Solar farms have been rapidly expanding on the Qinghai-Tibetan Plateau.However,the effects of photovoltaic arrays on the contribution of microbial necromass carbon(MNC)to soil organic carbon(SOC),along with the underl...Solar farms have been rapidly expanding on the Qinghai-Tibetan Plateau.However,the effects of photovoltaic arrays on the contribution of microbial necromass carbon(MNC)to soil organic carbon(SOC),along with the underlying mechanisms,remain unclear.To address this,we collected soil samples from the top 20 cm in under-panel,inter-panel and control plots at five solar farms constructed between 2012 and 2014 in the dry Yarlung Tsangpo and Lhasa River valleys on the Qinghai-Tibetan Plateau.We determined SOC,fungal and bacterial necromass and relevant soil properties.We found that the concentration of MNC in the under-panel plots(3.93±0.79 mg g-1)was significantly higher compared to the control plots(2.28±0.79 mg g-1)across all five solar farms.The proportion of MNC to SOC in the under-panel plots(34.7±2.4%)was also significantly higher than that in the control plots(27.5±1.4%).Specifically,the contribution of fungal necromass to SOC in the under-panel plots(26.4±2.2%)was significantly larger than that in the control plots(19.7±1.6%),while the increase in the bacterial necromass proportion was insignificant.Partial least squares structural equation modeling(PLS-SEM)indicated a significant and positive effect of increased soil moisture in the under-panel plots on the proportion of fungal necromass to SOC.These results highlight that beyond their economic benefits,solar farms in the arid regions on the Qinghai-Tibetan Plateau can enhance soil C sequestration by improving soil moisture and promoting microbial necromass accumulation.展开更多
Fungi play a crucial role in the utilization and storage of soil organic carbon(SOC).Biochars can potentially influence soil carbon(C)turnover by mediating extracellular electron transfer,which can be facilitated by f...Fungi play a crucial role in the utilization and storage of soil organic carbon(SOC).Biochars can potentially influence soil carbon(C)turnover by mediating extracellular electron transfer,which can be facilitated by fungi.However,the effects of biochar and soil type on the community,abundance,enzyme secretion,and necromass of fungi mediating SOC storage remain unclear.A mesocosm incubation experiment was conducted using forest and paddy soils from southern China to study the impact of biochars pyrolyzed at low(300℃BL)and high(700℃BH)temperatures on fungal abundance,community composition,necromass abundance,and C-degrading enzyme activities.The SOC retention ratio was higher under BL(84.0%)than under BH(76.3%).Addition of BL increased fungal abundance in the forest soil by 230%.In contrast,addition of BH decreased fungal abundance in the paddy soil by 20.8%.Biochar addition affected fungal necromass accumulation and oxidase activity and regulated SOC turnover.The high available C content and moderate liming effect of BL significantly increased fungal abundance and necromass abundance in the forest soil compared to the paddy soil.Moreover,after 16 weeks of incubation,BL addition decreased peroxidase activity by 32.1%in the forest soil due to the higher C use efficiency of fungi(i.e.,the enrichment of Talaromyces,Umbelopsis,and Trichoderma),decreasing C-degrading enzyme secretion and reducing SOC degradation compared to the paddy soil.However,BH addition increased the Fusarium abundance,which regulated the polyphenol oxidase activity and promoted SOC degradation in the paddy soil.We concluded that biochars could alter the soil environment and extracellular electron transfer to mediate fungal necromass content and C-degrading enzyme activities,thus affecting SOC storage in the forest and paddy soils.展开更多
●The Ascomycota played a major role in fungal necromass formation in soil.●Protists reduced fungal necromass while promoting bacterial ncromass accumulation.●Soil total nitrogen substantially decided the persistenc...●The Ascomycota played a major role in fungal necromass formation in soil.●Protists reduced fungal necromass while promoting bacterial ncromass accumulation.●Soil total nitrogen substantially decided the persistence of bacterial necromass in soil.Microbial necromass plays a crucial role in soil organic carbon(SOC)formation.However,underlying abiotic and biotic factors on necromass accumulation remain poorly understood.Here,based on a 27-year field fertilization experiment in upland Ultisols,we investigated how changes in fungal and bacterial necromass relate to the abundance,diversity,community structure,and trophic co-occurrence networks of microbial communities,including fungi,bacteria,and protists.Fungal necromass contributed an average of 32.4%to SOC,a greater contribution than the 14.6%from bacterial necromass,regardless of fertilization regimes.Modularity analysis of the protistan-fungal network indicated that Ascomycota fungi were the primary contributors to fungal necromass accumulation in arable soil.The protistan community structure had a significantly negative effect on fungal necromass by directly decomposing fungal residues,rather than altering the fungal community structure.In contrast,soil total nitrogen positively influenced the persistence of bacterial necromass.Bacterial abundance was positively correlated with bacterial necromass.Protists increased bacterial abundance,thereby increasing bacterial necromass in the soil.Overall,protists regulated microbial necromass storage in arable soils either by decomposing fungal necromass or by increasing bacterial abundance.展开更多
Rapidly improving infertile croplands and enhancing their soil organic carbon(SOC)pool necessitate substantial organic materials incorporation.Converting loose crop straw into granulated form facilitates uniform incor...Rapidly improving infertile croplands and enhancing their soil organic carbon(SOC)pool necessitate substantial organic materials incorporation.Converting loose crop straw into granulated form facilitates uniform incorporation within the plough soil layer.As an innovative soil amelioration approach,the efficiency and patterns of SOC accumulation remain unclear.Two field experiments were conducted in infertile subtropical upland and paddy soils with 0,30,60,and 90 Mg ha^(-1)granulated straw incorporation.After one year,SOC accumulation efficiency from straw input remained stable in upland(30.8–37.5%)with increasing amounts of straw incorporation,while declined from 60.0 to 38.3%in paddy.In both croplands,the contributions of lignin phenols to SOC increased with increasing straw incorporation,while the contributions from amino sugars remained constant at higher straw input levels.Subsequently,the ratios of lignin phenols to amino sugars increased with increasing straw incorporation,indicating faster plant residue accumulation compared to microbial necromass,as the granulation approach limited microbial involvement in straw transformation.Thus,single-time incorporation of substantial granulated straw presents an effective agricultural strategy for rapid amelioration of infertile croplands.展开更多
Boreal and temperate forests had higher MNC and FNC/BNC than other forest biomes.Mixed forests had higher MNC and lower FNC/BNC than other forest types.The dependence of MNC on forest type varied among forest biomes.M...Boreal and temperate forests had higher MNC and FNC/BNC than other forest biomes.Mixed forests had higher MNC and lower FNC/BNC than other forest types.The dependence of MNC on forest type varied among forest biomes.MAT and soil total N were the important factors on MNC and MNC/SOC.MAT,soil pH,and clay content were identified as direct factors on FNC/BNC.Soil microbial necromass carbon(MNC)is an important contributor to soil organic carbon(SOC)and plays a vital role in carbon sequestration and climate change mitigation.However,it remains unclear whether the content,contribution to SOC(MNC/SOC),and fungal-to-bacterial necromass carbon ratio(FNC/BNC)of MNC vary across forest biomes and types.By summarizing data from 1704 points across 93 forest sites,we explored the spatial patterns of MNC,MNC/SOC,and FNC/BNC in the surface layer of 0–20 cm of forest soils,as well as the controlling factors involved.Overall,boreal and temperate forests had higher MNC and FNC/BNC values than tropical,subtropical,and Mediterranean forests,whereas both boreal and Mediterranean forests had low MNC/SOC values.Mixed forests had higher MNC and lower FNC/BNC than broadleaved and coniferous forests,whereas MNC/SOC was higher in broad-leaved forests than that in coniferous forests.Interestingly,the dependence of MNC on forest type also varies among forest biomes.Regression analyses identified soil total N as one of the most important factors affecting MNC and MNC/SOC;whereas MAT,soil pH,and clay content were identified as the important factors affecting FNC/BNC.This synthesis is critical for managing soil MNC to mitigate climate change in forests.展开更多
The interactions of soil microorganisms and structure regulate the degradation and stabilization processes of soil organic carbon(SOC). Microbial necromass is a persistent component of SOC, and its magnitude of accumu...The interactions of soil microorganisms and structure regulate the degradation and stabilization processes of soil organic carbon(SOC). Microbial necromass is a persistent component of SOC, and its magnitude of accumulation dependent on management and aggregate sizes. A meta-analysis of 121 paired measurements was conducted to evaluate the management effects on contributions of microbial necromass to SOC depending on aggregate fractions. Results showed that the contribution of fungal necromass to SOC increased with aggregate sizes, while bacterial necromass had a higher proportion in silt and clay. Cropland management increased total and fungal necromass in large macroaggregates(47.1% and 45.6%), small macroaggregates(44.0% and 44.2%), and microaggregates(38.9% and 37.6%).Cropland management increased bacterial necromass independent of aggregate fraction sizes. Greater fungal necromass was increased in macroaggregates in response to manure(26.6% to 28.5%) and no or reduced tillage(68.0% to 73.5%). Cover crops increased bacterial necromass by 25.1%in small macroaggregates. Stimulation of microbial necromass was proportional to the increases of SOC within soil aggregates, and the correlation was higher in macroaggregates. Increasing microbial necromass accumulation in macroaggregates can, therefore, be considered as a central component of management strategies that aim to accelerate C sequestration in agricultural soils.展开更多
Soil organic carbon(SOC)plays a crucial role in mangrove blue carbon formation,yet the differences in microbemediated underlying SOC sequestration between introduced and native mangroves remain unclear.Here,we compare...Soil organic carbon(SOC)plays a crucial role in mangrove blue carbon formation,yet the differences in microbemediated underlying SOC sequestration between introduced and native mangroves remain unclear.Here,we compared the SOC pool,including recalcitrant organic carbon(ROC)and labile carbon pools,as well as three residual carbon sources(amino sugars,lignin phenols,and lipids)in sediments between mangroves of introduced Sonneratia apetala and native Kandelia obovata,and further connected them with microbial life strategies and C metabolism capability.The results showed that SOC accumulation in S.apetala(SA)sediment was about 30%-50% of that in K.obovata(KO)sediment.ROC was the dominant form of SOC in long-term sequestration(76%-83%),while lignin phenols,amino sugars,and lipids were important sources of ROC.In S.apetala sediments,the ROC content was positively correlated with amino sugars,resulting from the more r-strategist microbes that can rapidly convert plant-derived carbon into microbial biomass,which is subsequently transformed into microbial necromass.In contrast,in K.obovata sediments,ROC content showed a stronger positive correlation with the concentrations of lignin phenols and lipids.More K-strategist fungi in the topsoil of K.obovata increased enzyme activities,while more K-strategist bacteria in the subsoil enhanced carbon utilization capacity,thereby increasing lignin phenols and lipids from plant residues in both soil layers.Meanwhile,higher Ca^(2+)concentrations in K.obovata sediments protected three residual carbons from further microbe decomposition.This study provides valuable insights into the molecular mechanisms of SOC sequestration mediated by microbial life strategies in mangrove ecosystems.展开更多
基金financially supported by the second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0603)supported by the Western China Youth Scholar Program of Chinese Academy of Sciences,the Sichuan Science and Technology Program(Grant No.2024YFHZ0178)the Science and Technology Research Program of Institute of Mountain Hazards and Environment,Chinese Academy of Sciences(Grant No.IMHE-ZYTS11)。
文摘Solar farms have been rapidly expanding on the Qinghai-Tibetan Plateau.However,the effects of photovoltaic arrays on the contribution of microbial necromass carbon(MNC)to soil organic carbon(SOC),along with the underlying mechanisms,remain unclear.To address this,we collected soil samples from the top 20 cm in under-panel,inter-panel and control plots at five solar farms constructed between 2012 and 2014 in the dry Yarlung Tsangpo and Lhasa River valleys on the Qinghai-Tibetan Plateau.We determined SOC,fungal and bacterial necromass and relevant soil properties.We found that the concentration of MNC in the under-panel plots(3.93±0.79 mg g-1)was significantly higher compared to the control plots(2.28±0.79 mg g-1)across all five solar farms.The proportion of MNC to SOC in the under-panel plots(34.7±2.4%)was also significantly higher than that in the control plots(27.5±1.4%).Specifically,the contribution of fungal necromass to SOC in the under-panel plots(26.4±2.2%)was significantly larger than that in the control plots(19.7±1.6%),while the increase in the bacterial necromass proportion was insignificant.Partial least squares structural equation modeling(PLS-SEM)indicated a significant and positive effect of increased soil moisture in the under-panel plots on the proportion of fungal necromass to SOC.These results highlight that beyond their economic benefits,solar farms in the arid regions on the Qinghai-Tibetan Plateau can enhance soil C sequestration by improving soil moisture and promoting microbial necromass accumulation.
基金supported by the National Natural Science Foundation of China(Nos.32101397,42177195,42307527,and 42307567)the Guangdong Basic and Applied Basic Research Foundation,China(Nos.2021A1515011559,2024A1515012566,and 2023A1515012248)+1 种基金the Guangdong Foundation for Program of Science and Technology Research,China(No.2023B1212060044)GDAS'Project of Science and Technology Development,China(Nos.2023 GDASZH-2023010103 and 2020GDASYL-20200103074).
文摘Fungi play a crucial role in the utilization and storage of soil organic carbon(SOC).Biochars can potentially influence soil carbon(C)turnover by mediating extracellular electron transfer,which can be facilitated by fungi.However,the effects of biochar and soil type on the community,abundance,enzyme secretion,and necromass of fungi mediating SOC storage remain unclear.A mesocosm incubation experiment was conducted using forest and paddy soils from southern China to study the impact of biochars pyrolyzed at low(300℃BL)and high(700℃BH)temperatures on fungal abundance,community composition,necromass abundance,and C-degrading enzyme activities.The SOC retention ratio was higher under BL(84.0%)than under BH(76.3%).Addition of BL increased fungal abundance in the forest soil by 230%.In contrast,addition of BH decreased fungal abundance in the paddy soil by 20.8%.Biochar addition affected fungal necromass accumulation and oxidase activity and regulated SOC turnover.The high available C content and moderate liming effect of BL significantly increased fungal abundance and necromass abundance in the forest soil compared to the paddy soil.Moreover,after 16 weeks of incubation,BL addition decreased peroxidase activity by 32.1%in the forest soil due to the higher C use efficiency of fungi(i.e.,the enrichment of Talaromyces,Umbelopsis,and Trichoderma),decreasing C-degrading enzyme secretion and reducing SOC degradation compared to the paddy soil.However,BH addition increased the Fusarium abundance,which regulated the polyphenol oxidase activity and promoted SOC degradation in the paddy soil.We concluded that biochars could alter the soil environment and extracellular electron transfer to mediate fungal necromass content and C-degrading enzyme activities,thus affecting SOC storage in the forest and paddy soils.
基金supported by grants from the National Natural Science Foundation of China(Grant No.42307400)Natural Science Foundation of Jiangsu Province(Grant No.BK20231097)+1 种基金the National Key Research and Development Program of China(Grant No.2023YFD1902705)China Postdoctoral Science Foundation(Grant No.2022M723239)。
文摘●The Ascomycota played a major role in fungal necromass formation in soil.●Protists reduced fungal necromass while promoting bacterial ncromass accumulation.●Soil total nitrogen substantially decided the persistence of bacterial necromass in soil.Microbial necromass plays a crucial role in soil organic carbon(SOC)formation.However,underlying abiotic and biotic factors on necromass accumulation remain poorly understood.Here,based on a 27-year field fertilization experiment in upland Ultisols,we investigated how changes in fungal and bacterial necromass relate to the abundance,diversity,community structure,and trophic co-occurrence networks of microbial communities,including fungi,bacteria,and protists.Fungal necromass contributed an average of 32.4%to SOC,a greater contribution than the 14.6%from bacterial necromass,regardless of fertilization regimes.Modularity analysis of the protistan-fungal network indicated that Ascomycota fungi were the primary contributors to fungal necromass accumulation in arable soil.The protistan community structure had a significantly negative effect on fungal necromass by directly decomposing fungal residues,rather than altering the fungal community structure.In contrast,soil total nitrogen positively influenced the persistence of bacterial necromass.Bacterial abundance was positively correlated with bacterial necromass.Protists increased bacterial abundance,thereby increasing bacterial necromass in the soil.Overall,protists regulated microbial necromass storage in arable soils either by decomposing fungal necromass or by increasing bacterial abundance.
基金financially supported by the National Key R&D Program of China(2021YFD1901203 and 2021YFD1901204)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA0440404)+2 种基金the National Natural Science Foundation of China(42377348)the Science Foundation for Distinguished Young Scholars of Hunan Province,China(2024JJ2052)the Natural Science Foundation of Guangxi,China(2025GXNSFAA069337)。
文摘Rapidly improving infertile croplands and enhancing their soil organic carbon(SOC)pool necessitate substantial organic materials incorporation.Converting loose crop straw into granulated form facilitates uniform incorporation within the plough soil layer.As an innovative soil amelioration approach,the efficiency and patterns of SOC accumulation remain unclear.Two field experiments were conducted in infertile subtropical upland and paddy soils with 0,30,60,and 90 Mg ha^(-1)granulated straw incorporation.After one year,SOC accumulation efficiency from straw input remained stable in upland(30.8–37.5%)with increasing amounts of straw incorporation,while declined from 60.0 to 38.3%in paddy.In both croplands,the contributions of lignin phenols to SOC increased with increasing straw incorporation,while the contributions from amino sugars remained constant at higher straw input levels.Subsequently,the ratios of lignin phenols to amino sugars increased with increasing straw incorporation,indicating faster plant residue accumulation compared to microbial necromass,as the granulation approach limited microbial involvement in straw transformation.Thus,single-time incorporation of substantial granulated straw presents an effective agricultural strategy for rapid amelioration of infertile croplands.
基金financially supported by the National Natural Science Foundation of China(42122054,42192513,and 42321004)Guangdong Basic and Applied Basic Research Foundation(2021B1515020082)+1 种基金Key Platform and Scientific Research Projects of the Guangdong Provincial Education Department(2020KCXTD006)Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control(No.2023B1212060002).
文摘Boreal and temperate forests had higher MNC and FNC/BNC than other forest biomes.Mixed forests had higher MNC and lower FNC/BNC than other forest types.The dependence of MNC on forest type varied among forest biomes.MAT and soil total N were the important factors on MNC and MNC/SOC.MAT,soil pH,and clay content were identified as direct factors on FNC/BNC.Soil microbial necromass carbon(MNC)is an important contributor to soil organic carbon(SOC)and plays a vital role in carbon sequestration and climate change mitigation.However,it remains unclear whether the content,contribution to SOC(MNC/SOC),and fungal-to-bacterial necromass carbon ratio(FNC/BNC)of MNC vary across forest biomes and types.By summarizing data from 1704 points across 93 forest sites,we explored the spatial patterns of MNC,MNC/SOC,and FNC/BNC in the surface layer of 0–20 cm of forest soils,as well as the controlling factors involved.Overall,boreal and temperate forests had higher MNC and FNC/BNC values than tropical,subtropical,and Mediterranean forests,whereas both boreal and Mediterranean forests had low MNC/SOC values.Mixed forests had higher MNC and lower FNC/BNC than broadleaved and coniferous forests,whereas MNC/SOC was higher in broad-leaved forests than that in coniferous forests.Interestingly,the dependence of MNC on forest type also varies among forest biomes.Regression analyses identified soil total N as one of the most important factors affecting MNC and MNC/SOC;whereas MAT,soil pH,and clay content were identified as the important factors affecting FNC/BNC.This synthesis is critical for managing soil MNC to mitigate climate change in forests.
基金supported by the National Natural Science Foundation of China (32071629)Agricultural Carbon Neutral Account Establishment Program in Quzhou (202127)+1 种基金the National Key R&D Program of China (2022YFD1901300)the 2115 Talent Development Program of China Agricultural University。
文摘The interactions of soil microorganisms and structure regulate the degradation and stabilization processes of soil organic carbon(SOC). Microbial necromass is a persistent component of SOC, and its magnitude of accumulation dependent on management and aggregate sizes. A meta-analysis of 121 paired measurements was conducted to evaluate the management effects on contributions of microbial necromass to SOC depending on aggregate fractions. Results showed that the contribution of fungal necromass to SOC increased with aggregate sizes, while bacterial necromass had a higher proportion in silt and clay. Cropland management increased total and fungal necromass in large macroaggregates(47.1% and 45.6%), small macroaggregates(44.0% and 44.2%), and microaggregates(38.9% and 37.6%).Cropland management increased bacterial necromass independent of aggregate fraction sizes. Greater fungal necromass was increased in macroaggregates in response to manure(26.6% to 28.5%) and no or reduced tillage(68.0% to 73.5%). Cover crops increased bacterial necromass by 25.1%in small macroaggregates. Stimulation of microbial necromass was proportional to the increases of SOC within soil aggregates, and the correlation was higher in macroaggregates. Increasing microbial necromass accumulation in macroaggregates can, therefore, be considered as a central component of management strategies that aim to accelerate C sequestration in agricultural soils.
基金supported by grants from the National Natural Science Foundation of China(Nos.42076117 and 32160051)the Guangdong Basic and Applied Basic Research Foundation(Nos.2023A1515012772,2024A1515011721,and 2024A1515012249).
文摘Soil organic carbon(SOC)plays a crucial role in mangrove blue carbon formation,yet the differences in microbemediated underlying SOC sequestration between introduced and native mangroves remain unclear.Here,we compared the SOC pool,including recalcitrant organic carbon(ROC)and labile carbon pools,as well as three residual carbon sources(amino sugars,lignin phenols,and lipids)in sediments between mangroves of introduced Sonneratia apetala and native Kandelia obovata,and further connected them with microbial life strategies and C metabolism capability.The results showed that SOC accumulation in S.apetala(SA)sediment was about 30%-50% of that in K.obovata(KO)sediment.ROC was the dominant form of SOC in long-term sequestration(76%-83%),while lignin phenols,amino sugars,and lipids were important sources of ROC.In S.apetala sediments,the ROC content was positively correlated with amino sugars,resulting from the more r-strategist microbes that can rapidly convert plant-derived carbon into microbial biomass,which is subsequently transformed into microbial necromass.In contrast,in K.obovata sediments,ROC content showed a stronger positive correlation with the concentrations of lignin phenols and lipids.More K-strategist fungi in the topsoil of K.obovata increased enzyme activities,while more K-strategist bacteria in the subsoil enhanced carbon utilization capacity,thereby increasing lignin phenols and lipids from plant residues in both soil layers.Meanwhile,higher Ca^(2+)concentrations in K.obovata sediments protected three residual carbons from further microbe decomposition.This study provides valuable insights into the molecular mechanisms of SOC sequestration mediated by microbial life strategies in mangrove ecosystems.
