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 decomposition of deadwood is a crucial process for the accumulation and sequestration of soil organic carbon (SOC) in forest ecosystems. However, the response of SOC to different decay classes of deadwood and the ...The decomposition of deadwood is a crucial process for the accumulation and sequestration of soil organic carbon (SOC) in forest ecosystems. However, the response of SOC to different decay classes of deadwood and the underlying mechanisms remain poorly understood. Here, we investigated the dynamics of SOC, soil properties, extracellular enzyme activities, and phospholipid fatty acid biomarkers across five decay classes (ranging from 1 to 5) of Masson pine (Pinus massoniana Lamb.) downed deadwood in a subtropical–temperate ecotone forest in Central China. Our results revealed a nonlinear response pattern of SOC along the deadwood decomposition gradient, with the maximum value at the decay class 4. Soil available nitrogen content, bacterial biomass, fungal biomass, the ratio of fungal-to-bacterial biomass, cellulase, activity and ligninase activity all increased with the intensification of deadwood decay, while soil pH decreased. The increase in SOC content was associated with a direct positive effect of bacteria and both direct and indirect positive effects of fungi by cellulose activity, but ligninase activity showed no significant relationship with SOC content. These findings suggest that cellulose and microbial biomass are key determinants of soil C formation and sequestration during deadwood decomposition. This study highlights the importance of the nonlinear response of SOC to deadwood decay, providing valuable insights for predicting future carbon-climate feedbacks.展开更多
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 (32201362)the Henan Province Science and Technology Research Project (242102321157)the Research and Development Funds of Hubei University of Science and Technology (BK202404)。
文摘The decomposition of deadwood is a crucial process for the accumulation and sequestration of soil organic carbon (SOC) in forest ecosystems. However, the response of SOC to different decay classes of deadwood and the underlying mechanisms remain poorly understood. Here, we investigated the dynamics of SOC, soil properties, extracellular enzyme activities, and phospholipid fatty acid biomarkers across five decay classes (ranging from 1 to 5) of Masson pine (Pinus massoniana Lamb.) downed deadwood in a subtropical–temperate ecotone forest in Central China. Our results revealed a nonlinear response pattern of SOC along the deadwood decomposition gradient, with the maximum value at the decay class 4. Soil available nitrogen content, bacterial biomass, fungal biomass, the ratio of fungal-to-bacterial biomass, cellulase, activity and ligninase activity all increased with the intensification of deadwood decay, while soil pH decreased. The increase in SOC content was associated with a direct positive effect of bacteria and both direct and indirect positive effects of fungi by cellulose activity, but ligninase activity showed no significant relationship with SOC content. These findings suggest that cellulose and microbial biomass are key determinants of soil C formation and sequestration during deadwood decomposition. This study highlights the importance of the nonlinear response of SOC to deadwood decay, providing valuable insights for predicting future carbon-climate feedbacks.
