in rural areas and developing a theoretical framework and research paradigm of rural geography with unique Chinese characteristics.

Influenced by the interaction of various internal and external factors including urbanization, informatization, and globalization, rural areas in China are experiencing socioeconomic restructuring, regional function upgrading, and a series of transformations and reconstructions. Rural areas face a range of unprecedented opportunities and challenges, and the proposal of "rural revitalization strategy" puts forward new requirements for rural development and rural geography. Therefore, a comprehensive and systematic understanding of rural space system and accurate depiction of rural space are necessary prerequisites for further studies. Existing Chinese research focused more on the material space and to some extent placed less focus on the study of social-cultural space. Using a single material space view is very difficult to understand and interpret a large number of increasingly complex rural geographical problems. Based on a systematic analysis of the thinking on rural space and development in China and abroad, this article points out the deficiency of Chinese rural geographical research about rural society and culture. This article preliminarily expounds the complexity of rural territorial system and argues that the rural space system that is derived from the rural territorial system should not be limited within the range of rural material space but be understood through the multi-dimensional perspective of space. According to the human-environment system theory, this study tried to construct a rural space system that consists of three progressive layers including material space-social space-cultural space and clarify the connotations of every layer and the logical relations between them to fully understand the increasingly complex rural area. This article also highlights the necessity that multi-dimensional rural spatial restructuring should be developed. Based on the construction of multi-dimensional rural space system, forming an overview of the historical process and realistic situation of rural spatial restructuring and predicting the future path of rural development are very important research tasks to carry out in the future. In the end, this article appeals that Chinese geographers should continue to discuss and analyze concepts of rural issues in order to constantly improve our understanding about the changing countryside, and deepen the studies of rural spatial restructuring by using the theories and methods of related subjects from the perspective of multi-dimensional space. Finally, for the comprehensive empirical research of rural geographical issues, Chinese rural geographers should strengthen micro scale studies, actively devote themselves to field study, be observant of rural daily life, and understand the rural society and culture to make up for the deficiency of Chinese rural geographical research about rural society and culture.

With its focus on the increasingly complicated human-environment relationship under the background of rapid urbanization, rural restructuring study has become an important frontier research area of geography. Rural restructuring is a process of reshaping the socioeconomic forms and spatial patterns in rural areas in respond to the changes of factors both internal and external of the system, by optimally allocating and efficiently managing the material and non-material elements of rural development. It aims at ultimately optimizing the structures and improving the functions within rural territorial systems as well as realizing the structural coordination and functional complementation between urban and rural territorial system. Based on the perspective of "elements-structure-function" of rural territorial system, this article first elaborated the concept of rural restructuring from the aspects of behavioral mainstream, value system, and targets. Then, a framework of rural restructuring mechanism was analyzed, which consisted of inducing mechanism, supporting mechanism, constraining/promoting mechanism, guiding mechanism, and driving mechanism. Furthermore, in view of the guiding role of governments in optimal allocation of critical resources and rural restructuring, this article argued that it is necessary to restructure the contours of state intervention in rural societies and economies. Finally, the research contents of rural restructuring in the future were prospected.