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Dennis C. Flanagan - One of the best experts on this subject based on the ideXlab platform.
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quantifying the effects of Plant Litter in the topsoil on the soil detachment process by overland flow in typical grasslands of the loess plateau china
Hydrological Processes, 2020Co-Authors: Panpan Li, Dennis C. FlanaganAbstract:Plant Litter can be incorporated into topsoil by a natural process, affecting the soil erosion process. This is a widespread phenomenon in erosion‐prone areas. This study was conducted to investigate the effect of Litter incorporation on the process of soil detachment on the Loess Plateau, China. Four common Plant Litters (Bothriochloa ischaemum L. Keng., Artemisia sacrorum Ledeb., Setaria viridis L. Beauv., and Artemisia capillaris Thunb.) were collected, then incorporated into the silt loam soil at five rates (0.1, 0.4, 0.7, 1.0, and 1.3 kg m⁻²) on the basis of our field investigation. Twenty Litter–soil treatments and one bare soil control were prepared. After 50 days of natural stabilization, 30 soil samples of each treatment were collected. We used a flume test to scour the soil samples under six flow shear stress conditions (5.66, 8.31, 12.21, 15.55, 19.15, and 22.11 Pa). The results showed that the different incorporated Litter masses and morphological characteristics, such as Litter tissue density (ranging from 0.52 to 0.68 g cm⁻³), length density (2.34 to 91.00 km m⁻³), surface area density (LSAD; 27.9 to 674.2 m² m⁻³), and volume ratio (0.003 to 0.050 m³ m⁻³), caused varied soil detachment capacities (0.043 to 4.580 kg·m⁻²·s⁻¹), rill erodibilities (0.051 to 0.237 s m⁻¹), and critical shear stresses (2.02 to 6.83 Pa). The Plant Litter incorporated within the soil reduced the soil detachment capacities by 38%–59%, lowered the rill erodibilities by 32%–46%, and increased the critical shear stresses by 98%–193% compared with the bare soil control. The soil containing B. ischaemum (L.) Keng. Litter was more resistant to erosion. By comparing different parameters, we found that the contact area between the Litter and soil was the main factor affecting the soil detachment process. The soil erosion resistance increased with the increasing contact area between the soil and Litter. Furthermore, the Litter incorporation effect on rill erodibility can be comprehensively reflected by LSAD (R² = .93; Nash–Sutcliffe efficiency = 0.79), which could be used to adjust the rill erodibility parameter in physical process‐based soil erosion models.
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effects of soil incorporated Plant Litter morphological characteristics on the soil detachment process in grassland on the loess plateau of china
Science of The Total Environment, 2020Co-Authors: Dennis C. Flanagan, Zhongyu Wang, Bing Wang, Jing XiaoAbstract:: The Loess Plateau of China is one of the most eroded areas in the world. In the past 20 years, effective vegetation restoration measures have significantly changed the near-surface characteristics of soil. In natural conditions, Plant Litter is widespread in the topsoil. The effects of Litter incorporated into soil on the process of soil detachment, which is closely related to Plant Litter morphology, are still not well known. This study aimed to detect the variation of Litter morphological characteristics and quantify their effects on soil detachment capacity and rill erodibility when Litter is incorporated into the soil. Four Plant Litters (Bothriochloa ischaemum (L.) Keng., Artemisia sacrorum Ledeb., Setaria viridis (L.) Beauv., and Artemisia capillaris Thunb.) with five length levels (<0.5, 0.5-2, 2-4, 4-6, and 6-8 cm) were incorporated into soil (idle for 50 days) at the same Litter biomass rate (0.7 kg m-2). Then the soil was sampled and cores were subjected to overland flow under six flow shear stress levels (5.66, 8.31, 12.21, 15.55, 19.15 and, 22.11 Pa) using a hydraulic flume (4.0 m × 0.35 m). The results showed that the Litter morphological characteristics of Litter length density (LLD), Litter surface area density (LSAD) and Litter volume ratio (LVR) differed in Plant species at the same Litter biomass rate. Correspondingly, soil detachment capacity (ranging from 0.414 to 2.179 kg m-2 s-1) and rill erodibility (ranging from 0.037 to 0.177 s m-1) varied significantly and mean values from the Bothriochloa ischaemum (L.) Keng. treatments were the minimums, which were 28% to 37% and 23% to 35% less than that of the other treatments, respectively. The soil detachment capacity and rill erodibility were significantly correlated with the Litter morphological characteristics of LLD, LSAD and LVR (p < 0.01). The contact area between Litter and soil was the most critical factor affecting soil detachment. Incorporated Plant Litter residue Litter effect on rill erodibility could be well estimated by LSAD.
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effects of soil incorporated Plant Litter morphological characteristics on the soil detachment process in grassland on the loess plateau of china
Science of The Total Environment, 2020Co-Authors: Jiaxin Liu, Dennis C. Flanagan, Zhongyu Wang, Bing Wang, Guobin Liu, Jing XiaoAbstract:Abstract The Loess Plateau of China is one of the most eroded areas in the world. In the past 20 years, effective vegetation restoration measures have significantly changed the near-surface characteristics of soil. In natural conditions, Plant Litter is widespread in the topsoil. The effects of Litter incorporated into soil on the process of soil detachment, which is closely related to Plant Litter morphology, are still not well known. This study aimed to detect the variation of Litter morphological characteristics and quantify their effects on soil detachment capacity and rill erodibility when Litter is incorporated into the soil. Four Plant Litters (Bothriochloa ischaemum (L.) Keng., Artemisia sacrorum Ledeb., Setaria viridis (L.) Beauv., and Artemisia capillaris Thunb.) with five length levels (
Francois Rineau - One of the best experts on this subject based on the ideXlab platform.
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the ectomycorrhizal fungus paxillus involutus converts organic matter in Plant Litter using a trimmed brown rot mechanism involving fenton chemistry
Environmental Microbiology 14 6 1477-1487 June 2012, 2014Co-Authors: Francois RineauAbstract:The ectomycorrhizal fungus Paxillus involutus converts organic matter in Plant Litter using a trimmed brown-rot mechanism involving Fenton chemistry Francois Rineau,1 Doris Roth,2 Firoz Shah,1, Mark Smits,3 Tomas Johansson,1 Bjorn Canback,1 Peter Bjarke Olsen,4 Per Persson,5 Morten Nedergaard Grell,2 Erika Lindquist,6 Igor V. Grigoriev,6 Lene Lange2 and Anders Tunlid1* 1Department of Biology, Microbial Ecology Group,Ecology Building, SE-22362 Lund, Sweden. 2Department of Biotechnology and Chemistry, AalborgUniversity, Lautrupvang 15, DK- 2750, Ballerup,Denmark. 3Centre for Environmental Sciences, Hasselt University,Building D, Agoralaan, 3590 Diepenbeek, Limburg,Belgium. 4Novozymes, Krogshoejvej 36, DK- 2880 Bagsvaerd,Denmark. 5Department of Chemistry, Umea University, SE-901 87Umea, Sweden. 6US Department of Energy, Joint Genome Institute,2800 Mitchell Avenue, Walnut Creek, CA94598, USA. June 2012 The work conducted by the U.S. Department of Energy Joint Genome Institute is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02- 05CH11231
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the ectomycorrhizal fungus paxillus involutus converts organic matter in Plant Litter using a trimmed brown rot mechanism involving fenton chemistry
Environmental Microbiology, 2012Co-Authors: Francois Rineau, Doris Roth, Firoz Shah, Mark M Smits, Tomas Johansson, Bjorn Canback, Peter Bjarke Olsen, Per Persson, Morten Nedergaard Grell, Erika LindquistAbstract:Soils in boreal forests contain large stocks of carbon. Plants are the main source of this carbon through tissue residues and root exudates. A major part of the exudates are allocated to symbiotic ectomycorrhizal fungi. In return, the Plant receives nutrients, in particular nitrogen from the mycorrhizal fungi. To capture the nitrogen, the fungi must at least partly disrupt the recalcitrant organic matter-protein complexes within which the nitrogen is embedded. This disruption process is poorly characterized. We used spectroscopic analyses and transcriptome profiling to examine the mechanism by which the ectomycorrhizal fungus Paxillus involutus degrades organic matter when acquiring nitrogen from Plant Litter. The fungus partially degraded polysaccharides and modified the structure of polyphenols. The observed chemical changes were consistent with a hydroxyl radical attack, involving Fenton chemistry similar to that of brown-rot fungi. The set of enzymes expressed by Pa. involutus during the degradation of the organic matter was similar to the set of enzymes involved in the oxidative degradation of wood by brown-rot fungi. However, Pa. involutus lacked transcripts encoding extracellular enzymes needed for metabolizing the released carbon. The saprotrophic activity has been reduced to a radical-based biodegradation system that can efficiently disrupt the organic matter-protein complexes and thereby mobilize the entrapped nutrients. We suggest that the released carbon then becomes available for further degradation and assimilation by commensal microbes, and that these activities have been lost in ectomycorrhizal fungi as an adaptation to symbiotic growth on host photosynthate. The interdependence of ectomycorrhizal symbionts and saprophytic microbes would provide a key link in the turnover of nutrients and carbon in forest ecosystems.
Jing Xiao - One of the best experts on this subject based on the ideXlab platform.
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effects of soil incorporated Plant Litter morphological characteristics on the soil detachment process in grassland on the loess plateau of china
Science of The Total Environment, 2020Co-Authors: Dennis C. Flanagan, Zhongyu Wang, Bing Wang, Jing XiaoAbstract:: The Loess Plateau of China is one of the most eroded areas in the world. In the past 20 years, effective vegetation restoration measures have significantly changed the near-surface characteristics of soil. In natural conditions, Plant Litter is widespread in the topsoil. The effects of Litter incorporated into soil on the process of soil detachment, which is closely related to Plant Litter morphology, are still not well known. This study aimed to detect the variation of Litter morphological characteristics and quantify their effects on soil detachment capacity and rill erodibility when Litter is incorporated into the soil. Four Plant Litters (Bothriochloa ischaemum (L.) Keng., Artemisia sacrorum Ledeb., Setaria viridis (L.) Beauv., and Artemisia capillaris Thunb.) with five length levels (<0.5, 0.5-2, 2-4, 4-6, and 6-8 cm) were incorporated into soil (idle for 50 days) at the same Litter biomass rate (0.7 kg m-2). Then the soil was sampled and cores were subjected to overland flow under six flow shear stress levels (5.66, 8.31, 12.21, 15.55, 19.15 and, 22.11 Pa) using a hydraulic flume (4.0 m × 0.35 m). The results showed that the Litter morphological characteristics of Litter length density (LLD), Litter surface area density (LSAD) and Litter volume ratio (LVR) differed in Plant species at the same Litter biomass rate. Correspondingly, soil detachment capacity (ranging from 0.414 to 2.179 kg m-2 s-1) and rill erodibility (ranging from 0.037 to 0.177 s m-1) varied significantly and mean values from the Bothriochloa ischaemum (L.) Keng. treatments were the minimums, which were 28% to 37% and 23% to 35% less than that of the other treatments, respectively. The soil detachment capacity and rill erodibility were significantly correlated with the Litter morphological characteristics of LLD, LSAD and LVR (p < 0.01). The contact area between Litter and soil was the most critical factor affecting soil detachment. Incorporated Plant Litter residue Litter effect on rill erodibility could be well estimated by LSAD.
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effects of soil incorporated Plant Litter morphological characteristics on the soil detachment process in grassland on the loess plateau of china
Science of The Total Environment, 2020Co-Authors: Jiaxin Liu, Dennis C. Flanagan, Zhongyu Wang, Bing Wang, Guobin Liu, Jing XiaoAbstract:Abstract The Loess Plateau of China is one of the most eroded areas in the world. In the past 20 years, effective vegetation restoration measures have significantly changed the near-surface characteristics of soil. In natural conditions, Plant Litter is widespread in the topsoil. The effects of Litter incorporated into soil on the process of soil detachment, which is closely related to Plant Litter morphology, are still not well known. This study aimed to detect the variation of Litter morphological characteristics and quantify their effects on soil detachment capacity and rill erodibility when Litter is incorporated into the soil. Four Plant Litters (Bothriochloa ischaemum (L.) Keng., Artemisia sacrorum Ledeb., Setaria viridis (L.) Beauv., and Artemisia capillaris Thunb.) with five length levels (
Bing Wang - One of the best experts on this subject based on the ideXlab platform.
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effects of soil incorporated Plant Litter morphological characteristics on the soil detachment process in grassland on the loess plateau of china
Science of The Total Environment, 2020Co-Authors: Dennis C. Flanagan, Zhongyu Wang, Bing Wang, Jing XiaoAbstract:: The Loess Plateau of China is one of the most eroded areas in the world. In the past 20 years, effective vegetation restoration measures have significantly changed the near-surface characteristics of soil. In natural conditions, Plant Litter is widespread in the topsoil. The effects of Litter incorporated into soil on the process of soil detachment, which is closely related to Plant Litter morphology, are still not well known. This study aimed to detect the variation of Litter morphological characteristics and quantify their effects on soil detachment capacity and rill erodibility when Litter is incorporated into the soil. Four Plant Litters (Bothriochloa ischaemum (L.) Keng., Artemisia sacrorum Ledeb., Setaria viridis (L.) Beauv., and Artemisia capillaris Thunb.) with five length levels (<0.5, 0.5-2, 2-4, 4-6, and 6-8 cm) were incorporated into soil (idle for 50 days) at the same Litter biomass rate (0.7 kg m-2). Then the soil was sampled and cores were subjected to overland flow under six flow shear stress levels (5.66, 8.31, 12.21, 15.55, 19.15 and, 22.11 Pa) using a hydraulic flume (4.0 m × 0.35 m). The results showed that the Litter morphological characteristics of Litter length density (LLD), Litter surface area density (LSAD) and Litter volume ratio (LVR) differed in Plant species at the same Litter biomass rate. Correspondingly, soil detachment capacity (ranging from 0.414 to 2.179 kg m-2 s-1) and rill erodibility (ranging from 0.037 to 0.177 s m-1) varied significantly and mean values from the Bothriochloa ischaemum (L.) Keng. treatments were the minimums, which were 28% to 37% and 23% to 35% less than that of the other treatments, respectively. The soil detachment capacity and rill erodibility were significantly correlated with the Litter morphological characteristics of LLD, LSAD and LVR (p < 0.01). The contact area between Litter and soil was the most critical factor affecting soil detachment. Incorporated Plant Litter residue Litter effect on rill erodibility could be well estimated by LSAD.
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effects of soil incorporated Plant Litter morphological characteristics on the soil detachment process in grassland on the loess plateau of china
Science of The Total Environment, 2020Co-Authors: Jiaxin Liu, Dennis C. Flanagan, Zhongyu Wang, Bing Wang, Guobin Liu, Jing XiaoAbstract:Abstract The Loess Plateau of China is one of the most eroded areas in the world. In the past 20 years, effective vegetation restoration measures have significantly changed the near-surface characteristics of soil. In natural conditions, Plant Litter is widespread in the topsoil. The effects of Litter incorporated into soil on the process of soil detachment, which is closely related to Plant Litter morphology, are still not well known. This study aimed to detect the variation of Litter morphological characteristics and quantify their effects on soil detachment capacity and rill erodibility when Litter is incorporated into the soil. Four Plant Litters (Bothriochloa ischaemum (L.) Keng., Artemisia sacrorum Ledeb., Setaria viridis (L.) Beauv., and Artemisia capillaris Thunb.) with five length levels (
Erika Lindquist - One of the best experts on this subject based on the ideXlab platform.
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the ectomycorrhizal fungus paxillus involutus converts organic matter in Plant Litter using a trimmed brown rot mechanism involving fenton chemistry
Environmental Microbiology, 2012Co-Authors: Francois Rineau, Doris Roth, Firoz Shah, Mark M Smits, Tomas Johansson, Bjorn Canback, Peter Bjarke Olsen, Per Persson, Morten Nedergaard Grell, Erika LindquistAbstract:Soils in boreal forests contain large stocks of carbon. Plants are the main source of this carbon through tissue residues and root exudates. A major part of the exudates are allocated to symbiotic ectomycorrhizal fungi. In return, the Plant receives nutrients, in particular nitrogen from the mycorrhizal fungi. To capture the nitrogen, the fungi must at least partly disrupt the recalcitrant organic matter-protein complexes within which the nitrogen is embedded. This disruption process is poorly characterized. We used spectroscopic analyses and transcriptome profiling to examine the mechanism by which the ectomycorrhizal fungus Paxillus involutus degrades organic matter when acquiring nitrogen from Plant Litter. The fungus partially degraded polysaccharides and modified the structure of polyphenols. The observed chemical changes were consistent with a hydroxyl radical attack, involving Fenton chemistry similar to that of brown-rot fungi. The set of enzymes expressed by Pa. involutus during the degradation of the organic matter was similar to the set of enzymes involved in the oxidative degradation of wood by brown-rot fungi. However, Pa. involutus lacked transcripts encoding extracellular enzymes needed for metabolizing the released carbon. The saprotrophic activity has been reduced to a radical-based biodegradation system that can efficiently disrupt the organic matter-protein complexes and thereby mobilize the entrapped nutrients. We suggest that the released carbon then becomes available for further degradation and assimilation by commensal microbes, and that these activities have been lost in ectomycorrhizal fungi as an adaptation to symbiotic growth on host photosynthate. The interdependence of ectomycorrhizal symbionts and saprophytic microbes would provide a key link in the turnover of nutrients and carbon in forest ecosystems.
