土地系统：从集成到生成

 由于系统复杂性的存在，土地系统研究面临着越来越难以集成的挑战。通过梳理土地系统研究成果，借鉴系统科学中的生成论思想，从集成转向生成，以寻找能够深入理解和科学认知土地系统的有效途径。研究结果表明，从系统生成论的角度对土地系统的认知和理解更能接近其本质：土地系统是由人类对地球陆地表面及其上下一定空间的改造、利用和适应而生成的复杂开放系统，包括地理环境、土地利用和社会经济，三者相生相克，不可分割。作为一个开放的复杂系统，土地系统具有多功能性：能量转化、物质生产、生态维持、资源供给、社会保障、文化孕育等。以系统生成论为逻辑起点，基于超循环理论、地域分异理论和地理过程理论，土地系统研究除着重于土地系统生成机制、过程、适应性及远程耦合等基础研究外，还应解决科学与政策实践之间的双向协作问题。

Land system: From integration to generation

The land system science is indeed a fascinating field. However, it does face challenges, such as it is difficult to integrate due to its complexity. This paper reviews the researches of the land systems, in order to find an effective way to understand scientifically the land systems based on the ideas of the generative theory in the systems science. It is shown that the cognition and the understanding of the land systems from the perspective of the system generation theory can help more closely come to the essence that the land systems are complex open systems generated by the transformation, the utilization and the adaptation by human beings of the earth's land surface and certain spaces above and below it, including the geographical environment, the land use and the social economy, all of which are mutually interconnected. As open and complex systems, the land systems feature the multifunctionality, the energy conversion, the material production, the ecological maintenance, the resource supply, the social security, and the cultural nurture. With the system generation theory as the logical starting point, and based on the theory of the hypercycle, the regional differentiation and the geographical process, the study of the land systems should not only focus on the basic researches of the land system generation mechanism, the process, the adaptability, and the tele coupling, but also solve the problems of the two-way collaboration between the science and the policy practices.