<i><span style="font-family:Verdana;">Bacillus thuringiensis</span></i><span style="font-family:""><span style="font-family:Verdana;"> (Bt) produc...<i><span style="font-family:Verdana;">Bacillus thuringiensis</span></i><span style="font-family:""><span style="font-family:Verdana;"> (Bt) produces two families of insecticidal crystal proteins, </span><i><span style="font-family:Verdana;">i.e.</span></i><span style="font-family:Verdana;">, crystalline (Cry) and cytolytic (Cyt) toxins. Cyt3Aa1, the newest Cyt family member, is produced by Bt TD516. Bioassay results have shown that Cyt3Aa1 has weak hemolytic activity against human red blood cells and is not toxic to </span><i><span style="font-family:Verdana;">A.</span></i></span><i><span style="font-family:""> </span></i><i><span style="font-family:Verdana;">aegypti</span></i><span style="font-family:Verdana;"> larvae, but causing a teratogenic effect. The three-dimensional structure of Cyt3Aa1 ha</span><span style="font-family:Verdana;">s </span><span style="font-family:""><span style="font-family:Verdana;">a typical cytolysin fold containing a </span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">-sheet held by two surrounding </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-helical layers, resembling the previously reported Cyt1Aa and Cyt2Aa structures, which indicated that Cyt3Aa1 might be a membrane-perforation toxin and could induce synergism with Cry protein. This study provides a new source of insecticidal crystal proteins, and presents a foundation for understanding the biological characterization of it, which will aid in the development of strategies to cope with the potential problem of insect resistance.展开更多
Pollen fertility is an agronomic trait that strongly influences rice yield. Recent studies have revealed that the development of the pollen wall is required for pollen fertility and is regulated by several genes. Howe...Pollen fertility is an agronomic trait that strongly influences rice yield. Recent studies have revealed that the development of the pollen wall is required for pollen fertility and is regulated by several genes. However, the mechanisms underlying pollen and pollen wall development in rice remain largely unknown. In the present study, a point mutation in a gene on chromosome 1 was identified that resulted in the production of less and shrunken pollen(LSP) and led to defects in pollen wall formation. This gene was named LSP1 and was found to encode a member of the adenosine triphosphate-binding cassette(ABC)transporter G subfamily, OsABCG3. Two other loss-of-function mutants of LSP1/OsABCG3,generated using CRISPR/Cas9 technology, showed the same male sterile phenotype. The LSP1/OsABCG3 gene showed a spatio-temporal expression pattern in the developing anthers, and is an ortholog of the Arabidopsis genes At ABCG1 and At ABCG16, which play an important role in pollen wall development. Mutation of LSP1/OsABCG3 affected the expression of several genes involved in pollen and pollen wall formation. These results suggest that LSP1/OsABCG3 is critical for normal pollen fertility and shed light on the molecular mechanisms underlying rice pollen wall development.展开更多
To the Editor:Biologics have been used successfully for the treatment of psoriasis;however,some patients develop paradoxical reactions,particularly psoriasiform and eczematoid reactions.Eczematoid paradoxical reaction...To the Editor:Biologics have been used successfully for the treatment of psoriasis;however,some patients develop paradoxical reactions,particularly psoriasiform and eczematoid reactions.Eczematoid paradoxical reactions(EPRs)occur in 1%–6%of cases treated with tumor necrosis factor(TNF)-αinhibitors,2.4%with interleukin(IL)-12/23 inhibitors,3.5%with IL-17 inhibitors,and 0.01%with IL-23 inhibitors.[1]In practice,the incidence of EPRs induced by IL-17A inhibitors varies widely[2–4]and biologicals may have to be discontinued in some severe cases.展开更多
Grain size is an important factor determining yield in rice. Here, we identified a recessive mutant gene, grain length and awn 1 (gla1), which caused a significant increase in grain length and weight, and was associat...Grain size is an important factor determining yield in rice. Here, we identified a recessive mutant gene, grain length and awn 1 (gla1), which caused a significant increase in grain length and weight, and was associated with long awns. The gla1 mutation was mapped to a single-nucleotide polymorphism in a gene encoding a cytoplasmically-localized mitogen-activated protein kinase (MAPK) phosphatase. Overexpression of GLA1 caused a decrease in grain length, and the GLA1 protein interacted with OsMAPK6. These results suggest that GLA1 may serve as a negative regulator of the OsMAPKK4-OsMAPK6 cascade, controlling grain size via the dephosphorylation of OsMAPK6.展开更多
Arabinogalactan proteins(AGPs)are widely distributed in plant cells.Fasciclin-like AGPs(FLAs)belong to a subclass of AGPs that play important roles in plant growth and development.However,little is known about the bio...Arabinogalactan proteins(AGPs)are widely distributed in plant cells.Fasciclin-like AGPs(FLAs)belong to a subclass of AGPs that play important roles in plant growth and development.However,little is known about the biological functions of rice FLA.Herein,we report the identification of a male-sterile mutant of DEFECTIVE EXINE AND APERTURE PATTERNING1(DEAP1)in rice.The deap1 mutant anthers produced aberrant pollen grains with defective exine formation and a flattened aperture annulus and exhibited slightly delayed tapetum degradation.DEAP1 encodes a plasma membrane-associated member of groupⅢplant FLAs and is specifically and temporally expressed in reproductive cells and the tapetum layer during male development.Gene expression studies revealed reduced transcript accumulation of genes related to exine formation,aperture patterning,and tapetum development in deap1 mutants.Moreover,DEAP1 may interact with two rice D6 PROTEIN KINASE-LIKE3 s(OsD6PKL3s),homologs of a known Arabidopsis aperture protein,to affect rice pollen aperture development.Our findings suggested that DEAP1 is involved in male reproductive development and may affect exine formation and aperture patterning,thereby providing new insights into the molecular functions of plant FLAs in male fertility.展开更多
Soil erosion disturbs not only the global carbon cycle,but it is a complex environmental problem.Revegetation could reduce carbon emission by controlling soil erosion and increase carbon sequestration and accumulation...Soil erosion disturbs not only the global carbon cycle,but it is a complex environmental problem.Revegetation could reduce carbon emission by controlling soil erosion and increase carbon sequestration and accumulation by fixing carbon in vegetation and soil.The Grain for Green Program(GFGP)of China is the largest ecological restoration program in the world closely related to land-use/land-cover change(LUCC).Systematically assessing the carbon sequestration benefit of GFGP is crucial for a better understanding of the effects of implementing GFGP and providing reasonable vegetation management.Therefore,we selected the hilly red soil region(HRSR)of southern China as a study area,which is one of the main ecologically vulnerable areas in China.We assessed the carbon sequestration in the GFGP area of the HRSR using the InVEST(Integrated Valuation of Environmental Services and Tradeoffs)model based on land-use/land-cover datasets during 2000e2015.Our results show that implementing GFGP is conducive to the enhancement of carbon sequestration services.Total carbon sequestration showed an increasing trend at a rate of 15.43%from 2000 to 2015.The most significant change mainly happened in Hunan Province with the shortest implementation time.The carbon sequestration of each carbon pool(namely aboveground biomass,belowground biomass,soil,and dead organic matter)also increased slightly.Additionally,for carbon sequestration,unused land converted to forest land is the most effective LUCC.This study can provide scientific support for the management and implementation of GFGP in the HRSR of China.展开更多
Regulatory T(T_(reg))cells play an essential role in maintaining immune balance across various physiological and pathological conditions.However,the mechanisms underlying T_(reg)homeostasis remain incompletely underst...Regulatory T(T_(reg))cells play an essential role in maintaining immune balance across various physiological and pathological conditions.However,the mechanisms underlying T_(reg)homeostasis remain incompletely understood.Here,we report that RIPK1 is crucial for T_(reg) cell survival and homeostasis.We generated mice with T_(reg) cell-specific ablation of Ripk1 and found that these mice developed fatal systemic autoimmunity due to a dramatic reduction in the Treg cell compartment caused by excessive cell death.Unlike conventional T cells,Treg cells with Ripk1 deficiency were only partially rescued from cell death by blocking FADD-dependent apoptosis.However,simultaneous removal of both Fadd and Ripk3 completely restored the homeostasis of Ripk1-deficient Treg cells by blocking two cell death pathways.Thus,our study highlights the critical role of RIPK1 in regulating Treg cell homeostasis by controlling both apoptosis and necroptosis,thereby providing novel insights into the mechanisms of Treg cell homeostasis.展开更多
The hypersecretion of cytokines triggers life-threatening systemic inflammatory response syndrome(SIRS),leading to multiple organ dysfunction syndrome(MODS)and mortality.Although both coagulopathy and necroptosis have...The hypersecretion of cytokines triggers life-threatening systemic inflammatory response syndrome(SIRS),leading to multiple organ dysfunction syndrome(MODS)and mortality.Although both coagulopathy and necroptosis have been identified as important factors in the pathogenesis of SIRS,the specific cell types that undergo necroptosis and the interrelationships between coagulopathy and necroptosis remain unclear.In this study,we utilized visualization analysis via intravital microscopy to demonstrate that both anticoagulant heparin and nonanticoagulant heparin(NAH)pretreatment protect mice against TNF-α-induced mortality in SIRS.Moreover,the deletion of Mlkl or Ripk3 resulted in decreased coagulation and reduced mortality in TNF-α-induced SIRS.These findings suggest that necroptosis plays a key role upstream of coagulation in SIRS-related mortality.Furthermore,using a genetic lineage tracing mouse model(Tie2-Cre;Rosa26-tdT),we tracked endothelial cells(ECs)and verified that EC necroptosis is responsible for the vascular damage observed in TNF-α-treated mice.Importantly,Mlkl deletion in vascular ECs in mice had a similar protective effect against lethal SIRS by blocking EC necroptosis to protect the integrity of the endothelium.Collectively,our findings demonstrated that RIPK3–MLKL-dependent necroptosis disrupted vascular integrity,resulting in coagulopathy and multiorgan failure,eventually leading to mortality in SIRS patients.These results highlight the importance of targeting vascular EC necroptosis for the development of effective treatments for SIRS patients.展开更多
To improve soil carbon sequestration capacity,the full soil carbon cycle process needs to be understood and quantified.It is essential to evaluate whether water erosion acts as a net source or sink of atmospheric CO_(...To improve soil carbon sequestration capacity,the full soil carbon cycle process needs to be understood and quantified.It is essential to evaluate whether water erosion acts as a net source or sink of atmospheric CO_(2)at the basin scale,which encompasses the entire hydrological process.This study introduced an approach that combined a spatially distributed sediment delivery model and biogeochemical model to estimate the lateral and vertical carbon fluxes by water erosion at the basin scale.Applying this coupling model to the Dongting Lake Basin,the results showed that the annual average amount of soil erosion during 1980-2020 was 1.33×10^(8)t,displaying a decreasing trend followed by a slight increase.Only 12% of the soil organic carbon displacement was ultimately lost in the riverine systems,and the rest was deposited downhill within the basin.The average lateral soil organic carbon loss induced by erosion was 8.86×10^(11)g C in 1980 and 1.50×10^(11)g C in 2020,with a decline rate of 83%.A net land sink for atmospheric CO_(2)of 5.54×1011g C a^(-1)occurred during erosion,primarily through sediment burial and dynamic replacement.However,ecological restoration projects and tillage practice policies are still significant in reducing erosion,which could improve the capacity of the carbon sink for recovery beyond the rate of horizontal carbon removal.Moreover,our model enables the spatial explicit simulation of erosion-induced carbon fluxes using costeffective and easily accessible input data across large spatial scales and long timeframes.Consequently,it offers a valuable tool for predicting the interactions between carbon dynamics,land use changes,and future climate.展开更多
The variability of soil organic carbon(SOC)extends across three dimensions.However,quantitative analyses of the factors influencing spatiotemporal variations of SOC in various soil depth is scarce.This study leverages...The variability of soil organic carbon(SOC)extends across three dimensions.However,quantitative analyses of the factors influencing spatiotemporal variations of SOC in various soil depth is scarce.This study leverages legacy data from two soil surveys conducted in the Dongting Lake Basin during the 1980s and the 2010s,employing Random Forest models to generate three-dimensional SOC maps.Through correlation analysis and permutation importance,we identified the primary factors driving temporal and spatial changes of SOC.The results showed that in the 2010s,SOC storage up to a depth of 1 m in the Dongting Lake Basin was approximately 2.95 Pg,increasing at an average rate of 0.0047 Pg C per year since the 1980s.Regions with higher average SOC contents were predominantly found in the western,southern,and eastern parts of the basin,despite significant losses over the 30-year period.In contrast,the central and northern areas,which initially had lower SOC contents in the 1980s,exhibited increases by the 2010s.Soil depth was the most influential predictor of SOC patterns in both the 1980s and 2010s.Meanwhile,relief and organism factors were primarily responsible for spatial variations in SOC,with the influence of organism factors diminishing by the 2010s.The temporal variations of SOC were chiefly attributed to changes in soil conservation practices,extreme precipitation events,and grain production.Consequently,it is imperative to prioritize ecological restoration and conservation tillage practices to mitigate the impacts of extreme weather conditions and safeguard food security.展开更多
文摘<i><span style="font-family:Verdana;">Bacillus thuringiensis</span></i><span style="font-family:""><span style="font-family:Verdana;"> (Bt) produces two families of insecticidal crystal proteins, </span><i><span style="font-family:Verdana;">i.e.</span></i><span style="font-family:Verdana;">, crystalline (Cry) and cytolytic (Cyt) toxins. Cyt3Aa1, the newest Cyt family member, is produced by Bt TD516. Bioassay results have shown that Cyt3Aa1 has weak hemolytic activity against human red blood cells and is not toxic to </span><i><span style="font-family:Verdana;">A.</span></i></span><i><span style="font-family:""> </span></i><i><span style="font-family:Verdana;">aegypti</span></i><span style="font-family:Verdana;"> larvae, but causing a teratogenic effect. The three-dimensional structure of Cyt3Aa1 ha</span><span style="font-family:Verdana;">s </span><span style="font-family:""><span style="font-family:Verdana;">a typical cytolysin fold containing a </span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">-sheet held by two surrounding </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-helical layers, resembling the previously reported Cyt1Aa and Cyt2Aa structures, which indicated that Cyt3Aa1 might be a membrane-perforation toxin and could induce synergism with Cry protein. This study provides a new source of insecticidal crystal proteins, and presents a foundation for understanding the biological characterization of it, which will aid in the development of strategies to cope with the potential problem of insect resistance.
基金supported by the National Natural Science Foundation of China(31570004)the Open Research Fund of State Key Laboratory of Hybrid Rice,Hunan Hybrid Rice Research Center(2016KF10)+1 种基金the Sichuan Province Science and Technology Support Program(2016NZ0103 and2017NZDZX0001)the National Key Research and Development Program of China(2017YFD0100201)。
文摘Pollen fertility is an agronomic trait that strongly influences rice yield. Recent studies have revealed that the development of the pollen wall is required for pollen fertility and is regulated by several genes. However, the mechanisms underlying pollen and pollen wall development in rice remain largely unknown. In the present study, a point mutation in a gene on chromosome 1 was identified that resulted in the production of less and shrunken pollen(LSP) and led to defects in pollen wall formation. This gene was named LSP1 and was found to encode a member of the adenosine triphosphate-binding cassette(ABC)transporter G subfamily, OsABCG3. Two other loss-of-function mutants of LSP1/OsABCG3,generated using CRISPR/Cas9 technology, showed the same male sterile phenotype. The LSP1/OsABCG3 gene showed a spatio-temporal expression pattern in the developing anthers, and is an ortholog of the Arabidopsis genes At ABCG1 and At ABCG16, which play an important role in pollen wall development. Mutation of LSP1/OsABCG3 affected the expression of several genes involved in pollen and pollen wall formation. These results suggest that LSP1/OsABCG3 is critical for normal pollen fertility and shed light on the molecular mechanisms underlying rice pollen wall development.
基金supported by a grant from Bethune Charitable Foundation(No.J202301E036).
文摘To the Editor:Biologics have been used successfully for the treatment of psoriasis;however,some patients develop paradoxical reactions,particularly psoriasiform and eczematoid reactions.Eczematoid paradoxical reactions(EPRs)occur in 1%–6%of cases treated with tumor necrosis factor(TNF)-αinhibitors,2.4%with interleukin(IL)-12/23 inhibitors,3.5%with IL-17 inhibitors,and 0.01%with IL-23 inhibitors.[1]In practice,the incidence of EPRs induced by IL-17A inhibitors varies widely[2–4]and biologicals may have to be discontinued in some severe cases.
基金supported by the National Natural Science Foundation of China (31570004 and 31471474)the Open Research Fund of State Key Laboratory of Hybrid Rice (Hunan Hybrid Rice Research Center, 2016KF10)the Sichuan Science and Technology Support Project (2017NZDZX0001, 2016NZ0103)
文摘Grain size is an important factor determining yield in rice. Here, we identified a recessive mutant gene, grain length and awn 1 (gla1), which caused a significant increase in grain length and weight, and was associated with long awns. The gla1 mutation was mapped to a single-nucleotide polymorphism in a gene encoding a cytoplasmically-localized mitogen-activated protein kinase (MAPK) phosphatase. Overexpression of GLA1 caused a decrease in grain length, and the GLA1 protein interacted with OsMAPK6. These results suggest that GLA1 may serve as a negative regulator of the OsMAPKK4-OsMAPK6 cascade, controlling grain size via the dephosphorylation of OsMAPK6.
基金supported by funds from the National Natural Science Foundation of China(31901482,31971863,31971867 and 32171966)the Open Research Fund of the State Key Laboratory of Hybrid Rice(Hunan Hybrid Rice Research Centre,2016KF10)the Sichuan Province Science and Technology Support Program(2021YFYZ0016,2021YFYZ0027,2020YJ0139)。
文摘Arabinogalactan proteins(AGPs)are widely distributed in plant cells.Fasciclin-like AGPs(FLAs)belong to a subclass of AGPs that play important roles in plant growth and development.However,little is known about the biological functions of rice FLA.Herein,we report the identification of a male-sterile mutant of DEFECTIVE EXINE AND APERTURE PATTERNING1(DEAP1)in rice.The deap1 mutant anthers produced aberrant pollen grains with defective exine formation and a flattened aperture annulus and exhibited slightly delayed tapetum degradation.DEAP1 encodes a plasma membrane-associated member of groupⅢplant FLAs and is specifically and temporally expressed in reproductive cells and the tapetum layer during male development.Gene expression studies revealed reduced transcript accumulation of genes related to exine formation,aperture patterning,and tapetum development in deap1 mutants.Moreover,DEAP1 may interact with two rice D6 PROTEIN KINASE-LIKE3 s(OsD6PKL3s),homologs of a known Arabidopsis aperture protein,to affect rice pollen aperture development.Our findings suggested that DEAP1 is involved in male reproductive development and may affect exine formation and aperture patterning,thereby providing new insights into the molecular functions of plant FLAs in male fertility.
基金This research was funded by the National Key Research and Development Program of China(2017YFC0505401).
文摘Soil erosion disturbs not only the global carbon cycle,but it is a complex environmental problem.Revegetation could reduce carbon emission by controlling soil erosion and increase carbon sequestration and accumulation by fixing carbon in vegetation and soil.The Grain for Green Program(GFGP)of China is the largest ecological restoration program in the world closely related to land-use/land-cover change(LUCC).Systematically assessing the carbon sequestration benefit of GFGP is crucial for a better understanding of the effects of implementing GFGP and providing reasonable vegetation management.Therefore,we selected the hilly red soil region(HRSR)of southern China as a study area,which is one of the main ecologically vulnerable areas in China.We assessed the carbon sequestration in the GFGP area of the HRSR using the InVEST(Integrated Valuation of Environmental Services and Tradeoffs)model based on land-use/land-cover datasets during 2000e2015.Our results show that implementing GFGP is conducive to the enhancement of carbon sequestration services.Total carbon sequestration showed an increasing trend at a rate of 15.43%from 2000 to 2015.The most significant change mainly happened in Hunan Province with the shortest implementation time.The carbon sequestration of each carbon pool(namely aboveground biomass,belowground biomass,soil,and dead organic matter)also increased slightly.Additionally,for carbon sequestration,unused land converted to forest land is the most effective LUCC.This study can provide scientific support for the management and implementation of GFGP in the HRSR of China.
基金supported by the following grants:National Key Research and Development Program of China(2021YFA1301402)Shanghai Municipal Science and Technology Major Project(ZD2021CY001)+4 种基金National Key Research and Development Program of China(2021YFE0200900,2022YFA0807300)National Natural Science Foundation of China(82101833,82073901)Three-year Action Plan for Shanghai TCM Development and Inheritance Program[ZY(2021-2023)-0103]Top-level Clinical Discipline Project of Shanghai Pudong District(grant/award number:PWYgf 2021-01)Training Plan for Discipline Leaders of Shanghai Pudong New Area Health Commission(grant/award number:PWRd2020-09).
文摘Regulatory T(T_(reg))cells play an essential role in maintaining immune balance across various physiological and pathological conditions.However,the mechanisms underlying T_(reg)homeostasis remain incompletely understood.Here,we report that RIPK1 is crucial for T_(reg) cell survival and homeostasis.We generated mice with T_(reg) cell-specific ablation of Ripk1 and found that these mice developed fatal systemic autoimmunity due to a dramatic reduction in the Treg cell compartment caused by excessive cell death.Unlike conventional T cells,Treg cells with Ripk1 deficiency were only partially rescued from cell death by blocking FADD-dependent apoptosis.However,simultaneous removal of both Fadd and Ripk3 completely restored the homeostasis of Ripk1-deficient Treg cells by blocking two cell death pathways.Thus,our study highlights the critical role of RIPK1 in regulating Treg cell homeostasis by controlling both apoptosis and necroptosis,thereby providing novel insights into the mechanisms of Treg cell homeostasis.
基金supported by grants from the National Key Research and Development Program of China(2022YFA0807300)the National Natural Science Foundation of China(32270803,32300630,82272181,T2293734)+2 种基金the Shanghai Excellent Academic/Technical Leader Program(22XD1404500)the Shanghai Science and Technology Commission(23141902800)the China Postdoctoral Science Foundation(2020M671261).
文摘The hypersecretion of cytokines triggers life-threatening systemic inflammatory response syndrome(SIRS),leading to multiple organ dysfunction syndrome(MODS)and mortality.Although both coagulopathy and necroptosis have been identified as important factors in the pathogenesis of SIRS,the specific cell types that undergo necroptosis and the interrelationships between coagulopathy and necroptosis remain unclear.In this study,we utilized visualization analysis via intravital microscopy to demonstrate that both anticoagulant heparin and nonanticoagulant heparin(NAH)pretreatment protect mice against TNF-α-induced mortality in SIRS.Moreover,the deletion of Mlkl or Ripk3 resulted in decreased coagulation and reduced mortality in TNF-α-induced SIRS.These findings suggest that necroptosis plays a key role upstream of coagulation in SIRS-related mortality.Furthermore,using a genetic lineage tracing mouse model(Tie2-Cre;Rosa26-tdT),we tracked endothelial cells(ECs)and verified that EC necroptosis is responsible for the vascular damage observed in TNF-α-treated mice.Importantly,Mlkl deletion in vascular ECs in mice had a similar protective effect against lethal SIRS by blocking EC necroptosis to protect the integrity of the endothelium.Collectively,our findings demonstrated that RIPK3–MLKL-dependent necroptosis disrupted vascular integrity,resulting in coagulopathy and multiorgan failure,eventually leading to mortality in SIRS patients.These results highlight the importance of targeting vascular EC necroptosis for the development of effective treatments for SIRS patients.
基金supported by the National Natural Science Foundation of China(Grant No.U19A2047)the Natural Science Foundation of Hunan Province(Grant No.2023JJ20030)。
文摘To improve soil carbon sequestration capacity,the full soil carbon cycle process needs to be understood and quantified.It is essential to evaluate whether water erosion acts as a net source or sink of atmospheric CO_(2)at the basin scale,which encompasses the entire hydrological process.This study introduced an approach that combined a spatially distributed sediment delivery model and biogeochemical model to estimate the lateral and vertical carbon fluxes by water erosion at the basin scale.Applying this coupling model to the Dongting Lake Basin,the results showed that the annual average amount of soil erosion during 1980-2020 was 1.33×10^(8)t,displaying a decreasing trend followed by a slight increase.Only 12% of the soil organic carbon displacement was ultimately lost in the riverine systems,and the rest was deposited downhill within the basin.The average lateral soil organic carbon loss induced by erosion was 8.86×10^(11)g C in 1980 and 1.50×10^(11)g C in 2020,with a decline rate of 83%.A net land sink for atmospheric CO_(2)of 5.54×1011g C a^(-1)occurred during erosion,primarily through sediment burial and dynamic replacement.However,ecological restoration projects and tillage practice policies are still significant in reducing erosion,which could improve the capacity of the carbon sink for recovery beyond the rate of horizontal carbon removal.Moreover,our model enables the spatial explicit simulation of erosion-induced carbon fluxes using costeffective and easily accessible input data across large spatial scales and long timeframes.Consequently,it offers a valuable tool for predicting the interactions between carbon dynamics,land use changes,and future climate.
基金supported by the National Natural Science Foundation of China(U19A2047)the Natural Science Foundation of Hunan Province(2023JJ20030).
文摘The variability of soil organic carbon(SOC)extends across three dimensions.However,quantitative analyses of the factors influencing spatiotemporal variations of SOC in various soil depth is scarce.This study leverages legacy data from two soil surveys conducted in the Dongting Lake Basin during the 1980s and the 2010s,employing Random Forest models to generate three-dimensional SOC maps.Through correlation analysis and permutation importance,we identified the primary factors driving temporal and spatial changes of SOC.The results showed that in the 2010s,SOC storage up to a depth of 1 m in the Dongting Lake Basin was approximately 2.95 Pg,increasing at an average rate of 0.0047 Pg C per year since the 1980s.Regions with higher average SOC contents were predominantly found in the western,southern,and eastern parts of the basin,despite significant losses over the 30-year period.In contrast,the central and northern areas,which initially had lower SOC contents in the 1980s,exhibited increases by the 2010s.Soil depth was the most influential predictor of SOC patterns in both the 1980s and 2010s.Meanwhile,relief and organism factors were primarily responsible for spatial variations in SOC,with the influence of organism factors diminishing by the 2010s.The temporal variations of SOC were chiefly attributed to changes in soil conservation practices,extreme precipitation events,and grain production.Consequently,it is imperative to prioritize ecological restoration and conservation tillage practices to mitigate the impacts of extreme weather conditions and safeguard food security.
