Emergy evaluation of the coupling effects of ecological economic systems of two selected counties in the eco-tone between agriculture and pasture in the North China

Evaluation of the effects of system coupling has become a hot issue in the field of life and earth science although it roots in the physics science. Many researches focus on establishing system coupling models and procedures to evaluate the results of system coupling, however, due to lacks of methods to evaluate the results of system coupling quantitatively, few researches have involved in the coupling effects of the ecological economics system of fragile environmental area in China. In the light of Dr. Odum's emergy theories, the coupling effects of ecological economic systems of two selected counties in the eco-tone between agriculture and pasture in the North China were studied. This paper defined primarily the concept of system coupling degree between agriculture and animal husbandry based on the emergy theory and evaluated the state of system coupling in two typical counties located in the eco-tone between agriculture and pasture in North China. The results show that the effect of coupling between agriculture and animal husbandry is lower. The radical reason for lower ecosystem productivity and disharmonic development in this eco-tone is the improper configuration of inner animal husbandry. The results of case study in Ansai and Wuchuan counties show that the scales of animal husbandry have exceeded the threshold of the primary productivity, which leads to the fact that the harmonic coupling mechanism between agriculture and animal husbandry systems has not been established. According to the indices of emergy evaluation, related measures and policies were presented for raising the effect of the system coupling, the main suggestions presented as follows: making ful use of natural resources, raising the use of fossil-energy, increasing the input of technology, information and financing, adjusting the industrial structures for increasing the effects of systems coulping.