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Soil respiration response to precipitation reduction in a grassland and a Mongolian pine plantation in semi-arid northeast China

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Journal of Forestry Research 2019年第5期30卷 1925-1934页

作者： Yalin Hu Jintao Li Shanyu Zhao dehui zeng College of Forestry Fujian Agriculture and Forestry UniversityFuzhou 350002People’s Republic of China CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016People’s Republic of China State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China

Climate change is predicted to alter global precipitation ***,the response of soil carbon and nitrogen cycles and soil microorganisms to precipitation reduction is poorly understood but is dependent on ecosystem *** evaluate the impacts of reduced precipitation on soil respiration,soil inorganic nitrogen(i.e.,NH4^+–N and NO3^-–N),nitrogen mineralization,and soil microbial community composition,a precipitation manipulation experiment was initiated in a Mongolian pine plantation and a naturally restored grassland in semi-arid northeast *** reduction led to decreases of soil respiration rates by 14 and 8%in 2014 and 2015 in the Mongolian pine plantation but no changes in the *** inorganic nitrogen,ammonification and nitrification rate,and soil phospholipids fatty acids were not significantly changed by reduced precipitation but significantly differed between the two ecosystems and among growing *** results suggest that the impacts of precipitation reduction on soil respiration were different between the Mongolian pine plantation and the grassland,and that ecosystem type and growing season had more pronounced impacts on soil carbon and nitrogen cycles.

关键词： Precipitation reduction Soil respiration rate N mineralization Phospholipids fatty acids Semi-arid region

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Rhizosphere organic phosphorus fractions of Simon poplar and Mongolian pine plantations in a semiarid sandy land of northeastern China

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Journal of Arid Land 2015年第4期7卷 475-480页

作者： ZHAO Qiong WANG Hongquan YU Zhanyuan zeng dehui State Key Laboratory of Forest and Soil Ecology Institute of Applied Ecology Chinese Academy of Sciences Daqinggou Ecological Station Institute of Applied Ecology Chinese Academy of Sciences University of Chinese Academy of Sciences

The aim of this study was to investigate the role of rhizosphere organic phosphorus （P） in soil P supply in semiarid forests and the effects of tree species on rihizosphere organic P. We examined organic P fractions in rhizosphere and bulk soils of mono-specific Simon poplar （Populus simonii） and Mongolian pine （Pinus sylvestris var. mongolica） plantations in a semiarid sandy soil of Horqin Sandy Land in Northeast China. Total organic P （TPo） accounted for 76% of total P across the two stands. The concentration of organic P （Po） fractions decreased in the order of NaOH-Po〉Res-Po〉HCI-Po〉NaHCO3-Po in both plantations. The concentration of NaHCO3-Po was 38% and 43% lower in rhizosphere soil than in bulk soil in Simon poplar and Mongolian pine plantations, respectively. In contrast, total P, TPo and NaOH-Po significantly accumulated in rhizosphere soil in Simon poplar plantations, but no change in Mongolian pine plantations. Soil recalcitrant organic P fractions were positively correlated with soil organic carbon. The results suggest that rhizosphere labile organic P was an important source of plant-available P in this semiarid region, but the dynamic of rhizosphere recalcitrant organic P fractions varied with tree species and was correlated to organic carbon dynamics.

关键词： rhizosphere effect organic P fractions Populus simonii Pinus sylvestris var. mongolica

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Effects of ultraviolet(UV) radiation and litter layer thickness on litter decomposition of two tree species in a semi-arid site of Northeast China

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Journal of Arid Land 2018年第3期10卷 416-428页

作者： MAO Bing ZHAO Lei ZHAO Qiong zeng dehui CAS Key Laboratory of Forest Ecology and Management Institute of Applied Ecology Chinese Academy of Sciences College of Horticulture Jilin Agricultural University Daqinggou Ecological Station Institute of Applied Ecology Chinese Academy of Sciences

Forests and grasslands in arid and semi-arid regions receive high-intensity ultraviolet（UV） radiation year-round. However, how the UV radiation affects the litter decomposition on the forest floor remains unclear. Here, we conducted a field-based experiment in 2011 in the southeastern Horqin Sandy Land, Northeast China, to investigate the effects of UV radiation, litter layer thickness, and their interaction on the mass loss and chemical properties of decomposing litter from Xiaozhuan poplar（Populus × xiaozhuanica） and Mongolian pine（Pinus sylvestris var. mongolica） plantation trees. We found that UV radiation accelerated the decomposition rates of both the Xiaozhuan poplar litter and Mongolian pine litter. For both species, the thick-layered litter had a lower mass loss than the thin-layered litter. The interaction between UV radiation and litter layer thickness significantly affected the litter mass loss of both tree species. However, the effects of UV radiation on the chemical properties of decomposing litter differed between the two species, which may be attributed to the contrasting initial leaf litter chemical properties and morphology. UV radiation mostly had positive effects on the lignin concentration and lignin/N ratio of Xiaozhuan poplar litter, while it had negative effects on the N concentration of Mongolian pine litter. Moreover, litter layer thickness and its interaction with UV radiation showed mostly positive effects on the N concentration and lignin/N ratio of Xiaozhuan poplar litter and the ratios of C/N and lignin/N of Mongolian pine litter, and mostly negative effects on the C/N ratio of Xiaozhuan poplar litter and the N concentration of Mongolian pine litter. Together, these results reveal the important roles played by UV radiation and litter layer thickness in the process of litter decomposition in this semi-arid region, and highlight how changes in the litter layer thickness can exert strong influences on the photodegradation of litter in tre

关键词： lignin litter decomposition litter layer thickness nitrogen forest plantation photodegradation UV radiation

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Three-dimensional (3D) structure model and its parameters for poplar shelterbelts

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Science China Earth Sciences 2010年第10期53卷 1513-1526页

作者： FAN ZhiPing GAO JunGang zeng dehui ZHOU XinHua SUN XueKai Daqinggou Ecological Station Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China Graduate University of Chinese Academy of Sciences Beijing 100049China School of Natural Resources University of NebraskaLincolnNE 68583-0995USA

The spatial functions of surface area density(vegetative surface area per unit canopy volume) and cubic density(vegetative volume per unit canopy volume) have been used as two three-dimensional(3D) structural descriptors for *** functions were defined by models as a general ***,sub-models such as surface area,volume,and corresponding distributions were not explicitly defined for poplar trees,which are a dominant woody species in shelterbelts all over China,and this limits applications of the models in China and *** order to define and develop these sub-models for shelterbelts,poplar trees were destructively sampled from multiple-row shelterbelts and then were measured for their surface area and *** these measurements,we estimated parameters to define their equations *** on the architecture and planting patterns of trees in shelterbelts,the distribution of the surface areas and volumes vertically and across the width for different tree heights were constructed for the three components of trunks,branches and *** the defined equations into the models,we described the 3D structure of a multiple-row poplar *** results showed that,the spatial change in magnitude of surface area density(0.215-10.131 m2/m3) or cubic density(0.00007-0.04667 m3/m3) in shelterbelts is large and their distributions are not *** assumption for boundary-layer flow modeling efforts that the 3D distribution of shelterbelt structure was uniform is not the case in *** 3D structure model not only can be used to model the flow field as influenced by each tree component,but also can express the entire aerodynamic characteristics of a *** methodologies and equations that are developed in this study can be applied to estimate the 3D structure of a shelterbelt with a design similar to our studied poplar shelterbelts in terms of species composition and planting *** fitted models can be used to

关键词： aerodynamics cubic density porosity numerical simulation surface area density

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Decomposition of Mongolian pine litter in the presence of understory species in semi-arid northeast China

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Journal of Forestry Research 2016年第2期27卷 329-337页

作者： Bing Mao Rong Mao Yalin Hu Yue Huang dehui zeng State Key Laboratory of Forest and Soil Ecology Institute of Applied EcologyChinese Academy of SciencesShenyang 110164China University of Chinese Academy of Sciences Beijing 100049China Daqinggou Ecological Station Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130012China

The effects of understory plant litter on domi- nant tree litter decomposition are not well documented especially in semi-arid forests. In this study, we used a microcosm experiment to examine the effects of two understory species （Artemisia scoparia and Setaria viridis） litter on the mass loss and N release of Mongolian pine （Pinus sylvestris var. mongolica） litter in Keerqin Sandy Lands, northeast China, and identified the influencing mechanism from the chemical quality of decomposing litter. Four litter combinations were set up： one monocul- ture of Mongolian pine and three mixtures of Mongolian pine and one or two understory species in equal mass proportions of each species. Total C, total N, lignin, cel- lulose and polyphenol concentrations, and mass loss of pine litter were analyzed at days 84 and 182 of *** chemistry of pine litter not only changed with the stages of decomposition, but was also strongly influenced by the presence of understory species during decomposition. Both understory species promoted mass loss of pine litter at 84 days, while only the simultaneous presence of two understory species promoted mass loss of pine litter at 182 days. Mass loss of pine litter was negatively correlated with initial ratios of C/N, lignin/N and polyphenol/N of litter combinations during the entire incubation period; at 182 days it was negatively correlated with polyphenol concentration and ratios of C/N and polyphenol/N of litter combinations at 84 days of incubation. Nitrogen release of pine litter was promoted in the presence of understory species. Nitrogen release at 84 days was negatively correlated with initial N concentration; at 182 days it was negatively correlated with initial polyphenol concentration of litter combinations and positively correlated with lignin concentration of litter com- binations at 84 days of incubation. Our results suggest that the presence ofunderstory species causes substantial changes in chemical components of pine litt

关键词： Litter chemistry Litter mixture Mass loss Nitrogen release Understory species

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Leaf traits and their interrelationship of 23 plant species in southeast of Keerqin Sandy Lands,China

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Frontiers in Biology 2008年第3期3卷 332-337页

作者： Jinhuan LIU dehui zeng Don Koo LEE Zhiping FAN Lei ZHONG Institute of Applied Ecology Chinese Academy of SciencesShenyang 110016China Department of Forest Sciences Seoul National UniversitySeoul 151–921Korea

Six leaf traits,i.e.,fresh mass(FM),dry mass(DM),leaf dry matter content(DMC),area(AR),specific leaf area(SLA)and thickness(TH)from 23 plant species in the southeastern Keerqin Sandy Lands,China were *** results show that leaf traits of herbs were more diversified than those of shrubs and trees and aver-age SLA tended towards a decreasing trend from herbs to shrubs to *** the contrary,DMC and DM show an upward trend from herbs to shrubs to *** apparent difference was found in *** for DM and TH,there were significant variations in SLA and DMC among three different growth ***,a significant correlation was found between SLA and *** is concluded that SLA and DMC could be used to predict species position along a resource use gradient.

关键词： specific leaf area leaf dry matter content leaf thickness Keerqin Sandy Lands

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Leaf traits indicate survival strategies among 42 dominant plant species in a dry, sandy habitat, China

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Frontiers in Biology 2009年第4期4卷 477-485页

作者： Jinhuan LIU dehui zeng Zhiping FAN David PEPPER Guangsheng CHEN Lei ZHONG Daqinggou Ecological Station Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China School of Biological Earth and Environmental SciencesThe University of New South WalesSydney NSW 2052Australia School of Forestry and Wildlife Sciences Auburn UniversityAL 36830USA Graduate School of Chinese Academy of Sciences Beijing 100049China

The objective of this paper was to assess the congruency of leaf traits and soil characteristics and to analyze the survival strategies of different plant functional types in response to drought and nutrient-poor environ-ments in the southeastern Ke’erqin Sandy Lands in *** leaf traits—leaf thickness(TH),density(DN),specific leaf area(SLA),leaf dry weight to fresh weight ratio(DW/FW),leaf N concentration(N mass),and N resorption efficiency(NRE_(mass))-of 42 plant species were investi-gated at four *** correlations between leaf traits and soil characteristics-organic C(OC),total N(TN),total P(TP),and soil moisture(SM)-were *** found that the six leaf traits across all the 42 species showed large variations and that DW/FW was negatively correlated with OC,TN,TP,and SM(P<0.05),while other leaf traits showed no significant correlations with soil *** find the dissimilarity to accommodate environment,a hierarchical agglomerative clustering analysis was made of all the *** the species clustered into three groups except the Scutellaria *** of group III might be most tolerant of an arid environment,and species of group II might avoid nutrient stress in the nutrient-poor environment,while group I was somewhat ***,species from the different groups may be selected for use in vegetation restoration of different sites based on soil moisture and nutrient conditions.

关键词： leaf thickness leaf density specific leaf area leaf dry matter content leaf N concentration N resorption efficiency

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Research on Blended Teaching in Integrated English Course Based on BOPPPS Model

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Journal of Contemporary Educational Research 2024年第9期8卷 134-138页

作者： dehui zeng Southwest Jiaotong University Hope College Chengdu 610400Sichuan ProvinceChina

The BOPPPS model has been widely used in information-based teaching reform,which emphasizes studentcentered principles and student participation and interaction,including six steps:bridge-in,objective,pre-assessment,participatory learning,post-assessment,and *** paper applies the BOPPPS model in the Integrated English course at the three stages of teaching practice-before class,during class,and after class-to achieve blended *** shows that this teaching mode provides students with a more abundant learning experience,helps to stimulate students’learning interests,and improves their comprehensive language application skills.

关键词： BOPPPS model Integrated English Blended teaching

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Research on Chinese-English Translation of Enterprise Publicity Materials from the Perspective of Adaptation Theory

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Journal of Contemporary Educational Research 2024年第5期8卷 177-181页

作者： dehui zeng Southwest Jiaotong University Hope College Chengdu 610400Sichuan ProvinceChina

As the process of economic globalization continues to advance,China has undergone earth-shaking ***-quality products and promotional materials are crucial for Chinese companies to go global and build their *** English translation of external promotional materials is ***,some companies do not pay enough attention to their publicity,resulting in a low international *** paper analyzes the Chinese-English translation of enterprise external publicity materials from the perspective of adaptation theory,thereby exploring the translation strategies adopted under the guidance of adaptation theory,hoping to provide some references for related translation practices in the future.

关键词： Adaptation theory Enterprise publicity materials Translation strategy

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Fault Ride-Through Capability Enhancement of PV System with Voltage Support Control Strategy

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Open Journal of Applied Sciences 2013年第2期3卷 30-34页

作者： dehui zeng Gang Wang Guoqing Pan Haifeng Li School of Electric Power South China University of Technology Guangzhou China

With continuously increasing of photovoltaic (PV) plant’s penetration, it has become a critical issue to improve the fault ride-through capability of PV plant. This paper refers to the German grid code, and the PV system is controlled to keep grid connected, as well as inject reactive current to grid when fault occurs. The mathematical model of PV system is established and the fault characteristic is studied with respect to the control strategy. By analyzing the effect of reactive power supplied by the PV system to the point of common coupling (PCC) voltage, this paper proposes an adaptive voltage support control strategy to enhance the fault ride-through capability of PV system. The control strategy fully utilizes the PV system’s capability of voltage support and takes the safety of equipment into account as well. At last, the proposed control strategy is verified by simulation.

关键词： PV System Fault Ride-Through Voltage Support Control Strategy

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