The theories and methods for systematically understanding land resource

Land is a physical system formed by the interaction of near-surface climate, geomorphology, surface geology, hydrology, soil, flora and fauna, and the results of past and present human activities. Land resource is the land which can be used for human beings in a certain technical condition and a certain period of time. In the past, the recognition of land resources put too much emphasis on the direct use of land by human, which can easily lead to the neglect of the ecological connotation of land resources. Although the systematic characteristic of land has been widely accepted, a systematic view in the practice of land planning and management is often lacked, and results in unsustainable land resource utilization. Therefore, it is necessary to deepen the systematic theories and methodologies for further understanding land resources. Coupling pattern and process is the basic point of understanding land resource. Pattern refers to the size, shape, quantity, type and spatial composition of land; and the process includes the natural and social processes occurring in the land system. The land pattern affects the ecological and anthropogenic processes, and these processes also influence the land pattern, thus producing various spatiotemporal effects in the land system. The change of land pattern and process is the leading factor that affects ecosystem services. A clear understanding on the cascade of pattern-process-service would help to deeply understand the systematic relationship between the natural conditions and human needs in the spatiotemporal evolution of land resources. It will provide new important theoretical guidance for the systematic study of land resource. The methods of natural capital assessment and space planning are the new embodiment of the systematic land resource management. Deconstructing the natural capital stock and ecosystem service flow in the land system, as well as transforming the physical quantity of ecosystem service to ecosystem service value, can provide key methodological support for managing the land resource assets. Based on quantifying the size, pattern and quality of the production, living and ecological spaces, as well as identifying the interactions relationships and overlapping areas, the multifunctional landscape could be located and the ecological security pattern could be constructed, which can provide new methodological support for spatial planning. It has become an important requirement to seek an analytical approach for the relationship between supply and demand of ecosystem services, and reduce the uncertainty of the valuation on ecosystem services. Moreover, it has been a methodological difficulty to spatially trade-off and optimize the coordination of the land use purposes among production, living and ecological space. In conclusion, systematically understanding land resource is not only a theoretical need for comprehensive and in-depth understanding of the complex human-land system knowledge, but also a practical demand for China's ecological civilization strategy. Starting from the coupling of pattern and process, strengthening multi-scale space observation and model simulation, and effectively identifying the pattern-process-service cascade relationship, can provide more comprehensive theoretical knowledge for systematically understanding land resource. Relying on the concepts of ecosystem service supply and demand, ecological assets, multifunctional landscape, and ecological security pattern, etc., to improve the resource-capital-asset knowledge of land system, and effectively identify production-living-ecological space, can provide more powerful methods for systematically understanding land resource. Facing the great strategic demand of China's ecological civilization construction, by tackling the theoretical and methodological key problems of land resources research, the scientific results can be more effectively serve the governmental decision-making, and support the sustainable development of national society, economy, resources and environment.