Zhenke Zhu
Chinese Academy of Sciences
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Zhenke Zhu.
Journal of Climate | 2013
Alessandro Anav; Pierre Friedlingstein; M. Kidston; L. Bopp; Philippe Ciais; Peter M. Cox; Colin Jones; Martin Jung; Ranga B. Myneni; Zhenke Zhu
The authors assess the ability of 18 Earth system models to simulate the land and ocean carbon cycle for the presentclimate. These modelswill be used in the next Intergovernmental Panel onClimate Change(IPCC)Fifth Assessment Report (AR5) for climateprojections, and such evaluationallows identificationof thestrengths andweaknessesofindividualcoupledcarbon‐climatemodelsaswellasidentificationofsystematicbiasesof themodels. Resultsshowthat models correctlyreproducethemain climatic variablescontrolling thespatial and temporal characteristics of the carbon cycle. The seasonal evolution of the variables under examination is well captured. However, weaknesses appear when reproducing specific fields: in particular, considering the land carbon cycle, a general overestimation of photosynthesis and leaf area index is found for most of the models, while the ocean evaluation shows that quite a few models underestimate the primary production.The authors also propose climate and carbon cycle performance metrics in order to assess whether there is a set of consistently better models for reproducing the carbon cycle. Averaged seasonal cycles and probability density functions (PDFs) calculated from model simulations are compared with the corresponding seasonal cycles and PDFs from different observed datasets. Although the metrics used in this study allow identificationofsomemodels as betterorworsethantheaverage, therankingofthisstudyispartiallysubjective because of the choice of the variables under examination and also can be sensitive to the choice of reference data. In addition, it was found that the model performances show significant regional variations.
Applied Physics Letters | 2015
P. Luo; Zhong-Yi Lu; Zhenke Zhu; Y. Z. Li; H. Y. Bai; W. Wang
Most metallic glasses (MGs) exhibit weak slow β-relaxation. We report the prominent β-relaxation in YNiAl metallic glass with a wide composition range. Compared with other MGs, the MGs show a pronounced β-relaxation peak and high β-relaxation peak temperature, and the β-relaxation behavior varies significantly with the changes of the constituent elements, which is attributed to the fluctuations of chemical interactions between the components. We demonstrate the correlation between the β-relaxation and the activation of flow units for mechanical behaviors of the MG and show that the MG is model system for studying some controversial issues in glasses.
Frontiers in Microbiology | 2015
Xiaohong Wu; Tida Ge; Wei Wang; Hongzhao Yuan; Carl-Eric Wegner; Zhenke Zhu; Andrew S. Whiteley; Jinshui Wu
The effect of different cropping systems on CO2 fixation by soil microorganisms was studied by comparing soils from three exemplary cropping systems after 10 years of agricultural practice. Studied cropping systems included: continuous cropping of paddy rice (rice-rice), rotation of paddy rice and rapeseed (rice-rapeseed), and rotated cropping of rapeseed and corn (rapeseed-corn). Soils from different cropping systems were incubated with continuous 14C-CO2 labeling for 110 days. The CO2-fixing bacterial communities were investigated by analyzing the cbbL gene encoding ribulose-1,5-bisphosphate carboxylase oxygenase (RubisCO). Abundance, diversity and activity of cbbL-carrying bacteria were analyzed by quantitative PCR, cbbL clone libraries and enzyme assays. After 110 days incubation, substantial amounts of 14C-CO2 were incorporated into soil organic carbon (14C-SOC) and microbial biomass carbon (14C-MBC). Rice-rice rotated soil showed stronger incorporation rates when looking at 14C-SOC and 14C-MBC contents. These differences in incorporation rates were also reflected by determined RubisCO activities. 14C-MBC, cbbL gene abundances and RubisCO activity were found to correlate significantly with 14C-SOC, indicating cbbL-carrying bacteria to be key players for CO2 fixation in these soils. The analysis of clone libraries revealed distinct cbbL-carrying bacterial communities for the individual soils analyzed. Most of the identified operational taxonomic units (OTU) were related to Nitrobacter hamburgensis, Methylibium petroleiphilum, Rhodoblastus acidophilus, Bradyrhizobium, Cupriavidus metallidurans, Rubrivivax, Burkholderia, Stappia, and Thiobacillus thiophilus. OTUs related to Rubrivivax gelatinosus were specific for rice-rice soil. OTUs linked to Methylibium petroleiphilum were exclusively found in rice-rapeseed soil. Observed differences could be linked to differences in soil parameters such as SOC. We conclude that the long-term application of cropping systems alters underlying soil parameters, which in turn selects for distinct autotrophic communities.
Biology and Fertility of Soils | 2017
Xiaomeng Wei; Yajun Hu; Peiqin Peng; Zhenke Zhu; Cornelius Talade Atere; Anthony G. O’Donnell; Jinshui Wu; Tida Ge
AbstractPrevious studies have shown that phosphorus addition to P-limited soils increases gaseous N loss. A possible explanation for this phenomenon is element stoichiometry (specifically of C:N:P) modifying linked nutrient cycling, leading to enhanced nitrification and denitrification. In this study, we investigated how P stoichiometry influenced the dynamics of soil N-cycle functional genes. Rice seedlings were planted in P-poor soils and incubated with or without P application. Quantitative PCR was then applied to analyze the abundance of ammonia-oxidizing (amoA) and denitrifying (narG nirK, nirS, nosZ) genes in soil. P addition reduced bacterial amoA abundance but increased denitrifying gene abundance. We suggest this outcome is due to P-induced shifts in soil C:P and N:P ratios that limited ammonia oxidization while enhancing P availability for denitrification. Under P application, the rhizosphere effect raised ammonia-oxidizing bacterial abundance (amoA gene) and reduced nirK, nirS, and nosZ in rhizosphere soils. The change likely occurred through greater C input and O2 release from roots, thus altering C availability and redox conditions for microbes. Our results show that P application enhances gaseous N loss potential in paddy fields mainly through stimulating denitrifier growth. We conclude that nutrient availability and elemental stoichiometry are important in regulating microbial gene responses, thereby influencing key ecosystem processes such as denitrification. Graphical abstractᅟ
Journal of Chemical Physics | 2016
Zhong-Yi Lu; B. S. Shang; Yanming Sun; Zhenke Zhu; Peng-Fei Guan; W. Wang; H. Y. Bai
The β-relaxation, which is the source of the dynamics in glass state and has practical significance to relaxation and mechanical properties of glasses, has been an open question for decades. Here, we propose a flow unit perspective to explain the structural origin and evolution of β-relaxation based on experimentally obtained energy distribution of flow units using stress relaxation method under isothermal and linear heating modes. Through the molecular dynamics simulations, we creatively design various artificial metallic glass systems and build a direct relation between β-relaxation behavior and features of flow units. Our results demonstrate that the β-relaxation in metallic glasses originates from flow units and is modulated by the energy distribution of flow units, and the density and distribution of flow units can effectively regulate the β-relaxation behavior. The results provide a better understanding of the structural origin of β-relaxation and also afford a method for designing metallic glasses with obvious β-relaxation and better mechanical properties.
Scientific Reports | 2016
Tida Ge; Xiaohong Wu; Qiong Liu; Zhenke Zhu; Hongzhao Yuan; Wei Wang; Andrew S. Whiteley; Jinshui Wu
Tillage is a common agricultural practice affecting soil structure and biogeochemistry. To evaluate how tillage affects soil microbial CO2 fixation, we incubated and continuously labelled samples from two paddy soils and two upland soils subjected to simulated conventional tillage (CT) and no-tillage (NT) treatments. Results showed that CO2 fixation (14C-SOC) in CT soils was significantly higher than in NT soils. We also observed a significant, soil type- and depth-dependent effect of tillage on the incorporation rates of labelled C to the labile carbon pool. Concentrations of labelled C in the carbon pool significantly decreased with soil depth, irrespective of tillage. Additionally, quantitative PCR assays revealed that for most soils, total bacteria and cbbL-carrying bacteria were less abundant in CT versus NT treatments, and tended to decrease in abundance with increasing depth. However, specific CO2 fixation activity was significantly higher in CT than in NT soils, suggesting that the abundance of cbbL-containing bacteria may not always reflect their functional activity. This study highlights the positive effect of tillage on soil microbial CO2 fixation, and the results can be readily applied to the development of sustainable agricultural management.
Plant and Soil | 2017
Zhenke Zhu; Tida Ge; Yajun Hu; Ping Zhou; Tingting Wang; Olga Shibistova; Georg Guggenberger; Yirong Su; Jinshui Wu
Background and aimsThe turnover of plant- and microbial- derived carbon (C) plays a significant role in the soil organic C (SOC) cycle. However, there is limited information about the turnover of the recently photosynthesized plant- and soil microbe-derived C in paddy soil.MethodsWe conducted an incubation study with four different 13C–labeled substrates: rice shoots (Shoot-C), rice roots (Root-C), rice rhizodeposits (Rhizo-C), and microbe-assimilated C (Micro-C).ResultsShoot- and Root-C were initially rapidly transformed into the dissolved organic C (DOC) pool, while their recovery in microbial biomass C (MBC) and SOC increased with incubation time. There were 0.05%, 9.8% and 10.0% of shoot-C, and 0.06%, 15.9% and 16.5% of root-C recovered in DOC, MBC and SOC pools, respectively at the end of incubation. The percentages of Rhizo- and Micro-C recovered in DOC, MBC, and SOC pools slowly decreased over time. Less than 0.1% of the Rhizo- and Micro-C recovered in DOC pools at the end of experiment; while 45.2% and 33.8% of Rhizo- and Micro-C recovered in SOC pools. Shoot- and Root-C greatly increased the amount of 13C–PLFA in the initial 50 d incubation, which concerned PLFA being indicative for fungi and actinomycetes while those assigning gram-positive bacteria decreased. The dynamic of soil microbes utilizing Rhizo- and Micro-C showed an inverse pattern than those using Shoot- and Root-C. Principal component analysis of 13C–PLFA showed that microbial community composition shifted obviously in the Shoot-C and Root-C treatments over time, but that composition changed little in the Rhizo-C and Micro-C treatments.ConclusionsThe input C substrates drive soil microbial community structure and function with respect to carbon stabilization. Rhizodeposited and microbial assimilated C have lower input rates, however, they are better stabilized than shoot- and root-derived C, and thus are preferentially involved in the formation of stable SOC in paddy soils.
Science of The Total Environment | 2018
Yajun Hu; Yinhang Xia; Qi Sun; Kunping Liu; Xiangbi Chen; Tida Ge; Baoli Zhu; Zhenke Zhu; Zhenhua Zhang; Yirong Su
Phosphorus (P) acquisition by plants from soil organic P mainly relies on microorganisms. Examining the community of functional microbes that encode phosphatases (e.g. PhoD) under different fertilization managements may provide valuable information for promoting soil organic P availability. Here, we investigated how the abundance and community diversity of phoD-harboring bacteria responded to long-term fertilization in Karst soils. Six fertilization treatments were designed as follows: non-fertilized control (CK), inorganic fertilization only (NPK), and inorganic fertilization combined with low- and high amounts of straw (LSNPK and HSNPK), or cattle manure (LMNPK and HMNPK). We found that soil available phosphorus (AP) content and the activity of alkaline phosphatase (ALP) were significantly higher in all combined inorganic/organic fertilization treatments, while the abundance of the phoD gene was only higher in the HMPNK treatment, compared to NPK. The combination of inorganic/organic fertilizations had no effect on the diversity of phoD genes compared to NPK alone, but the phoD gene richness was greater in these treatments as compared to the control. Only organic fertilization combinations with high amounts of organic matter (both HSNPK and HMNPK) significantly affected the phoD community structure. A structure equation model demonstrated that soil organic carbon (SOC), rather than P, greatly affected the phoD community structure, suggesting that organic P mineralization in soils is decoupled from C mineralization. Our results suggested that optimized combinations of inorganic/organic fertilizations could promote P availability via regulating soil phoD-harboring bacteria community diversity and ALP activity.
Archives of Agronomy and Soil Science | 2016
Yan Jian; Zhenke Zhu; Mouliang Xiao; Hongzhao Yuan; Jiurong Wang; Dongsheng Zou; Tida Ge; Jinshui Wu
ABSTRACT Similar to higher plants, microbial autotrophs possess photosynthetic systems that enable them to fix CO2. To measure the activity of microbial autotrophs in assimilating atmospheric CO2, five paddy soils were incubated with 14C-labeled CO2 for 45 days to determine the amount of 14C-labeled organic C being synthesized. The results showed that a significant amount of 14C-labeled CO2 incorporated into microbial biomass was soil specific, accounting for 0.37%–1.18% of soil organic carbon (14C-labeled organic C range: 81.6–156.9 mg C kg−1 of the soil after 45 days). Consequently, high amounts of C-labeled organic C were synthesized (the synthesis rates ranged from 86 to 166 mg C m−2 d−1). The amount of atmospheric 14CO2 incorporated into microbial biomass (14C-labeled microbial biomass) was significantly correlated with organic C components (14C-labeled organic C) in the soil (r = 0.80, p < 0.0001). Our results indicate that the microbial assimilation of atmospheric CO2 is an important process for the sequestration and cycling of terrestrial C. Our results showed that microbial assimilation of atmospheric CO2 has been underestimated by researchers globally, and that it should be accounted for in global terrestrial carbon cycle models.
Biogeosciences | 2015
Stephen Sitch; Pierre Friedlingstein; Nicolas Gruber; S. D. Jones; Guillermo Murray-Tortarolo; Anders Ahlström; Scott C. Doney; Heather Graven; Christoph Heinze; Chris Huntingford; Samuel Levis; Peter E. Levy; Mark R. Lomas; Benjamin Poulter; Nicolas Viovy; Sönke Zaehle; Ning Zeng; Almut Arneth; Gordon B. Bonan; Laurent Bopp; Josep G. Canadell; F. Chevallier; Philippe Ciais; Richard J. Ellis; Manuel Gloor; Philippe Peylin; Shilong Piao; C. Le Quéré; Benjamin Smith; Zhenke Zhu