Wedelia （Sphagneticola trilobata （L.） Pruski） has become one of the most dominant invasive plant species in Fiji. However, the soil seed bank of its monospecific stand and its ability to reproduce by seed is relat...Wedelia （Sphagneticola trilobata （L.） Pruski） has become one of the most dominant invasive plant species in Fiji. However, the soil seed bank of its monospecific stand and its ability to reproduce by seed is relatively unknown. A soil seed bank study was undertaken in a monospecific stand ofS. trilobata in Sawani, Natavea and Wainivesi in south-east Viti Levu, Fiji in March 2012. The soil samples were collected from within 1.0 m2 quadrat taken at 10 spots in each of the study areas and spread thinly over a base of Yates Thrive Premium potting mix in seedling trays and placed in a glasshouse at Koronivia Research Station, Fiji. A total of 23, 26 and 33 plant species were found in the soil seed bank in Wainivesi, Sawani and Natavea respectively which may have succumbed to S. trilobata invasiability. There were ca. 3,800 （17%）, 2,100 （11%） and 2,600 （6%） germinable S. trilobata seeds-m-2 in the soil seed bank in Wainivesi, Sawani and Natavea areas respectively. This study has demonstrated that S. trilobata seeds may have a role in the spread of the invasive species in Fiji and movement of soil to S. trilobata free areas should be restricted.展开更多
Aims Natural hybridization between invasive and native species,as a form of adaptive evolution,threatens biodiversity worldwide.However,the potential invasive mechanisms of hybrids remain essentially unexplored,especi...Aims Natural hybridization between invasive and native species,as a form of adaptive evolution,threatens biodiversity worldwide.However,the potential invasive mechanisms of hybrids remain essentially unexplored,especially insights from soil chemical properties and soil microbial communities.Methods In a field experiment,soil microbial community,potassium-solubilizing bacteria,phosphorus-solubilizing bacteria,enzyme activities,and light-saturated photosynthetic rate were measured in invasive Sphagneticola trilobata and its hybrid with native Sphagneticola calendulacea in 2 years.Important Findings In general,soil dissolved organic carbon and the biomass of phosphorus-solubilizing bacteria were significantly higher under the hybrid treatment than S.trilobata and S.calendulacea.However,there were no significant differences in acid phosphatase,total PLFAs,bacterial PLFAs,fungi PLFAs,cellulase,and urase in these treatments.The hybrids had significantly higher light-saturated photosynthetic rate,photosynthetic nitrogen-,phosphorus-,potassium-use efficiencies than the invasive S.trilobata,but no significant difference with S.calendulacea.The total biomass and root biomass of hybrids were higher than S.calendulacea.Our results indicate that the hybrids species have a higher invasive potential than S.calendulacea,which may aggravate the local extinction of S.calendulacea in the future.展开更多
文摘Wedelia （Sphagneticola trilobata （L.） Pruski） has become one of the most dominant invasive plant species in Fiji. However, the soil seed bank of its monospecific stand and its ability to reproduce by seed is relatively unknown. A soil seed bank study was undertaken in a monospecific stand ofS. trilobata in Sawani, Natavea and Wainivesi in south-east Viti Levu, Fiji in March 2012. The soil samples were collected from within 1.0 m2 quadrat taken at 10 spots in each of the study areas and spread thinly over a base of Yates Thrive Premium potting mix in seedling trays and placed in a glasshouse at Koronivia Research Station, Fiji. A total of 23, 26 and 33 plant species were found in the soil seed bank in Wainivesi, Sawani and Natavea respectively which may have succumbed to S. trilobata invasiability. There were ca. 3,800 （17%）, 2,100 （11%） and 2,600 （6%） germinable S. trilobata seeds-m-2 in the soil seed bank in Wainivesi, Sawani and Natavea areas respectively. This study has demonstrated that S. trilobata seeds may have a role in the spread of the invasive species in Fiji and movement of soil to S. trilobata free areas should be restricted.
基金funded by the National Natural Science Foundation of China(41907023,31870374)the China Postdoctoral Science Foundation(2018M643112)and the China Postdoctoral Science Foundation(2018M643112)+1 种基金the State Key Laboratory for Biology of Plant Diseases and Insect Pests(SKLOF201914)supported by Guangdong Province Natural Science Foundation(2017A030313167,2015A030311023).
文摘Aims Natural hybridization between invasive and native species,as a form of adaptive evolution,threatens biodiversity worldwide.However,the potential invasive mechanisms of hybrids remain essentially unexplored,especially insights from soil chemical properties and soil microbial communities.Methods In a field experiment,soil microbial community,potassium-solubilizing bacteria,phosphorus-solubilizing bacteria,enzyme activities,and light-saturated photosynthetic rate were measured in invasive Sphagneticola trilobata and its hybrid with native Sphagneticola calendulacea in 2 years.Important Findings In general,soil dissolved organic carbon and the biomass of phosphorus-solubilizing bacteria were significantly higher under the hybrid treatment than S.trilobata and S.calendulacea.However,there were no significant differences in acid phosphatase,total PLFAs,bacterial PLFAs,fungi PLFAs,cellulase,and urase in these treatments.The hybrids had significantly higher light-saturated photosynthetic rate,photosynthetic nitrogen-,phosphorus-,potassium-use efficiencies than the invasive S.trilobata,but no significant difference with S.calendulacea.The total biomass and root biomass of hybrids were higher than S.calendulacea.Our results indicate that the hybrids species have a higher invasive potential than S.calendulacea,which may aggravate the local extinction of S.calendulacea in the future.
