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Fire occurrence in relation to bamboo dominance in the Qinling Mountains of China: Evidence from phytolith and charcoal records in Holocene sediments

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Science China Earth Sciences 2015年第7期58卷 1182-1190页

作者： Courtney Marie RAYLE Scott B.FRANKLIN lu zhijun School of Biological Sciences University of Northern Colorado Key Laboratory of Aquatic Botany and Watershed Ecology the Chinese Academy of Sciences

he internal genetic clock of semelparous mast-flowering bamboo species creates gregarious regions of flowering and death, thus leading to fuel-load accumulation that potentially promotes fire（Fire-Cycle Hypothesis）. Higher abundance of bamboo could be expected to provide greater fuel loads after flowering. Here, we investigated the possible link between bamboo dominance and fire occurrence. As the main food source for the giant panda in the Qinling Mountains of China, Bashania fargesii（Farges Canebrake） and Fargesia qinlingensis（Arrow Bamboo） dominate lower（1000–1900 m） and higher elevations（1800–2700 m）, respectively. Four soil profiles（elevation ranging from 1240 to 2170 m） in areas of known recent bamboo flowering events（~1980） and adjacent non-flowering sites were assessed for phytoliths and charcoal. Characteristic phytoliths were chosen to describe bamboo dynamics, and charcoal particles were extracted from the soil to reconstruct fire history. Carbon 14 dating of soil charcoal samples was conducted using an accelerator mass spectrometry technique. In addition, we chose two depths（28–52 and 90–100 cm） in one Bashania profile（B. fargesii forest） and one Fargesia profile（F. qinlingensis forest） for phytolith dating. Our findings indicate that bamboo has been a dominant component of these ecosystems almost for the entire profile; some 6400 yrs for Bashania and ca. 10000 yrs for the Fargesia. It is also clear from the charcoal and phytolith data that bamboo abundance and recent mast flowering were significantly related to fire occurrence for lower elevation Bashania while the higher elevation Fargesia was not. One of the four profiles had chronological charcoal records throughout and the oldest charcoal aged was ~1410 yr BP, suggesting an anthropogenic origin. The mixing of phytolith and charcoal made it unrealistic to describe temporal dynamics of bamboo and fire events, and thus our interpretation is cognizant of the dating discrepancies and conservative（less-sp

关键词： bamboo dynamics Bashania Fargesia fire cycle hypothesis phytolith Qinling Mountains

Arctic sea ice distribution in summer based on aerial photos

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Acta Oceanologica Sinica 2005年第6期24卷 62-67页

作者： lu Peng LI zhijun ZHANG Zhanhai DONG Xilu State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China Polar Research Institute of China Shanghai 200129 China School of Electronics and Information Engineering Dalian University of Technology Dalian 116024 China

On the basis of aerial photos of sea ice in the Second Chinese NationalArctic Research Expdition during July and September 2003 in the area of 74.11°～79.56°N and144.17°～169.95°W, image processing techniques are used to acquire some geometric parameters offloes, such as fractal dimension, roundness and mean caliper diameter. Latitudinal variation ofmorphology of arctic ice floes is then obtained, after comparing fractal dimension and roundnesswhich represent geometry of floe edge, the latter is found to show a more obvious tendency withlatitude but still not enough to describe floe abrasion. Then mean caliper diameter of ice floe isused as characteristic size to analyze floe size distribution, the result reveals that cumulativeprobabilities of floe sizes agree well with a power-law function, and distribution dimension isgenerally in the range of 1.05～1.25 and slightly increases as the latitude increases. Howeverslight curvatures are still observed in the plots of cumulative probabilities as in formerresearches, which can be attributed to both the limitation of sampling area and effect ofthermodynamic process.

关键词： sea ice arctic ocean image processing fractals

Research on modeling of heat source for electron beam welding fusion-solidification zone

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Chinese Journal of Aeronautics 2013年第1期26卷 217-223页

作者： Wang Yajun Fu Pengfei Guan Yongjun lu zhijun Wei Yintao School of Mechanical Engineering and Automation Beihang University Science and Technology on Power Beam Processes Laboratory Beijing Aeronautical Manufacturing Technology Research Institute State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences State Key Laboratory of Automotive Safety and Energy Department of Automotive Engineering Tsinghua University

In this paper, the common heat source model of point and linear heat source in the numerical simulation of electron beam welding （EBW） were summarized and introduced. The combined point-linear heat source model was brought forward and to simulate the welding temperature fields of EBW and predicting the weld shape. The model parameters were put forward and regulated in the combined model, which included the ratio of point heat source to linear heat source Qpr and the distribution of linear heat source Lr. Based on the combined model, the welding temperature fields of EBW were investigated. The results show that the predicted weld shapes are conformable to those of the actual, the temperature fields are reasonable and correct by simulating with combined point-linear heat source model and the typical weld shapes are gained.

关键词： Electron beam welding (EBW) Fusion-solidification zone Heat source model Temperature fields Weld shape

Density dependence and habitat preference shape seedling survival in a subtropical forest in central China

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Journal of Plant Ecology 2015年第6期8卷 568-577页

作者： Junmeng lu Daniel J.Johnson Xiujuan Qiao zhijun lu Qinggang Wang Mingxi Jiang Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of Sciences1 Moshan RoadWuhanHubei 430074China Department of Life Science University of Chinese Academy of Sciences19A YuQuan RoadBeijing 100049China School of Forestry and Environmental Studies Yale University195 Prospect StreetNew HavenCT 06511USA

Aims seedlings are vulnerable to many kinds of fatal abiotic and biotic agents,and examining the causes of seedling dynamics can help understand mechanisms of species *** disentangle the relative importance of neighborhood densities,habitat factors and phylogenetic relatedness on focal seedling survival,we monitored the survival of 5306 seedlings of 104 species>15 *** address the following questions:(i)How do neighborhood densities,habitat variables and phylogenetic relatedness affect seedling survival?What is the relative importance of conspecific densities,habitat variables and phylogenetic relatedness to seedling survival?(ii)Does the importance of the neighborhood densities,habitat variables and phylogenetic relatedness vary among growth forms,leaf habits or dispersal modes?specially,does the conspecific negative density dependence inhibit tree and decidu-ous seedlings more compared with shrub and evergreen species?Does density dependence affect the wind and animal-dispersed species equally?Methods We established 135 census stations to monitor seedling dynamics in a 25-ha subtropical forest plot in central *** and heterospecific seedling density in the 1-m2 seedling plot and adult basal area within a 20-m radius provided neighborhood density *** elevation,convexity and aspect of every 5-×5-m grid with seedling plots were used to quantify habitat *** calculated the relative average phylodiversity between focal seed-ling and heterospecific neighbors to quantify the species related-ness in the *** candidate generalized linear mixed models with binominal error distribution were used to compare the relative importance of these variables to seedling ***’s information criteria were used to identify the most parsimonious *** Findingsat the community level,both the neighborhood densities and phylogenetic relatedness were important to seedling *** found negative effec

关键词： generalized linear mixed models negative density dependence niche partitioning phylodiversity seedling dynamics species coexistence

Disentangling the effects of topography and space on the distributions of dominant species in a subtropical forest

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Chinese Science Bulletin 2014年第35期59卷 5113-5122页

作者： Qinggang Wang Yaozhan Xu zhijun lu Dachuan Bao Yili Guo Junmeng lu Kuihan Zhang Haibo Liu Hongjie Meng Xiujuan Qiao Handong Huang Mingxi Jiang Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of Sciences University of Chinese Academy of Sciences

Topography and space are two important factors determining plant species assemblages in forest *** of the contribution of these two factors in determining species distribution helps us to evaluate their relative importance in determining species *** study aims to disentangle the effect of topography and space on the distributions of 14 dominant species in a subtropical mixed *** correlation analysis and the torustranslation test were used to test the species–habitat *** partitioning was used to quantify the relative contributions of topography and space at three sampling scales and three life *** analyses and torus-translation tests showed species abundance was mostly correlated with topographic wetness index,vertical distance from the channel network and *** partitioning showed that pure topography,pure space and spatially structured topography explained about 2.1 %,41.2 % and 13.8 %of the variation in species distributions,*** nine species,total topography fractions peaked in 20 m *** ten species,the pure space fractions peaked in 50 m *** many species,the total topography fraction andthe pure space fraction were larger for the most abundant life stages,which reflected the importance of sampling ***,some cases did not follow this trend suggesting that the effects of ecological processes such as habitat filtering,density dependence or dispersal limitation may exceed the sampling *** conclusion,we found that spatially structured topography and pure space primarily shaped the distribution of dominant tree ***,their effects were both scale- and life stage-dependent.

关键词：亚热带森林和空间优势种地形物种分布相关分析方差分解物种丰富度

Effects of topography on structuring species assemblages in a subtropical forest

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Journal of Plant Ecology 2017年第3期10卷 440-449页

作者： Qinggang Wang Ruwan Punchi-Manage zhijun lu Scott B.Franklin Zhiheng Wang Yaoqi Li Xiulian Chi Dachuan Bao Yili Guo Junmeng lu Yaozhan Xu Xiujuan Qiao Mingxi Jiang Key Laboratory of Aquatic Botany and Watershed Ecology Chinese Academy of SciencesWuhanHubei 430074PR China Department of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education College of Urban and Environmental SciencesPeking UniversityBeijing 100871PR China Department of Ecosystem Modeling University of GöttingenBüsgenweg 437077 GöttingenGermany Department of Ecological Modelling UFZ Helmholtz Centre for Environmental Research-UFZPF 50013604301 LeipzigGermany School of Biological Sciences University of Northern ColoradoGreeleyCO 80639-0017USA National Resource Center for Chinese Materia Medica China Academy of Chinese Medical SciencesBeijing 100700PR China College of Life Sciences University of Chinese Academy of SciencesBeijing 100049PR China

Aims Topography has long been recognized as an important factor in shaping species *** studies revealed that species may show species-habitat ***,few studies inves-tigate how species assemblages are associated with local habitats,and it still remains unclear how the community-habitat associa-tions vary with species abundance class and life *** this study,we analyzed the community-habitat associations in a subtropical montane *** The fully mapped 25-ha(500×500 m)forest plot is located in Badagongshan Nature Reserve in Hunan Province,Central *** was divided into 625(20×20 m)*** types were classified by multivariate regression tree analyses that cluster areas with similar species composition according to the topographic *** species analysis was used to identify the most important species for structuring species *** also compared the community-habitat associations for two levels of species abundances(*** and rare)and three different life stages(***,juveniles and adults),while accounting for sample size *** Findings The Badagongshan plot was divided into five distinct habitat types,which explained 34.7%of the variance in tree species *** with sample size taken into account,community-habi-tat associations for rare species were much weaker than those for abundant *** when accounting for sample size,very small differences were found in the variance explained by topography for the three life *** species of habitat types were mainly abundant species,and nearly all adult stage indicator species were also indicators in juvenile and sapling *** study manifested that topographical habitat filtering was important in shaping over-all local species ***,habitat filtering was not important in shaping rare species’distributions in this *** community-habitat association patterns in this fores

关键词： multivariate regression tree analysis habitat filtering rare species Badagongshan

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敦煌壁画中的古代举重活动

成都体育学院学报 2007年第3期33卷 34-35,39页

作者：路志峻兰州理工大学丝绸之路文化研究所

通过对敦煌莫高窟的考察发现,敦煌壁画和嶓画中生动形象地反映出古代举重活动,如举象、举钟、举车、举铁等。敦煌壁画中的举重运动是我国所见较为珍贵的举重形象资料,它具有重要的研究价值。

关键词：举重壁画幡画体育

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论敦煌文献和壁画中的儿童游戏与体育

敦煌学辑刊 2006年第4期4卷 85-88页

作者：路志峻兰州理工大学丝绸之路文史研究所甘肃兰州730050

无论是从社会生活角度、还是从艺术角度来研究儿童体育内容,都是非常有价值的。中国出土的古代文物表现儿童体育的材料极其有限,然而在敦煌文献与壁画中有很多有关儿童生活习惯、游戏、体育的珍贵材料,本文将对其中所体现的文化与精神... 详细信息

无论是从社会生活角度、还是从艺术角度来研究儿童体育内容,都是非常有价值的。中国出土的古代文物表现儿童体育的材料极其有限,然而在敦煌文献与壁画中有很多有关儿童生活习惯、游戏、体育的珍贵材料,本文将对其中所体现的文化与精神价值展开思考。

关键词：儿童壁画体育

C:N:P stoichiometry of Ericaceae species in shrubland biomes across Southern China:influences of climate,soil and species identity

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Journal of Plant Ecology 2019年第2期12卷 346-357页

作者： Qiang Zhang Qing Liu Huajun Yin Chunzhang Zhao Lin Zhang Guoying Zhou Chunying Yin zhijun lu Gaoming Xiong Yuelin Li Jiaxiang Li Wenting Xu Zhiyao Tang Zongqiang Xie State Key Laboratory of Vegetation and Environment Change Institute of BotanyChinese Academy of SciencesBeijing 100093China University of Chinese Academy of Sciences Beijing 100049China Key laboratory of Mountain Ecological Restoration and Bioresource Utilization&Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province Chengdu Institute of BiologyChinese Academy of SciencesChengdu 610041China Key Laboratory of Alpine Ecology and Biodiversity of Chinese Academy of Sciences Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Northwest Institute of Plateau Biology Chinese Academy of SciencesXining 810008 Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhan 430074China South China Botanical Garden Chinese Academy of SciencesGuangzhou 510650China College of Forest Central South University of Forestry&TechnologyChangsha 410004China Department of Ecology College of Urban and Environmental Sciences and Key Laboratory for Earth Surface ProcessesPeking UniversityBeijing 100871China

Aims Carbon(C),nitrogen(N)and phosphorus(P)stoichiometry strongly affect functions and nutrient cycling within ***,the related researches in shrubs were very *** this study,we aimed to inves-tigate leaf stoichiometry and its driving factors in shrubs,and whether stoichiometry significantly differs among closely related *** We analyzed leaf C,N and P concentrations and their ratios in 32 species of Ericaceae from 161 sites across southern *** examined the relationships of leaf stoichiometry with environmen-tal variables using linear regressions,and quantified the interactive and independent effects of climate,soil and species on foliar stoi-chiometry using general linear models(GLM).Important Findings The foliar C,N and P contents of Ericaceae were 484.66,14.44 and 1.06 mg g−1,*** C,N and P concentrations and their ratios in Ericaceae were significantly related with latitude and altitude,except the N:P insignificantly correlated with ***(mean annual temperature and precipitation)and soil properties(soil C,N and P and bulk density)were significantly influenced element *** GLM analysis showed that soil exerted a greater direct effect on leaf stoichiometry than climate did,and climate affected leaf traits mainly via indirect ***,soil properties had stronger influ-ences on leaf P than on leaf C and *** all independent factors examined,we found species accounted for the largest proportion of the variation in foliar *** results suggest that species can largely influence foliar stoichiometry,even at a lower taxonomic level.

关键词： biogeographic pattern phylogenetic effect closely related species,Ericoid Mycorrhiza shrub