In China, fireweed (Crassocephalum crepioides) is listed as an invasive plant that is also cultivated as a vegetable.To gain a clearer understanding of its invasiveness and rapid spread, we evaluated its seed dispersal ability, and the influences of light, temperature, pH, NaCl stress, moisture content, and storage periods on its seed germination. Its seed dispersal ability is limited. The seed germination of fireweed is inhibited by darkness, temperatures <10°C or >35°C, and a NaCl solution with a concentration >0.15 mol L -1 . The optimal conditions under which nearly all the seeds could germinate are light, with temperatures from 20 to 30°C, and a neutral soil with 40% moisture content.The seeds of fireweed have no apparent dormancy and retain a high viability after room storage for 10 months. Fireweed only has a moderate invasive capacity and its wide distribution in China possibly correlates with its cultivation.

Ecological safety problem from mining activities can not be ignored. Mining ecological security not only relates to ecological environment, also involves technology environment, political environment and cultural environment, etc. Through comprehensive analysis of situation and problems of mining ecological security, we can find Hengyang must go green mining road and must construct ecological mining from the environmental ecology, the political ecology and the cultural ecology, in order to realize mining sustainable development.

The development of nuclear power has become an important way to solve the problems of environment and energy in many countries, also it is an important policy to solve the problems of e energy structure in China. But moral hazard in the safety supervision of nuclear power has happened. By adopting the game analysis method and establishing the game model of moral hazard in the safety supervision of nuclear power, the paper analysis the model with static mixed game and finite iterations of dynamic game. As a result, it can lower the moral hazard if the governments strengthen the punishment in violation of safety rules and reduce the supervision cost.