Understanding the impacts of co-invasion of multiple invaders on soil bacterial communities is significant in understanding the mechanisms driving successful invasion.This study aimed to determine the response of soil...Understanding the impacts of co-invasion of multiple invaders on soil bacterial communities is significant in understanding the mechanisms driving successful invasion.This study aimed to determine the response of soil bacterial communities to co-invasion of two invaders daisy fleabane(Erigeron annuus)and Canada goldenrod(Solidago canadensis).Daisy fleabane and/or Canada goldenrod invasion significantly enhanced the operational taxonomic unit richness,Shannon index,and Chao1 index of soil bacterial communities.Canada goldenrod under light degree of invasion and co-invasion of daisy fleabane and Canada goldenrod regardless of invasion degree signally improved the ACE index of soil bacterial communities.Thus,the two invaders can enhance soil bacterial diversity and richness to facilitating subsequent invasion due to the fact that higher soil bacterial diversity and richness can enhance the levels of soil function and nutrients acquisition of plant species.ACE index of soil bacterial communities subjected to co-invasion of daisy fleabane and Canada goldenrod regardless of invasion degree was greater than that under the independent invasion of either daisy fleabane or Canada goldenrod.Hence,co-invasion of the two invaders can impose synergistic impacts on soil bacterial richness,which may build a preferable soil micro-environment via the intensified soil bacterial communities,which is contributive to their following invasion.展开更多
The vegetation of alpine tundra in the Changbai Mountains has experienced great changes in recent decades. Narrowleaf small reed(Deyeuxia angustifolia), a perennial herb from the birch forest zone had crossed the tree...The vegetation of alpine tundra in the Changbai Mountains has experienced great changes in recent decades. Narrowleaf small reed(Deyeuxia angustifolia), a perennial herb from the birch forest zone had crossed the tree line and invaded into the alpine tundra zone. To reveal the driven mechanism of D. angustifolia invasion, there is an urgent need to figure out the effective seed distribution pattern, which could tell us where the potential risk regions are and help us to interpret the invasion process. In this study, we focus on the locations of the seeds in the soil layer and mean to characterize the effective seed distribution pattern of D. angustifolia. The relationship between the environmental variables and the effective seed distribution pattern was also assessed by redundancy analysis. Results showed that seeds of D. angustifolia spread in the alpine tundra with a considerable number(mean value of 322 per m2). They were mainly distributed in the low elevation areas with no significant differences in different slope positions. Effective seed number(ESN) occurrences of D. angustifolia were different in various plant communities. Plant communities with lower canopy cover tended to have more seeds of D. angustifolia. Our research indicated reliable quantitative information on the extent to which habitats are susceptible to invasion.展开更多
Nitrogen(N)deposition,precipitation and their interaction affect plant invasions in temperate ecosystems with limiting N and water resources,but whether and how they affect plant invasions in subtropical native commun...Nitrogen(N)deposition,precipitation and their interaction affect plant invasions in temperate ecosystems with limiting N and water resources,but whether and how they affect plant invasions in subtropical native communities with abundant N and precipitation remains unclear.We constructed in situ artificial communities with 12 common native plant species in a subtropical system and introduced four common invasive plant species and their native counterparts to these communities.We compared plant growth and establishment of introduced invasive species and native counterparts in communities exposed to ambient(CK),N addition(N+),increased precipitation(P+)and N addition plus increased precipitation(P+N+).We also investigated the density and aboveground biomass of communities under such conditions.P+alone did not enhance the performance of invasive species or native counterparts.N+enhanced only the aboveground biomass and relative density of invasive species.P+N+enhanced the growth and establishment performance of both invasive species and native counterparts.Most growth and establishment parameters of invasive species were greater than those of native counterparts under N+,P+and P+N+conditions.The density and aboveground biomass of native communities established by invasive species were significantly lower than those of native communities established by native counterparts under P+N+conditions.These results suggest that P+may magnify the effects of N+on performance of invasive species in subtropical native communities where N and water are often abundant,which may help to understand the effect of global change on plant invasion in subtropical ecosystems.展开更多
基金Project(31300343)supported by the National Natural Science Foundation of ChinaProject(PCRRF19009)supported by Open Science Research Fund of State Key Laboratory of Pollution Control and Resource Reuse(Tongji University),ChinaProject supported by Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,China。
文摘Understanding the impacts of co-invasion of multiple invaders on soil bacterial communities is significant in understanding the mechanisms driving successful invasion.This study aimed to determine the response of soil bacterial communities to co-invasion of two invaders daisy fleabane(Erigeron annuus)and Canada goldenrod(Solidago canadensis).Daisy fleabane and/or Canada goldenrod invasion significantly enhanced the operational taxonomic unit richness,Shannon index,and Chao1 index of soil bacterial communities.Canada goldenrod under light degree of invasion and co-invasion of daisy fleabane and Canada goldenrod regardless of invasion degree signally improved the ACE index of soil bacterial communities.Thus,the two invaders can enhance soil bacterial diversity and richness to facilitating subsequent invasion due to the fact that higher soil bacterial diversity and richness can enhance the levels of soil function and nutrients acquisition of plant species.ACE index of soil bacterial communities subjected to co-invasion of daisy fleabane and Canada goldenrod regardless of invasion degree was greater than that under the independent invasion of either daisy fleabane or Canada goldenrod.Hence,co-invasion of the two invaders can impose synergistic impacts on soil bacterial richness,which may build a preferable soil micro-environment via the intensified soil bacterial communities,which is contributive to their following invasion.
基金Special Fund of National Seismological Bureau,China(No.201208005)Doctorial Innovation Fund of Northeast Normal University(No.10SSXT133,2412013XS001)+1 种基金National Natural Science Foundation of China(No.41171038,41171072,41101523)Doctoral Fund of Ministry of Education of China(No.20120043110014)
文摘The vegetation of alpine tundra in the Changbai Mountains has experienced great changes in recent decades. Narrowleaf small reed(Deyeuxia angustifolia), a perennial herb from the birch forest zone had crossed the tree line and invaded into the alpine tundra zone. To reveal the driven mechanism of D. angustifolia invasion, there is an urgent need to figure out the effective seed distribution pattern, which could tell us where the potential risk regions are and help us to interpret the invasion process. In this study, we focus on the locations of the seeds in the soil layer and mean to characterize the effective seed distribution pattern of D. angustifolia. The relationship between the environmental variables and the effective seed distribution pattern was also assessed by redundancy analysis. Results showed that seeds of D. angustifolia spread in the alpine tundra with a considerable number(mean value of 322 per m2). They were mainly distributed in the low elevation areas with no significant differences in different slope positions. Effective seed number(ESN) occurrences of D. angustifolia were different in various plant communities. Plant communities with lower canopy cover tended to have more seeds of D. angustifolia. Our research indicated reliable quantitative information on the extent to which habitats are susceptible to invasion.
基金funded by the National Natural Science Foundation of China(31460165,31960282)Natural Science Foundation of Guangxi Province(2018GXNSFAA281112)Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain(19-050-6).
文摘Nitrogen(N)deposition,precipitation and their interaction affect plant invasions in temperate ecosystems with limiting N and water resources,but whether and how they affect plant invasions in subtropical native communities with abundant N and precipitation remains unclear.We constructed in situ artificial communities with 12 common native plant species in a subtropical system and introduced four common invasive plant species and their native counterparts to these communities.We compared plant growth and establishment of introduced invasive species and native counterparts in communities exposed to ambient(CK),N addition(N+),increased precipitation(P+)and N addition plus increased precipitation(P+N+).We also investigated the density and aboveground biomass of communities under such conditions.P+alone did not enhance the performance of invasive species or native counterparts.N+enhanced only the aboveground biomass and relative density of invasive species.P+N+enhanced the growth and establishment performance of both invasive species and native counterparts.Most growth and establishment parameters of invasive species were greater than those of native counterparts under N+,P+and P+N+conditions.The density and aboveground biomass of native communities established by invasive species were significantly lower than those of native communities established by native counterparts under P+N+conditions.These results suggest that P+may magnify the effects of N+on performance of invasive species in subtropical native communities where N and water are often abundant,which may help to understand the effect of global change on plant invasion in subtropical ecosystems.
