Soil samples were collected with distance at 5, 20, 40, 80, 160, and 320 m from the Shen-Ha （Shenyang-Harbin） Highway, Northeast China, to investigate the effect of heavy metals of highway origin on soil nematode gu...Soil samples were collected with distance at 5, 20, 40, 80, 160, and 320 m from the Shen-Ha （Shenyang-Harbin） Highway, Northeast China, to investigate the effect of heavy metals of highway origin on soil nematode guilds. The contents of soil Pb, Cu, Zn, and the nematode community structure were analyzed. The results showed that the contents of total and available Pb, Ca, Zn varied significantly with the different distances from the highway. Pb was the main pollutant in the soils in the vicinity of Shen-Ha Highway. The zone from 20 to 40 m away from the highway was the most polluted area. The highest abundance of soil nematodes was found at 5 m while the lowest at 20 m away from the highway. Thirty six genera of nematodes belonging to 23 families were identified. Nematode guilds having different responses to soil heavy metals were classified into four types. Soil nematode guilds may act as a prominent indicator to heavy metal pollution of highway origin.展开更多
Elevated atmospheric CO2 can influence soil C dynamics in agroecosystems. The effects of free-air CO2 enrichment （FACE） and N fertilization on soil organic C （Corg）, dissolved organic C （DOC）, microbial biomass...Elevated atmospheric CO2 can influence soil C dynamics in agroecosystems. The effects of free-air CO2 enrichment （FACE） and N fertilization on soil organic C （Corg）, dissolved organic C （DOC）, microbial biomass C （Cmic） and soil basal respiration （SBR） were investigated in a Chinese wheat field after expose to elevated CO2 for four full years. The results indicated that elevated CO2 has stimulative effects on soil C concentrations regardless of N fertilization. Following the elevated CO2, the concentrations of Corg and SBR were increased at wheat jointing stage, and those of DOC and Cmic were enhanced obviously across the wheat jointing stage and the fallow period after wheat harvest. On the other hand, N fertilization did not significantly affect the content of soil C. Significant correlations were found among DOC, Cmic, and SBR in this study.展开更多
Land use changes affect belowground ecosystems.During the past few decades,land use in Northeast China has changed considerably,and the area of paddy fields has increased rapidly from upland.In this study,soil charact...Land use changes affect belowground ecosystems.During the past few decades,land use in Northeast China has changed considerably,and the area of paddy fields has increased rapidly from upland.In this study,soil characteristics and soil biotic community in paddy fields with different years of rice cultivation were measured to examine the effects of land use change from upland to paddy fields on soil micro-food web.The upland maize fields were selected as control and the microbial community composition was characterized using phospholipid fatty acids(PLFAs) analysis.The microbial biomass(total PLFA),bacteria biomass,and fungi biomass were higher in the 20-40-year(late-stage) than 1-10-year(early-stage) paddy fields.The abundances of total nematodes and bacterivores were lower in the early-stage than late-stage paddy fields.The abundance of herbivores was the highest in the early-stage paddy fields but that of omnivore-predators was the highest in the late-stage paddy fields.Structural equation model indicated that soil food web was developed and structured after 20 years of paddy cultivation.Our results suggested that soil micro-food web may be a good indicator for soil development and stabilization of paddy fields following land use change.展开更多
基金supported by the National NaturalScience Foundation of China (No. 30600087)the Scientific Research Startup Special Foundation on Excellent Ph.D Thesis and Presidential Award of Chinese Academyof Sciences (No. 2007356).
文摘Soil samples were collected with distance at 5, 20, 40, 80, 160, and 320 m from the Shen-Ha （Shenyang-Harbin） Highway, Northeast China, to investigate the effect of heavy metals of highway origin on soil nematode guilds. The contents of soil Pb, Cu, Zn, and the nematode community structure were analyzed. The results showed that the contents of total and available Pb, Ca, Zn varied significantly with the different distances from the highway. Pb was the main pollutant in the soils in the vicinity of Shen-Ha Highway. The zone from 20 to 40 m away from the highway was the most polluted area. The highest abundance of soil nematodes was found at 5 m while the lowest at 20 m away from the highway. Thirty six genera of nematodes belonging to 23 families were identified. Nematode guilds having different responses to soil heavy metals were classified into four types. Soil nematode guilds may act as a prominent indicator to heavy metal pollution of highway origin.
基金supported by the National Natural Science Foundation of China(No.30770400,40231003)the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-408)
文摘Elevated atmospheric CO2 can influence soil C dynamics in agroecosystems. The effects of free-air CO2 enrichment （FACE） and N fertilization on soil organic C （Corg）, dissolved organic C （DOC）, microbial biomass C （Cmic） and soil basal respiration （SBR） were investigated in a Chinese wheat field after expose to elevated CO2 for four full years. The results indicated that elevated CO2 has stimulative effects on soil C concentrations regardless of N fertilization. Following the elevated CO2, the concentrations of Corg and SBR were increased at wheat jointing stage, and those of DOC and Cmic were enhanced obviously across the wheat jointing stage and the fallow period after wheat harvest. On the other hand, N fertilization did not significantly affect the content of soil C. Significant correlations were found among DOC, Cmic, and SBR in this study.
基金supported by the National Key Research & Development(R&D) Plan of China(No. 2016YFD0300204)the National Basic Research Program(973 Program) of China(No.2011CB100504)
文摘Land use changes affect belowground ecosystems.During the past few decades,land use in Northeast China has changed considerably,and the area of paddy fields has increased rapidly from upland.In this study,soil characteristics and soil biotic community in paddy fields with different years of rice cultivation were measured to examine the effects of land use change from upland to paddy fields on soil micro-food web.The upland maize fields were selected as control and the microbial community composition was characterized using phospholipid fatty acids(PLFAs) analysis.The microbial biomass(total PLFA),bacteria biomass,and fungi biomass were higher in the 20-40-year(late-stage) than 1-10-year(early-stage) paddy fields.The abundances of total nematodes and bacterivores were lower in the early-stage than late-stage paddy fields.The abundance of herbivores was the highest in the early-stage paddy fields but that of omnivore-predators was the highest in the late-stage paddy fields.Structural equation model indicated that soil food web was developed and structured after 20 years of paddy cultivation.Our results suggested that soil micro-food web may be a good indicator for soil development and stabilization of paddy fields following land use change.
