摘要
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.
Since the 1950s of the last century, the exotic plant, Eupatoriumadenophorum, has spread rapidly across southwest China, damaging native ecosystems and causing greateconomic losses. We examined the pH, N, P, K, and organic matter concentrations, and the bacterialcommunity character (by Biolog EcoPlate^(TM)) in soils from sites heavily and lightly invaded bythis 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 plantspecies, one native and two exotic, in pot experiment using soil from heavily invaded site toexamine 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 onlyslightly different from those of the lightly invaded site, but concentrations of NH_4^+, NO_3^- andavailable 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 fromthat in the lightly invaded site. The catabolic activity of bacterial community in soils treated bythe water extract of E. adenophorum roots changed and became similar to that in soils from theheavily invaded site. The pot experiment showed that the exotic plants growth in heavily invadedsoil were not different from in lightly invaded soil; however, the native plant biomass decreaseddramatically when grown in soil from the heavily invaded site as compared to soil from the lightlyinvaded site; and the same phenomenon was found when any potential allelopathic effects by E.adenophorum were eliminated by added activated carbon to those soils. Difference in soil nutrientavailability and allelopathy could not explain this phenomenon of the native plant in the soils fromthe heavily and lightly invaded sites. Changes observed in the soil bacterial community wereobviously related to native plant growth in those tow soils. Those results suggest that changingsoil microbial community may be an important part of E. adenophorum invasion process. Since the soilmicrobial community serves as bridge in connection of exotic and natural plants, the exotic plantcould inhibit the natural plant growth and reproduction by changing the soil microbial community ininvaded site.
基金
the Major Project of Knowledge Innovation of the Chinese Academy of Sciences(KSCX1-SW -13-0X-0X)．
关键词
外来植物
泽兰属植物
土壤营养
微生物菌落
培植方式
exotic plant invasion
eupatorium adenophorum
soil bacterial community
soilnutrition
