Tropical mountain peatlands in Brazil’s Southern Espinhaço Range are vital ecosystems,acting as carbon reservoirs,hydrological buffers,and biodiversity hotspots while sustaining traditional livelihoods and prese...Tropical mountain peatlands in Brazil’s Southern Espinhaço Range are vital ecosystems,acting as carbon reservoirs,hydrological buffers,and biodiversity hotspots while sustaining traditional livelihoods and preserving paleoenvironmental records.Despite their importance,peatlands outside protected areas face degradation by grazing and fires,threatening their ability to regulate ecosystem processes sensitive to temperature,such as greenhouse gas emissions,water cycling,biological activity,and organic matter decomposition.Since 2016,we have monitored peat temperatures in two contrasting peatlands–one preserved(within a protected area)and one disturbed(outside the protected area)–to understand how anthropogenic disturbances and climate variability impact these fragile ecosystems.Seasonal patterns dominated temperature variation,accounting for 60% of air and 81%–92% of peatland temperature variation.However,average temperatures and amplitudes differed between peatlands and depths.Interannual variability revealed stronger trends in the disturbed peatland,where a 1℃ increase in air temperature caused the trend to increase 0.70℃–0.87℃ on average at depths of 0.85 m–0.92 m.By contrast,the preserved peatland showed smaller increases(0.20℃–0.24℃)at comparable depths(1.06 m–1.24 m),suggesting a greater resilience.Temperature variation in the monitored peatlands was majorly driven by seasonal patterns,as revealed by time series decomposition and sinewave fit.Average temperature and amplitude varied between the two peatlands and among sampling sites,reflecting differences in environmental conditions and measurement depth.Interannual variability also exhibited distinct effects between peatlands and monitoring sites.The time series trend component showed more pronounced fluctuations at shallower depths and in the disturbed peatland.For every 1℃ increase in the trend component of the air temperature,the trend component of the peatland time series increased by 0.70℃ and 0.87℃on average at depths of 0.85 m and 0.92 m,respectively,in the disturbed peatland.In contrast,the preserved peatland exhibited smaller increases of 0.20℃ and 0.24℃ at comparable depths(1.06 m and 1.24 m).These findings highlight the potential for feedback responses between peatland disturbance and climate change,threatening their critical role in regulating carbon and water cycles.Expanding long-term monitoring,strengthening conservation efforts,and raising public awareness are essential to safeguard the ecosystem services provided by tropical mountain peatlands.展开更多
The draining and conversion of peatlands for agriculture has led to their degradation globally,diminishing their carbon(C)storage capacity and functioning.However,rewetting,alongside the addition of organic/inorganic ...The draining and conversion of peatlands for agriculture has led to their degradation globally,diminishing their carbon(C)storage capacity and functioning.However,rewetting,alongside the addition of organic/inorganic amendments,has the potential to accelerate peat formation and C accrual.The aim of this experiment was therefore to examine the combined benefits of altering water table depth and adding organic(e.g.,biochar,paper waste,biosolids,cereal straw;20 t C ha^(−1)and inorganic(e.g.,FeSO_(4);0.5 t ha^(−1))materials on net C storage and peatland functioning(i.e.,microbial communities,greenhouse gas emissions and biogeochemical cycling).The experiment consisted of outdoor agricultural peat mesocosms monitored over 1 year.The relative effectiveness of the amendments in preserving peat-C(t C ha^(−1))followed the series:Miscanthus biochar(18.9 t C ha^(−1))>Miscanthus residues(17.3 t C ha^(−1))>biosolids(17.2 t C ha^(−1))>cereal straw(14.5 t C ha^(−1))>paper waste(13.3 t C ha^(−1))based on C additional rate(20 t C ha^(−1)).Overall,a high-water table combined with biochar and FeSO_(4)addition was the most effective at suppressing enzyme activity(e.g.,β-glucosidase,phenol oxidase,cellobiase),methanogen activity(e.g.,Methanosarcina)and peat mineralization rate.We ascribe this in part to changes in the fungal and bacterial community structure(e.g.,reductions in Actinobacteria by−22%and Ascomycota by−61%).FeSO_(4)also increased the Fe-bound C content in the non-rewetted treatment,supporting the‘iron gate’mechanism for C preservation.The mechanisms behind our results appear to be both abiotic(affecting SOC solubility through changes in redox conditions and Fe–C interactions)and biotic(via shifts in microbial community and enzyme activities),creating conditions that enhance C preservation.These findings provide evidence for implementing biochar and FeSO_(4)amendments alongside water table management as practical,scalable strategies for restoring C storage capacity in agricultural peatlands.展开更多
基金This study was financed in part by the Coordenacao de Aperfeiçoamento de Pessoal de Nivel Superior-Brasil(CAPES)-Finance Code 001the Brazilian Conselho Nacional de Pesquisa-CNPq(study and research grants and research funding-Process 303666/2018-8,408162/2018-0,441335/2020-9,302969/2021-7,and 50484/2022-4)Fundacao de ApoioaPesquisa do Estado de Minas Gerais-FAPEMIG(study grants and research funding-Process CRA/APQ 0100-18,APQ-03364-21 and CAG/PPM 00568-16).
文摘Tropical mountain peatlands in Brazil’s Southern Espinhaço Range are vital ecosystems,acting as carbon reservoirs,hydrological buffers,and biodiversity hotspots while sustaining traditional livelihoods and preserving paleoenvironmental records.Despite their importance,peatlands outside protected areas face degradation by grazing and fires,threatening their ability to regulate ecosystem processes sensitive to temperature,such as greenhouse gas emissions,water cycling,biological activity,and organic matter decomposition.Since 2016,we have monitored peat temperatures in two contrasting peatlands–one preserved(within a protected area)and one disturbed(outside the protected area)–to understand how anthropogenic disturbances and climate variability impact these fragile ecosystems.Seasonal patterns dominated temperature variation,accounting for 60% of air and 81%–92% of peatland temperature variation.However,average temperatures and amplitudes differed between peatlands and depths.Interannual variability revealed stronger trends in the disturbed peatland,where a 1℃ increase in air temperature caused the trend to increase 0.70℃–0.87℃ on average at depths of 0.85 m–0.92 m.By contrast,the preserved peatland showed smaller increases(0.20℃–0.24℃)at comparable depths(1.06 m–1.24 m),suggesting a greater resilience.Temperature variation in the monitored peatlands was majorly driven by seasonal patterns,as revealed by time series decomposition and sinewave fit.Average temperature and amplitude varied between the two peatlands and among sampling sites,reflecting differences in environmental conditions and measurement depth.Interannual variability also exhibited distinct effects between peatlands and monitoring sites.The time series trend component showed more pronounced fluctuations at shallower depths and in the disturbed peatland.For every 1℃ increase in the trend component of the air temperature,the trend component of the peatland time series increased by 0.70℃ and 0.87℃on average at depths of 0.85 m and 0.92 m,respectively,in the disturbed peatland.In contrast,the preserved peatland exhibited smaller increases of 0.20℃ and 0.24℃ at comparable depths(1.06 m and 1.24 m).These findings highlight the potential for feedback responses between peatland disturbance and climate change,threatening their critical role in regulating carbon and water cycles.Expanding long-term monitoring,strengthening conservation efforts,and raising public awareness are essential to safeguard the ecosystem services provided by tropical mountain peatlands.
基金supported by UK Research and Innovation(UKRI)through the Biotechnology and Biological Sciences Research Council(BBSRC)funded Greenhouse Gas Removal Peatland Demonstrator project(BB/V011561/1).
文摘The draining and conversion of peatlands for agriculture has led to their degradation globally,diminishing their carbon(C)storage capacity and functioning.However,rewetting,alongside the addition of organic/inorganic amendments,has the potential to accelerate peat formation and C accrual.The aim of this experiment was therefore to examine the combined benefits of altering water table depth and adding organic(e.g.,biochar,paper waste,biosolids,cereal straw;20 t C ha^(−1)and inorganic(e.g.,FeSO_(4);0.5 t ha^(−1))materials on net C storage and peatland functioning(i.e.,microbial communities,greenhouse gas emissions and biogeochemical cycling).The experiment consisted of outdoor agricultural peat mesocosms monitored over 1 year.The relative effectiveness of the amendments in preserving peat-C(t C ha^(−1))followed the series:Miscanthus biochar(18.9 t C ha^(−1))>Miscanthus residues(17.3 t C ha^(−1))>biosolids(17.2 t C ha^(−1))>cereal straw(14.5 t C ha^(−1))>paper waste(13.3 t C ha^(−1))based on C additional rate(20 t C ha^(−1)).Overall,a high-water table combined with biochar and FeSO_(4)addition was the most effective at suppressing enzyme activity(e.g.,β-glucosidase,phenol oxidase,cellobiase),methanogen activity(e.g.,Methanosarcina)and peat mineralization rate.We ascribe this in part to changes in the fungal and bacterial community structure(e.g.,reductions in Actinobacteria by−22%and Ascomycota by−61%).FeSO_(4)also increased the Fe-bound C content in the non-rewetted treatment,supporting the‘iron gate’mechanism for C preservation.The mechanisms behind our results appear to be both abiotic(affecting SOC solubility through changes in redox conditions and Fe–C interactions)and biotic(via shifts in microbial community and enzyme activities),creating conditions that enhance C preservation.These findings provide evidence for implementing biochar and FeSO_(4)amendments alongside water table management as practical,scalable strategies for restoring C storage capacity in agricultural peatlands.
