Invasive plant Ageratina adenophora(Sprengel)R.King&H.Robinson has invaded majority of the temperate forests in Kumaun,Central Himalaya.Information on A.adenophora invaded forest types,their structural attributes,...Invasive plant Ageratina adenophora(Sprengel)R.King&H.Robinson has invaded majority of the temperate forests in Kumaun,Central Himalaya.Information on A.adenophora invaded forest types,their structural attributes,population demography and regeneration status are still at rudimentary level.Considering this,the present study was conducted to assess the impacts of A.adenophora on vegetational attributes and regeneration status of three forest types,viz.,Oak(Quercus oblongata D.Don),Pine(Pinus roxburghii Sarg.)and Cypress(Cupressus torulosa D.Don).We selected three sites for each forest type and each site was further purposively stratified into paired sampling plots of 1 ha each i.e.,A.adenophora invaded and uninvaded sites.Our results showed large densities of cut stumps or felled trees throughout invaded sites,but with fewer fire signs in comparison to uninvaded sites.In uninvaded sites,total density and basal area calculated for woody species were relatively higher than those in invaded sites,although results were insignificant(p>0.05).With the exception for Cypress forests,vegetation indices showed low woody species richness and diversity in invaded Oak and Pine forests.Also,regeneration of Q.oblongata,P.roxburghii and C.torulosa tree species did not differ significantly(p>0.05)between invaded and uninvaded sites.These insignificant differences clearly imply that A.adenophora's presence has not entirely changed the perennial plant communities in terms of composition,structure and natural regeneration.However,tree species with poor or no regeneration status requires special attention and needs management strategies involving control of invasive species in forest ecosystems.展开更多
Rhizosphere microbial communities play important roles in facilitating or inhibiting the establishment of exotic species.Since some invasive plants interact with soil microbial communities such as rhizosphere bacteria...Rhizosphere microbial communities play important roles in facilitating or inhibiting the establishment of exotic species.Since some invasive plants interact with soil microbial communities such as rhizosphere bacteria,changes triggered by rhizosphere bacteria may alter competitive interactions between exotic and native plants.This study compared the Bacillus cereus content in soils with different degrees of Ageratina adenophora invasion,and investigated the effects of A.adenophora allelochemicals on B.cereus growth and soil characteristics and the feedback effects of B.cereus on A.adenophora growth.Bacillus cereus content in the rhizosphere of A.adenophora increased with intensification of the invasion process,and newly invaded soil contained almost twice as much bacteria as noninvaded soil.When rhizosphere soil was added to the root exudates of A.adenophora,the contents of B.cereus were twice as much as the control,except on the first day.Certain soil parameters increased significantly,such as ammonium nitrogen(NH_(4)^(+)-N)and available phosphorus(AP),which were increased by 41 and 27%,respectively.Soil treatment with B.cereus promoted the degradation of two allelochemicals from the rhizosphere of A.adenophora,amorpha-4,7(11)-dien-8-one and 6-hydroxy-5-isopropy1-3,8-dimethyl-4 a,5,6,7,8,8 ahexahydraphthalen-2(1 H)-one,to varying degrees;and increased the germination rate by 50%,root length by 117%,shoot length by 48%and fresh weight by 81%for A.adenophora compared to those of untreated soil.Our results confirmed that the invasion of A.adenophora will promote an increase of B.cereus,a beneficial rhizosphere bacterium,which in turn induces a positive feedback effect on A.adenophora.展开更多
紫茎泽兰(Ageratina adenophora)是多年生草本植物,主要分布于热带与温带,是入侵植物中危害最严重的物种之一。基于中国知网和Web of Science核心库集,对已发表的紫茎泽兰相关文献进行计量分析,旨在了解国内外对该植物防治、利用以及研...紫茎泽兰(Ageratina adenophora)是多年生草本植物,主要分布于热带与温带,是入侵植物中危害最严重的物种之一。基于中国知网和Web of Science核心库集,对已发表的紫茎泽兰相关文献进行计量分析,旨在了解国内外对该植物防治、利用以及研究的现状和发展趋势,明确研究前沿与热点问题,为进一步开展紫茎泽兰相关研究提供参考。结果表明,紫茎泽兰是国内外生态与环境保护领域重点研究的入侵物种。我国科研工作者在其防控、利用研究中发挥着重大作用,但科研机构、研究人员间的交流与合作有待加强,同时学科交叉发展不足。近年来该领域的研究热点主要集中于探究紫茎泽兰的性能及其开发利用上,未来应拓展更多的研究方向,尤其是在开发利用中的“变害为宝”方面应加大研究力度。展开更多
In order to ascertain the invasive mechanism and control strategy of the invasive Crofton weed, Ageratina adenophora, its ecological adaptability and population differentiation,the formation of single dominant populat...In order to ascertain the invasive mechanism and control strategy of the invasive Crofton weed, Ageratina adenophora, its ecological adaptability and population differentiation,the formation of single dominant population, displacement of native plants and sustainable management strategies were investigated. The present results helped to clarify and explain such issues as the adaptability post invasion,interaction and competition between inter-and intra-species and community resistance, thereby providing important references to researches on other invasive alien species.展开更多
基金Department of Science&Technology,New Delhi(DST-SERB/CRG/2019/004139)for providing financial support。
文摘Invasive plant Ageratina adenophora(Sprengel)R.King&H.Robinson has invaded majority of the temperate forests in Kumaun,Central Himalaya.Information on A.adenophora invaded forest types,their structural attributes,population demography and regeneration status are still at rudimentary level.Considering this,the present study was conducted to assess the impacts of A.adenophora on vegetational attributes and regeneration status of three forest types,viz.,Oak(Quercus oblongata D.Don),Pine(Pinus roxburghii Sarg.)and Cypress(Cupressus torulosa D.Don).We selected three sites for each forest type and each site was further purposively stratified into paired sampling plots of 1 ha each i.e.,A.adenophora invaded and uninvaded sites.Our results showed large densities of cut stumps or felled trees throughout invaded sites,but with fewer fire signs in comparison to uninvaded sites.In uninvaded sites,total density and basal area calculated for woody species were relatively higher than those in invaded sites,although results were insignificant(p>0.05).With the exception for Cypress forests,vegetation indices showed low woody species richness and diversity in invaded Oak and Pine forests.Also,regeneration of Q.oblongata,P.roxburghii and C.torulosa tree species did not differ significantly(p>0.05)between invaded and uninvaded sites.These insignificant differences clearly imply that A.adenophora's presence has not entirely changed the perennial plant communities in terms of composition,structure and natural regeneration.However,tree species with poor or no regeneration status requires special attention and needs management strategies involving control of invasive species in forest ecosystems.
基金the National Natural Science Foundations of China(31772229 and 31660546)。
文摘Rhizosphere microbial communities play important roles in facilitating or inhibiting the establishment of exotic species.Since some invasive plants interact with soil microbial communities such as rhizosphere bacteria,changes triggered by rhizosphere bacteria may alter competitive interactions between exotic and native plants.This study compared the Bacillus cereus content in soils with different degrees of Ageratina adenophora invasion,and investigated the effects of A.adenophora allelochemicals on B.cereus growth and soil characteristics and the feedback effects of B.cereus on A.adenophora growth.Bacillus cereus content in the rhizosphere of A.adenophora increased with intensification of the invasion process,and newly invaded soil contained almost twice as much bacteria as noninvaded soil.When rhizosphere soil was added to the root exudates of A.adenophora,the contents of B.cereus were twice as much as the control,except on the first day.Certain soil parameters increased significantly,such as ammonium nitrogen(NH_(4)^(+)-N)and available phosphorus(AP),which were increased by 41 and 27%,respectively.Soil treatment with B.cereus promoted the degradation of two allelochemicals from the rhizosphere of A.adenophora,amorpha-4,7(11)-dien-8-one and 6-hydroxy-5-isopropy1-3,8-dimethyl-4 a,5,6,7,8,8 ahexahydraphthalen-2(1 H)-one,to varying degrees;and increased the germination rate by 50%,root length by 117%,shoot length by 48%and fresh weight by 81%for A.adenophora compared to those of untreated soil.Our results confirmed that the invasion of A.adenophora will promote an increase of B.cereus,a beneficial rhizosphere bacterium,which in turn induces a positive feedback effect on A.adenophora.
文摘紫茎泽兰(Ageratina adenophora)是多年生草本植物,主要分布于热带与温带,是入侵植物中危害最严重的物种之一。基于中国知网和Web of Science核心库集,对已发表的紫茎泽兰相关文献进行计量分析,旨在了解国内外对该植物防治、利用以及研究的现状和发展趋势,明确研究前沿与热点问题,为进一步开展紫茎泽兰相关研究提供参考。结果表明,紫茎泽兰是国内外生态与环境保护领域重点研究的入侵物种。我国科研工作者在其防控、利用研究中发挥着重大作用,但科研机构、研究人员间的交流与合作有待加强,同时学科交叉发展不足。近年来该领域的研究热点主要集中于探究紫茎泽兰的性能及其开发利用上,未来应拓展更多的研究方向,尤其是在开发利用中的“变害为宝”方面应加大研究力度。
基金supported by the National Basic Research Program of China (Grant Nos.2009CB119200 and 2002CB111400)the National Natural Science Foundation of China (Grant No.30871654)
文摘In order to ascertain the invasive mechanism and control strategy of the invasive Crofton weed, Ageratina adenophora, its ecological adaptability and population differentiation,the formation of single dominant population, displacement of native plants and sustainable management strategies were investigated. The present results helped to clarify and explain such issues as the adaptability post invasion,interaction and competition between inter-and intra-species and community resistance, thereby providing important references to researches on other invasive alien species.
