Project description:Land cover change has long been recognized that marked effect the amount of soil organic carbon. However, little is known about microbial-mediated effect processes and mechanism on soil organic carbon. In this study, the soil samples in a degenerated succession from alpine meadow to alpine steppe meadow in Qinghai-Tibetan Plateau degenerated, were analyzed by using GeoChip functional gene arrays.
2017-01-05 | GSE93158 | GEO
Project description:soil under different reductive soil disinfestation
Project description:Aeolian soil erosion, exacerbated by anthropogenic perturbations, has become one of the most alarming processes of land degradation and desertification. By contrast, dust deposition might confer a potential fertilization effect. To examine how they affect topsoil microbial community, we conducted a study GeoChip techniques in a semiarid grassland of Inner Mongolia, China. We found that microbial communities were significantly (P<0.039) altered and most of microbial functional genes associated with carbon, nitrogen, phosphorus and potassium cycling were decreased or remained unaltered in relative abundance by both erosion and deposition, which might be attributed to acceleration of organic matter mineralization by the breakdown of aggregates during dust transport and deposition. As a result, there were strong correlations between microbial carbon and nitrogen cycling genes. amyA genes encoding alpha-amylases were significantly (P=0.01) increased by soil deposition, reflecting changes of carbon profiles. Consistently, plant abundance, total nitrogen and total organic carbon were correlated with functional gene composition, revealing the importance of environmental nutrients to soil microbial function potentials. Collectively, our results identified microbial indicator species and functional genes of aeolian soil transfer, and demonstrated that functional genes had higher susceptibility to environmental nutrients than taxonomy. Given the ecological importance of aeolian soil transfer, knowledge gained here are crucial for assessing microbe-mediated nutrient cyclings and human health hazard.
Project description:Anthropogenic nitrogen (N) deposition may affect soil organic carbon (SOC) decomposition, thus affecting the global terrestrial carbon (C) cycle. However, it remains unclear how the level of N deposition affects SOC decomposition by regulating microbial community composition and function, especially C-cycling functional genes structure. We investigated the effects of short-term N addition on soil microbial C-cycling functional gene composition, SOC-degrading enzyme activities, and CO2 emission in a 5-year field experiment established in an artificial Pinus tabulaeformis forest on the Loess Plateau, China.
Project description:Aeolian soil erosion, exacerbated by anthropogenic perturbations, has become one of the most alarming processes of land degradation and desertification. By contrast, dust deposition might confer a potential fertilization effect. To examine how they affect topsoil microbial community, we conducted a study GeoChip techniques in a semiarid grassland of Inner Mongolia, China. We found that microbial communities were significantly (P<0.039) altered and most of microbial functional genes associated with carbon, nitrogen, phosphorus and potassium cycling were decreased or remained unaltered in relative abundance by both erosion and deposition, which might be attributed to acceleration of organic matter mineralization by the breakdown of aggregates during dust transport and deposition. As a result, there were strong correlations between microbial carbon and nitrogen cycling genes. amyA genes encoding alpha-amylases were significantly (P=0.01) increased by soil deposition, reflecting changes of carbon profiles. Consistently, plant abundance, total nitrogen and total organic carbon were correlated with functional gene composition, revealing the importance of environmental nutrients to soil microbial function potentials. Collectively, our results identified microbial indicator species and functional genes of aeolian soil transfer, and demonstrated that functional genes had higher susceptibility to environmental nutrients than taxonomy. Given the ecological importance of aeolian soil transfer, knowledge gained here are crucial for assessing microbe-mediated nutrient cyclings and human health hazard. The experimental sites comprised of three treatments of control, soil erosion and deposition, with 5 replicates of each treatment.
Project description:Microbial decomposition of soil organic carbon (SOC) in Arctic permafrost is one of the most important, but poorly understood, factors in determining the greenhouse gas feedback of tundra ecosystems to climate. Here, we examine changes in the structure of microbial communities in an anoxic incubation experiment at either –2 or 8 °C for up to 122 days using both an organic and a mineral soil collected from the Barrow Environmental Observatory in northern Alaska, USA. Soils were characterized for SOC and geochemistry, and GeoChips 5.0 were used to determine microbial community structure and functional genes associated with C availability and Fe(III) reduction.
2016-11-09 | GSE89644 | GEO
Project description:Reductive Soil Disinfestation Improvement Fusarium Wilt of Ginger
Project description:Soil microorganisms act as gatekeepers for soil-atmosphere carbon exchange by balancing the accumulation and release of soil organic matter. However, poor understanding of the mechanisms responsible hinders the development of effective land management strategies to enhance soil carbon storage. Here we empirically test the link between microbial ecophysiological traits and topsoil carbon content across geographically distributed soils and land use contrasts. We discovered distinct pH-controls on microbial mechanisms of carbon accumulation. Land use intensification in low-pH soils that increased pH above a threshold (~ 6.2) lead to carbon loss through increased decomposition following alleviation of acid-retardation of microbial growth. However, loss of carbon with intensification in near neutral-pH soils was linked to decreased microbial biomass and reduced growth efficiency that was, in turn, related to tradeoffs with stress alleviation and resource acquisition. Thus, less intensive management practices in near neutral-pH soils have more potential for carbon storage through increased microbial growth efficiency; whereas, in acidic soils microbial growth is a bigger constraint on decomposition rates.
2018-07-26 | PXD010526 | Pride
Project description:Reductive soil disinfestation and watermelon cultivation on soil microbial communities
Project description:Many trees form ectomycorrhizal symbiosis with fungi. During symbiosis, the tree roots supply sugar to the fungi in exchange for nitrogen, and this process is critical for the nitrogen and carbon cycles in forest ecosystems. However, the extents to which ectomycorrhizal fungi can liberate nitrogen and modify the soil organic matter and the mechanisms by which they do so remain unclear since they have lost many enzymes for litter decomposition that were present in their free-living, saprotrophic ancestors. Using time-series spectroscopy and transcriptomics, we examined the ability of two ectomycorrhizal fungi from two independently evolved ectomycorrhizal lineages to mobilize soil organic nitrogen. Both species oxidized the organic matter and accessed the organic nitrogen. The expression of those events was controlled by the availability of glucose and inorganic nitrogen. Despite those similarities, the decomposition mechanisms, including the type of genes involved as well as the patterns of their expression, differed markedly between the two species. Our results suggest that in agreement with their diverse evolutionary origins, ectomycorrhizal fungi use different decomposition mechanisms to access organic nitrogen entrapped in soil organic matter. The timing and magnitude of the expression of the decomposition activity can be controlled by the below-ground nitrogen quality and the above-ground carbon supply.