Adaptive evolution mechanism of rural human-land system in farming-and-pastoral areas of northern China

The theory on the cyclic adaptaion between society and ecosystem sheds new light on the evolution and internal structure of human-land system. This paper introduces the risk index (RI) and adaptation capacity index (ACI) to evaluate the rural human-land system, and sets up an evaluation index system for the adaptability of rural human-land system, under the effects of climate change and policy implementation. On this basis, the stages, features, control factors, and evolution mechanism were examined for the adaptability of rural human-land system in Darhan Mumingan United Banner from 1952 to 2017. The main results are as follows: (1) The evolution of the rural human-land system can be divided into three stages, namely, the reorganization and rapid development stage from 1952 to 2002 (population: +260%; cultivated land area: +13%; livestock: +134%; degradated grassland area: +16.33%), the rapid to stable development stage from 2003 to 2010 (population: +2.8%; cultivated land area: -2.3%; livestock: -13.6%; degradated grassland area: -10.7%), and the stable to release stage from 2011 to 2017 (population: -2.6%; cultivated land area: -0.2%; livestock: -10.6%; degradated grassland area: -3.8%). (2) With the elapse of time, the ACI of the rural human-land system went through a slow rise (-0.016-0.031), a slow decline (0.031-0.003), and a rapid rise (0.003-0.088). In terms of space, the adaptability is high in the middle, moderate in the north, and low in the south. (3) The adaptability evolution of the rural human-land system was mainly controlled by the per-capita effective irrigation area (22.31%) and the per-capita number of livestocks (23.47%) from 1990 to 2000, the desertification area of land (25.06%) and the land use intensity (21.27%) from 2000 to 2005, and the per-capita income of farmers and herdsmen (20.08%) and the per-capita number of livestocks (18.52%) from 2010 to 2007. (4) Under the effects of climate change and policy implementation, the cyclic adaptaion of the rural human-land system was propelled by the interactions between two kinds of subjects: farmers and herdsmen, and rural communities. The interaction affects the adaptive behavior of the two kinds of subjects, which in turn drives the cyclic evolution of the system. As a result, the system structure and functions developed alternatively between coordinated and uncoordinated states. Small-scale adaptive behaviors of farmers and herdsmen have a profound impact on the evolution of rural human-land system. © 2021, Science Press. All right reserved.