Over the past three decades, China忆s gradual transition toward an urbanization-oriented development strategy has generated a spectacular urbanization development with an average annual growth rate at 0.93%. Although, China achieved a great success in urbanization process, many serious challenges appeared at the same time, such as, population explosion, resources scarcity, and eco鄄environmental deterioration. Accordingly, China忆s rapid urbanization has been characterized by high鄄speed economic growth and a series of environmental issues. As it is widely known that there exists an extremely complex interactive coupling and coercing relationship between urbanization and eco鄄environment, which indicates that urbanization has a strong coercing effect on eco鄄environment, and eco鄄environment has a lagged constraint force on urbanization. How to realize the coordinated development of urbanization and eco鄄environment is not only the key issue in the world economic and social development, but also a hot topic in domestic research in recent years. To start with, this paper establishes a comprehensive index system for assessment of the level of urbanization based on four aspects ( population

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Arbuscular mycorrhizal (AM) is the most widespread form of plant symbiosis and has been found to enhance photosynthesis rate, biomass accumulation, pathogen defense, and tolerance to heavy metals and cold stress. In addition, it affects the production of plant secondary metabolites, one of which is camptothecin, an anti-cancer compound used in clinical practice. Camptothecin is a water-insoluble cytotoxic monoterpene derived from indole alkaloid and was initially isolated from the Chinese tree Camptotheca acuminate (Nyssaceae). It has gained great attention for its remarkable inhibitory activity against tumor cells. Based on our previous study on the correlation between the formation of mycorrhiza and camptothecin content in mycorrhizal C. acuminata seedlings, the effect of co-cultivation time on camptothecin accumulation in C. acuminata seedlings after inoculation with Acaulospora mellea and Glomus intraradices was investigated in the present study. Seeds of C. acuminata were sterilized and sown in sterilized matrix (a mixture of soil and sand) in the