Vegetation maps are important sources of information for biodiversity conservation,ecological studies,vegetation management and restoration,and national strategic decision making.The current Vegetation Map of China(1:...Vegetation maps are important sources of information for biodiversity conservation,ecological studies,vegetation management and restoration,and national strategic decision making.The current Vegetation Map of China(1:1000000)was generated by a team of more than 250 scientists in an effort that lasted over 20 years starting in the 1980s.However,the vegetation distribution of China has experienced drastic changes during the rapid development of China in the last three decades,and it urgently needs to be updated to better represent the distribution of current vegetation types.Here,we describe the process of updating the Vegetation Map of China(1:1000000)generated in the 1980s using a‘‘crowdsourcing-change detection-classification-expert knowledge"vegetation mapping strategy.A total of 203,024 field samples were collected,and 50 taxonomists were involved in the updating process.The resulting updated map has 12 vegetation type groups,55 vegetation types/subtypes,and 866 vegetation formation/sub-formation types.The overall accuracy and kappa coefficient of the updated map are 64.8%and 0.52 at the vegetation type group level,61%and 0.55 at the vegetation type/subtype level and 40%and 0.38 at the vegetation formation/sub-formation level.When compared to the original map,the updated map showed that 3.3 million km^2 of vegetated areas of China have changed their vegetation type group during the past three decades due to anthropogenic activities and climatic change.We expect this updated map to benefit the understanding and management of China’s terrestrial ecosystems.展开更多
Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and s...Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.展开更多
Temperature sensitivity and tolerance play a key role in plant survival and production.Perennial ryegrass(Lolium perenne L.),widely cultivated in cool-season for forage supply and turfgrass,is extremely susceptible to...Temperature sensitivity and tolerance play a key role in plant survival and production.Perennial ryegrass(Lolium perenne L.),widely cultivated in cool-season for forage supply and turfgrass,is extremely susceptible to high temperatures,therefore serving as an excellent grass for dissecting the genomic and genetic basis of high-temperature adaptation.In this study,expression analysis revealed that LpHsfA2,an important gene associated with high-temperature tolerance in perennial ryegrass,is rapidly and substantially induced under heat stress.Additionally,heat-tolerant varieties consistently display elevated expression levels of LpHsfA2 compared with heat-sensitive ones.Comparative haplotype analysis of the LpHsfA2 promoter indicated an uneven distribution of two haplotypes(HsfA2^(Hap1) and HsfA2^(Hap2)) across varieties with differing heat tolerance.Specifically,the HsfA2^(Hap1) allele is predominantly present in heat-tolerant varieties,while the HsfA2^(Hap2) allele exhibits the opposite pattern.Overexpression of LpHsfA2 confers enhanced thermotolerance,whereas silencing of LpHsfA2 compromises heat tolerance.Furthermore,LpHsfA2 orchestrates its protective effects by directly binding to the promoters of LpHSP18.2 and LpAPX1 to activate their expression,preventing the non-specific misfolding of intracellular protein and the accumulation of reactive oxygen species in cells.Additionally,LpHsf A4 and LpHsf A5 were shown to engage directly with the promoter of LpHsfA2,upregulating its expression as well as the expression of LpHSP18.2 and LpAPX1,thus contributing to enhanced heat tolerance.Markedly,LpHsfA2 possesses autoregulatory ability by directly binding to its own promoter to modulate the self-transcription.Based on these findings,we propose a model for modulating the thermotolerance of perennial ryegrass by precisely regulating the expression of LpHsfA2.Collectively,these findings provide a scientific basis for the development of thermotolerant perennial ryegrass cultivars.展开更多
The present study was designed to evaluate the effect of 12 6+ C ion beam (10～80 Gy) on biological changes of wheat seedlings. Reactive oxygen species (ROS)-related biomarkers and the quantification of plant survival...The present study was designed to evaluate the effect of 12 6+ C ion beam (10～80 Gy) on biological changes of wheat seedlings. Reactive oxygen species (ROS)-related biomarkers and the quantification of plant survival and growth were examined at 10 day after carbon ions irradiation (LET: 30.8 keV/μm). The results showed that heavy ions obviously enhanced ROSs reflected by the production of O2 and H2O2 as well as TBARS, and - treatment with 20 Gy achieved the peak value, suggesting that higher mutagenic potential may occur at 20 Gy. Simultaneously, increase of SOD activity was induced by heavy ions to counteract ROS accumulation. On the other hand, higher doses at 40 and 80 Gy inhibited wheat growth and survival in comparison with the control, and reversely lower doses at 10 or 20 Gy stimulated wheat growth and survival. In conclusion, the above observations imply that a dose range of 20~40 Gy is likely promised for wheat mutation breeding.展开更多
Three alpine meadows were chosen from the eastern margin of the Qilian Mountain：Polygonum viviparum meadow（P）,Stipa capillata grassland（S）and Rhododendron simsii shrub meadow（R）;LI-8100 A soil CO2 flux auto-mon...Three alpine meadows were chosen from the eastern margin of the Qilian Mountain：Polygonum viviparum meadow（P）,Stipa capillata grassland（S）and Rhododendron simsii shrub meadow（R）;LI-8100 A soil CO2 flux auto-monitoring system and lab analysis were applied to analyze the soil organic carbon density,dynamics of carbon flux,and their relationship with environmental factors.The results showed that different vegetations varied greatly in soil organic carbon density：R 〉 S 〉 P,and the soil carbon density reduced with the increasing depth;soil CO2flux：S 〉 P 〉 R,and sample plot P and S showed unimodal changes.The peak values appeared at 14：00-15：00 p.m.;soil CO2 flux was negatively correlated with near-ground air humidity and carbon content,positively correlated with soil temperature and near-ground air temperature,and showed no obvious correlation with soil moisture.展开更多
Organic chemical priming is an effective strategy in mitigating salt stress to plants.The objective of this study was to determine effects and associated mechanisms of acetic acid regulating plant tolerance to salt st...Organic chemical priming is an effective strategy in mitigating salt stress to plants.The objective of this study was to determine effects and associated mechanisms of acetic acid regulating plant tolerance to salt stress.Perennial ryegrass plants were pre-treated with 20 mM acetic acid and subsequently subjected to salt stress for 28 days.Salt stress caused increased endogenous acetic acid content with up-regulated expression of its key biosynthetic gene LpPDC1.Application of acetic acid effectively alleviated salt caused damage in perennial ryegrass.Acetic acid treatment increased K^(+) content and suppressed Na^(+) accumulation to maintain a higher K^(+)/Na^(+) ratio in leaves exposed to salt stress.Plants O_(2)^(−) treated with acetic acid also had significantly lower levels of and H_(2)O_(2),but higher SOD and CAT activities than those of the control after 21 days of salt stress.Acetic acid treatment also altered the plants endogenous phytohormone content with higher content of jasmonate(including JA,JA-ILe,and cis-OPDA),auxin(IAA),and cytokinins(CK,such as tZ,cZR,and iP),but lower content of abscisic acid(ABA)under salt stress conditions.Furthermore,expression of genes involved in JA,IAA,and CK biosynthesis and signaling pathways were up-regulated,while those involved in ABA were down-regulated by acetic acid treatment under salt stress.The results demonstrate that acetic acid could mitigate salt stress in perennial ryegrass by regulating K^(+) and Na^(+) balance,promoting ROS scavenging,and activating stress-protection hormone synthesis and signaling.展开更多
In order to investigate the correlation between the variations in the environmental water quality indexes and the distance of water bodies from the planting region of vetiver, samples of surface water were gathered fr...In order to investigate the correlation between the variations in the environmental water quality indexes and the distance of water bodies from the planting region of vetiver, samples of surface water were gathered from the water bodies surrounding an abandoned coal gangue mountain of Dahead coal mine (Dahe, Liupanshui, Guizhou Province) based on the method of field survey and typical analysis. According to the results, the planting of vetiver could effectively purify the water bodies surrounding the coal gangue mountain. Detailed findings include three aspects:(1) The main pollutants detected in water bodies around the coal gangue mountain were SO4 2-, NO3 -, Fe and Cu, with a concentration of 869.45, 35.16, 26.06, and 40.85 mg/L respectively in wet season and all exceeded the national environmental standards for surface water.(2) The pH values of water bodies 150~200 m away from the vetiver planting region stayed within the limits of national environmental standards for surface water and presented a homogeneous feature, revealing that vetiver has the capacity to adjust the pH of the surrounding water body.(3) The contents of Fe, Mn, Cu, SO4 2-, and NO3 - under all treatments, tended to increase with the increasing distance of water bodies from the vetiver planting region;it means the shorter the distance between the water body and the vetiver planting region is, the higher the adsorption rate and purification effects will be;the optimal concentrations of Fe, Mn, and Cu were 0 mg/L, much lower than the national environmental standards for surface water.展开更多
Large sample sampling was adopted in this paper for the statistical analysis of leaves of four populations of Vetiveria zizanioides （ introduced, local wild, domesticated wild populations of different years）. The re...Large sample sampling was adopted in this paper for the statistical analysis of leaves of four populations of Vetiveria zizanioides （ introduced, local wild, domesticated wild populations of different years）. The results showed that four populations varied in different degrees in terms of tiller height, leaf biomass, and leaf biomass ratio. Leaf length, leaf width, and ratio of leaf width to length of different populations also varied, but had similar power-function change regularity, and showed converging leaf biomass growth pattern and leaf growth process.展开更多
Ca^(2+)plays an important role in cell signal transduction.Its intracellular propagation is the most basic process of Ca^(2+)signaling,such as calcium wave and double messenger system.In this work,with both numerical ...Ca^(2+)plays an important role in cell signal transduction.Its intracellular propagation is the most basic process of Ca^(2+)signaling,such as calcium wave and double messenger system.In this work,with both numerical simulation and mean field ansatz,the three-dimensional probability distribution of Ca^(2+),which is read out by phosphorylation,is studied in two scenarios with boundaries.The coverage of distribution of Ca^(2+)is found at an order of magnitude ofμm,which is consistent with experimental observed calcium spike and wave.Our results suggest that the double messenger system may occur in the ER-PM junction to acquire great efficiency.The buffer effect of kinase is also discussed by calculating the average position of phosphorylations and free Ca^(2+).The results are helpful to understand the mechanism of Ca^(2+)signaling.展开更多
Minqin oasis in the lower reaches of the Shiyang River is a main natural barrier for the Wuwei Basin. Due to the combined influence of human activities and natural factors in the past half a century, water quality in ...Minqin oasis in the lower reaches of the Shiyang River is a main natural barrier for the Wuwei Basin. Due to the combined influence of human activities and natural factors in the past half a century, water quality in the lower reaches of the Shiyang River decreased and ecological environment deteriorated, which influenced sustainable development of this area and surrounding area seriously. This paper analyzed current situation and reasons of the deteriorated ecological environment in the lower reaches of the Shiyang River, and proposed that water environment regulation was the primary task in the eco-environment control of Minqin area, specifically,(a) By using existing policies, accelerating the construction of water-saving agriculture in the middle reaches of the Shiyang River, water quantity in the lower reaches would be guanranted, water shortage for agricultural production and ecological use in Minqin oasis would be relieved;(b) Unreasonable human activities such as overexploitation of underground water should be controlled strictly;(c) Water conservancy project should be developed vigorously to ensure rate of flow. It was expected that the above schemes would contribute to the benign circulation of ecological environment in Minqin oasis.展开更多
Two-year-old Medicago sativa at budding initial stage was taken as research materials.Five methods were used to make green hay,including flatting stems ＋ spraying 2.5% K2CO3,flatting stems,sun curing,drying in shade ...Two-year-old Medicago sativa at budding initial stage was taken as research materials.Five methods were used to make green hay,including flatting stems ＋ spraying 2.5% K2CO3,flatting stems,sun curing,drying in shade and drying under 105 ℃ condition（CK）.Besides,effects of different green hay making methods on dry characteristics and nutritional quality of M.sativa green hay were studied,and a comprehensive evaluation of M.sativa green hays was conducted.Results showed that,except CK,the drying rates in other making methods were all fast at first,and then slow down.Both of drying under 105 ℃ condition and flatting stems ＋ spraying K2CO3 could speed up drying rate and reduce nutritional losses of green hay.Sun curing could also speed up drying rate,but it could not maintain the quality of green hay.The results of Grey Relational Analysis on five green hay making methods indicated that CK had the best comprehensive performance,followed by green hays made by flatting stems ＋ spraying K2CO3.Therefore,flatting stems ＋ spraying K2CO3 was a quick and easy method to make green hay,and it was worth to be recommended in practical production.展开更多
As shown by the changes in physiological characteristics and seed vigor of three Medicago ruthenica samples during artificial aging process, the germination potential, germination rate, germination index, vigor index ...As shown by the changes in physiological characteristics and seed vigor of three Medicago ruthenica samples during artificial aging process, the germination potential, germination rate, germination index, vigor index and simple vigor index declined with the extension of aging time on the whole. After artificial aging for 6 min, the vigor was higher than that of the control. The conductivity, malondialdehyde content and soluble polysaccharide content of seed leachate increased with the aging time and negatively correlated （ P 〈 0.05） with the seed vigor indicators. The physiological indicators were very significantly correlated （P 〈 0.01 ） with the vigor indicators in the Medicago ruthenica sample from Dorbod Qi, UIanqab City（China）.展开更多
Erect milkvetch(Astragalus adsurgens)is a perennial legume forage crop with economic and ecological value in livestock grazing and soil-erosion control in arid and semiarid areas worldwide.Genomic information and mole...Erect milkvetch(Astragalus adsurgens)is a perennial legume forage crop with economic and ecological value in livestock grazing and soil-erosion control in arid and semiarid areas worldwide.Genomic information and molecular tools to support breeding and research in the species are limited.The objectives of this investigation were to map its genome using DNA markers and to identify quantitative trait loci(QTL)in the species.An F1 mapping population of 250 plants was developed from a cross between two parents with differing flowering-related traits.A high-density genetic linkage map containing 4821 markers on eight linkage groups(LGs)with a total genetic length of 1395 cM and a mean interval of 0.29 cM between adjacent markers was constructed with SLAF-seq technology.Comparative genomic analyses revealed the highest genome sequence similarity(8.71%)between erect milkvetch and Medicago truncatula,followed by Glycine max(7.65%),Cicer arietinum(7.53%),and Lupinus angustifolius(5.21%).A total of 64 significant QTL for flowering-related traits on six LGs were detected,accounting for 9.38 to 19.1%of the associated phenotype variation.Five and 48 key candidate genes for floret number and inflorescence length were identified based on the Glycyrrhiza uralensis genome.These candidate genes were involved in ubiquitination/degradation,pollen development,cell division,cytokinin biosynthetic process,and plant flowering.These findings shed light on the regulation of flowering traits in erect milkvetch and provide genomic resources for future molecular breeding of the crop.展开更多
This paper aims at summarized the research progress of soil microbes,in amount of soil microbes including bacteria,fungi and actinomycetes,soil microbial biomass,including microbial biomass carbon,microbial biomass ni...This paper aims at summarized the research progress of soil microbes,in amount of soil microbes including bacteria,fungi and actinomycetes,soil microbial biomass,including microbial biomass carbon,microbial biomass nitrogen and microbial biomass phosphorus,function of microbial and screening and application of beneficial microorganisms etc.,and future research are discussed combined with our project team for many years of work.展开更多
Aims Shrub encroachment has taken place in many of China’s northern grasslands.This study attempts to answer the following questions:which plant communities are present in these shrub-encroached grasslands(SEGs)?What...Aims Shrub encroachment has taken place in many of China’s northern grasslands.This study attempts to answer the following questions:which plant communities are present in these shrub-encroached grasslands(SEGs)?What are the species richness and composition of these communities?Which environmental factors determine the spatial distribution thereof?Methods We investigated the community characteristics of 255 SEG plots with a size of 20 m×20 m at 69 locations across grasslands in northern China.In each plot,paired 1-m^(2) quadrats were estab-lished within shrub patches and the neighbouring grassy matrix to record herb species composition.The quantitative character-istics(abundance,coverage and height)of herbs were meas-ured in 0.25-m2 subquadrats,and soil samples were collected in the quadrats.Two-way indicator species analysis(TWINSPAN),detrended canonical analysis(DCA)and canonical correspond-ence analysis(CCA)were used for community clustering and ordination.Important Findings The DCA and TWINSPAN results suggested that the SEGs in northern China can be divided into six community types:Potentilla fruticosa+Carex atrofusca,Spiraea hypericifolia+Festuca ovina,Caragana acanthophylla+Stipa sareptana,Caragana microphylla+Leymus chinensis,Caragana microphylla+Stipa klemenzii and Caragana tibetica+Cleistogenes songorica.At a regional scale,climate and soil nutrients controlled the spatial patterns of species richness and community composition of the SEGs in northern China.Temperature exerted a negative impact,whereas precipitation and nutrients had positive effects on species richness.Among the environmental factors used,climate was the major controller of the variations in commu-nity structure.These results provide new insights into the community composition of SEGs in China and enrich the global dataset of SEGs.展开更多
The application of n-alkane as markers to estimate herbage intake, apparent digestibility and species composition of diet consumed by grazing sheep was studied. Six local Mongolian sheep were used to determine dry mat...The application of n-alkane as markers to estimate herbage intake, apparent digestibility and species composition of diet consumed by grazing sheep was studied. Six local Mongolian sheep were used to determine dry matter （DM） intake, apparent DM digestibility and species composition of diet during summer, autumn and winter. Animals were orally dosed twice daily with n-alkane gelatin capsules containing 60 mg C32-alkane as an external marker. Diet composition was estimated by comparing the odd-chain n-alkanes pattern profile （C27-C31） of the consumed plant species with the n-alkanes fecal concentrations of grazing animals, using a non-negative least squares algorithm called EATWHAT software package. The alkane pair C32：C33 and C33 alkane were used to estimate DM intake and diet apparent DM digestibility, respectively. The results showed that daily dry matter intake of the sheep were 1.77, 1.61 and 1.18 kg d-1 in summer, autumn and winter, respectively. Apparent DM digestibility, crude protein （CP）, metabolizable energy （ME） and neutral detergent fiber （NDF） intake of diet consumed by sheep decreased significantly （P〈0.01） from summer to winter, with no evident changes in ADF and ADL intake. Diet composition indicated Artemisia frigida Willd was the most dominant diet component, contributed 79.68, 68.12 and 86.26% of sheep＇s diets in summer, autumn and winter, respectively. Cleistogenes songorica Ohwi and Convolvulus arnmannii Desr were the important components of the diet. Although Stipa breviflora Griseb is one of the main plant species in the study area, the sheep rarely choosed it. The study indicated that CP and ME in diet consumed by sheep were deficient in winter. Therefore, appropriate supplementation strategies should be indispensable during this period.展开更多
In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts f...In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts from aboveground and belowground parts of A.inebrians significantly inhibited the germination rate,germination potential,germination index,vigor index,seedling height,root length,and fresh weight of E.nutans,but increased malondialdehyde content,catalase,peroxidase and superoxide dismutase activity of E.nutans seedlings(p<0.05).The allelopathy of aqueous extracts of the aboveground parts of A.inebrians was stronger than that of the pre-cipitates.Aqueous extracts of the aboveground parts of A.inebrians decreased seed germination rate,germination potential,germination index,vigor index,seedling length,root length,and seedling fresh weight by 10.45%-74.63%,24.18%-32.50%,19.03%-73.36%,37.83%-88.41%,21.42%-53.14%,2.65%-40.21%,and 20.45%-61.36%,respectively,and malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity increased by 8.09%-62.24%,27.83%-86.47%,22.90%-93.17%,and 11.15%-75.91%,respectively.The above indexes were higher in live soil than in sterilized soil.Soil microorganisms increased the allelopathy of A.inebrians.The seed germination rate,germination potential,germination index,vigor index,seedling length,and seedling fresh weight of E.nutans planted in live soil decreased by 8.22%-48.48%,10.00%-51.85%,8.19%-53.26%,16.43%-60.03%,12.91%-28.81%,and 9.09%-22.86%compared with sterilized soil,respectively.Malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity of E.nutans planted in live soil increased by 53.91%-81.06%,15.71%-57.34%,33.33%-86.31%,and 9.78%-52.51%compared with sterilized soil,respectively.The existence of soil microorganisms enhanced the allelopathy of the secondary metabolites of A.inebrians.A combination of microorganisms and aqueous extracts from the aboveground parts of A.inebrians had the strongest allelopathic effect on E.nutans.展开更多
In accordance with the objective to construct a major province in grassland animal husbandry,the following ways were used for enhancing development,improving the scientific and technological content,increasing the sca...In accordance with the objective to construct a major province in grassland animal husbandry,the following ways were used for enhancing development,improving the scientific and technological content,increasing the scale of the industry and market development to set up our own ecological grass industry brand and finally reach sustainable development strategy.This paper discussed the status of Guizhou Province grass industry development from the grass industry resources,grassland and animal husbandry production,prataculture technology problem.展开更多
Anthropogenic activities profoundly influence carbon sequestration in the Eurasian Steppe. In particular, grazing has been identified as having a major effect on carbon sequestration. However, the extent to which graz...Anthropogenic activities profoundly influence carbon sequestration in the Eurasian Steppe. In particular, grazing has been identified as having a major effect on carbon sequestration. However, the extent to which grazing affects regional patterns or carbon sequestration is unknown. In this study, we evaluated the impact of regional grazing on grassland carbon seques- tration using the Boreal Ecosystem Productivity Simulator （BEPS） and the Shiyomi grazing model. Model performances were validated against the results from field measurements and eddy covariance （EC） sites. Model outputs showed that in 2008, the regional net primary productivity （NPP） was 79.5 g C m-2, and the net ecosystem productivity （NEP） was -6.5 g C m-2, characterizing the region as a Weak carbon source. The Mongol Steppe （MS） was identified as a carbon sink, whereas the Kazakh Steppe （KS） was either carbon neutral or a weak carbon source. The spatial patterns of grazing density are divergent between the MS and the KS. in the MS, livestock was mainly distributed in China with relatively good management, while in the KS livestock was mainly concentrated in the southern countries （especially Uzbekistan and Turkmenistan） with harsh environments and poor management. The consumption percentages of NPP in Turkmenistan, Tajikistan and Uzbekistan were 5.3, 3.3 and 1.2%, respectively, whereas the percentages in other countries were lower than 1%. Correspondingly, grazing consumption contributed to the carbon sources of Turkmenistan, Tajikistan and Uzbekistan by 11.6, 6.3 and 4.3%, respectively, while it weakened the carbon sink in Inner Mongolia, China and Mongolia by 1.6 and 0.5%. This regional pattern should be affected by different sub-regional characteristics, e.g., the continuous degradation of grassland in the southern part of the KS and the restoration of grassland in Inner Mongolia, China.展开更多
Changes in precipitation and nitrogen(N)addition may significantly affect the processes of soil carbon(C)cycle in terrestrial ecosystems,such as soil respiration.However,relatively few studies have investigated the ef...Changes in precipitation and nitrogen(N)addition may significantly affect the processes of soil carbon(C)cycle in terrestrial ecosystems,such as soil respiration.However,relatively few studies have investigated the effects of changes in precipitation and N addition on soil respiration in the upper soil layer in desert steppes.In this study,we conducted a control experiment that involved a field simulation from July 2020 to December 2021 in a desert steppe in Yanchi County,China.Specifically,we measured soil parameters including soil temperature,soil moisture,total nitrogen(TN),soil organic carbon(SOC),soil microbial biomass carbon(SMBC),soil microbial biomass nitrogen(SMBN),and contents of soil microorganisms including bacteria,fungi,actinomyces,and protozoa,and determined the components of soil respiration including soil respiration with litter(RS+L),soil respiration without litter(RS),and litter respiration(RL)under short-term changes in precipitation(control,increased precipitation by 30%,and decreased precipitation by 30%)and N addition(0.0 and 10.0 g/(m^(2)·a))treatments.Our results indicated that short-term changes in precipitation and N addition had substantial positive effects on the contents of TN,SOC,and SMBC,as well as the contents of soil actinomyces and protozoa.In addition,N addition significantly enhanced the rates of RS+L and RS by 4.8%and 8.0%(P<0.05),respectively.The increase in precipitation markedly increased the rates of RS+L and RS by 2.3%(P<0.05)and 5.7%(P<0.001),respectively.The decrease in precipitation significantly increased the rates of RS+L and RS by 12.9%(P<0.05)and 23.4%(P<0.001),respectively.In contrast,short-term changes in precipitation and N addition had no significant effects on RL rate(P>0.05).The mean RL/RS+L value observed under all treatments was 27.63%,which suggested that RL is an important component of soil respiration in the desert steppe ecosystems.The results also showed that short-term changes in precipitation and N addition had significant interactive effects on th展开更多
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDA19050401)Maps in this article were reviewed by Ministry of Natural Resources of the People’s Republic of China(GS(2020)1044)。
文摘Vegetation maps are important sources of information for biodiversity conservation,ecological studies,vegetation management and restoration,and national strategic decision making.The current Vegetation Map of China(1:1000000)was generated by a team of more than 250 scientists in an effort that lasted over 20 years starting in the 1980s.However,the vegetation distribution of China has experienced drastic changes during the rapid development of China in the last three decades,and it urgently needs to be updated to better represent the distribution of current vegetation types.Here,we describe the process of updating the Vegetation Map of China(1:1000000)generated in the 1980s using a‘‘crowdsourcing-change detection-classification-expert knowledge"vegetation mapping strategy.A total of 203,024 field samples were collected,and 50 taxonomists were involved in the updating process.The resulting updated map has 12 vegetation type groups,55 vegetation types/subtypes,and 866 vegetation formation/sub-formation types.The overall accuracy and kappa coefficient of the updated map are 64.8%and 0.52 at the vegetation type group level,61%and 0.55 at the vegetation type/subtype level and 40%and 0.38 at the vegetation formation/sub-formation level.When compared to the original map,the updated map showed that 3.3 million km^2 of vegetated areas of China have changed their vegetation type group during the past three decades due to anthropogenic activities and climatic change.We expect this updated map to benefit the understanding and management of China’s terrestrial ecosystems.
基金supported by the Doctor Foundation of Gansu Academy of Agricultural Sciences,China(2020GAAS33)the Young Science and Technology Lifting Engineering Talents in Gansu Province,China(2020-18)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2017-ICS)。
文摘Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.
基金supported by the National Key R&D Program of China(2022YFF1003200)the National Natural Science Foundation of China(NSFC)(Grant Nos.32001394,32102431 and 32101430)+2 种基金the Science&Technology Specific Projects in Agricultural High-tech Industrial Demonstration Area of the Yellow River Delta(Grant No.2022SZX13)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA26050201)the Major Science and Technology Innovation Project of Shandong Province(2022LZGC018)。
文摘Temperature sensitivity and tolerance play a key role in plant survival and production.Perennial ryegrass(Lolium perenne L.),widely cultivated in cool-season for forage supply and turfgrass,is extremely susceptible to high temperatures,therefore serving as an excellent grass for dissecting the genomic and genetic basis of high-temperature adaptation.In this study,expression analysis revealed that LpHsfA2,an important gene associated with high-temperature tolerance in perennial ryegrass,is rapidly and substantially induced under heat stress.Additionally,heat-tolerant varieties consistently display elevated expression levels of LpHsfA2 compared with heat-sensitive ones.Comparative haplotype analysis of the LpHsfA2 promoter indicated an uneven distribution of two haplotypes(HsfA2^(Hap1) and HsfA2^(Hap2)) across varieties with differing heat tolerance.Specifically,the HsfA2^(Hap1) allele is predominantly present in heat-tolerant varieties,while the HsfA2^(Hap2) allele exhibits the opposite pattern.Overexpression of LpHsfA2 confers enhanced thermotolerance,whereas silencing of LpHsfA2 compromises heat tolerance.Furthermore,LpHsfA2 orchestrates its protective effects by directly binding to the promoters of LpHSP18.2 and LpAPX1 to activate their expression,preventing the non-specific misfolding of intracellular protein and the accumulation of reactive oxygen species in cells.Additionally,LpHsf A4 and LpHsf A5 were shown to engage directly with the promoter of LpHsfA2,upregulating its expression as well as the expression of LpHSP18.2 and LpAPX1,thus contributing to enhanced heat tolerance.Markedly,LpHsfA2 possesses autoregulatory ability by directly binding to its own promoter to modulate the self-transcription.Based on these findings,we propose a model for modulating the thermotolerance of perennial ryegrass by precisely regulating the expression of LpHsfA2.Collectively,these findings provide a scientific basis for the development of thermotolerant perennial ryegrass cultivars.
文摘The present study was designed to evaluate the effect of 12 6+ C ion beam (10～80 Gy) on biological changes of wheat seedlings. Reactive oxygen species (ROS)-related biomarkers and the quantification of plant survival and growth were examined at 10 day after carbon ions irradiation (LET: 30.8 keV/μm). The results showed that heavy ions obviously enhanced ROSs reflected by the production of O2 and H2O2 as well as TBARS, and - treatment with 20 Gy achieved the peak value, suggesting that higher mutagenic potential may occur at 20 Gy. Simultaneously, increase of SOD activity was induced by heavy ions to counteract ROS accumulation. On the other hand, higher doses at 40 and 80 Gy inhibited wheat growth and survival in comparison with the control, and reversely lower doses at 10 or 20 Gy stimulated wheat growth and survival. In conclusion, the above observations imply that a dose range of 20~40 Gy is likely promised for wheat mutation breeding.
基金Sponsored by Natural Science Foundation of China(31360569)Key Laboratory of Grassland Ecosystem Program(CYZS-2011007)Modern Agricultural Technical System of Gansu Agricultural University CARS-35
文摘Three alpine meadows were chosen from the eastern margin of the Qilian Mountain：Polygonum viviparum meadow（P）,Stipa capillata grassland（S）and Rhododendron simsii shrub meadow（R）;LI-8100 A soil CO2 flux auto-monitoring system and lab analysis were applied to analyze the soil organic carbon density,dynamics of carbon flux,and their relationship with environmental factors.The results showed that different vegetations varied greatly in soil organic carbon density：R 〉 S 〉 P,and the soil carbon density reduced with the increasing depth;soil CO2flux：S 〉 P 〉 R,and sample plot P and S showed unimodal changes.The peak values appeared at 14：00-15：00 p.m.;soil CO2 flux was negatively correlated with near-ground air humidity and carbon content,positively correlated with soil temperature and near-ground air temperature,and showed no obvious correlation with soil moisture.
基金supported by the Natural Science Foundation of Jiangsu Province(Grant No.BK20180546)by the discipline construction fund project of Gansu Agricultural University(Grant No.GAU-XKJS-2018-002)by National Natural Science Foundation of China(Grant No.31760701).
文摘Organic chemical priming is an effective strategy in mitigating salt stress to plants.The objective of this study was to determine effects and associated mechanisms of acetic acid regulating plant tolerance to salt stress.Perennial ryegrass plants were pre-treated with 20 mM acetic acid and subsequently subjected to salt stress for 28 days.Salt stress caused increased endogenous acetic acid content with up-regulated expression of its key biosynthetic gene LpPDC1.Application of acetic acid effectively alleviated salt caused damage in perennial ryegrass.Acetic acid treatment increased K^(+) content and suppressed Na^(+) accumulation to maintain a higher K^(+)/Na^(+) ratio in leaves exposed to salt stress.Plants O_(2)^(−) treated with acetic acid also had significantly lower levels of and H_(2)O_(2),but higher SOD and CAT activities than those of the control after 21 days of salt stress.Acetic acid treatment also altered the plants endogenous phytohormone content with higher content of jasmonate(including JA,JA-ILe,and cis-OPDA),auxin(IAA),and cytokinins(CK,such as tZ,cZR,and iP),but lower content of abscisic acid(ABA)under salt stress conditions.Furthermore,expression of genes involved in JA,IAA,and CK biosynthesis and signaling pathways were up-regulated,while those involved in ABA were down-regulated by acetic acid treatment under salt stress.The results demonstrate that acetic acid could mitigate salt stress in perennial ryegrass by regulating K^(+) and Na^(+) balance,promoting ROS scavenging,and activating stress-protection hormone synthesis and signaling.
文摘In order to investigate the correlation between the variations in the environmental water quality indexes and the distance of water bodies from the planting region of vetiver, samples of surface water were gathered from the water bodies surrounding an abandoned coal gangue mountain of Dahead coal mine (Dahe, Liupanshui, Guizhou Province) based on the method of field survey and typical analysis. According to the results, the planting of vetiver could effectively purify the water bodies surrounding the coal gangue mountain. Detailed findings include three aspects:(1) The main pollutants detected in water bodies around the coal gangue mountain were SO4 2-, NO3 -, Fe and Cu, with a concentration of 869.45, 35.16, 26.06, and 40.85 mg/L respectively in wet season and all exceeded the national environmental standards for surface water.(2) The pH values of water bodies 150~200 m away from the vetiver planting region stayed within the limits of national environmental standards for surface water and presented a homogeneous feature, revealing that vetiver has the capacity to adjust the pH of the surrounding water body.(3) The contents of Fe, Mn, Cu, SO4 2-, and NO3 - under all treatments, tended to increase with the increasing distance of water bodies from the vetiver planting region;it means the shorter the distance between the water body and the vetiver planting region is, the higher the adsorption rate and purification effects will be;the optimal concentrations of Fe, Mn, and Cu were 0 mg/L, much lower than the national environmental standards for surface water.
基金Sponsored by National Spark Program(2012GA780024)Program of Marginal Tropical Characteristic Plant Resources Development Center of Guangdong Universities and Colleges(GCZX-B1002)
文摘Large sample sampling was adopted in this paper for the statistical analysis of leaves of four populations of Vetiveria zizanioides （ introduced, local wild, domesticated wild populations of different years）. The results showed that four populations varied in different degrees in terms of tiller height, leaf biomass, and leaf biomass ratio. Leaf length, leaf width, and ratio of leaf width to length of different populations also varied, but had similar power-function change regularity, and showed converging leaf biomass growth pattern and leaf growth process.
基金This project is partially supported by the National Natural Science Foundation of China under Grant No.11675228China postdoctoral Science Foundation under Grant No.2015M572662XB.
文摘Ca^(2+)plays an important role in cell signal transduction.Its intracellular propagation is the most basic process of Ca^(2+)signaling,such as calcium wave and double messenger system.In this work,with both numerical simulation and mean field ansatz,the three-dimensional probability distribution of Ca^(2+),which is read out by phosphorylation,is studied in two scenarios with boundaries.The coverage of distribution of Ca^(2+)is found at an order of magnitude ofμm,which is consistent with experimental observed calcium spike and wave.Our results suggest that the double messenger system may occur in the ER-PM junction to acquire great efficiency.The buffer effect of kinase is also discussed by calculating the average position of phosphorylations and free Ca^(2+).The results are helpful to understand the mechanism of Ca^(2+)signaling.
基金Sponsored by Sci-tech Innovation Program of Gansu Provincial Department of Agriculture and Animal Husbandry(GNXC-2012-45)National Natural Science Foundation of China(41161049,31160264)
文摘Minqin oasis in the lower reaches of the Shiyang River is a main natural barrier for the Wuwei Basin. Due to the combined influence of human activities and natural factors in the past half a century, water quality in the lower reaches of the Shiyang River decreased and ecological environment deteriorated, which influenced sustainable development of this area and surrounding area seriously. This paper analyzed current situation and reasons of the deteriorated ecological environment in the lower reaches of the Shiyang River, and proposed that water environment regulation was the primary task in the eco-environment control of Minqin area, specifically,(a) By using existing policies, accelerating the construction of water-saving agriculture in the middle reaches of the Shiyang River, water quantity in the lower reaches would be guanranted, water shortage for agricultural production and ecological use in Minqin oasis would be relieved;(b) Unreasonable human activities such as overexploitation of underground water should be controlled strictly;(c) Water conservancy project should be developed vigorously to ensure rate of flow. It was expected that the above schemes would contribute to the benign circulation of ecological environment in Minqin oasis.
基金Supported by Tibet High Quality Freeze Resistance Bluegrass Varieties Breeding(Z2013C02N02_02)National Wool Sheep Grazing Grassland Ecological Position of Scientific Research Project(CARS-40-09B)
文摘Two-year-old Medicago sativa at budding initial stage was taken as research materials.Five methods were used to make green hay,including flatting stems ＋ spraying 2.5% K2CO3,flatting stems,sun curing,drying in shade and drying under 105 ℃ condition（CK）.Besides,effects of different green hay making methods on dry characteristics and nutritional quality of M.sativa green hay were studied,and a comprehensive evaluation of M.sativa green hays was conducted.Results showed that,except CK,the drying rates in other making methods were all fast at first,and then slow down.Both of drying under 105 ℃ condition and flatting stems ＋ spraying K2CO3 could speed up drying rate and reduce nutritional losses of green hay.Sun curing could also speed up drying rate,but it could not maintain the quality of green hay.The results of Grey Relational Analysis on five green hay making methods indicated that CK had the best comprehensive performance,followed by green hays made by flatting stems ＋ spraying K2CO3.Therefore,flatting stems ＋ spraying K2CO3 was a quick and easy method to make green hay,and it was worth to be recommended in practical production.
基金funded by National Key Technology R & DProgram during the 11th Five-Year Plan Period (2008BADB3B01)Crops Germplasm Resource Conservation Project of Ministry of Agriculture (NB08-2130135-43)
文摘As shown by the changes in physiological characteristics and seed vigor of three Medicago ruthenica samples during artificial aging process, the germination potential, germination rate, germination index, vigor index and simple vigor index declined with the extension of aging time on the whole. After artificial aging for 6 min, the vigor was higher than that of the control. The conductivity, malondialdehyde content and soluble polysaccharide content of seed leachate increased with the aging time and negatively correlated （ P 〈 0.05） with the seed vigor indicators. The physiological indicators were very significantly correlated （P 〈 0.01 ） with the vigor indicators in the Medicago ruthenica sample from Dorbod Qi, UIanqab City（China）.
基金supported by the Chinese Universities Scientific Fund(2021RC001)the China Agriculture Research System(CARS34)the National Program for Forage Germplasm Conservation(2130135).
文摘Erect milkvetch(Astragalus adsurgens)is a perennial legume forage crop with economic and ecological value in livestock grazing and soil-erosion control in arid and semiarid areas worldwide.Genomic information and molecular tools to support breeding and research in the species are limited.The objectives of this investigation were to map its genome using DNA markers and to identify quantitative trait loci(QTL)in the species.An F1 mapping population of 250 plants was developed from a cross between two parents with differing flowering-related traits.A high-density genetic linkage map containing 4821 markers on eight linkage groups(LGs)with a total genetic length of 1395 cM and a mean interval of 0.29 cM between adjacent markers was constructed with SLAF-seq technology.Comparative genomic analyses revealed the highest genome sequence similarity(8.71%)between erect milkvetch and Medicago truncatula,followed by Glycine max(7.65%),Cicer arietinum(7.53%),and Lupinus angustifolius(5.21%).A total of 64 significant QTL for flowering-related traits on six LGs were detected,accounting for 9.38 to 19.1%of the associated phenotype variation.Five and 48 key candidate genes for floret number and inflorescence length were identified based on the Glycyrrhiza uralensis genome.These candidate genes were involved in ubiquitination/degradation,pollen development,cell division,cytokinin biosynthetic process,and plant flowering.These findings shed light on the regulation of flowering traits in erect milkvetch and provide genomic resources for future molecular breeding of the crop.
基金Supported by Scientific and Technological Innovation Project of Gansu Agriculture and Animal Husbandry Bureaus(GNXC-2012-45)National Natural Science Foundation of China(41161049)
文摘This paper aims at summarized the research progress of soil microbes,in amount of soil microbes including bacteria,fungi and actinomycetes,soil microbial biomass,including microbial biomass carbon,microbial biomass nitrogen and microbial biomass phosphorus,function of microbial and screening and application of beneficial microorganisms etc.,and future research are discussed combined with our project team for many years of work.
基金This study was funded by the National Natural Science Foundation of China(31330012,31470525,31300360,31400364)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA05050000)the China Postdoctoral Science Foundation(2013M530767,2016M591282).
文摘Aims Shrub encroachment has taken place in many of China’s northern grasslands.This study attempts to answer the following questions:which plant communities are present in these shrub-encroached grasslands(SEGs)?What are the species richness and composition of these communities?Which environmental factors determine the spatial distribution thereof?Methods We investigated the community characteristics of 255 SEG plots with a size of 20 m×20 m at 69 locations across grasslands in northern China.In each plot,paired 1-m^(2) quadrats were estab-lished within shrub patches and the neighbouring grassy matrix to record herb species composition.The quantitative character-istics(abundance,coverage and height)of herbs were meas-ured in 0.25-m2 subquadrats,and soil samples were collected in the quadrats.Two-way indicator species analysis(TWINSPAN),detrended canonical analysis(DCA)and canonical correspond-ence analysis(CCA)were used for community clustering and ordination.Important Findings The DCA and TWINSPAN results suggested that the SEGs in northern China can be divided into six community types:Potentilla fruticosa+Carex atrofusca,Spiraea hypericifolia+Festuca ovina,Caragana acanthophylla+Stipa sareptana,Caragana microphylla+Leymus chinensis,Caragana microphylla+Stipa klemenzii and Caragana tibetica+Cleistogenes songorica.At a regional scale,climate and soil nutrients controlled the spatial patterns of species richness and community composition of the SEGs in northern China.Temperature exerted a negative impact,whereas precipitation and nutrients had positive effects on species richness.Among the environmental factors used,climate was the major controller of the variations in commu-nity structure.These results provide new insights into the community composition of SEGs in China and enrich the global dataset of SEGs.
基金financially supported in part by China Agriculture Research System (CARS-37)
文摘The application of n-alkane as markers to estimate herbage intake, apparent digestibility and species composition of diet consumed by grazing sheep was studied. Six local Mongolian sheep were used to determine dry matter （DM） intake, apparent DM digestibility and species composition of diet during summer, autumn and winter. Animals were orally dosed twice daily with n-alkane gelatin capsules containing 60 mg C32-alkane as an external marker. Diet composition was estimated by comparing the odd-chain n-alkanes pattern profile （C27-C31） of the consumed plant species with the n-alkanes fecal concentrations of grazing animals, using a non-negative least squares algorithm called EATWHAT software package. The alkane pair C32：C33 and C33 alkane were used to estimate DM intake and diet apparent DM digestibility, respectively. The results showed that daily dry matter intake of the sheep were 1.77, 1.61 and 1.18 kg d-1 in summer, autumn and winter, respectively. Apparent DM digestibility, crude protein （CP）, metabolizable energy （ME） and neutral detergent fiber （NDF） intake of diet consumed by sheep decreased significantly （P〈0.01） from summer to winter, with no evident changes in ADF and ADL intake. Diet composition indicated Artemisia frigida Willd was the most dominant diet component, contributed 79.68, 68.12 and 86.26% of sheep＇s diets in summer, autumn and winter, respectively. Cleistogenes songorica Ohwi and Convolvulus arnmannii Desr were the important components of the diet. Although Stipa breviflora Griseb is one of the main plant species in the study area, the sheep rarely choosed it. The study indicated that CP and ME in diet consumed by sheep were deficient in winter. Therefore, appropriate supplementation strategies should be indispensable during this period.
基金This work was supported by the Budgetary Project the Chinese Academy of Sciences Leads the Sub-Project of Class A Project(XDA26020202)the National“973”Program Project Topics(2014CB138702)+2 种基金the Basic Scientific Research Business Expenses of Central Universities(Lzujbky-2022-kb10)the 111 Wisdom Base(B12002)the Fundamental Research Funds for the Central Public Welfare Research Institutes(Chinese Academy of Forestry)(CAFYBB2021ZD001).
文摘In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts from aboveground and belowground parts of A.inebrians significantly inhibited the germination rate,germination potential,germination index,vigor index,seedling height,root length,and fresh weight of E.nutans,but increased malondialdehyde content,catalase,peroxidase and superoxide dismutase activity of E.nutans seedlings(p<0.05).The allelopathy of aqueous extracts of the aboveground parts of A.inebrians was stronger than that of the pre-cipitates.Aqueous extracts of the aboveground parts of A.inebrians decreased seed germination rate,germination potential,germination index,vigor index,seedling length,root length,and seedling fresh weight by 10.45%-74.63%,24.18%-32.50%,19.03%-73.36%,37.83%-88.41%,21.42%-53.14%,2.65%-40.21%,and 20.45%-61.36%,respectively,and malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity increased by 8.09%-62.24%,27.83%-86.47%,22.90%-93.17%,and 11.15%-75.91%,respectively.The above indexes were higher in live soil than in sterilized soil.Soil microorganisms increased the allelopathy of A.inebrians.The seed germination rate,germination potential,germination index,vigor index,seedling length,and seedling fresh weight of E.nutans planted in live soil decreased by 8.22%-48.48%,10.00%-51.85%,8.19%-53.26%,16.43%-60.03%,12.91%-28.81%,and 9.09%-22.86%compared with sterilized soil,respectively.Malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity of E.nutans planted in live soil increased by 53.91%-81.06%,15.71%-57.34%,33.33%-86.31%,and 9.78%-52.51%compared with sterilized soil,respectively.The existence of soil microorganisms enhanced the allelopathy of the secondary metabolites of A.inebrians.A combination of microorganisms and aqueous extracts from the aboveground parts of A.inebrians had the strongest allelopathic effect on E.nutans.
文摘In accordance with the objective to construct a major province in grassland animal husbandry,the following ways were used for enhancing development,improving the scientific and technological content,increasing the scale of the industry and market development to set up our own ecological grass industry brand and finally reach sustainable development strategy.This paper discussed the status of Guizhou Province grass industry development from the grass industry resources,grassland and animal husbandry production,prataculture technology problem.
基金supported by the National Key Research and Development Program of China (2016YFC0500202)the Natural Science Foundation of Jiangsu Province,China (BK20140413)+1 种基金the Asia-Pacific Network (APN) Global Change Fund Project (ARCP2013-16NMY-Li)the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions,China
文摘Anthropogenic activities profoundly influence carbon sequestration in the Eurasian Steppe. In particular, grazing has been identified as having a major effect on carbon sequestration. However, the extent to which grazing affects regional patterns or carbon sequestration is unknown. In this study, we evaluated the impact of regional grazing on grassland carbon seques- tration using the Boreal Ecosystem Productivity Simulator （BEPS） and the Shiyomi grazing model. Model performances were validated against the results from field measurements and eddy covariance （EC） sites. Model outputs showed that in 2008, the regional net primary productivity （NPP） was 79.5 g C m-2, and the net ecosystem productivity （NEP） was -6.5 g C m-2, characterizing the region as a Weak carbon source. The Mongol Steppe （MS） was identified as a carbon sink, whereas the Kazakh Steppe （KS） was either carbon neutral or a weak carbon source. The spatial patterns of grazing density are divergent between the MS and the KS. in the MS, livestock was mainly distributed in China with relatively good management, while in the KS livestock was mainly concentrated in the southern countries （especially Uzbekistan and Turkmenistan） with harsh environments and poor management. The consumption percentages of NPP in Turkmenistan, Tajikistan and Uzbekistan were 5.3, 3.3 and 1.2%, respectively, whereas the percentages in other countries were lower than 1%. Correspondingly, grazing consumption contributed to the carbon sources of Turkmenistan, Tajikistan and Uzbekistan by 11.6, 6.3 and 4.3%, respectively, while it weakened the carbon sink in Inner Mongolia, China and Mongolia by 1.6 and 0.5%. This regional pattern should be affected by different sub-regional characteristics, e.g., the continuous degradation of grassland in the southern part of the KS and the restoration of grassland in Inner Mongolia, China.
基金supported by the National Natural Science Foundation of China(31960359)the Ningxia Hui Autonomous Region Key Research and Development Project(2021BEG02005,2023BEG02049)the Natural Science Foundation of Ningxia Hui Autonomous Region,China(2020AAC03102,2023AAC03061)。
文摘Changes in precipitation and nitrogen(N)addition may significantly affect the processes of soil carbon(C)cycle in terrestrial ecosystems,such as soil respiration.However,relatively few studies have investigated the effects of changes in precipitation and N addition on soil respiration in the upper soil layer in desert steppes.In this study,we conducted a control experiment that involved a field simulation from July 2020 to December 2021 in a desert steppe in Yanchi County,China.Specifically,we measured soil parameters including soil temperature,soil moisture,total nitrogen(TN),soil organic carbon(SOC),soil microbial biomass carbon(SMBC),soil microbial biomass nitrogen(SMBN),and contents of soil microorganisms including bacteria,fungi,actinomyces,and protozoa,and determined the components of soil respiration including soil respiration with litter(RS+L),soil respiration without litter(RS),and litter respiration(RL)under short-term changes in precipitation(control,increased precipitation by 30%,and decreased precipitation by 30%)and N addition(0.0 and 10.0 g/(m^(2)·a))treatments.Our results indicated that short-term changes in precipitation and N addition had substantial positive effects on the contents of TN,SOC,and SMBC,as well as the contents of soil actinomyces and protozoa.In addition,N addition significantly enhanced the rates of RS+L and RS by 4.8%and 8.0%(P<0.05),respectively.The increase in precipitation markedly increased the rates of RS+L and RS by 2.3%(P<0.05)and 5.7%(P<0.001),respectively.The decrease in precipitation significantly increased the rates of RS+L and RS by 12.9%(P<0.05)and 23.4%(P<0.001),respectively.In contrast,short-term changes in precipitation and N addition had no significant effects on RL rate(P>0.05).The mean RL/RS+L value observed under all treatments was 27.63%,which suggested that RL is an important component of soil respiration in the desert steppe ecosystems.The results also showed that short-term changes in precipitation and N addition had significant interactive effects on th
