Climate changes in cold-temperate zones are increasingly altering the state of climatic constraints on photosynthesis and growth,leading to adaptive changes in plant phenology and subsequent seasonal carbon assimilati...Climate changes in cold-temperate zones are increasingly altering the state of climatic constraints on photosynthesis and growth,leading to adaptive changes in plant phenology and subsequent seasonal carbon assimilation.However,the spatio-temporal patterns of climatic constraints and seasonal carbon assimilation are poorly understood.In this study,the timing of peak photosynthetic activity(DOY_(pmax))was employed as a proxy for plant adap-tive state to climatic constraints on growth to examine the spatio-temporal dynamics of DOY_(pmax).By using multiple remote sensing metrics,DOY_(pmax)was characterized with changes in the solar-induced chlorophyll fluorescence(SIF)and leaf area index(LAI)from 2000 to 2018.Based on SIF,the DOY_(pmax)was generally around day 190,while based on LAI was about 10 d later.Peak photosynthetic activity of forests occurs earlier compared to other vegetation types.Overall,the advanced DOY_(pmax)were observed based on both SIF and LAI,with annual rates of 0.2(P=0.31)and 0.3(P<0.05)d,respectively.DOY_(pmax)dynamics were influ-enced by hot temperature extremes and vapor pressure defi-cits(VPD)during the early growing season,regardless of sub-zone and different vegetation type.The generalized lin-ear mixed model(GLMM)showed the largest contribution by hot extremes to DOY_(pmax)dynamics accounted for 55.5%(DOY_(pmax_SIF))and 49.1%(DOY_(pmax_LAI)),respectively,fol-lowed by VPD(DOY_(pmax_SIF):23.1%;DOY_(pmax_LAI):29.5%).These findings highlight the crucial role of climate extremes in shaping seasonal carbon dynamics and regional carbon balance.展开更多
There is an increasing concern that the continuous use of chemical fertilizers might lead to harmful effects on soil ecosystem.Accordingly, a biocompatible approach involving inoculation of beneficial microorganisms i...There is an increasing concern that the continuous use of chemical fertilizers might lead to harmful effects on soil ecosystem.Accordingly, a biocompatible approach involving inoculation of beneficial microorganisms is presented to promote plant growth and simultaneously minimize the negative effect of chemical fertilizers. In this study, Rhodopseudomonas palustris, a plant growth-promoting rhizobacterium(PGPR), was inoculated into both fertilized and unfertilized soils to assess its influence on Stevia rebaudiana plant growth and microbial community in rhizosphere soils in a 122-d field experiment. Soil enzyme assays(dehydrogenase, urease, invertase, and phosphomonoesterase), real-time quantitative polymerase chain reaction(RT-_qPCR), and a high-throughput sequencing technique were employed to determine the microbial activity and characterize the bacterial community. Results showed that the R.palustris inoculation did not significantly influence Stevia yields and root biomass in either the fertilized or unfertilized soil. Chemical fertilization had strong negative effects on soil bacterial community properties, especially on dehydrogenase and urease activities.However, R. palustris inoculation counteracted the effect of chemical fertilizer on dehydrogenase and urease activities, and increased the abundances of some bacterial lineages(including Bacteroidia, Nitrospirae, Planctomycetacia, Myxococcales, and Legionellales). In contrast, inoculation into the unfertilized soil did not significantly change the soil enzyme activities or the soil bacterial community structure. For both the fertilized and unfertilized soils, R. palustris inoculation decreased the relative abundances of some bacterial lineages possessing photosynthetic ability, such as Cyanobacteria, Rhodobacter, Sphingomonadales, and Burkholderiales. Taken together, our observations stress the potential utilization of R. palustris as PGPR in agriculture, which might further ameliorate the soil microbial properties in the long run.展开更多
Background:Old-growth forests are irreplaceable with respect to climate change mitigation and have considerable carbon(C)sink potential in soils.However,the relationship between the soil organic carbon(SOC)turnover ra...Background:Old-growth forests are irreplaceable with respect to climate change mitigation and have considerable carbon(C)sink potential in soils.However,the relationship between the soil organic carbon(SOC)turnover rate and forest development is poorly understood,which hinders our ability to assess the C sequestration capacity of soil in old-growth forests.Methods:In this study,we evaluated the SOC turnover rate by calculating the isotopic enrichment factor β(defined as the slope of the regression between ^(13)C natural abundance and log-transformed C concentrations)along 0-30 cm soil profiles in three successional forests in subtropical China.A lower β(steeper slope)is associated with a higher turnover rate.The three forests were a 60-year-old P.massoniana forest(PF),a 100-year-old coniferous and broadleaved mixed forest(MF),and a 400-year-old monsoon evergreen broadleaved forest(BF).We also analyzed the soil physicochemical properties in these forests to examine the dynamics of SOC turnover during forest succession and the main regulators.Results:The β value for the upper 30-cm soils in the BF was significantly(p<0.05)higher than that in the PF,in addition to the SOC stock,although there were nonsignificant differences between the BF and MF.The β value was significantly(p<0.05)positively correlated with the soil recalcitrance index,total nitrogen,and available nitrogen contents but was significantly(p<0.01)negatively correlated with soil pH.Conclusions:Our results demonstrate that SOC has lower turnover rates in old-growth forests,accompanied by higher soil chemical recalcitrance,nitrogen status,and lower soil pH.This finding helps to elucidate the mechanism underlying C sequestration in old-growth forest soils,and emphasizes the important value of old-growth forests among global C sinks.展开更多
Potato grows in most part of China, it achieves higher yield and better quality in Gansu Province than in others. With global warming, its growth duration has been prolonged and sowing date become earlier than before....Potato grows in most part of China, it achieves higher yield and better quality in Gansu Province than in others. With global warming, its growth duration has been prolonged and sowing date become earlier than before. Therefore, to regulate its sowing date and growing period is of great significance for better harvest. In this study, experiments were conducted with six sowing-date treatments of potato in Dingxi, which is in the Loess Plateau of central Gansu Province in Northwest China in 2010. The growth period, morphological index and change in yield and their relationships with temperature, precipitation, and other climatic factors were investigated for each treatment. Results show that the crop with different sowing dates experienced different climate conditions, leading to distinct growth duration, plant height, and leaf area index. The growth duration was shortened due to a delay in sowing date. For each 15-day delay in sowing, the growth duration was reduced by 12 days on average. A significant linear relationship was found between numbers of days either from seeding to emergence or from flowering to harvest and mean temperature over the corresponding period. Dry matter accumulation, tuber fresh weight, and final yield were all decreased because of insufficient cumulative temperature over the shorter growing periods. Marked differences in tuber yield were discovered among the six treatments of sowing date, the potato planted on May 27 giving the highest yield. The potato planted either earlier or later would produce invariably lower yield than the treatment of May 27. Late May therefore can be taken as the optimum sowing time of potato in this region because the crop can fully utilize thermal resource. We conclude that to postpone sowing time is a good practice for potato production to adapt to climate warming in the Loess Plateau of central Gansu, China.展开更多
The terrestrial carbon(C) cycle plays an important role in global climate change, but the vegetation and environmental drivers of C fluxes are poorly understood. We established a global dataset with 1194 available dat...The terrestrial carbon(C) cycle plays an important role in global climate change, but the vegetation and environmental drivers of C fluxes are poorly understood. We established a global dataset with 1194 available data across site-years including gross primary productivity(GPP), ecosystem respiration(ER), net ecosystem productivity(NEP), and relevant environmental factors to investigate the variability in GPP, ER and NEP, as well as their covariability with climate and vegetation drivers.The results indicated that both GPP and ER increased exponentially with the increase in mean annual temperature(MAT)for all biomes. Besides MAT, annual precipitation(AP) had a strong correlation with GPP(or ER) for non-wetland biomes.Maximum leaf area index(LAI) was an important factor determining C fluxes for all biomes. The variations in both GPP and ER were also associated with variations in vegetation characteristics. The model including MAT, AP and LAI explained 53%of the annual GPP variations and 48% of the annual ER variations across all biomes. The model based on MAT and LAI explained 91% of the annual GPP variations and 92.9% of the annual ER variations for the wetland sites. The effects of LAI on GPP, ER or NEP highlighted that canopy-level measurement is critical for accurately estimating ecosystem–atmosphere exchange of carbon dioxide. The present study suggests a significance of the combined effects of climate and vegetation(e.g.,LAI) drivers on C fluxes and shows that climate and LAI might influence C flux components differently in different climate regions.展开更多
Carbon sequestration and water conservation are two of the key ecosystem services that forests provide for societal need to address environmental issues.Optimization of the dual services is the ultimate goal in forest...Carbon sequestration and water conservation are two of the key ecosystem services that forests provide for societal need to address environmental issues.Optimization of the dual services is the ultimate goal in forest management for mitigating global climate change and safeguarding terrestrial water balance.However,there are some tradeoff s between gain in forest productivity and ecosystem water balance.We conducted literature review based on published articles for learned knowledge on forest carbon fi xation and hydrological regulations.Some knowledge gaps and research needs are identifi ed by examining the inter-connections between forest carbon sequestration and water conservation.Past researches have helped gain basic understanding of the mechanisms and controls of forest carbon fi xation and hydrological regulations as two separate issues.Tools and approaches are well established for quantifying and monitoring forest carbon and hydrological issues,operating at diff erent spatial and temporal scales.There are knowledge gaps on how to design aff orestation schemes facilitating enhanced ecosystem services in forest carbon sequestration and water conservation.For the top-down planning of aff orestation in regions where water availability is anticipated to be problematic,the questions of how much and where to plant for given land availability,known environmental implications,and sustained regional development and livelihood need to be addressed.For local management considerations,the questions of what and how to plant prevail.Eff orts are needed in joint studies of forest carbon sequestration and water conservation functionalities,specifi cally in relation to establishment and management of planted forests aiming for delivering regulatory ecosystem services in carbon sequestration,water conservation and other social values.We propose an integrated framework with dual consideration of carbon sequestration and water conservation in forest management for future research pursue.展开更多
Ground-level ozone(O_(3)) aff ects vegetation and threatens environmental health when levels exceed critical values,above which adverse eff ects are expected.Cyprus is expected to be a hotspot for O_(3)concentrations ...Ground-level ozone(O_(3)) aff ects vegetation and threatens environmental health when levels exceed critical values,above which adverse eff ects are expected.Cyprus is expected to be a hotspot for O_(3)concentrations due to its unique position in the eastern Mediterranean,receiving air masses from Europe,African,and Asian continents,and experiencing a warm Mediterranean climate.In Cyprus,the spatiotemporal features of O_(3) are poorly understood and the potential risks for forest health have not been explored.We evaluated O_(3) and nitrogen oxides(NO and NO 2)at four regional background stations at different altitudes over 2014−2016.O_(3) risks to vegetation and human health were estimated by calculating accumulated O_(3)exposure over a threshold of 40 nmol mol^(−1)(AOT40)and cumulative exposure to mixing ratios above 35 nmol mol^(−1)(SOMO35)indices.The data reveal that mean O_(3)concentrations follow a seasonal pattern,with higher levels in spring(51.8 nmol mol^(−1))and summer(53.2 nmol mol^(−1))and lower levels in autumn(46.9 nmol mol^(−1))and winter(43.3 nmol mol^(−1)).The highest mean O_(3)exposure(59.5 nmol mol^(−1)) in summer occurred at the high elevation station Mt.Troodos(1819 m a.s.l.).Increasing(decreasing)altitudinal gradients were found for O_(3)(NO x),driven by summer–winter diff erences.The diurnal patterns of O_(3) showed little variation.Only at the lowest altitude O_(3) displayed a typical O_(3) diurnal pattern,with hourly diff erences smaller than 15 nmol mol^(−1).Accumulated O_(3) exposures at all stations and in all years exceeded the European Union’s limits for the protection of vegetation,with average values of 3-month(limit:3000 nmol mol^(−1)h)and 6-month(limit:5000 nmol mol^(−1)h)AOT40 for crops and forests of 16,564 and 31,836 nmol mol^(−1)h,respectively.O_(3) exposures were considerably high for human health,with an average SOMO35 value of 7270 nmol mol^(−1) days across stations and years.The results indicate that O_(3) is a major environmental and public health issue in Cyprus,and policies must be adopted to mitigate O_(3) precursor emissions at local and regional scales.展开更多
Biogenic volatile organic compounds(BVOCs)are widely involved in a variety of atmospheric chemical processes due to their high reactivity and species diversity.To date,however,research on BVOCs in agroecosystems,parti...Biogenic volatile organic compounds(BVOCs)are widely involved in a variety of atmospheric chemical processes due to their high reactivity and species diversity.To date,however,research on BVOCs in agroecosystems,particularly fruit trees,remains scarce despite their large cultivation area and economic interest.BVOC emissions from different organs(leaf or fruit)of apple and peach trees were investigated throughout the stages of fruit development(FS,fruit swelling;FC,fruit coloration;FM,fruit maturity;and FP,fruit postharvest)using a proton-transfer-reaction mass spectrometer.Results indicated that methanol was the most abundant compound emitted by the leaf(apple tree leaf 492.5±47.9 ng/(g·hr),peach tree leaf 938.8±154.5 ng/(g·hr)),followed by acetic acid and green leaf volatiles.Beside the above three compounds,acetaldehyde had an important contribution to the emissions from the fruit.Overall,the total BVOCs(sum of eight compounds studied in this paper)emitted by both leaf and fruit gradually decreased along the fruit development,although the effect was significant only for the leaf.The leaf(2020.8±258.8 ng/(g·hr))was a stronger BVOC emitter than the fruit(146.0±45.7 ng/(g·hr))(P=0.006),and there were no significant differences in total BVOC emission rates between apple and peach trees.These findings contribute to our understanding on BVOC emissions from different plant organs and provide important insights into the variation of BVOC emissions across different fruit developmental stages.展开更多
Concurrent ground-level ozone(O_(3))pollution and anthropogenic nitrogen(N)deposition can markedly influence dynamics and productivity in forests.Most studies evaluating the functional traits responses of rapid-turnov...Concurrent ground-level ozone(O_(3))pollution and anthropogenic nitrogen(N)deposition can markedly influence dynamics and productivity in forests.Most studies evaluating the functional traits responses of rapid-turnover organs to O_(3) have specifically examined leaves,despite fine roots are another major source of soil carbon and nutrient input in forest ecosystems.How elevated O_(3) levels impact fine root biomass and biochemistry remains to be resolved.This study was to assess poplar leaf and fine root biomass and biochemistry responses to five different levels of O_(3) pollution,while additionally examining whether four levels of soil N supplementation were sufficient to alter the impact of O_(3) on these two organs.Elevated O_(3) resulted in a more substantial reduction in fine root biomass than leafbiomass;relative to leaves,more biochemically-resistant components were present within fine root litter,which contained high concentrations of lignin,condensed tannins,and elevated C:N and lignin:N ratios that were associated with slower rates of litter decomposition.In contrast,leaves contained more labile components,including nonstructural carbohydrates and N,as well as a higher N:P ratio.Elevated O_(3) significantly reduced labile components and increased biochemically-resistant components in leaves,whereas they had minimal impact on fine root biochemistry.This suggests that O_(3) pollution has the potential to delay leaf litter decomposition and associated nutrient cycling.N addition largely failed to affect the impact of elevated O_(3) levels on leaves or fine root chemistry,suggesting that soil N supplementation is not a suitable approach to combating the impact of O_(3) pollution on key functional traits of poplars.These results indicate that the significant differences in the responses of leaves and fine roots to O_(3) pollution will result in marked changes in the relative belowground roles of these two litter sources within forest ecosystems,and such changes will independently of nitrogen load.展开更多
P values based on standard hypothesis testing are commonly reported in articles published by the Journal of Forestry Research(JFR).However,effect sizes are barely used and reported,even if they are of direct relevance...P values based on standard hypothesis testing are commonly reported in articles published by the Journal of Forestry Research(JFR).However,effect sizes are barely used and reported,even if they are of direct relevance to the primary questions of many of the published studies.The incorporation of effect sizes in studies published by JFR should be encouraged and promoted.Inclusion of effect sizes as a requirement in the journal guidelines will facilitate a major change in the way data are tested and interpreted,with the ultimate goal to exempt researchers from the custom of drawing conclusions merely based upon a dichotomous statistical result(P value).Such a policy can also lead to more informed decisions of whether identified effects are of practical relevance to the forestry.展开更多
Background:Shifts in forest phenological events serve as strong indicators of climate change.However,the sensitivity of phenology events to climate change in relation to forest origins has received limited attention.M...Background:Shifts in forest phenological events serve as strong indicators of climate change.However,the sensitivity of phenology events to climate change in relation to forest origins has received limited attention.Moreover,it is unknown whether forest phenology changes with the proximity to forest edge.Methods:This study examined the green-up dates,dormancy dates,time-integrated NDVI(LiNDVI,a measure of vegetation productivity in growing season),and their sensitivities to climatic factors along the gradients of distance(i.e.proximity)to forest edge(0–2 km)in China's natural forests(NF)and planted forests(PF).For the analysis,field-surveyed data were integrated with Moderate Resolution Imaging Spectroradiometer(MODIS)NDVI from 2000 to 2022.Results:Our results reveal that PF had earlier green-up dates,later dormancy dates,and higher LiNDVI than NF.However,green-up sensitivities to temperature were higher at the edges of NF,whereas no such pattern was observed in PF.Conversely,the sensitivity of dormancy dates remains relatively stable from the inner to the edge of both NF and PF,except for a quadratic change in dormancy date sensitivity to precipitation found in NF.Additionally,we found that the green-up sensitivity to temperature increased with decreasing proximity to edge in NF evergreen forests,while it showed the opposite trend in PF evergreen forests.Furthermore,we observed that the precipitation impact on green-up dates shifts from postponing to advancing from the inner to the edge of NF,whereas precipitation dominantly postpones PF's green-up dates regardless of the proximity to edge.The LiNDVI exhibits higher sensitivity to precipitation at the edge areas,a phenomenon observed in NF but not in PF.Conclusions:These results suggest that the responses of forests to climate change vary with the distance to the edge.With increasing edge forests,which results from fragmentation caused by global changes,we anticipate that desynchronized phenological events along the distance to the edge could alter biogeochemical cycles and reshape ecosystem services such as energy flows,pollination duration,and the tourism industry.Therefore,we advocate for further investigations of edge effects to improve ecosystem modelling,enhance forest stability,and promote sustainable tourism.展开更多
Abstarct In recognition of the rising threats of groundlevel ozone(O_(3))pollution to forests,agricultural crops,and other types of vegetation,accurate and realistic risk assessment is urgently needed.The accumulated ...Abstarct In recognition of the rising threats of groundlevel ozone(O_(3))pollution to forests,agricultural crops,and other types of vegetation,accurate and realistic risk assessment is urgently needed.The accumulated O_(3)exposure over a concentration threshold of 40 nmol mol-1(AOT40)is the most commonly used metric to investigate O3 exposure and its effects on vegetation and to conduct vegetation risk assessment.It is also used by international regulatory authorities for deriving critical levels and setting standards to protect vegetation against surface O_(3).However,fixed periods of the growing season are used universally,yet growing seasons vary with latitudes and elevations,and the periods of plant lifespan also differ among annual species.Here,we propose the concept of the Annual O_(3)Spectrum Profile(AO_(3)SP)and apply it to calculate the profile of AOT40 throughout the year(AAOT40SP,Annual AOT40 Spectrum Profile)using the International Organization for Standardization(ISO)weeks as a shorter window ISO-based accumulated exposure.Using moving time periods of three(for crops)or six(for forests)months,the i so AOT40 behavior throughout the year can be examined as a diagnostic tool for O_(3)risks in the short-or long-term during the lifecycle of local vegetation.From this analysis,AOT40(i so AOT40)that is most representative for the local conditions and specific situations can be identified,depending on the exact growing season and lifecycle of the target vegetation.We applied this novel approach to data from five background monitoring stations located at different elevations in Cyprus.Our results show that the AAOT40SP approach can be used for improved and more realistic assessment of O3 risks to vegetation.The AO_(3)SP approach can also be applied using metrics other than AOT40(exposure-or flux-based),adding a new dimension to the way O_(3)risk to vegetation is assessed.展开更多
Climate change can intensify drought in many regions of the world and lead to more frequent drought events or altered cycles of soil water status.Therefore,it is important to enhance the tolerance to drought and thus ...Climate change can intensify drought in many regions of the world and lead to more frequent drought events or altered cycles of soil water status.Therefore,it is important to enhance the tolerance to drought and thus health,vigor,and success of transplantation seedlings used in the forestry by modifying fertilization and promoting mycorrhization.Here,we sowed seeds of Japanese larch(Larix kaempferi)in 0.2-L containers with 0.5 g(low fertilization;LF)or 2 g(high fertilization;HF)of slow-release fertilizer early in the growing season.One month later,we irrigated seedlings with non-sterilized ectomycorrhizal inoculum(ECM)or sterilized solution(non-ECM),and after about 2 months,plants were either kept well watered(WW;500 mL water/plant/week)or subjected to drought(DR;50 mL water per plant/week)until the end of the growing season.HF largely stimulated plant growth and above-and belowground biomass production,eff ects that are of practical signifi cance,but caused a small decrease in stomatal conductance(Gs 390)and transpiration rate(E 390),which in practice is insignifi cant.ECM treatment resulted in moderate inhibition of seedling growth and biomass and largely canceled out the enhancement of biomass and foliar K content by HF.DR caused a large decrease in CO 2 assimilation,and enhanced stomatal closure and induced senescence.DR also largely depleted foliar Mg and enriched foliar K.Although DR caused a large decrease in foliar P content in LF,it moderately increased P in HF.Likewise,DR increased foliar K in HF but not in LF,and decreased foliar P in ECM plants but not in non-ECM plants.Conversely,ECM plants exhibited a large enrichment in foliar P under WW and had a lower water potential under DR when grown in LF.These results indicate that the drought tolerance and health and vigor of Japanese larch seedlings can be modifi ed by soil fertility and soil microorganisms.This study provides a basis for new multifactorial research programs aimed at producing seedlings of superior quality for forestation under climate change.展开更多
The effect of evolutionary history on wood density variation may play an important role in shaping variation in wood density,but this has largely not been tested.Using a comprehensive global dataset including 27,297 m...The effect of evolutionary history on wood density variation may play an important role in shaping variation in wood density,but this has largely not been tested.Using a comprehensive global dataset including 27,297 measurements of wood density from 2621 tree species worldwide,we test the hypothesis that the legacy of evolutionary history plays an important role in driving the variation of wood density among tree species.We assessed phylogenetic signal in different taxonomic(e.g.,angiosperms and gymnosperms)and ecological(e.g.,tropical,temperate,and boreal)groups of tree species,explored the biogeographical and phylogenetic patterns of wood density,and quantified the relative importance of current environmental factors(e.g.,climatic and soil variables)and evolutionary history(i.e.,phylogenetic relatedness among species and lineages)in driving global wood density variation.We found that wood density displayed a significant phylogenetic signal.Wood density differed among different biomes and climatic zones,with higher mean values of wood density in relatively drier regions(highest in subtropical desert).Our study revealed that at a global scale,for angiosperms and gymnosperms combined,phylogeny and species(representing the variance explained by taxonomy and not direct explained by long-term evolution process)explained 84.3%and 7.7%of total wood density variation,respectively,whereas current environment explained 2.7%of total wood density variation when phylogeny and species were taken into account.When angiosperms and gymnosperms were considered separately,the three proportions of explained variation are,respectively,84.2%,7.5%and 6.7%for angiosperms,and 45.7%,21.3%and 18.6%for gymnosperms.Our study shows that evolutionary history outpaced current environmental factors in shaping global variation in wood density.展开更多
Communication plays an important role in advancing scientific fields and disciplines,defining what knowledge is made accessible to the public,and guiding policymaking and regulation of public authorities for the benef...Communication plays an important role in advancing scientific fields and disciplines,defining what knowledge is made accessible to the public,and guiding policymaking and regulation of public authorities for the benefit of the environment and society.Hence,what is finally published is of great importance for scientific advancement,social development,environmental and public health,and economic agendas.In recognition of these,the goal of a researcher is to communicate research findings to the scientific community and ultimately,to the public.However,this may often be challenging due to competition for publication space,although to a lesser extent nowadays that online-only publications have expanded.This editorial introduces six statistics-related issues in scientific writing that you should be aware of.These issues can lead to desk rejection or rejection following a peer review,but even if papers containing such issues are published,they may prevent cumulative science,undermine scientific advancement,mislead the public,and result in incorrect or weak policies and regulations.Therefore,addressing these issues from the early research stages can facilitate scientific advancement and prevent rejection of your paper.展开更多
Ground-level ozone pollution is a menace for vegetation in the northern hemisphere,limiting photosynthetic pigments and suppressing photosynthesis in trees and other types of plants.Phaeophytinization is the process o...Ground-level ozone pollution is a menace for vegetation in the northern hemisphere,limiting photosynthetic pigments and suppressing photosynthesis in trees and other types of plants.Phaeophytinization is the process of converting chlorophylls into phaeophytins,for example by acidifi cation.Ozone is a highly oxidizing molecule and well known to degrade chlorophylls;however,the eff ect of ozone on phaeophytinization in leaves of higher plants is largely unknown.To reveal ozone eff ect on phaeophytinization and evaluate the potential of phaeophytinization as an index of ozone stress in trees,the absorbance at the optical density of 665 nm was measured before(OD_(665))and after(OD_(665a))acidifi cation in three independent experiments with nearly 30 conditions of ozone exposure.Both current ambient and elevated ozone widely aff ected phaeophytinization,as indicated by decreases or increases in the phaeophytinization quotient OD_(665)/OD_(665a).These eff ects were commonly moderate to large in magnitude and practically signifi cant,and occurred even in ozone-asymptomatic leaves.It emerges that the ozone eff ect on phaeophytinization is bimodal,likely depending on the intensity of ozone stress.These results indicate a promising feature of OD_(665)/OD_(665a)as a thorough index of ozone stress in the future,but further studies are needed to reveal the underlying biochemical mechanisms of the bimodal eff ect on phaeophytinization.展开更多
MODTRAN model was used for the atmospheric correction of one HJ-1B / CCD2 image,and the effect of atmospheric correction was evaluated from the changes of spectral characteristics of typical ground objects,the compari...MODTRAN model was used for the atmospheric correction of one HJ-1B / CCD2 image,and the effect of atmospheric correction was evaluated from the changes of spectral characteristics of typical ground objects,the comparison with the MODIS surface reflectance product,and the effect on normalized differential vegetation index( NDVI). The results show that atmospheric correction eliminated the increase effect in visible bands and the absorption in near-infrared band. Atmospheric correction results and the MODIS surface reflectance product with high accuracy were highly consistent in the reflectance of vegetation,water and residents,and the average error of vegetation was 12.8%. According to the comparison of changing characteristics of NDVI before and after atmospheric correction,it could be found that atmospheric correction had corrected NDVI of mixed pixels and made it more reasonable. NDVI of each kind of ground objects improved,among which NDVI of vegetation increased most greatly,which can help differentiate vegetation from other ground objects. In a word,MODTRAN model has a good effect on atmospheric correction of HJ /CCD images.展开更多
The configurations of molecular clusters have significant impacts on their growth into fine particles in atmosphere.In this paper,we explore the topology space of the structure of H2SO4·NH3 dimer with a novel sam...The configurations of molecular clusters have significant impacts on their growth into fine particles in atmosphere.In this paper,we explore the topology space of the structure of H2SO4·NH3 dimer with a novel sampling technique of meta-dynamics(MTD)method and ab initio molecular dynamics simulations.The simulations are carried out at the temperatures of both 50 K and 242 K,which represent the typical high and low latitudes of troposphere.The results show that,compared with only traditional MD simulations,the structure samplings are significantly accelerated with MTD method.Therefore,more isomers of the dimer are discovered within the same simulation time scale.In addition,the results show that MTD is more efficient for circumstances with high temperature.展开更多
Meteo-hydrological forecasting models are an effective way to generate high-resolution gridded rainfall data for water source research and flood forecast.The quality of rainfall data in terms of both intensity and dis...Meteo-hydrological forecasting models are an effective way to generate high-resolution gridded rainfall data for water source research and flood forecast.The quality of rainfall data in terms of both intensity and distribution is very important for establishing a reliable meteo-hydrological forecasting model.To improve the accuracy of rainfall data,the successive correction method is introduced to correct the bias of rainfall,and a meteo-hydrological forecasting model based on WRF and WRF-Hydro is applied for streamflow forecast over the Zhanghe River catchment in China.The performance of WRF rainfall is compared with the China Meteorological Administration Multi-source Precipitation Analysis System(CMPAS),and the simulated streamflow from the model is further studied.It shows that the corrected WRF rainfall is more similar to the CMPAS in both temporal and spatial distribution than the original WRF rainfall.By contrast,the statistical metrics of the corrected WRF rainfall are better.When the corrected WRF rainfall is used to drive the WRF-Hydro model,the simulated streamflow of most events is significantly improved in both hydrographs and volume than that of using the original WRF rainfall.Among the studied events,the largest improvement of the NSE is from-0.68 to 0.67.It proves that correcting the bias of WRF rainfall with the successive correction method can greatly improve the performance of streamflow forecast.In general,the WRF/WRF-Hydro meteo-hydrological forecasting model based on the successive correction method has the potential to provide better streamflow forecast in the Zhanghe River catchment.展开更多
The interactive eff ects of ozone,soil nutrient availability and root microorganisms on physiological,growth,and productivity traits were studied for the fi rst time for Japanese larch(Larix kaempferi)seedlings grown ...The interactive eff ects of ozone,soil nutrient availability and root microorganisms on physiological,growth,and productivity traits were studied for the fi rst time for Japanese larch(Larix kaempferi)seedlings grown in containers over a growing season,using a free air ozoneconcentration enrichment exposure system.High nutrient availability altered leaf and root nutrient dynamics and enhanced plant growth;however,it also enhanced seedling susceptibility to damping-off disease compared to low nutrient availability.Negative eff ects of elevated ozone,as compared with ambient ozone,on leaf gas exchange and plant stem form were neither off set nor exacerbated by soil nutrient availability and root colonizers.Such negative eff ects suggest that elevated ozone may have implications for ecological health even when plant vigor is limited by factors other than ozone.Inoculation of roots with ectomycorrhizae had negligible infl uence on the eff ects of either soil nutrient availability or ozone.However,this lack of eff ect may be upon impeded formation of complete mycorrhizal root tips due to factors other than the manipulated variables.B and Na appeared to have an important role in stress responses,so further studies to examine their link with physiological mechanisms as a function of time.This study provides an important perspective for designing forestry practices to enhance seedling health.展开更多
基金supported by the National Key R&D Program of China(2021YFD2200405)the National Natural Science Foundationof China(Nos.U23A2002,31930078,and 31670450)the Fundamental Research Funds for ICBR(1632021023,1632019006,and1630032023002).
文摘Climate changes in cold-temperate zones are increasingly altering the state of climatic constraints on photosynthesis and growth,leading to adaptive changes in plant phenology and subsequent seasonal carbon assimilation.However,the spatio-temporal patterns of climatic constraints and seasonal carbon assimilation are poorly understood.In this study,the timing of peak photosynthetic activity(DOY_(pmax))was employed as a proxy for plant adap-tive state to climatic constraints on growth to examine the spatio-temporal dynamics of DOY_(pmax).By using multiple remote sensing metrics,DOY_(pmax)was characterized with changes in the solar-induced chlorophyll fluorescence(SIF)and leaf area index(LAI)from 2000 to 2018.Based on SIF,the DOY_(pmax)was generally around day 190,while based on LAI was about 10 d later.Peak photosynthetic activity of forests occurs earlier compared to other vegetation types.Overall,the advanced DOY_(pmax)were observed based on both SIF and LAI,with annual rates of 0.2(P=0.31)and 0.3(P<0.05)d,respectively.DOY_(pmax)dynamics were influ-enced by hot temperature extremes and vapor pressure defi-cits(VPD)during the early growing season,regardless of sub-zone and different vegetation type.The generalized lin-ear mixed model(GLMM)showed the largest contribution by hot extremes to DOY_(pmax)dynamics accounted for 55.5%(DOY_(pmax_SIF))and 49.1%(DOY_(pmax_LAI)),respectively,fol-lowed by VPD(DOY_(pmax_SIF):23.1%;DOY_(pmax_LAI):29.5%).These findings highlight the crucial role of climate extremes in shaping seasonal carbon dynamics and regional carbon balance.
基金supported by the National Natural Science Foundation of China (No. 41501264)the Natural Science Foundation of Jiangsu Province, China (No. BK20140991)the Research Fund of State Key Laboratory of Soil and Sustainable Agriculture, Nanjing Institute of Soil Science, Chinese Academy of Sciences (No. Y412201441)
文摘There is an increasing concern that the continuous use of chemical fertilizers might lead to harmful effects on soil ecosystem.Accordingly, a biocompatible approach involving inoculation of beneficial microorganisms is presented to promote plant growth and simultaneously minimize the negative effect of chemical fertilizers. In this study, Rhodopseudomonas palustris, a plant growth-promoting rhizobacterium(PGPR), was inoculated into both fertilized and unfertilized soils to assess its influence on Stevia rebaudiana plant growth and microbial community in rhizosphere soils in a 122-d field experiment. Soil enzyme assays(dehydrogenase, urease, invertase, and phosphomonoesterase), real-time quantitative polymerase chain reaction(RT-_qPCR), and a high-throughput sequencing technique were employed to determine the microbial activity and characterize the bacterial community. Results showed that the R.palustris inoculation did not significantly influence Stevia yields and root biomass in either the fertilized or unfertilized soil. Chemical fertilization had strong negative effects on soil bacterial community properties, especially on dehydrogenase and urease activities.However, R. palustris inoculation counteracted the effect of chemical fertilizer on dehydrogenase and urease activities, and increased the abundances of some bacterial lineages(including Bacteroidia, Nitrospirae, Planctomycetacia, Myxococcales, and Legionellales). In contrast, inoculation into the unfertilized soil did not significantly change the soil enzyme activities or the soil bacterial community structure. For both the fertilized and unfertilized soils, R. palustris inoculation decreased the relative abundances of some bacterial lineages possessing photosynthetic ability, such as Cyanobacteria, Rhodobacter, Sphingomonadales, and Burkholderiales. Taken together, our observations stress the potential utilization of R. palustris as PGPR in agriculture, which might further ameliorate the soil microbial properties in the long run.
基金jointly supported by the China Postdoctoral Science Foundation(No.2020 M682951)the National Natural Science Foundation of China(No.NSFC41773088)the Key Research Program of the Chinese Academy of Sciences(No.QYZDJ-SSW-DQC003).
文摘Background:Old-growth forests are irreplaceable with respect to climate change mitigation and have considerable carbon(C)sink potential in soils.However,the relationship between the soil organic carbon(SOC)turnover rate and forest development is poorly understood,which hinders our ability to assess the C sequestration capacity of soil in old-growth forests.Methods:In this study,we evaluated the SOC turnover rate by calculating the isotopic enrichment factor β(defined as the slope of the regression between ^(13)C natural abundance and log-transformed C concentrations)along 0-30 cm soil profiles in three successional forests in subtropical China.A lower β(steeper slope)is associated with a higher turnover rate.The three forests were a 60-year-old P.massoniana forest(PF),a 100-year-old coniferous and broadleaved mixed forest(MF),and a 400-year-old monsoon evergreen broadleaved forest(BF).We also analyzed the soil physicochemical properties in these forests to examine the dynamics of SOC turnover during forest succession and the main regulators.Results:The β value for the upper 30-cm soils in the BF was significantly(p<0.05)higher than that in the PF,in addition to the SOC stock,although there were nonsignificant differences between the BF and MF.The β value was significantly(p<0.05)positively correlated with the soil recalcitrance index,total nitrogen,and available nitrogen contents but was significantly(p<0.01)negatively correlated with soil pH.Conclusions:Our results demonstrate that SOC has lower turnover rates in old-growth forests,accompanied by higher soil chemical recalcitrance,nitrogen status,and lower soil pH.This finding helps to elucidate the mechanism underlying C sequestration in old-growth forest soils,and emphasizes the important value of old-growth forests among global C sinks.
基金supported by the Scientific Research and Innovation Plan for College Graduates of Jiangsu Province, China(CXZZ13_0521)
文摘Potato grows in most part of China, it achieves higher yield and better quality in Gansu Province than in others. With global warming, its growth duration has been prolonged and sowing date become earlier than before. Therefore, to regulate its sowing date and growing period is of great significance for better harvest. In this study, experiments were conducted with six sowing-date treatments of potato in Dingxi, which is in the Loess Plateau of central Gansu Province in Northwest China in 2010. The growth period, morphological index and change in yield and their relationships with temperature, precipitation, and other climatic factors were investigated for each treatment. Results show that the crop with different sowing dates experienced different climate conditions, leading to distinct growth duration, plant height, and leaf area index. The growth duration was shortened due to a delay in sowing date. For each 15-day delay in sowing, the growth duration was reduced by 12 days on average. A significant linear relationship was found between numbers of days either from seeding to emergence or from flowering to harvest and mean temperature over the corresponding period. Dry matter accumulation, tuber fresh weight, and final yield were all decreased because of insufficient cumulative temperature over the shorter growing periods. Marked differences in tuber yield were discovered among the six treatments of sowing date, the potato planted on May 27 giving the highest yield. The potato planted either earlier or later would produce invariably lower yield than the treatment of May 27. Late May therefore can be taken as the optimum sowing time of potato in this region because the crop can fully utilize thermal resource. We conclude that to postpone sowing time is a good practice for potato production to adapt to climate warming in the Loess Plateau of central Gansu, China.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 41775151, 41530533 and 41775152)
文摘The terrestrial carbon(C) cycle plays an important role in global climate change, but the vegetation and environmental drivers of C fluxes are poorly understood. We established a global dataset with 1194 available data across site-years including gross primary productivity(GPP), ecosystem respiration(ER), net ecosystem productivity(NEP), and relevant environmental factors to investigate the variability in GPP, ER and NEP, as well as their covariability with climate and vegetation drivers.The results indicated that both GPP and ER increased exponentially with the increase in mean annual temperature(MAT)for all biomes. Besides MAT, annual precipitation(AP) had a strong correlation with GPP(or ER) for non-wetland biomes.Maximum leaf area index(LAI) was an important factor determining C fluxes for all biomes. The variations in both GPP and ER were also associated with variations in vegetation characteristics. The model including MAT, AP and LAI explained 53%of the annual GPP variations and 48% of the annual ER variations across all biomes. The model based on MAT and LAI explained 91% of the annual GPP variations and 92.9% of the annual ER variations for the wetland sites. The effects of LAI on GPP, ER or NEP highlighted that canopy-level measurement is critical for accurately estimating ecosystem–atmosphere exchange of carbon dioxide. The present study suggests a significance of the combined effects of climate and vegetation(e.g.,LAI) drivers on C fluxes and shows that climate and LAI might influence C flux components differently in different climate regions.
基金Ministry of Science and Technology of China(Grant No.2016YFC0502104).
文摘Carbon sequestration and water conservation are two of the key ecosystem services that forests provide for societal need to address environmental issues.Optimization of the dual services is the ultimate goal in forest management for mitigating global climate change and safeguarding terrestrial water balance.However,there are some tradeoff s between gain in forest productivity and ecosystem water balance.We conducted literature review based on published articles for learned knowledge on forest carbon fi xation and hydrological regulations.Some knowledge gaps and research needs are identifi ed by examining the inter-connections between forest carbon sequestration and water conservation.Past researches have helped gain basic understanding of the mechanisms and controls of forest carbon fi xation and hydrological regulations as two separate issues.Tools and approaches are well established for quantifying and monitoring forest carbon and hydrological issues,operating at diff erent spatial and temporal scales.There are knowledge gaps on how to design aff orestation schemes facilitating enhanced ecosystem services in forest carbon sequestration and water conservation.For the top-down planning of aff orestation in regions where water availability is anticipated to be problematic,the questions of how much and where to plant for given land availability,known environmental implications,and sustained regional development and livelihood need to be addressed.For local management considerations,the questions of what and how to plant prevail.Eff orts are needed in joint studies of forest carbon sequestration and water conservation functionalities,specifi cally in relation to establishment and management of planted forests aiming for delivering regulatory ecosystem services in carbon sequestration,water conservation and other social values.We propose an integrated framework with dual consideration of carbon sequestration and water conservation in forest management for future research pursue.
基金supported by the National Natural Science Foundation of China(NSFC)(No.4210070867)the Foreign Young Talents Fund of the National Ministry of Science and Technology,China(No.31950410547)+1 种基金The Startup Foundation for Introducing Talent of Nanjing University of Information Science&Technology(NUIST),Nanjing,China(No.003080)the Jiangsu Distinguished Professor program of the People’s Government of Jiangsu Province,China.
文摘Ground-level ozone(O_(3)) aff ects vegetation and threatens environmental health when levels exceed critical values,above which adverse eff ects are expected.Cyprus is expected to be a hotspot for O_(3)concentrations due to its unique position in the eastern Mediterranean,receiving air masses from Europe,African,and Asian continents,and experiencing a warm Mediterranean climate.In Cyprus,the spatiotemporal features of O_(3) are poorly understood and the potential risks for forest health have not been explored.We evaluated O_(3) and nitrogen oxides(NO and NO 2)at four regional background stations at different altitudes over 2014−2016.O_(3) risks to vegetation and human health were estimated by calculating accumulated O_(3)exposure over a threshold of 40 nmol mol^(−1)(AOT40)and cumulative exposure to mixing ratios above 35 nmol mol^(−1)(SOMO35)indices.The data reveal that mean O_(3)concentrations follow a seasonal pattern,with higher levels in spring(51.8 nmol mol^(−1))and summer(53.2 nmol mol^(−1))and lower levels in autumn(46.9 nmol mol^(−1))and winter(43.3 nmol mol^(−1)).The highest mean O_(3)exposure(59.5 nmol mol^(−1)) in summer occurred at the high elevation station Mt.Troodos(1819 m a.s.l.).Increasing(decreasing)altitudinal gradients were found for O_(3)(NO x),driven by summer–winter diff erences.The diurnal patterns of O_(3) showed little variation.Only at the lowest altitude O_(3) displayed a typical O_(3) diurnal pattern,with hourly diff erences smaller than 15 nmol mol^(−1).Accumulated O_(3) exposures at all stations and in all years exceeded the European Union’s limits for the protection of vegetation,with average values of 3-month(limit:3000 nmol mol^(−1)h)and 6-month(limit:5000 nmol mol^(−1)h)AOT40 for crops and forests of 16,564 and 31,836 nmol mol^(−1)h,respectively.O_(3) exposures were considerably high for human health,with an average SOMO35 value of 7270 nmol mol^(−1) days across stations and years.The results indicate that O_(3) is a major environmental and public health issue in Cyprus,and policies must be adopted to mitigate O_(3) precursor emissions at local and regional scales.
基金supported by the Open Fund by Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control(No.KHK1801)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)+1 种基金CAS President’s International Fellowship Initiative(No.PIFI-2016VBA057)the National Natural Science Foundation of China(No.41907383)。
文摘Biogenic volatile organic compounds(BVOCs)are widely involved in a variety of atmospheric chemical processes due to their high reactivity and species diversity.To date,however,research on BVOCs in agroecosystems,particularly fruit trees,remains scarce despite their large cultivation area and economic interest.BVOC emissions from different organs(leaf or fruit)of apple and peach trees were investigated throughout the stages of fruit development(FS,fruit swelling;FC,fruit coloration;FM,fruit maturity;and FP,fruit postharvest)using a proton-transfer-reaction mass spectrometer.Results indicated that methanol was the most abundant compound emitted by the leaf(apple tree leaf 492.5±47.9 ng/(g·hr),peach tree leaf 938.8±154.5 ng/(g·hr)),followed by acetic acid and green leaf volatiles.Beside the above three compounds,acetaldehyde had an important contribution to the emissions from the fruit.Overall,the total BVOCs(sum of eight compounds studied in this paper)emitted by both leaf and fruit gradually decreased along the fruit development,although the effect was significant only for the leaf.The leaf(2020.8±258.8 ng/(g·hr))was a stronger BVOC emitter than the fruit(146.0±45.7 ng/(g·hr))(P=0.006),and there were no significant differences in total BVOC emission rates between apple and peach trees.These findings contribute to our understanding on BVOC emissions from different plant organs and provide important insights into the variation of BVOC emissions across different fruit developmental stages.
基金supported by the National Natural Science Foundation of China (Nos.31870458,41675153)the National Key Research and Development Program of China(No.2017YFE0127700).
文摘Concurrent ground-level ozone(O_(3))pollution and anthropogenic nitrogen(N)deposition can markedly influence dynamics and productivity in forests.Most studies evaluating the functional traits responses of rapid-turnover organs to O_(3) have specifically examined leaves,despite fine roots are another major source of soil carbon and nutrient input in forest ecosystems.How elevated O_(3) levels impact fine root biomass and biochemistry remains to be resolved.This study was to assess poplar leaf and fine root biomass and biochemistry responses to five different levels of O_(3) pollution,while additionally examining whether four levels of soil N supplementation were sufficient to alter the impact of O_(3) on these two organs.Elevated O_(3) resulted in a more substantial reduction in fine root biomass than leafbiomass;relative to leaves,more biochemically-resistant components were present within fine root litter,which contained high concentrations of lignin,condensed tannins,and elevated C:N and lignin:N ratios that were associated with slower rates of litter decomposition.In contrast,leaves contained more labile components,including nonstructural carbohydrates and N,as well as a higher N:P ratio.Elevated O_(3) significantly reduced labile components and increased biochemically-resistant components in leaves,whereas they had minimal impact on fine root biochemistry.This suggests that O_(3) pollution has the potential to delay leaf litter decomposition and associated nutrient cycling.N addition largely failed to affect the impact of elevated O_(3) levels on leaves or fine root chemistry,suggesting that soil N supplementation is not a suitable approach to combating the impact of O_(3) pollution on key functional traits of poplars.These results indicate that the significant differences in the responses of leaves and fine roots to O_(3) pollution will result in marked changes in the relative belowground roles of these two litter sources within forest ecosystems,and such changes will independently of nitrogen load.
基金co-supported by the Outstanding Action Plan of Chinese Sci-tech Journals(Grant No.OAP–C–077)the Startup Foundation for Introducing Talent of Nanjing University of Information Science&Technology(NUIST),Nanjing,China(Grant No.003080)the Jiangsu Distinguished Professor Program of the People’s Government of Jiangsu Province。
文摘P values based on standard hypothesis testing are commonly reported in articles published by the Journal of Forestry Research(JFR).However,effect sizes are barely used and reported,even if they are of direct relevance to the primary questions of many of the published studies.The incorporation of effect sizes in studies published by JFR should be encouraged and promoted.Inclusion of effect sizes as a requirement in the journal guidelines will facilitate a major change in the way data are tested and interpreted,with the ultimate goal to exempt researchers from the custom of drawing conclusions merely based upon a dichotomous statistical result(P value).Such a policy can also lead to more informed decisions of whether identified effects are of practical relevance to the forestry.
基金supported by National Science Foundation of China(Nos.32001166,32371663)the Forestry Peak Discipline Construction Project of Fujian Agriculture and Forestry University,China(No.72202200205).
文摘Background:Shifts in forest phenological events serve as strong indicators of climate change.However,the sensitivity of phenology events to climate change in relation to forest origins has received limited attention.Moreover,it is unknown whether forest phenology changes with the proximity to forest edge.Methods:This study examined the green-up dates,dormancy dates,time-integrated NDVI(LiNDVI,a measure of vegetation productivity in growing season),and their sensitivities to climatic factors along the gradients of distance(i.e.proximity)to forest edge(0–2 km)in China's natural forests(NF)and planted forests(PF).For the analysis,field-surveyed data were integrated with Moderate Resolution Imaging Spectroradiometer(MODIS)NDVI from 2000 to 2022.Results:Our results reveal that PF had earlier green-up dates,later dormancy dates,and higher LiNDVI than NF.However,green-up sensitivities to temperature were higher at the edges of NF,whereas no such pattern was observed in PF.Conversely,the sensitivity of dormancy dates remains relatively stable from the inner to the edge of both NF and PF,except for a quadratic change in dormancy date sensitivity to precipitation found in NF.Additionally,we found that the green-up sensitivity to temperature increased with decreasing proximity to edge in NF evergreen forests,while it showed the opposite trend in PF evergreen forests.Furthermore,we observed that the precipitation impact on green-up dates shifts from postponing to advancing from the inner to the edge of NF,whereas precipitation dominantly postpones PF's green-up dates regardless of the proximity to edge.The LiNDVI exhibits higher sensitivity to precipitation at the edge areas,a phenomenon observed in NF but not in PF.Conclusions:These results suggest that the responses of forests to climate change vary with the distance to the edge.With increasing edge forests,which results from fragmentation caused by global changes,we anticipate that desynchronized phenological events along the distance to the edge could alter biogeochemical cycles and reshape ecosystem services such as energy flows,pollination duration,and the tourism industry.Therefore,we advocate for further investigations of edge effects to improve ecosystem modelling,enhance forest stability,and promote sustainable tourism.
基金supported by the National Natural Science Foundation of China(NSFC)(No.4210070867)The Startup Foundation forIntroducing Talent(No.003080)of Nanjing University of Information Science&Technology(NUIST),Nanjing,China+2 种基金the Jiangsu Distinguished Professor Program of the People s Government of Jiangsu Province,Chinathe Foreign 1000 Young Talents Program Fund(No.31950410547)of the NationalMinistry of Science and Technology,Chinathe project URBFLUX(PID2021-125941OB-I00,MINECO-FEDER)。
文摘Abstarct In recognition of the rising threats of groundlevel ozone(O_(3))pollution to forests,agricultural crops,and other types of vegetation,accurate and realistic risk assessment is urgently needed.The accumulated O_(3)exposure over a concentration threshold of 40 nmol mol-1(AOT40)is the most commonly used metric to investigate O3 exposure and its effects on vegetation and to conduct vegetation risk assessment.It is also used by international regulatory authorities for deriving critical levels and setting standards to protect vegetation against surface O_(3).However,fixed periods of the growing season are used universally,yet growing seasons vary with latitudes and elevations,and the periods of plant lifespan also differ among annual species.Here,we propose the concept of the Annual O_(3)Spectrum Profile(AO_(3)SP)and apply it to calculate the profile of AOT40 throughout the year(AAOT40SP,Annual AOT40 Spectrum Profile)using the International Organization for Standardization(ISO)weeks as a shorter window ISO-based accumulated exposure.Using moving time periods of three(for crops)or six(for forests)months,the i so AOT40 behavior throughout the year can be examined as a diagnostic tool for O_(3)risks in the short-or long-term during the lifecycle of local vegetation.From this analysis,AOT40(i so AOT40)that is most representative for the local conditions and specific situations can be identified,depending on the exact growing season and lifecycle of the target vegetation.We applied this novel approach to data from five background monitoring stations located at different elevations in Cyprus.Our results show that the AAOT40SP approach can be used for improved and more realistic assessment of O3 risks to vegetation.The AO_(3)SP approach can also be applied using metrics other than AOT40(exposure-or flux-based),adding a new dimension to the way O_(3)risk to vegetation is assessed.
基金supported by JSPS KAKENHI Grant Number JP17F17102 (to EA and MK)Startup Foundation for Introducing Talent of Nanjing University of Information Science and Technology (NUIST)(No. 003080)the Jiangsu Distinguished Professor program of the People’s Government of Jiangsu Province
文摘Climate change can intensify drought in many regions of the world and lead to more frequent drought events or altered cycles of soil water status.Therefore,it is important to enhance the tolerance to drought and thus health,vigor,and success of transplantation seedlings used in the forestry by modifying fertilization and promoting mycorrhization.Here,we sowed seeds of Japanese larch(Larix kaempferi)in 0.2-L containers with 0.5 g(low fertilization;LF)or 2 g(high fertilization;HF)of slow-release fertilizer early in the growing season.One month later,we irrigated seedlings with non-sterilized ectomycorrhizal inoculum(ECM)or sterilized solution(non-ECM),and after about 2 months,plants were either kept well watered(WW;500 mL water/plant/week)or subjected to drought(DR;50 mL water per plant/week)until the end of the growing season.HF largely stimulated plant growth and above-and belowground biomass production,eff ects that are of practical signifi cance,but caused a small decrease in stomatal conductance(Gs 390)and transpiration rate(E 390),which in practice is insignifi cant.ECM treatment resulted in moderate inhibition of seedling growth and biomass and largely canceled out the enhancement of biomass and foliar K content by HF.DR caused a large decrease in CO 2 assimilation,and enhanced stomatal closure and induced senescence.DR also largely depleted foliar Mg and enriched foliar K.Although DR caused a large decrease in foliar P content in LF,it moderately increased P in HF.Likewise,DR increased foliar K in HF but not in LF,and decreased foliar P in ECM plants but not in non-ECM plants.Conversely,ECM plants exhibited a large enrichment in foliar P under WW and had a lower water potential under DR when grown in LF.These results indicate that the drought tolerance and health and vigor of Japanese larch seedlings can be modifi ed by soil fertility and soil microorganisms.This study provides a basis for new multifactorial research programs aimed at producing seedlings of superior quality for forestation under climate change.
基金supported by the Scientific Research Project of Anhui Province(2022AH050873)the State Key Laboratory of Subtropical Silviculture(SKLSS-KF2023-08)+1 种基金the Provincial Natural Resources Fund(1908085QC140)the National Key R&D Program of China(2018YFD1000600).
文摘The effect of evolutionary history on wood density variation may play an important role in shaping variation in wood density,but this has largely not been tested.Using a comprehensive global dataset including 27,297 measurements of wood density from 2621 tree species worldwide,we test the hypothesis that the legacy of evolutionary history plays an important role in driving the variation of wood density among tree species.We assessed phylogenetic signal in different taxonomic(e.g.,angiosperms and gymnosperms)and ecological(e.g.,tropical,temperate,and boreal)groups of tree species,explored the biogeographical and phylogenetic patterns of wood density,and quantified the relative importance of current environmental factors(e.g.,climatic and soil variables)and evolutionary history(i.e.,phylogenetic relatedness among species and lineages)in driving global wood density variation.We found that wood density displayed a significant phylogenetic signal.Wood density differed among different biomes and climatic zones,with higher mean values of wood density in relatively drier regions(highest in subtropical desert).Our study revealed that at a global scale,for angiosperms and gymnosperms combined,phylogeny and species(representing the variance explained by taxonomy and not direct explained by long-term evolution process)explained 84.3%and 7.7%of total wood density variation,respectively,whereas current environment explained 2.7%of total wood density variation when phylogeny and species were taken into account.When angiosperms and gymnosperms were considered separately,the three proportions of explained variation are,respectively,84.2%,7.5%and 6.7%for angiosperms,and 45.7%,21.3%and 18.6%for gymnosperms.Our study shows that evolutionary history outpaced current environmental factors in shaping global variation in wood density.
基金co-supported by the Startup Foundation for Introducing Talent of Nanjing University of Information Science&Technology (NUIST),Nanjing,China (Grant No. 003080)the Jiangsu Distinguished Professor program of the People’s Government of Jiangsu Provincethe Outstanding Action Plan of Chinese Sci-tech Journals (Grant No. OAP–C–077)
文摘Communication plays an important role in advancing scientific fields and disciplines,defining what knowledge is made accessible to the public,and guiding policymaking and regulation of public authorities for the benefit of the environment and society.Hence,what is finally published is of great importance for scientific advancement,social development,environmental and public health,and economic agendas.In recognition of these,the goal of a researcher is to communicate research findings to the scientific community and ultimately,to the public.However,this may often be challenging due to competition for publication space,although to a lesser extent nowadays that online-only publications have expanded.This editorial introduces six statistics-related issues in scientific writing that you should be aware of.These issues can lead to desk rejection or rejection following a peer review,but even if papers containing such issues are published,they may prevent cumulative science,undermine scientific advancement,mislead the public,and result in incorrect or weak policies and regulations.Therefore,addressing these issues from the early research stages can facilitate scientific advancement and prevent rejection of your paper.
基金partly supported by the National Natural Science Foundation of China (No. 4210070867)the Research grant#201605 of the Forestry and Forest Products Research Institute (FFPRI),JapanKAKENHI grant#JP17F17102 of the Japan Society for the Promotion of Science (JSPS)
文摘Ground-level ozone pollution is a menace for vegetation in the northern hemisphere,limiting photosynthetic pigments and suppressing photosynthesis in trees and other types of plants.Phaeophytinization is the process of converting chlorophylls into phaeophytins,for example by acidifi cation.Ozone is a highly oxidizing molecule and well known to degrade chlorophylls;however,the eff ect of ozone on phaeophytinization in leaves of higher plants is largely unknown.To reveal ozone eff ect on phaeophytinization and evaluate the potential of phaeophytinization as an index of ozone stress in trees,the absorbance at the optical density of 665 nm was measured before(OD_(665))and after(OD_(665a))acidifi cation in three independent experiments with nearly 30 conditions of ozone exposure.Both current ambient and elevated ozone widely aff ected phaeophytinization,as indicated by decreases or increases in the phaeophytinization quotient OD_(665)/OD_(665a).These eff ects were commonly moderate to large in magnitude and practically signifi cant,and occurred even in ozone-asymptomatic leaves.It emerges that the ozone eff ect on phaeophytinization is bimodal,likely depending on the intensity of ozone stress.These results indicate a promising feature of OD_(665)/OD_(665a)as a thorough index of ozone stress in the future,but further studies are needed to reveal the underlying biochemical mechanisms of the bimodal eff ect on phaeophytinization.
基金Supported by National Natural Science Foundation of China(41171336)
文摘MODTRAN model was used for the atmospheric correction of one HJ-1B / CCD2 image,and the effect of atmospheric correction was evaluated from the changes of spectral characteristics of typical ground objects,the comparison with the MODIS surface reflectance product,and the effect on normalized differential vegetation index( NDVI). The results show that atmospheric correction eliminated the increase effect in visible bands and the absorption in near-infrared band. Atmospheric correction results and the MODIS surface reflectance product with high accuracy were highly consistent in the reflectance of vegetation,water and residents,and the average error of vegetation was 12.8%. According to the comparison of changing characteristics of NDVI before and after atmospheric correction,it could be found that atmospheric correction had corrected NDVI of mixed pixels and made it more reasonable. NDVI of each kind of ground objects improved,among which NDVI of vegetation increased most greatly,which can help differentiate vegetation from other ground objects. In a word,MODTRAN model has a good effect on atmospheric correction of HJ /CCD images.
文摘The configurations of molecular clusters have significant impacts on their growth into fine particles in atmosphere.In this paper,we explore the topology space of the structure of H2SO4·NH3 dimer with a novel sampling technique of meta-dynamics(MTD)method and ab initio molecular dynamics simulations.The simulations are carried out at the temperatures of both 50 K and 242 K,which represent the typical high and low latitudes of troposphere.The results show that,compared with only traditional MD simulations,the structure samplings are significantly accelerated with MTD method.Therefore,more isomers of the dimer are discovered within the same simulation time scale.In addition,the results show that MTD is more efficient for circumstances with high temperature.
基金Program of Key Laboratory of Meteorological Disaster(KLME202209)National Key R&D Program of China(2017YFC1502102)。
文摘Meteo-hydrological forecasting models are an effective way to generate high-resolution gridded rainfall data for water source research and flood forecast.The quality of rainfall data in terms of both intensity and distribution is very important for establishing a reliable meteo-hydrological forecasting model.To improve the accuracy of rainfall data,the successive correction method is introduced to correct the bias of rainfall,and a meteo-hydrological forecasting model based on WRF and WRF-Hydro is applied for streamflow forecast over the Zhanghe River catchment in China.The performance of WRF rainfall is compared with the China Meteorological Administration Multi-source Precipitation Analysis System(CMPAS),and the simulated streamflow from the model is further studied.It shows that the corrected WRF rainfall is more similar to the CMPAS in both temporal and spatial distribution than the original WRF rainfall.By contrast,the statistical metrics of the corrected WRF rainfall are better.When the corrected WRF rainfall is used to drive the WRF-Hydro model,the simulated streamflow of most events is significantly improved in both hydrographs and volume than that of using the original WRF rainfall.Among the studied events,the largest improvement of the NSE is from-0.68 to 0.67.It proves that correcting the bias of WRF rainfall with the successive correction method can greatly improve the performance of streamflow forecast.In general,the WRF/WRF-Hydro meteo-hydrological forecasting model based on the successive correction method has the potential to provide better streamflow forecast in the Zhanghe River catchment.
基金The authors are grateful to Mr.Tatsushiro Ueda of Dalton Co.(Hokkaido Branch,Japan)for managing the O3 FACE system and to Mr.Yamamoto and Mr.Noda of Hokkaido University,Japan,for contributing to the ectomycorrhizae analysis.E.A.acknowledges multiyear support from The Startup Foundation for Introducing Talent of Nanjing University of Information Science&Technology(NUIST),Nanjing,China(Grant No.1411021901008).
文摘The interactive eff ects of ozone,soil nutrient availability and root microorganisms on physiological,growth,and productivity traits were studied for the fi rst time for Japanese larch(Larix kaempferi)seedlings grown in containers over a growing season,using a free air ozoneconcentration enrichment exposure system.High nutrient availability altered leaf and root nutrient dynamics and enhanced plant growth;however,it also enhanced seedling susceptibility to damping-off disease compared to low nutrient availability.Negative eff ects of elevated ozone,as compared with ambient ozone,on leaf gas exchange and plant stem form were neither off set nor exacerbated by soil nutrient availability and root colonizers.Such negative eff ects suggest that elevated ozone may have implications for ecological health even when plant vigor is limited by factors other than ozone.Inoculation of roots with ectomycorrhizae had negligible infl uence on the eff ects of either soil nutrient availability or ozone.However,this lack of eff ect may be upon impeded formation of complete mycorrhizal root tips due to factors other than the manipulated variables.B and Na appeared to have an important role in stress responses,so further studies to examine their link with physiological mechanisms as a function of time.This study provides an important perspective for designing forestry practices to enhance seedling health.
