Glomalin-related soil protein(GRSP)sequesters large amounts of carbon and plays important roles in maintaining terrestrial soil ecosystem functions and ecological restoration;however,little is known about GRSP variati...Glomalin-related soil protein(GRSP)sequesters large amounts of carbon and plays important roles in maintaining terrestrial soil ecosystem functions and ecological restoration;however,little is known about GRSP variation in 1-m soil profiles and its association with stand characteristics,soil properties,and climatic conditions,hindering GRSP-related degraded soil improvement and GRSP evaluation.In this study,we sampled soils from 1-m profiles from poplar(Populus spp.)shelterbelts in Northeast China.GRSP contents were 1.8–2.0 times higher in the upper 40 cm soil layers than at 40–100 cm.GRSP-related soil organic carbon(SOC)sequestration in deeper soil layers was*1.2 times higher than in surface layers.The amounts of GRSP-related nutrients were similar throughout the soil profile.A redundancy analysis showed that in both surface and deeper layers,soil properties(pH,electrical conductivity,water,SOC,and soil nutrients)explained the majority of the GRSP variation(59.5–84.2%);the second-most-important factor in GRSP regulation was climatic conditions(temperature,precipitation,and altitude),while specific shelterbelt characteristics had negligible effects(<5%).Soil depth and climate indirectly affected GRSP features via soil properties,as manifested by structural equation model analysis.Our findings demonstrate that GRSP is important for carbon storage in deep soils,regardless of shelterbelt characteristics.Future glomalin assessments should consider these vertical patterns and possible regulating mechanisms that are related to soil properties and climatic changes.展开更多
The soil environment is linked to aboveground management including plant species composition, grazing intensity, levels of soil disturbance, residue management, and the length of time of a living plant is growing. Soi...The soil environment is linked to aboveground management including plant species composition, grazing intensity, levels of soil disturbance, residue management, and the length of time of a living plant is growing. Soil samples were collected under rangeland [native grass, rotational grazing (NGRG);tame grass, heavy grazing (TGRG);and tame grass, rotational grazing (TGHG)] and cropland [conventional till (CT);CT plus manure (CTM);and long term no till (NT)] systems. The rangeland systems were hypothesized to have higher glomalin content [measured as Bradford-reactive soil protein (BRSP)] and water stable aggregation (WSA) than the cropland systems. In addition, within both rangeland and cropland systems, BRSP and WSA were expected to decline with increased disturbance due to grazing or tillage and going from native to introduced plant species. Differences were detected for BRSP with NGRG and CTM having the highest values in range and cropland systems, respectively. However, the CTM system had higher BRSP values than one or both of the tame grass systems while the CT and NT systems had similar values. Correlation analysis showed strong relationships between all of the BRSP values and WSA.展开更多
In semi-arid region of northwestern China, underground mining subsidence often results in decreased vegetation coverage, impoverishment of soil fertility and water stress. In addition, the physical-chemical and biolog...In semi-arid region of northwestern China, underground mining subsidence often results in decreased vegetation coverage, impoverishment of soil fertility and water stress. In addition, the physical-chemical and biological properties of soil also change, resulting in more susceptible to degradation. In particular, subsidence causes disturbance of the symbioses of plant and microbe that can play a beneficial role in the establishment of vegetation communities in degraded ecosystems. The objective of this study was to evaluate the effects of revegetation with exotic arbuscular mycorrhizal fungi(AMF) inoculum on the chemical and biological properties of soil over time in mining subsidence areas. Soils were sampled at a depth up to 30 cm in the adjacent rhizosphere of Amorpha fruticose Linn. from five reclaimed vegetation communities in northwestern China. In August 2015, a field trial was set up with five historical revegetation experiments established in 2008(7-year), 2011(4-year), 2012(3-year), 2013(2-year) and 2014(1-year), respectively. Each reclamation experiment included two treatments, i.e., revegetation with exotic AMF inoculum(AMF) and non-AMF inoculum(the control). Root mycorrhizal colonization, glomalin-related soil protein(GRSP), soil organic carbon(SOC), soil nutrients, and enzyme activities were also assessed. The results showed that mycorrhizal colonization of inoculated plants increased by 33.3%–163.0% compared to that of non-inoculated plants(P<0.05). Revegetation with exotic AMF inoculum also significantly improved total GRSR(T-GRSP) and easily extracted GRSP(EE-GRSP) concentrations compared to control, besides the T-GRSP in 1-year experiment and the EE-GRSP in 2-year experiment. A significant increase in SOC content was only observed in 7-year AMF reclaimed soils compared to non-AMF reclaimed soils. Soil total N(TN), Olsen phosphorus(P) and available potassium(K) were significantly higher in inoculated soil after 1–7 years of reclamation(except for individual cases), and increased with reclamation time(besides soil Olsen P). The exotic AMF inoculum markedly increased the average soil invertase, catalase, urease and alkaline phosphatase by 23.8%, 21.3%, 18.8% and 8.6%, respectively(P<0.01), compared with the control. Root mycorrhizal colonization was positively correlated with soil parameters(SOC, TN and soil available K) and soil enzyme activities(soil invertase, catalase, urease and alkaline phosphatase) in both AMF and non-AMF reclaimed soils(P<0.05), excluding availableK in non-AMF reclaimed soils. T-GRSP(P<0.01) and EE-GRSP(P<0.05) were significantly correlated with the majority of edaphic factors, except for soil Olsen P. The positive correlation between root mycorrhizal colonization and available K was observed in AMF reclaimed soils, indicating that the AMF reclaimed soil with a high root mycorrhizal colonization could potentially accumulate available K in soils. Our findings concluded that revegetation with exotic AMF inoculum influenced soil nutrient availability and enzyme activities in the semi-arid ecosystem, suggesting that inoculating AMF can be an effective method to improve soil fertility and support restoration of vegetation communities under poor conditions like soil nutrient deficiency and drought.展开更多
Arbuscular-mycorrhizal fungi (AMF) are integral components of most terrestrial ecosystems, with complex interactions between plants and AMF. Our study assessed the impact of plant diversity of native grassland species...Arbuscular-mycorrhizal fungi (AMF) are integral components of most terrestrial ecosystems, with complex interactions between plants and AMF. Our study assessed the impact of plant diversity of native grassland species on AMF infectivity and production of glomalin, an AMF hyphal glycoprotein that may play an important role in soil aggregation. The study was conducted over a 3-year period in field plots planted with 1, 2, 8, or 16 plant species. The mycorrhizal infection potential (MIP) of the plots was assayed in the greenhouse. Glomalin production and MIP were lowest in monocultures and were more closely correlated with plant diversity than with plant cover. Spore density was also greater in higher diversity plots. Lower AMF activity in monoculture plots may contribute to lower productivity and soil quality in plant monocultures. Immunoreactive glomalin levels varied seasonally, with higher levels in late summer than in late spring. Positive correlations were found between glomalin levels and spore density, and between MIP and spore density, but not between MIP and glomalin.展开更多
基金supported financially by China’s National Foundation of Natural Sciences(41877324,41730641)Fundamental Research Funds for the Central Universities(2572017DG04,2572017EA03)+1 种基金13-5 Key Research and Development Project from China Ministry of Science and Technology(2016YFA0600802)Heilongjiang Province for Distinguished Young Scholars(JC201401)
文摘Glomalin-related soil protein(GRSP)sequesters large amounts of carbon and plays important roles in maintaining terrestrial soil ecosystem functions and ecological restoration;however,little is known about GRSP variation in 1-m soil profiles and its association with stand characteristics,soil properties,and climatic conditions,hindering GRSP-related degraded soil improvement and GRSP evaluation.In this study,we sampled soils from 1-m profiles from poplar(Populus spp.)shelterbelts in Northeast China.GRSP contents were 1.8–2.0 times higher in the upper 40 cm soil layers than at 40–100 cm.GRSP-related soil organic carbon(SOC)sequestration in deeper soil layers was*1.2 times higher than in surface layers.The amounts of GRSP-related nutrients were similar throughout the soil profile.A redundancy analysis showed that in both surface and deeper layers,soil properties(pH,electrical conductivity,water,SOC,and soil nutrients)explained the majority of the GRSP variation(59.5–84.2%);the second-most-important factor in GRSP regulation was climatic conditions(temperature,precipitation,and altitude),while specific shelterbelt characteristics had negligible effects(<5%).Soil depth and climate indirectly affected GRSP features via soil properties,as manifested by structural equation model analysis.Our findings demonstrate that GRSP is important for carbon storage in deep soils,regardless of shelterbelt characteristics.Future glomalin assessments should consider these vertical patterns and possible regulating mechanisms that are related to soil properties and climatic changes.
文摘The soil environment is linked to aboveground management including plant species composition, grazing intensity, levels of soil disturbance, residue management, and the length of time of a living plant is growing. Soil samples were collected under rangeland [native grass, rotational grazing (NGRG);tame grass, heavy grazing (TGRG);and tame grass, rotational grazing (TGHG)] and cropland [conventional till (CT);CT plus manure (CTM);and long term no till (NT)] systems. The rangeland systems were hypothesized to have higher glomalin content [measured as Bradford-reactive soil protein (BRSP)] and water stable aggregation (WSA) than the cropland systems. In addition, within both rangeland and cropland systems, BRSP and WSA were expected to decline with increased disturbance due to grazing or tillage and going from native to introduced plant species. Differences were detected for BRSP with NGRG and CTM having the highest values in range and cropland systems, respectively. However, the CTM system had higher BRSP values than one or both of the tame grass systems while the CT and NT systems had similar values. Correlation analysis showed strong relationships between all of the BRSP values and WSA.
基金funded by the National Natural Science Foundation of China (51574253)the National High Technology Research and Development Program of China (2013AA102904)the Open Research Project of the State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology (Beijing) (SKLCRSM16KFA01)
文摘In semi-arid region of northwestern China, underground mining subsidence often results in decreased vegetation coverage, impoverishment of soil fertility and water stress. In addition, the physical-chemical and biological properties of soil also change, resulting in more susceptible to degradation. In particular, subsidence causes disturbance of the symbioses of plant and microbe that can play a beneficial role in the establishment of vegetation communities in degraded ecosystems. The objective of this study was to evaluate the effects of revegetation with exotic arbuscular mycorrhizal fungi(AMF) inoculum on the chemical and biological properties of soil over time in mining subsidence areas. Soils were sampled at a depth up to 30 cm in the adjacent rhizosphere of Amorpha fruticose Linn. from five reclaimed vegetation communities in northwestern China. In August 2015, a field trial was set up with five historical revegetation experiments established in 2008(7-year), 2011(4-year), 2012(3-year), 2013(2-year) and 2014(1-year), respectively. Each reclamation experiment included two treatments, i.e., revegetation with exotic AMF inoculum(AMF) and non-AMF inoculum(the control). Root mycorrhizal colonization, glomalin-related soil protein(GRSP), soil organic carbon(SOC), soil nutrients, and enzyme activities were also assessed. The results showed that mycorrhizal colonization of inoculated plants increased by 33.3%–163.0% compared to that of non-inoculated plants(P<0.05). Revegetation with exotic AMF inoculum also significantly improved total GRSR(T-GRSP) and easily extracted GRSP(EE-GRSP) concentrations compared to control, besides the T-GRSP in 1-year experiment and the EE-GRSP in 2-year experiment. A significant increase in SOC content was only observed in 7-year AMF reclaimed soils compared to non-AMF reclaimed soils. Soil total N(TN), Olsen phosphorus(P) and available potassium(K) were significantly higher in inoculated soil after 1–7 years of reclamation(except for individual cases), and increased with reclamation time(besides soil Olsen P). The exotic AMF inoculum markedly increased the average soil invertase, catalase, urease and alkaline phosphatase by 23.8%, 21.3%, 18.8% and 8.6%, respectively(P<0.01), compared with the control. Root mycorrhizal colonization was positively correlated with soil parameters(SOC, TN and soil available K) and soil enzyme activities(soil invertase, catalase, urease and alkaline phosphatase) in both AMF and non-AMF reclaimed soils(P<0.05), excluding availableK in non-AMF reclaimed soils. T-GRSP(P<0.01) and EE-GRSP(P<0.05) were significantly correlated with the majority of edaphic factors, except for soil Olsen P. The positive correlation between root mycorrhizal colonization and available K was observed in AMF reclaimed soils, indicating that the AMF reclaimed soil with a high root mycorrhizal colonization could potentially accumulate available K in soils. Our findings concluded that revegetation with exotic AMF inoculum influenced soil nutrient availability and enzyme activities in the semi-arid ecosystem, suggesting that inoculating AMF can be an effective method to improve soil fertility and support restoration of vegetation communities under poor conditions like soil nutrient deficiency and drought.
文摘Arbuscular-mycorrhizal fungi (AMF) are integral components of most terrestrial ecosystems, with complex interactions between plants and AMF. Our study assessed the impact of plant diversity of native grassland species on AMF infectivity and production of glomalin, an AMF hyphal glycoprotein that may play an important role in soil aggregation. The study was conducted over a 3-year period in field plots planted with 1, 2, 8, or 16 plant species. The mycorrhizal infection potential (MIP) of the plots was assayed in the greenhouse. Glomalin production and MIP were lowest in monocultures and were more closely correlated with plant diversity than with plant cover. Spore density was also greater in higher diversity plots. Lower AMF activity in monoculture plots may contribute to lower productivity and soil quality in plant monocultures. Immunoreactive glomalin levels varied seasonally, with higher levels in late summer than in late spring. Positive correlations were found between glomalin levels and spore density, and between MIP and spore density, but not between MIP and glomalin.
