United Nations(UN)encourages sovereign states to take prompt and concrete measures to accomplish net-zero emissions by year 2050,requesting carbon dioxide removal(CDR)technologies to be prepared and implemented in suc...United Nations(UN)encourages sovereign states to take prompt and concrete measures to accomplish net-zero emissions by year 2050,requesting carbon dioxide removal(CDR)technologies to be prepared and implemented in such ambitious climate action roadmap.However,whether CDR technologies should be further promoted or discontinued post net-zero emission year remains unclear.In this Earth-system modelling research,we compare UN-suggested 2050 net-zero emission scenario against other common climate mitigation scenarios outlined by shared social-economic pathways(SSPs).We also simulate continued CDR implementations after net-zero emissions,which is hypothetically achieved in year 2050 and 2070 respectively,to investigate how CDR can impact the global climate throughout the whole 21st and 22nd centuries.The modelling results find if the 2050 UN net-zero emission goal is accomplished,the global average surface air temperature(SAT)in the end of 21st century is around 1.5℃higher compared to the pre-industrial level,promising an Earth environment more habitable than other scenarios without CDR.When CDR is applied to remove equal amount of anthropogenic CO_(2)emissions since industrial revolution,it restores the global average SAT close to pre-industrial level of 13.5℃.However,CDR-induced global carbon distribution within ocean,atmosphere,and land pools is different from the pre-industrial condition,causing reduced atmospheric CO_(2)concentration by 9 to 38 ppm compared to the pre-industrial cases,and more alkalinized ocean surface with pH increase of 0.004 to 0.024.This study affirms CDR cannot be viewed as a reversed process to anthropogenic CO_(2)emissions,accordingly climate policies to overcome the uncertainties after for late 21st century still require careful trade-offs for the decarbonation and the cost-benefits of CDR measures.展开更多
Climate warming and atmospheric nitrogen(N)deposition have profound influences on the terrestrial biosphere.However,how these two global change drivers affect phytoplankton which are important primary producers in wet...Climate warming and atmospheric nitrogen(N)deposition have profound influences on the terrestrial biosphere.However,how these two global change drivers affect phytoplankton which are important primary producers in wetlands with large carbon stocks and complex hydrological fluctuations remain largely unclear.As part of a two-year field experiment in a freshwater wetland,this study was conducted to investigate the effects of nighttime warming and N addition on phytoplankton biomass in the North China Plain.The results showed that neither nighttime warming nor N addition influenced the Shannon-Wiener index of phytoplankton community.Nighttime warming did not change phytoplankton biomass,likely due to the different warming impacts on dominant phyla and in different seasons.Decreased phytoplankton biomass in spring because of the increased water pH and submerged plant coverage was compensated by the enhanced biomass in autumn due to the reduced dissolved oxygen and submerged plant coverage,leading to the neutral change of phytoplankton biomass under warming.Nitrogen addition elevated phytoplankton biomass by 11.6%,which could be attributed to the enhanced nutrient availability and reduced submerged plant coverage.Positive relationships of methane(CH4)emission rates at the water-air interface with phytoplankton biomass indicated the potentially crucial role of phytoplankton in mediating wetland CH4 cycling through photosynthesis-driven metabolisms.The findings suggested the seasonal variation of phytoplankton and their potential responses to nighttime warming and N deposition,which may provide a more accurate basis for assessing the global change-carbon feedback in wetland ecosystems.展开更多
Viral infections play a crucial role in marine biogeochemical cycles,by regulating bacterial mortality and mediating nutrient and carbon fluxes.However,despite of their ecological significance,existing climate change ...Viral infections play a crucial role in marine biogeochemical cycles,by regulating bacterial mortality and mediating nutrient and carbon fluxes.However,despite of their ecological significance,existing climate change models generally fail to incorporate virus-mediated ecological processes due to the current limited understanding of marine viral dynamics under global warming.While numerous studies have explored the effect of warming for viral decay and production,how temperature regulates the total abundance of marine viruses remains unclear.In this study,we conducted year-round measurements of viral production and decay rates in Qingdao's coastal waters,with additional experimental warming treatments.The result showed that under in-situ temperature,the viral decay and production rate displayed distinct seasonal variations.With the exception of summer,elevated temperature stimulated both viral decay rate and production rate,and further improved the net viral production rate.While in summer,the net viral production rate turned negative,implying divergent threshold viral decay and viral production rate on warming.Our study deepens the understanding of the effect of global warming on marine viruses and provides scientific data for climate change models.展开更多
Despite its significant societal and scientific importance,projected changes in the characteristics of intraseasonal oscillations(ISOs)associated with Indian summer monsoon rainfall under increased greenhouse gas conc...Despite its significant societal and scientific importance,projected changes in the characteristics of intraseasonal oscillations(ISOs)associated with Indian summer monsoon rainfall under increased greenhouse gas concentrations remain largely unexplored.This study utilizes downscaled and bias-corrected historical simulations and projections from 17 CMIP6 models to investigate the future evolution of ISOs.Our findings reveal a twofold increase in ISO variability over India in the far future under the very high emissions scenario,raising critical concerns about its adverse socioeconomic impacts.Our analysis suggests that the increased magnitude of precipitation anomalies associated with northwardpropagating ISOs may intensify active monsoon spells,potentially triggering extreme rainfall events.Additionally,the phase speed of these northward-propagating ISOs over the Bay of Bengal is projected to accelerate owing to weakened air-sea coupling and feedback.This acceleration reduces the northwest-southeast tilt of the precipitation band,altering the spatial structure of the ISOs.Concurrently,the strengthening of circulation-precipitation feedback and warming of the Indian Ocean are projected to enhance the phase speed of monsoon ISOs,leading to more frequent active spells.This study underscores the critical role of regional ocean-atmosphere feedback in shaping future ISO characteristics,highlighting the urgent need for improved understanding and prediction of these changes in the context of a warming climate.展开更多
Giant kelp Macrocystis pyrifera,an important foundation species with great ecological and economic value,is threatened by climate change.To better understand the impact of climate warming on M.pyrifera,we investigated...Giant kelp Macrocystis pyrifera,an important foundation species with great ecological and economic value,is threatened by climate change.To better understand the impact of climate warming on M.pyrifera,we investigated its global distribution dynamics by an optimized species distribution model(SDM).Results showed that wave height,sea surface temperature,benthic temperature,and benthic phosphate concentration were key factors shaping the distribution of M.pyrifera.In addition to currently known distribution regions,the model revealed potential suitable habitats globally.Under future climate scenarios,the habitat suitability of M.pyrifera would decrease at low latitudes and increase at high latitudes,resulting in a poleward shift of suitable habitats.In the regions currently occupied by M.pyrifera,the high suitable habitats were predicted to shrink,which implies that the existing M.pyrifera would be adversely impacted.These results serve as references for the conservation and utilization of M.pyrifera resource.展开更多
Irradiating hard rocks by a high-power laser can reduce localized hardness in the rocks;however,continuous lasers produce a large amount of melt that inhibits further heat absorption.Pulsed lasers allow rocks to absor...Irradiating hard rocks by a high-power laser can reduce localized hardness in the rocks;however,continuous lasers produce a large amount of melt that inhibits further heat absorption.Pulsed lasers allow rocks to absorb and dissipate energy and avoid melt formation.In this study,200 W nanosecond pulsed laser was used to irradiate granite.The effects of laser parameters on the thermal cracking morphology,temperature field,warming pattern,and Leeb hardness of the granite surface were analyzed.The optimal laser parameters for softening granite were determined by performing objective optimization in MATLAB using granite's melting point as the reference.Nanoindentation techniques were employed to assess the softening characteristics of the granite surface along the longitudinal direction.The results showed that three main forms of thermal damage occurred on the granite surface:oxidative decomposition,spalling,and melting.The damage state was affected by the average laser power,with the pulse width and repetition frequency affecting surface damage differently.Appropriate laser parameters effectively controlled the melt damage on the granite surface,and irradiation with nanosecond pulsed lasers effectively reduced surface hardness.However,excessive power can generate large amounts of hard melts and weaken the softening effect.展开更多
The onset,cessation,and length of the rainy season are crucial for global water resources,agricultural practices,and food security.However,the response of precipitation seasonality to global warming remains uncertain....The onset,cessation,and length of the rainy season are crucial for global water resources,agricultural practices,and food security.However,the response of precipitation seasonality to global warming remains uncertain.In this study,we analyze how global warming levels(GWLs)of 1.5℃ and 2℃ could affect the timing of rainfall onset(RODs),rainfall cessation(RCDs),and the overall duration of the rainy season(LRS)over global land monsoon(GLM)regions using simulations from CMIP6 under the SSP2-4.5 and SSP5-8.5 scenarios.With high model consensus,our results reveal that RODs are projected to occur later over Southern Africa,North Africa,and South America,but earlier over South Asia and Australia,in a warmer climate.The projected early RODs in Australia are more pronounced at the 2℃ GWL under SSP5-8.5.On the other hand,early RCDs are projected over South America and East Asia,while late RCDs are projected over North Africa,with high inter-model agreement.These changes are associated with a future decrease in LRS in most GLM regions.Additionally,we found that continuous warming over 1.5℃ will further reduce the length of the rainy season,especially over the South America,North Africa,and Southern Africa monsoon regions.The findings underscore the urgent need to mitigate global warming.展开更多
Accurately assessing the relationship between tree growth and climatic factors is of great importance in dendrochronology.This study evaluated the consistency between alternative climate datasets(including station and...Accurately assessing the relationship between tree growth and climatic factors is of great importance in dendrochronology.This study evaluated the consistency between alternative climate datasets(including station and gridded data)and actual climate data(fixed-point observations near the sampling sites),in northeastern China’s warm temperate zone and analyzed differences in their correlations with tree-ring width index.The results were:(1)Gridded temperature data,as well as precipitation and relative humidity data from the Huailai meteorological station,was more consistent with the actual climate data;in contrast,gridded soil moisture content data showed significant discrepancies.(2)Horizontal distance had a greater impact on the representativeness of actual climate conditions than vertical elevation differences.(3)Differences in consistency between alternative and actual climate data also affected their correlations with tree-ring width indices.In some growing season months,correlation coefficients,both in magnitude and sign,differed significantly from those based on actual data.The selection of different alternative climate datasets can lead to biased results in assessing forest responses to climate change,which is detrimental to the management of forest ecosystems in harsh environments.Therefore,the scientific and rational selection of alternative climate data is essential for dendroecological and climatological research.展开更多
The latitudinal diversity gradient(LDG)is one of the most notable biodiversity patterns in biogeography.The metabolic theory of ecology(MTE)explains ecological patterns,including the LDG.However,little is known about ...The latitudinal diversity gradient(LDG)is one of the most notable biodiversity patterns in biogeography.The metabolic theory of ecology(MTE)explains ecological patterns,including the LDG.However,little is known about whether the LDG remains stable over time as climate warming progresses and whether MTE remains applicable to clarify this pattern.In this study,forest data spanning temperate,subtropical,and tropical zones across China were used to analyze long-term changes in the LDG of tree species over 2005-2020.Based on the MTE framework,spatial scales were considered to assess temperature dependence of typical forest trees species.Our results show that species richness decreased with increasing latitude,and that temperature was the primary driver of this change.Although temperature in China has significantly increased over the past two decades,the LDG of tree species has remained stable.However,there was a decrease in species richness in tropical regions over time.With predictions of the MTE,the logarithm of typical forest tree species richness exhibited negative linear relationships with the inverse of ambient temperature,indicating temperature dependence of species richness.However,the relationship remained stable and was strongly influenced by spatial scale,intensifying as spatial scale increased.The findings emphasize the important role of temperature in shaping the LDG.The effects of spatial scale,in particular,should be considered when biodiversity management plans are developed for future climate change.展开更多
Maintaining a stable body temperature is essential for survival.Multiple brain regions contribute to thermoregulation,but their specific characteristics and underlying neural mechanisms in the coordination of thermore...Maintaining a stable body temperature is essential for survival.Multiple brain regions contribute to thermoregulation,but their specific characteristics and underlying neural mechanisms in the coordination of thermoregulation are not fully clarified.Here,we reveal the distinct roles of two preoptic subregions in warm defense in mice:the anterior ventromedial preoptic area(VMPO)and the ventral part of the lateral preoptic nucleus(vLPO).VMPO vesicular glutamate transporter 2(Vglut2)neurons exhibited dramatic responses to rising temperatures,producing a marked decrease in core temperature by warm defense responses.In contrast,excitatory and inhibitory vLPO neurons responded gently to warm stimuli,exerting moderate effects on warm defense.Further postsynaptic tracing and caspase ablation identified distinct cell type-specific downstream targets in the dorsomedial hypothalamus(DMH)mediating these different warm defense responses.Taken together,our findings reveal distinct yet complementary pathways in the preoptic DMH network that enable both rapid and fine-tuned regulation of body temperature under elevated thermal conditions.展开更多
The increase in soil temperature associated with climate change has introduced considerable challenges to crop production.Split nitrogen application(SN)represents a potential strategy for improving crop nitrogen use e...The increase in soil temperature associated with climate change has introduced considerable challenges to crop production.Split nitrogen application(SN)represents a potential strategy for improving crop nitrogen use efficiency and enhancing crop stress resistance.Nevertheless,the precise interaction between soil warming(SW)and SN remains unclear.In order to ascertain the impact of SW on maize growth and whether SN can improve the tolerance of maize to SW,a two-year field experiment was conducted(2022-2023).The aim was to examine the influence of two SW ranges(MT,warming 1.40℃;HT,warming 2.75℃)and two nitrogen application methods(N1,one-time basal application of nitrogen fertilizer;N2,one third of base nitrogen fertilizer+two thirds of jointing stage supplemental nitrogen fertilizer)on maize root growth,photosynthetic characteristics,nitrogen use efficiency,and yield.The results demonstrated that SW impeded root growth and precipitated the premature aging of maize leaves following anthesis,particularly in the HT,which led to a notable reduction in maize yield.In comparison to N1,SN has been shown to increase root length density by 8.54%,root bleeding rate by 8.57%,and enhance root distribution ratio in the middle soil layers(20-60 cm).The interaction between SW and SN had a notable impact on maize growth and yield.The SN improved the absorption and utilization efficiency of nitrogen by promoting root development and downward canopy growth,thus improving the tolerance of maize to SW at the later stage of growth.In particular,the N2HT resulted in a 14.51%increase in the photosynthetic rate,a 18.58%increase in nitrogen absorption efficiency,and a 18.32%increase in maize yield compared with N1HT.It can be posited that the SN represents a viable nitrogen management measure with the potential to enhance maize tolerance to soil high-temperature stress.展开更多
A complex system is inherently high-dimensional.Recent studies indicate that,even without complete knowledge of its evolutionary dynamics,the future behavior of such a system can be predicted using time-series data(da...A complex system is inherently high-dimensional.Recent studies indicate that,even without complete knowledge of its evolutionary dynamics,the future behavior of such a system can be predicted using time-series data(data-driven prediction).This suggests that the essential dynamics of a complex system can be captured through a low-dimensional representation.Virus evolution and climate change are two examples of complex,time-varying systems.In this article,we show that mutations in the spike protein provide valuable data for predicting SARS-CoV-2 variants,forecasting the possible emergence of the new macro-lineage Q in the near future.Our analysis also demonstrates that carbon dioxide concentration is a reliable indicator for predicting the evolution of the climate system,extending global surface air temperature(GSAT)forecasts through 2500.展开更多
The Taklimakan Desert,located in the heart of central Asia,covers approximately 330000 km^(2),making it China's largest desert and the world's second-largest shifting desert(Dong et al.,2024).With an average a...The Taklimakan Desert,located in the heart of central Asia,covers approximately 330000 km^(2),making it China's largest desert and the world's second-largest shifting desert(Dong et al.,2024).With an average annual precipitation of less than 100 mm and evaporation rates ranging from 2000 to 3000 mm(Yang et al.,2020),it is recognized as one of the driest regions on Earth,often referred to as the“sea of death”.展开更多
Increasing temperatures and severe droughts threaten forest vitality globally.Prediction of forest response to climate change requires knowledge of the spatiotemporal patterns of monthly or seasonal climatic impacts o...Increasing temperatures and severe droughts threaten forest vitality globally.Prediction of forest response to climate change requires knowledge of the spatiotemporal patterns of monthly or seasonal climatic impacts on the growth of tree species,likely driven by local climatic aridity,climate trends,edaphic conditions,and the climatic adaption of tree species.The ability of tree species to cope with changing climate and the effects of environmental variables on growth trends and growth-climate relationships across diverse bioclimatic regions are still poorly understood for many species.This study investigated radial growth trends,interannual growth variability,and growth-climate sensitivity of two dominant tree species,Pinus tabulaeformis(PT)and Pinus sylvestris var.mongolica(PS),across a broad climatic gradient with a variety of soil properties in temperate Northern China.Using a network of 83 tree ring chronologies(54 for PT and 29 for PS)from 1971 to 2010,we documented that both species maintained constant growth trends at wet sites,while both displayed rapid declines at dry sites.We reported the species-specific drivers of spatial heterogeneity in growth trends,interannual growth variability,and growth-climate relationships.Calculated climatic variables and soil properties were identified as the most critical factors affecting the growth trends and growth-climate relationships.However,climatic variables play more essential roles than soil properties in determining the spatial heterogeneity of the growth-climate relationship.Lower clay content and higher soil nutrient regimes can exacerbate the moisture-related susceptibility of tree growth.Our findings highlight that soil properties emerged as important modulating factors to predict the drought vulnerability of forests in addition to climatic variables.Considering the continued climate warmingdrying trend in the future,both pines will face a more severe growth decline and increase in drought vulnerability at drier sites with lower clayed soil or higher nutrient regimes.展开更多
Heating in the ocean has continued in 2024 in response to increased greenhouse gas concentrations in the atmosphere,despite the transition from an El Ni?o to neutral conditions. In 2024, both global sea surface temper...Heating in the ocean has continued in 2024 in response to increased greenhouse gas concentrations in the atmosphere,despite the transition from an El Ni?o to neutral conditions. In 2024, both global sea surface temperature(SST) and upper2000 m ocean heat content(OHC) reached unprecedented highs in the historical record. The 0–2000 m OHC in 2024exceeded that of 2023 by 16 ± 8 ZJ(1 Zetta Joules = 1021 Joules, with a 95% confidence interval)(IAP/CAS data), which is confirmed by two other data products: 18 ± 7 ZJ(CIGAR-RT reanalysis data) and 40 ± 31 ZJ(Copernicus Marine data,updated to November 2024). The Indian Ocean, tropical Atlantic, Mediterranean Sea, North Atlantic, North Pacific, and Southern Ocean also experienced record-high OHC values in 2024. The global SST continued its record-high values from2023 into the first half of 2024, and declined slightly in the second half of 2024, resulting in an annual mean of 0.61°C ±0.02°C(IAP/CAS data) above the 1981–2010 baseline, slightly higher than the 2023 annual-mean value(by 0.07°C ±0.02°C for IAP/CAS, 0.05°C ± 0.02°C for NOAA/NCEI, and 0.06°C ± 0.11°C for Copernicus Marine). The record-high values of 2024 SST and OHC continue to indicate unabated trends of global heating.展开更多
To tackle the common issue of green defects in material extrusion(MEX)additive manufacturing(AM)cemented carbides,warm isostatic pressing(WIP)was introduced to eliminate defects of MEX WC-9Co cemented carbide greens,t...To tackle the common issue of green defects in material extrusion(MEX)additive manufacturing(AM)cemented carbides,warm isostatic pressing(WIP)was introduced to eliminate defects of MEX WC-9Co cemented carbide greens,thereby improving both microstructure uniformity and mechanical properties of sintered bodies.The results indicate that WIP reduces defects in MEX greens,thus decreasing the dimensions and numbers of defects,modifying shapes of pores within sintered bodies,while preserving surface quality and shape characteristics.Compared with WC-9Co prepared via MEX followed by debinding and sintering(DS),the hardness of WC-9Co prepared using MEX-WIP-DS does not change significantly,ranging HV_(30)1494-1508,the transverse rupture strength increases by up to 49.3%,reaching 2998-3514 MPa,and the fracture toughness remains high,ranging 14.8-17.0 MPa·m^(1/2).The mechanical properties surpass comparable cemented carbides fabricated through other AM methods and are comparable to those produced by powder metallurgy.The integration of green WIP into MEX-DS broadens the MEX processing window,and improves the overall mechanical properties of MEX AM WC-Co cemented carbides.展开更多
Global warming and nitrogen(N)deposition have a profound impact on greenhouse gas(GHG)fluxes and consequently,they also affect climate change.However,the global combined effects of warming and N addition on GHG fluxes...Global warming and nitrogen(N)deposition have a profound impact on greenhouse gas(GHG)fluxes and consequently,they also affect climate change.However,the global combined effects of warming and N addition on GHG fluxes remain to be fully understood.To address this knowledge gap,a globalmeta-analysis of 197 datasets was performed to assess the response of GHG fluxes to warming and N addition and their interactions under various climate and experimental conditions.The results indicate that warming significantly increased CO_(2)emissions,while N addition and the combined warming and N addition treatments had no impact on CO_(2)emissions.Moreover,both warming and N addition and their interactions exhibited positive effects on N_(2)O emissions.Under the combined warming and N addition treatments,warming was observed to exert a positive main effect on CO_(2)emissions,while N addition had a positive main effect on N_(2)O emissions.The interactive effects of warming and N addition exhibited antagonistic effects on CO_(2),N_(2)O,and CH_(4)emissions,with CH_(4)uptake dominated by additive effects.Furthermore,we identified biome and climate factors as the two treatments.These findings indicate that both warming and N addition substantially impact soil GHG fluxes and highlight the urgent need to investigate the influence of the combination of warming and N addition on terrestrial carbon and N cycling under ongoing global change.展开更多
The effects of different warm rolling(WR)reductions on the microstructure and mechanical properties of low-Cr FeCrAl alloys at both room and elevated temperatures were investigated.The study revealed that when the WR ...The effects of different warm rolling(WR)reductions on the microstructure and mechanical properties of low-Cr FeCrAl alloys at both room and elevated temperatures were investigated.The study revealed that when the WR reduction is small,it effectively refines the grains and forms a large number of subgrains in the matrix,while also inducing the dissolution of the Laves phase.This enhances the mechanical properties of FeCrAl alloys primarily through grain refinement and solid solution strengthening.Conversely,with larger WR reductions,the grain refinement effect diminishes,but a significant number of Laves phases form in the matrix,strengthening the alloys primarily through precipitation strengthening.WR exhibited a remarkable enhancing effect on the comprehensive mechanical properties at both room and high temperatures,with a signi-ficant enhancement in ductility at high temperatures.Notably,a 10%WR reduction resulted in the optimal overall mechanical properties at both room and elevated temperatures.展开更多
The Tibetan Plateau(TP),known as the“Third Pole of Earth”,and its ecosystem is quite sensitive to climate change(Yao et al.,2012;Qiu,2008).In recent decades,the main TP has experienced warming and humidification(alt...The Tibetan Plateau(TP),known as the“Third Pole of Earth”,and its ecosystem is quite sensitive to climate change(Yao et al.,2012;Qiu,2008).In recent decades,the main TP has experienced warming and humidification(although there has been a drying trend in the southern region),and researchers anticipate that this change will continue in the future(Jiang et al.,2023;Sun et al.,2020;Chen et al.,2015).展开更多
High-altitude peatlands(HAPs;defined as>1,500 m)provide important ecosystem services including soil carbon(C)storage.However,temperatures in high-altitude regions have been rising rapidly in recent decades,while HA...High-altitude peatlands(HAPs;defined as>1,500 m)provide important ecosystem services including soil carbon(C)storage.However,temperatures in high-altitude regions have been rising rapidly in recent decades,while HAPs are increasingly affected by human activities such as intensive drainage and grazing.Collectively,climate change and land management may strongly affect the HAP C cycle.Here,we synthesise current global progress on the HAP C cycle,focussing on the impacts of climate change and land management.Warming increased both ecosystem respiration(ER)and methane(CH_(4))emissions(26%–86%),while impacts on net ecosystem exchange(NEE)of CO_(2)were still unclear.However,short-term drought decreased ER and CH_(4)emissions(7%–96%),along with NEE(12%–52%).Snow,permafrost,and glacier decline may also impact the C cycle in HAPs,although a limited number of studies have been conducted.Grazing and vegetation degradation impacts on HAP C cycling were related to grazing and degradation intensity,while generally decreasing soil organic C stocks(3%–51%).Moving from shallower to deeper WTLs stimulated ER(9%–812%),while reducing CH_(4)emissions(13%–100%),with variable effects on NEE(-53%–700%).Restoration by rewetting began to reverse the trend of drainage.We highlight several knowledge gaps,including limited understanding of climate change and land-management effects on gross primary productivity and dissolved organic carbon,while there is still limited knowledge of regional differences in HAP C cycling.Future research should focus on the interaction of land-use and climate change in HAPs,including HAP restoration,which may help future conservation of these valuable ecosystems.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(No.202242001)the Mount Tai Research Grant。
文摘United Nations(UN)encourages sovereign states to take prompt and concrete measures to accomplish net-zero emissions by year 2050,requesting carbon dioxide removal(CDR)technologies to be prepared and implemented in such ambitious climate action roadmap.However,whether CDR technologies should be further promoted or discontinued post net-zero emission year remains unclear.In this Earth-system modelling research,we compare UN-suggested 2050 net-zero emission scenario against other common climate mitigation scenarios outlined by shared social-economic pathways(SSPs).We also simulate continued CDR implementations after net-zero emissions,which is hypothetically achieved in year 2050 and 2070 respectively,to investigate how CDR can impact the global climate throughout the whole 21st and 22nd centuries.The modelling results find if the 2050 UN net-zero emission goal is accomplished,the global average surface air temperature(SAT)in the end of 21st century is around 1.5℃higher compared to the pre-industrial level,promising an Earth environment more habitable than other scenarios without CDR.When CDR is applied to remove equal amount of anthropogenic CO_(2)emissions since industrial revolution,it restores the global average SAT close to pre-industrial level of 13.5℃.However,CDR-induced global carbon distribution within ocean,atmosphere,and land pools is different from the pre-industrial condition,causing reduced atmospheric CO_(2)concentration by 9 to 38 ppm compared to the pre-industrial cases,and more alkalinized ocean surface with pH increase of 0.004 to 0.024.This study affirms CDR cannot be viewed as a reversed process to anthropogenic CO_(2)emissions,accordingly climate policies to overcome the uncertainties after for late 21st century still require careful trade-offs for the decarbonation and the cost-benefits of CDR measures.
基金supported by the Science and Technology Project of Hebei Education Department(No.QN2023028)the Natural Science Foundation of Hebei Province(No.C2022201042)+1 种基金the High-level Talent Research Funding Project of Hebei University(Nos.521000981405 and 521000981186)the Collaborative Innovation Center for Baiyangdian Basin Ecological Protection and Beijing-Tianjin-Hebei Sustainable Development.
文摘Climate warming and atmospheric nitrogen(N)deposition have profound influences on the terrestrial biosphere.However,how these two global change drivers affect phytoplankton which are important primary producers in wetlands with large carbon stocks and complex hydrological fluctuations remain largely unclear.As part of a two-year field experiment in a freshwater wetland,this study was conducted to investigate the effects of nighttime warming and N addition on phytoplankton biomass in the North China Plain.The results showed that neither nighttime warming nor N addition influenced the Shannon-Wiener index of phytoplankton community.Nighttime warming did not change phytoplankton biomass,likely due to the different warming impacts on dominant phyla and in different seasons.Decreased phytoplankton biomass in spring because of the increased water pH and submerged plant coverage was compensated by the enhanced biomass in autumn due to the reduced dissolved oxygen and submerged plant coverage,leading to the neutral change of phytoplankton biomass under warming.Nitrogen addition elevated phytoplankton biomass by 11.6%,which could be attributed to the enhanced nutrient availability and reduced submerged plant coverage.Positive relationships of methane(CH4)emission rates at the water-air interface with phytoplankton biomass indicated the potentially crucial role of phytoplankton in mediating wetland CH4 cycling through photosynthesis-driven metabolisms.The findings suggested the seasonal variation of phytoplankton and their potential responses to nighttime warming and N deposition,which may provide a more accurate basis for assessing the global change-carbon feedback in wetland ecosystems.
基金supported by the National Natural Science Foundation of China(No.42276108)the Young Scientists Fund of Shandong Provincial Natural Science Foundation(No.ZR2022QD052)。
文摘Viral infections play a crucial role in marine biogeochemical cycles,by regulating bacterial mortality and mediating nutrient and carbon fluxes.However,despite of their ecological significance,existing climate change models generally fail to incorporate virus-mediated ecological processes due to the current limited understanding of marine viral dynamics under global warming.While numerous studies have explored the effect of warming for viral decay and production,how temperature regulates the total abundance of marine viruses remains unclear.In this study,we conducted year-round measurements of viral production and decay rates in Qingdao's coastal waters,with additional experimental warming treatments.The result showed that under in-situ temperature,the viral decay and production rate displayed distinct seasonal variations.With the exception of summer,elevated temperature stimulated both viral decay rate and production rate,and further improved the net viral production rate.While in summer,the net viral production rate turned negative,implying divergent threshold viral decay and viral production rate on warming.Our study deepens the understanding of the effect of global warming on marine viruses and provides scientific data for climate change models.
文摘Despite its significant societal and scientific importance,projected changes in the characteristics of intraseasonal oscillations(ISOs)associated with Indian summer monsoon rainfall under increased greenhouse gas concentrations remain largely unexplored.This study utilizes downscaled and bias-corrected historical simulations and projections from 17 CMIP6 models to investigate the future evolution of ISOs.Our findings reveal a twofold increase in ISO variability over India in the far future under the very high emissions scenario,raising critical concerns about its adverse socioeconomic impacts.Our analysis suggests that the increased magnitude of precipitation anomalies associated with northwardpropagating ISOs may intensify active monsoon spells,potentially triggering extreme rainfall events.Additionally,the phase speed of these northward-propagating ISOs over the Bay of Bengal is projected to accelerate owing to weakened air-sea coupling and feedback.This acceleration reduces the northwest-southeast tilt of the precipitation band,altering the spatial structure of the ISOs.Concurrently,the strengthening of circulation-precipitation feedback and warming of the Indian Ocean are projected to enhance the phase speed of monsoon ISOs,leading to more frequent active spells.This study underscores the critical role of regional ocean-atmosphere feedback in shaping future ISO characteristics,highlighting the urgent need for improved understanding and prediction of these changes in the context of a warming climate.
基金Supported by the National Key Research and Development Program of China(No.2023YFD2400800)the Laoshan Laboratory(Nos.LSKJ202203801,LSKJ202203204)+4 种基金the Natural Science Foundation of Shandong Province(Nos.ZR2023MD127,ZR2021MD075)the Central Public-interest Scientific Institution Basal Research Fund CAFS(Nos.2023TD28,20603022023012)the National Natural Science Foundation of China(No.32373107)the China Agriculture Research System(No.CARS-50)the Taishan Scholars Program。
文摘Giant kelp Macrocystis pyrifera,an important foundation species with great ecological and economic value,is threatened by climate change.To better understand the impact of climate warming on M.pyrifera,we investigated its global distribution dynamics by an optimized species distribution model(SDM).Results showed that wave height,sea surface temperature,benthic temperature,and benthic phosphate concentration were key factors shaping the distribution of M.pyrifera.In addition to currently known distribution regions,the model revealed potential suitable habitats globally.Under future climate scenarios,the habitat suitability of M.pyrifera would decrease at low latitudes and increase at high latitudes,resulting in a poleward shift of suitable habitats.In the regions currently occupied by M.pyrifera,the high suitable habitats were predicted to shrink,which implies that the existing M.pyrifera would be adversely impacted.These results serve as references for the conservation and utilization of M.pyrifera resource.
基金Project(52378425)supported by the National Natural Science Foundation of ChinaProject(1053320221044)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Irradiating hard rocks by a high-power laser can reduce localized hardness in the rocks;however,continuous lasers produce a large amount of melt that inhibits further heat absorption.Pulsed lasers allow rocks to absorb and dissipate energy and avoid melt formation.In this study,200 W nanosecond pulsed laser was used to irradiate granite.The effects of laser parameters on the thermal cracking morphology,temperature field,warming pattern,and Leeb hardness of the granite surface were analyzed.The optimal laser parameters for softening granite were determined by performing objective optimization in MATLAB using granite's melting point as the reference.Nanoindentation techniques were employed to assess the softening characteristics of the granite surface along the longitudinal direction.The results showed that three main forms of thermal damage occurred on the granite surface:oxidative decomposition,spalling,and melting.The damage state was affected by the average laser power,with the pulse width and repetition frequency affecting surface damage differently.Appropriate laser parameters effectively controlled the melt damage on the granite surface,and irradiation with nanosecond pulsed lasers effectively reduced surface hardness.However,excessive power can generate large amounts of hard melts and weaken the softening effect.
基金supported by the Australian Research Council(Grant No.CE230100012)。
文摘The onset,cessation,and length of the rainy season are crucial for global water resources,agricultural practices,and food security.However,the response of precipitation seasonality to global warming remains uncertain.In this study,we analyze how global warming levels(GWLs)of 1.5℃ and 2℃ could affect the timing of rainfall onset(RODs),rainfall cessation(RCDs),and the overall duration of the rainy season(LRS)over global land monsoon(GLM)regions using simulations from CMIP6 under the SSP2-4.5 and SSP5-8.5 scenarios.With high model consensus,our results reveal that RODs are projected to occur later over Southern Africa,North Africa,and South America,but earlier over South Asia and Australia,in a warmer climate.The projected early RODs in Australia are more pronounced at the 2℃ GWL under SSP5-8.5.On the other hand,early RCDs are projected over South America and East Asia,while late RCDs are projected over North Africa,with high inter-model agreement.These changes are associated with a future decrease in LRS in most GLM regions.Additionally,we found that continuous warming over 1.5℃ will further reduce the length of the rainy season,especially over the South America,North Africa,and Southern Africa monsoon regions.The findings underscore the urgent need to mitigate global warming.
基金supported by the International Partnership program of the Chinese Academy of Sciences(170GJHZ2023074GC)National Natural Science Foundation of China(42425706 and 42488201)+1 种基金National Key Research and Development Program of China(2024YFF0807902)Beijing Natural Science Foundation(8242041),and China Postdoctoral Science Foundation(2025M770353).
文摘Accurately assessing the relationship between tree growth and climatic factors is of great importance in dendrochronology.This study evaluated the consistency between alternative climate datasets(including station and gridded data)and actual climate data(fixed-point observations near the sampling sites),in northeastern China’s warm temperate zone and analyzed differences in their correlations with tree-ring width index.The results were:(1)Gridded temperature data,as well as precipitation and relative humidity data from the Huailai meteorological station,was more consistent with the actual climate data;in contrast,gridded soil moisture content data showed significant discrepancies.(2)Horizontal distance had a greater impact on the representativeness of actual climate conditions than vertical elevation differences.(3)Differences in consistency between alternative and actual climate data also affected their correlations with tree-ring width indices.In some growing season months,correlation coefficients,both in magnitude and sign,differed significantly from those based on actual data.The selection of different alternative climate datasets can lead to biased results in assessing forest responses to climate change,which is detrimental to the management of forest ecosystems in harsh environments.Therefore,the scientific and rational selection of alternative climate data is essential for dendroecological and climatological research.
基金supported by the Key Program of National Science of China(Grant No.:42030509 and 42141005)。
文摘The latitudinal diversity gradient(LDG)is one of the most notable biodiversity patterns in biogeography.The metabolic theory of ecology(MTE)explains ecological patterns,including the LDG.However,little is known about whether the LDG remains stable over time as climate warming progresses and whether MTE remains applicable to clarify this pattern.In this study,forest data spanning temperate,subtropical,and tropical zones across China were used to analyze long-term changes in the LDG of tree species over 2005-2020.Based on the MTE framework,spatial scales were considered to assess temperature dependence of typical forest trees species.Our results show that species richness decreased with increasing latitude,and that temperature was the primary driver of this change.Although temperature in China has significantly increased over the past two decades,the LDG of tree species has remained stable.However,there was a decrease in species richness in tropical regions over time.With predictions of the MTE,the logarithm of typical forest tree species richness exhibited negative linear relationships with the inverse of ambient temperature,indicating temperature dependence of species richness.However,the relationship remained stable and was strongly influenced by spatial scale,intensifying as spatial scale increased.The findings emphasize the important role of temperature in shaping the LDG.The effects of spatial scale,in particular,should be considered when biodiversity management plans are developed for future climate change.
基金supported by the National Natural Science Foundation of China(32171001,32371050,and 82371554).
文摘Maintaining a stable body temperature is essential for survival.Multiple brain regions contribute to thermoregulation,but their specific characteristics and underlying neural mechanisms in the coordination of thermoregulation are not fully clarified.Here,we reveal the distinct roles of two preoptic subregions in warm defense in mice:the anterior ventromedial preoptic area(VMPO)and the ventral part of the lateral preoptic nucleus(vLPO).VMPO vesicular glutamate transporter 2(Vglut2)neurons exhibited dramatic responses to rising temperatures,producing a marked decrease in core temperature by warm defense responses.In contrast,excitatory and inhibitory vLPO neurons responded gently to warm stimuli,exerting moderate effects on warm defense.Further postsynaptic tracing and caspase ablation identified distinct cell type-specific downstream targets in the dorsomedial hypothalamus(DMH)mediating these different warm defense responses.Taken together,our findings reveal distinct yet complementary pathways in the preoptic DMH network that enable both rapid and fine-tuned regulation of body temperature under elevated thermal conditions.
基金supported by the Natural Science Fund of China(31771724)the Key Research and Development Project of Shaanxi Province(2024NC-ZDCYL-01-10).
文摘The increase in soil temperature associated with climate change has introduced considerable challenges to crop production.Split nitrogen application(SN)represents a potential strategy for improving crop nitrogen use efficiency and enhancing crop stress resistance.Nevertheless,the precise interaction between soil warming(SW)and SN remains unclear.In order to ascertain the impact of SW on maize growth and whether SN can improve the tolerance of maize to SW,a two-year field experiment was conducted(2022-2023).The aim was to examine the influence of two SW ranges(MT,warming 1.40℃;HT,warming 2.75℃)and two nitrogen application methods(N1,one-time basal application of nitrogen fertilizer;N2,one third of base nitrogen fertilizer+two thirds of jointing stage supplemental nitrogen fertilizer)on maize root growth,photosynthetic characteristics,nitrogen use efficiency,and yield.The results demonstrated that SW impeded root growth and precipitated the premature aging of maize leaves following anthesis,particularly in the HT,which led to a notable reduction in maize yield.In comparison to N1,SN has been shown to increase root length density by 8.54%,root bleeding rate by 8.57%,and enhance root distribution ratio in the middle soil layers(20-60 cm).The interaction between SW and SN had a notable impact on maize growth and yield.The SN improved the absorption and utilization efficiency of nitrogen by promoting root development and downward canopy growth,thus improving the tolerance of maize to SW at the later stage of growth.In particular,the N2HT resulted in a 14.51%increase in the photosynthetic rate,a 18.58%increase in nitrogen absorption efficiency,and a 18.32%increase in maize yield compared with N1HT.It can be posited that the SN represents a viable nitrogen management measure with the potential to enhance maize tolerance to soil high-temperature stress.
基金Natural science foundation of Inner Mongolia(2024LHMS06018)The basic scientific research funding for directly affiliated universities in the Inner Mongolia(JY20250094)。
文摘A complex system is inherently high-dimensional.Recent studies indicate that,even without complete knowledge of its evolutionary dynamics,the future behavior of such a system can be predicted using time-series data(data-driven prediction).This suggests that the essential dynamics of a complex system can be captured through a low-dimensional representation.Virus evolution and climate change are two examples of complex,time-varying systems.In this article,we show that mutations in the spike protein provide valuable data for predicting SARS-CoV-2 variants,forecasting the possible emergence of the new macro-lineage Q in the near future.Our analysis also demonstrates that carbon dioxide concentration is a reliable indicator for predicting the evolution of the climate system,extending global surface air temperature(GSAT)forecasts through 2500.
基金supported by the National Natural Science Foundation of China(No.42072211)the National Natural Science Foundation of China(No.42401048)the Third Xinjiang Scientific Expedition and Research Program(No.2021xjkk0302)。
文摘The Taklimakan Desert,located in the heart of central Asia,covers approximately 330000 km^(2),making it China's largest desert and the world's second-largest shifting desert(Dong et al.,2024).With an average annual precipitation of less than 100 mm and evaporation rates ranging from 2000 to 3000 mm(Yang et al.,2020),it is recognized as one of the driest regions on Earth,often referred to as the“sea of death”.
基金funded by the National Key Research and Development Plan of China(No.2022YFE0127900)the National Natural Science Foundation of China(Nos.32071558,32171559)+2 种基金the Natural Science Foundation Key Project of Inner Mongolia Autonomous Region,China(No.2023ZD23)the Hulunbuir Science and Technology Plan Project(No.SF2022001)the Fundamental Research Funds of CAF(CAFYBB2023ZA002).
文摘Increasing temperatures and severe droughts threaten forest vitality globally.Prediction of forest response to climate change requires knowledge of the spatiotemporal patterns of monthly or seasonal climatic impacts on the growth of tree species,likely driven by local climatic aridity,climate trends,edaphic conditions,and the climatic adaption of tree species.The ability of tree species to cope with changing climate and the effects of environmental variables on growth trends and growth-climate relationships across diverse bioclimatic regions are still poorly understood for many species.This study investigated radial growth trends,interannual growth variability,and growth-climate sensitivity of two dominant tree species,Pinus tabulaeformis(PT)and Pinus sylvestris var.mongolica(PS),across a broad climatic gradient with a variety of soil properties in temperate Northern China.Using a network of 83 tree ring chronologies(54 for PT and 29 for PS)from 1971 to 2010,we documented that both species maintained constant growth trends at wet sites,while both displayed rapid declines at dry sites.We reported the species-specific drivers of spatial heterogeneity in growth trends,interannual growth variability,and growth-climate relationships.Calculated climatic variables and soil properties were identified as the most critical factors affecting the growth trends and growth-climate relationships.However,climatic variables play more essential roles than soil properties in determining the spatial heterogeneity of the growth-climate relationship.Lower clay content and higher soil nutrient regimes can exacerbate the moisture-related susceptibility of tree growth.Our findings highlight that soil properties emerged as important modulating factors to predict the drought vulnerability of forests in addition to climatic variables.Considering the continued climate warmingdrying trend in the future,both pines will face a more severe growth decline and increase in drought vulnerability at drier sites with lower clayed soil or higher nutrient regimes.
基金supported by the National Key R&D Program of China (Grant No.2023YFF0806500)the International Partnership Program of the Chinese Academy of Sciences (Grant No.060GJHZ2024064MI)+10 种基金the Chinese Academy of Sciences and the National Research Council of Italy Scientific Cooperative Programmethe new Cornerstone Science Foundation through the XPLORER PRIZEthe National Key Scientific and Technological Infrastructure project “Earth System Science Numerical Simulator Facility” (Earth Lab), and Ocean Negative Carbon Emissions (ONCE)sponsored by the US National Science Foundationsupported by the Young Talent Support Project of Guangzhou Association for Science and Technologythe Open Research Cruise NORC2022-10+NORC2022-303 supported by NSFC shiptime Sharing Projects 42149910supported by NASA Awards 80NSSC17K0565, 80NSSC21K1191, and 80NSSC22K0046by the Regional and Global Model Analysis (RGMA) component of the Earth and Environmental System Modeling Program of the U.S.Department of Energy’s Office of Biological & Environmental Research (BER) via National Science Foundation IA 1947282supported by NOAA (Grant No.NA19NES4320002 to CISESS-MD at the University of Maryland)supported by the Austrian Science Fund (P33177)ESA (contract ref.4000145298/24/I-LR)。
文摘Heating in the ocean has continued in 2024 in response to increased greenhouse gas concentrations in the atmosphere,despite the transition from an El Ni?o to neutral conditions. In 2024, both global sea surface temperature(SST) and upper2000 m ocean heat content(OHC) reached unprecedented highs in the historical record. The 0–2000 m OHC in 2024exceeded that of 2023 by 16 ± 8 ZJ(1 Zetta Joules = 1021 Joules, with a 95% confidence interval)(IAP/CAS data), which is confirmed by two other data products: 18 ± 7 ZJ(CIGAR-RT reanalysis data) and 40 ± 31 ZJ(Copernicus Marine data,updated to November 2024). The Indian Ocean, tropical Atlantic, Mediterranean Sea, North Atlantic, North Pacific, and Southern Ocean also experienced record-high OHC values in 2024. The global SST continued its record-high values from2023 into the first half of 2024, and declined slightly in the second half of 2024, resulting in an annual mean of 0.61°C ±0.02°C(IAP/CAS data) above the 1981–2010 baseline, slightly higher than the 2023 annual-mean value(by 0.07°C ±0.02°C for IAP/CAS, 0.05°C ± 0.02°C for NOAA/NCEI, and 0.06°C ± 0.11°C for Copernicus Marine). The record-high values of 2024 SST and OHC continue to indicate unabated trends of global heating.
基金supported by the Key Project of Chinese Academy of Engineering(No.2019-XZ-11)the General Project of Chinese Academy of Engineering(No.2023-XY-18)+1 种基金the Open Fund of National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials of China(No.HKDNM201907)the Independent Project of State Key Laboratory of Powder Metallurgy,China。
文摘To tackle the common issue of green defects in material extrusion(MEX)additive manufacturing(AM)cemented carbides,warm isostatic pressing(WIP)was introduced to eliminate defects of MEX WC-9Co cemented carbide greens,thereby improving both microstructure uniformity and mechanical properties of sintered bodies.The results indicate that WIP reduces defects in MEX greens,thus decreasing the dimensions and numbers of defects,modifying shapes of pores within sintered bodies,while preserving surface quality and shape characteristics.Compared with WC-9Co prepared via MEX followed by debinding and sintering(DS),the hardness of WC-9Co prepared using MEX-WIP-DS does not change significantly,ranging HV_(30)1494-1508,the transverse rupture strength increases by up to 49.3%,reaching 2998-3514 MPa,and the fracture toughness remains high,ranging 14.8-17.0 MPa·m^(1/2).The mechanical properties surpass comparable cemented carbides fabricated through other AM methods and are comparable to those produced by powder metallurgy.The integration of green WIP into MEX-DS broadens the MEX processing window,and improves the overall mechanical properties of MEX AM WC-Co cemented carbides.
基金supported by Ningxia Key Research and Development Fund Project of China(No.2023BCF01048)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2023-JC-YB-182).
文摘Global warming and nitrogen(N)deposition have a profound impact on greenhouse gas(GHG)fluxes and consequently,they also affect climate change.However,the global combined effects of warming and N addition on GHG fluxes remain to be fully understood.To address this knowledge gap,a globalmeta-analysis of 197 datasets was performed to assess the response of GHG fluxes to warming and N addition and their interactions under various climate and experimental conditions.The results indicate that warming significantly increased CO_(2)emissions,while N addition and the combined warming and N addition treatments had no impact on CO_(2)emissions.Moreover,both warming and N addition and their interactions exhibited positive effects on N_(2)O emissions.Under the combined warming and N addition treatments,warming was observed to exert a positive main effect on CO_(2)emissions,while N addition had a positive main effect on N_(2)O emissions.The interactive effects of warming and N addition exhibited antagonistic effects on CO_(2),N_(2)O,and CH_(4)emissions,with CH_(4)uptake dominated by additive effects.Furthermore,we identified biome and climate factors as the two treatments.These findings indicate that both warming and N addition substantially impact soil GHG fluxes and highlight the urgent need to investigate the influence of the combination of warming and N addition on terrestrial carbon and N cycling under ongoing global change.
文摘The effects of different warm rolling(WR)reductions on the microstructure and mechanical properties of low-Cr FeCrAl alloys at both room and elevated temperatures were investigated.The study revealed that when the WR reduction is small,it effectively refines the grains and forms a large number of subgrains in the matrix,while also inducing the dissolution of the Laves phase.This enhances the mechanical properties of FeCrAl alloys primarily through grain refinement and solid solution strengthening.Conversely,with larger WR reductions,the grain refinement effect diminishes,but a significant number of Laves phases form in the matrix,strengthening the alloys primarily through precipitation strengthening.WR exhibited a remarkable enhancing effect on the comprehensive mechanical properties at both room and high temperatures,with a signi-ficant enhancement in ductility at high temperatures.Notably,a 10%WR reduction resulted in the optimal overall mechanical properties at both room and elevated temperatures.
基金supported by the Basic Science Center for Tibetan Plateau Earth System(No.41988101)the Science and Technology Plan Project of the Xizang Autonomous Region(No.XZ202201ZD0005G01)。
文摘The Tibetan Plateau(TP),known as the“Third Pole of Earth”,and its ecosystem is quite sensitive to climate change(Yao et al.,2012;Qiu,2008).In recent decades,the main TP has experienced warming and humidification(although there has been a drying trend in the southern region),and researchers anticipate that this change will continue in the future(Jiang et al.,2023;Sun et al.,2020;Chen et al.,2015).
基金supported by the National Natural Science Foundation of China(Grants No.U2243226 and 42250410326)the Research Start-up Fund of the Institute of Geographic Sciences and Natural Resources Research(Chinese Academy of Sciences)。
文摘High-altitude peatlands(HAPs;defined as>1,500 m)provide important ecosystem services including soil carbon(C)storage.However,temperatures in high-altitude regions have been rising rapidly in recent decades,while HAPs are increasingly affected by human activities such as intensive drainage and grazing.Collectively,climate change and land management may strongly affect the HAP C cycle.Here,we synthesise current global progress on the HAP C cycle,focussing on the impacts of climate change and land management.Warming increased both ecosystem respiration(ER)and methane(CH_(4))emissions(26%–86%),while impacts on net ecosystem exchange(NEE)of CO_(2)were still unclear.However,short-term drought decreased ER and CH_(4)emissions(7%–96%),along with NEE(12%–52%).Snow,permafrost,and glacier decline may also impact the C cycle in HAPs,although a limited number of studies have been conducted.Grazing and vegetation degradation impacts on HAP C cycling were related to grazing and degradation intensity,while generally decreasing soil organic C stocks(3%–51%).Moving from shallower to deeper WTLs stimulated ER(9%–812%),while reducing CH_(4)emissions(13%–100%),with variable effects on NEE(-53%–700%).Restoration by rewetting began to reverse the trend of drainage.We highlight several knowledge gaps,including limited understanding of climate change and land-management effects on gross primary productivity and dissolved organic carbon,while there is still limited knowledge of regional differences in HAP C cycling.Future research should focus on the interaction of land-use and climate change in HAPs,including HAP restoration,which may help future conservation of these valuable ecosystems.
