| 1 | A new mechanism of invader success: Exotic plant inhibits natural vegetation restoration by changing soil microbe com-munity显示文摘Since the 1950s of the last century, the exotic plant, Eupatorium adenophorum, has spread rapidly across southwest China, damaging native ecosystems and causing great economic losses. We examined the pH, N, P, K, and organic matter concentrations, and the bacterial community character (by Biolog EcoPlateTM) in soils from sites heavily and lightly invaded by this exotic species. Also, soil from the lightly invaded site was treated with a water extract of E. adenophorum roots to examine the effect of the plant on soil properties. We grew three plant species, one native and two exotic, in pot experiment using soil from heavily invaded site to examine the effects of the soil on these plants growth. The soil analysis demonstrated that the pH, organic matter, total N, total P and total K in soils from the heavily invaded site were only slightly different from those of the lightly invaded site, but concentrations of NH4+, NO?3 and available P and K in the heavily invaded site were greater than those in the lightly invaded site. The catabolic activity of soil bacterial community in the heavily invaded site was different from that in the lightly invaded site. The catabolic activity of bac- terial community in soils treated by the water extract of E. adenophorum roots changed and became similar to that in soils from the heavily invaded site. The pot experiment showed that the exotic plants growth in heavily invaded soil were not different from in lightly invaded soil; however, the native plant biomass decreased dramatically when grown in soil from the heavily invaded site as compared to soil from the lightly invaded site; and the same phenomenon was found when any potential allelopathic effects by E. adeno- phorum were eliminated by added activated carbon to those soils. Difference in soil nutrient availability and allelopathy could not explain this phenomenon of the native plant in the soils from the heavily and lightly invaded sites. Changes ob- served in the soil bacterial community were obviously related to native plant growth in those tow soils. Those results sug- gest that changing soil microbial community may be an im- portant part of E. adenophorum invasion process. Since the soil microbial community serves as bridge in connection of exotic and natural plants, the exotic plant could inhibit the natural plant growth and reproduction by changing the soil microbial community in invaded site. | YUXingjun YUDan LUZhijun MAKeping | 2005 | Chinese Science Bulletin2005，50，11： | 41 |
| 2 | GMOs:The new hotspot in ecological research显示文摘Gene flow is an important ecological and genetic process, and the fitness conferred by the insertion of a foreign gene could be important in ecology after it becomes introgressed into the wild genetic background of organisms, which is the determinative factor for the fate of GMOs or foreign genes in natural ecosystem and for the competition with native species. Trophic interrelation fulfilled by food chains is the most important correlation between species in ecosystem and could be affected by the modified genotypes after the introduction of GMOs. The technology enabling the precise manipulation of genotype is a great opportunity for the study of ecological genetics in an unknown way prior to the biotechnology era. Especially interesting is the impact of genes on ecosystem function when GMOs are released into environment. A variety of ecological terminology has been frequently used in assessment of ecological risks related to the release of GMOs in environment, e.g. gene flow, fitness, interspecific competition and food chain. The value of GMOs in ecological research is illustrated through several examples in biosafety assessment related to those terms here. It is proposed that ecologists should pay attention to the study of gene function in ecosystem and take the opportunity to enrich ecological theory with the release of GMOs. | WEIWei MAKeping SHIJicheng | 2003 | Chinese Science Bulletin2003，48，22： | 3 |
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