Exotic plant invasions and increased atmospheric carbon dioxide(CO_(2))concentration have been determined to independently affect soil nematodes,a key component of soil biota.However,little is known about the long-ter...Exotic plant invasions and increased atmospheric carbon dioxide(CO_(2))concentration have been determined to independently affect soil nematodes,a key component of soil biota.However,little is known about the long-term effects of these two global change factors and their interactive effects.Over three consecutive years,we cultivated invasive alien plant Xanthium strumarium and its two phylogenetically related natives under both ambient(aCO_(2))and elevated(eCO_(2))atmospheric CO_(2)concentrations,and determined the effects of the invader and natives on soil nematodes under different CO_(2)concentrations and the relevant mechanism.The abundance of total soil nematodes and that of the dominant trophic group(herbivores)were significantly affected by plant species and CO_(2)concentration,and these effects were dependent on the experimental duration,however,the Shannon-diversity of nematodes was not affected by these factors.Under aCO_(2),both invasive and native species significantly increased the total nematode abundance and that of the dominant trophic group with increasing experimental duration,and the amplitude of the increase was greater under the invader relative to the natives.The eCO_(2)increased total nematode abundance(second year)and that of the dominant trophic group(third year)under the invader,but not under the natives(or even decreased)with increasing experimental duration.Root litter had greater effects on soil nematode abundance than leaf litter and root exudates did.This study indicates that eCO_(2)would aggravate effects of invasive plants on soil nematodes by increasing abundance,and these effects would vary with the duration.展开更多
Global changes such as atmospheric CO_(2)enrichment often facilitate exotic plant invasions and alter soil arbuscular mycorrhizal fungi(AMF)community.However,it is still unclear whether the effects of CO_(2)enrichment...Global changes such as atmospheric CO_(2)enrichment often facilitate exotic plant invasions and alter soil arbuscular mycorrhizal fungi(AMF)community.However,it is still unclear whether the effects of CO_(2)enrichment on exotic plant invasions are associated with its effects on root-AMF symbiosis of invasive and native plants.To address this issue,the annual invasive plant Xanthium strumarium and two phylogenetically related annual natives were compared under ambient and elevated CO_(2)concentrations for three consecutive years.Atmospheric CO_(2)enrichment increased AMF colonization rates for the species only in few cases,and the invader did not benefit more from CO_(2)enrichment in terms of AMF colonization.Under ambient CO_(2)concentration,however,the invader had a higher AMF colonization rate than the natives in the first year of the study,which disappeared in the second and third year of the study due to the increase of AMF colonization rates in the natives but not in the invader.The influences of species,CO_(2)concentrations and planting year on AMF colonization were associated with their effects on both soil nutrient and AMF community,and the former may be more important as it also influenced the latter.Our results indicate that the invader could more quickly form symbiosis with soil AMF,contributing to adaptation and occupation of new habitats,and that it is necessary to consider the roles of AMF and the effects of time when determining the effects of global changes such as atmospheric CO_(2)enrichment on exotic plant invasions.展开更多
基金supported by the National Key R&D Program of China(2023YFC2604500)the National Natural Science Foundation of China(32171662,32471753 and 32171666)the Natural Science Foundation of Liaoning(2020-MS-199).
文摘Exotic plant invasions and increased atmospheric carbon dioxide(CO_(2))concentration have been determined to independently affect soil nematodes,a key component of soil biota.However,little is known about the long-term effects of these two global change factors and their interactive effects.Over three consecutive years,we cultivated invasive alien plant Xanthium strumarium and its two phylogenetically related natives under both ambient(aCO_(2))and elevated(eCO_(2))atmospheric CO_(2)concentrations,and determined the effects of the invader and natives on soil nematodes under different CO_(2)concentrations and the relevant mechanism.The abundance of total soil nematodes and that of the dominant trophic group(herbivores)were significantly affected by plant species and CO_(2)concentration,and these effects were dependent on the experimental duration,however,the Shannon-diversity of nematodes was not affected by these factors.Under aCO_(2),both invasive and native species significantly increased the total nematode abundance and that of the dominant trophic group with increasing experimental duration,and the amplitude of the increase was greater under the invader relative to the natives.The eCO_(2)increased total nematode abundance(second year)and that of the dominant trophic group(third year)under the invader,but not under the natives(or even decreased)with increasing experimental duration.Root litter had greater effects on soil nematode abundance than leaf litter and root exudates did.This study indicates that eCO_(2)would aggravate effects of invasive plants on soil nematodes by increasing abundance,and these effects would vary with the duration.
基金supported by the National Natural Science Foundation of China(31971557,31670545 and 31470575)the National Key R&D Program of China(2017YFC1200101).
文摘Global changes such as atmospheric CO_(2)enrichment often facilitate exotic plant invasions and alter soil arbuscular mycorrhizal fungi(AMF)community.However,it is still unclear whether the effects of CO_(2)enrichment on exotic plant invasions are associated with its effects on root-AMF symbiosis of invasive and native plants.To address this issue,the annual invasive plant Xanthium strumarium and two phylogenetically related annual natives were compared under ambient and elevated CO_(2)concentrations for three consecutive years.Atmospheric CO_(2)enrichment increased AMF colonization rates for the species only in few cases,and the invader did not benefit more from CO_(2)enrichment in terms of AMF colonization.Under ambient CO_(2)concentration,however,the invader had a higher AMF colonization rate than the natives in the first year of the study,which disappeared in the second and third year of the study due to the increase of AMF colonization rates in the natives but not in the invader.The influences of species,CO_(2)concentrations and planting year on AMF colonization were associated with their effects on both soil nutrient and AMF community,and the former may be more important as it also influenced the latter.Our results indicate that the invader could more quickly form symbiosis with soil AMF,contributing to adaptation and occupation of new habitats,and that it is necessary to consider the roles of AMF and the effects of time when determining the effects of global changes such as atmospheric CO_(2)enrichment on exotic plant invasions.
