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Crown and leaf traits as predictors of subtropical tree sapling growth rates

Journal of Plant Ecology 2017年第1期10卷 136-145页

作者： Ying Li Wenzel Kröber helge Bruelheide werner härdtle Goddert von Oheimb Faculty of Sustainability Leuphana University LüneburgInstitute of EcologyScharnhorststraße 1D-21335 LüneburgGermany Martin Luther University halle Wittenberg Institute of Biology/Geobotany and Botanical GardenAm Kirchtor 1D-06108 HalleGermany German Centre of Integrative Biodiversity Research(iDiv)halle-Jena-Leipzig Deutscher Platz 5eD-04103 LeipzigGermany Faculty of Environmental Sciences Technische Universität DresdenInstitute of General Ecology and Environmental ProtectionPienner Straße 7D-01735 TharandtGermany

Aims Growth rates of plants are driven by factors that influence the amount of resources captured and the efficiency of resource *** trees,the amount of light captured and the efficiency of light use strongly depends on crown characteristics and leaf *** theory predicts that both crown and leaf traits affect tree growth,few studies have yet to integrate these two types of traits to explain species-specific growth *** 37 broad-leaved tree species of subtropical forests in SE China,we investigated how interspecific differences in wood volume growth rates were affected by crown and leaf *** tested the hypotheses that(i)larger crown dimensions promote growth rates,(ii)species-specific growth rates are positively related to leaf stomatal conductance,leaf water potential and leaf chemical components,and negatively related to leaf C/N and leaf toughness and(iii)the two sets of traits better explain growth rates in combination than either *** Our study was conducted in a large-scale forest Biodiversity and Ecosystem Functioning experiment in China(BEF-China),located in a mountainous region in Jiangxi *** related 17 functional traits(two crown dimension and three crown structure traits;six physiological and six morphological leaf traits)to the mean annual growth rate of wood volume of young trees of the studied *** between crown and leaf traits were analyzed using principal component *** linear regression analysis was used to test the effect of each trait *** used multiple regression analysis to establish the relationship of growth rate to each set of traits(crown traits,physiological and morphological leaf traits)and to the combination of all types of *** coefficients of determination(R^(2)_(adj))of the best multiple regression models were compared to determine the relative explanatory power of crown and leaf traits and a combination of *** Findings The species-spec

关键词： BEF China crown characteristics physiological leaf traits morphological leaf traits wood volume

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Interspecific and intraspecific variation in specific root length drives aboveground biodiversity effects in young experimental forest stands

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Journal of Plant Ecology 2017年第1期10卷 158-169页

作者： Wensheng Bu Bernhard Schmid Xiaojuan Liu Ying Li werner härdtle Goddert von Oheimb Yu Liang Zhenkai Sun Yuanyuan huang helge Bruelheide Keping Ma State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China College of Forestry Jiangxi Agricultural UniversityNanchang 330045China Department of Evolutionary Biology and Environmental Studies University of ZürichWinterthurerstr.190Zürich 8057Switzerland Institute of Ecology Leuphana University LüneburgScharnhorststr.1Lüneburg 21335Germany Institute of General Ecology and Environmental Protection Technische Universität DresdenPienner Str.7Tharandt 01737Germany Institute of Biology/Geobotany and Botanical Garden Martin Luther University Halle-WittenbergAm Kirchtor 1Halle 06120Germany German Centre for Integrative Biodiversity Research(iDiv)halle-Jena-Leipzig DeutscherPlatz 5eLeipzig 04103Germany

Aims Although the net biodiversity effect(NE)can be statistically partitioned into complementarity and selection effects(CE and SE),there are different underlying mechanisms that can cause a certain *** objective was to assess the role of resource partitioning and species interactions as two important mechanisms that can bring about CEs by interspecific and intraspecific trait *** We measured tree height of 2493 living individuals in 57 plots and specific root length(SRL)on first-order roots of 368 of these individuals across different species richness levels(1,2,4,8 species)in a large-scale forest biodiversity and ecosystem functioning experiment in subtropical China(BEF-China)established in *** describe the effects of resource partitioning between species by a fixed component of interspecific functional diversity(RaoQ)and further effects of species interactions by variable components of interspecific and intraspecific functional diversity(community weighted trait similarity and trait dissimilarity,CWS and CWD).Finally,we examined the relationships between biodiversity effects on stand-level tree height and functional diversity(RaoQ,CWS and CWD)in SRL using linear regression and assessed the relative importance of these three components of functional diversity in explaining the diversity *** Findings Our results show that species richness significantly affected SRL in five and tree height in ten out of 16 species.A positive NE was generally brought about by a positive CE on stand-level tree height and related to high values of RaoQ and CWS in SRL.A positive CE was related to high values of all three components of root functional diversity(RaoQ,CWS and CWD).Our study suggests that both resource partitioning and species interactions are the underlying mechanisms of biodiversity effects on stand-level tree growth in subtropical forest.

关键词： aboveground complementarity effects belowground resource partitioning biodiversity and ecosystem functioning species interactions tree height

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Impact of tree diversity and environmental conditions on the survival of shrub species in a forest biodiversity experiment in subtropical China

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Journal of Plant Ecology 2017年第1期10卷 179-189页

作者： Bo Yang Ying Li Bingyang Ding Sabine Both Alexandra Erfmeier werner härdtle Keping Ma Bernhard Schmid Thomas Scholten Gunnar Seidler Goddert von Oheimb Xuefei Yang helge Bruelheide Institute of Biology/Geobotany and Botanical Garden Martin Luther University Halle-WittenbergAm Kirchtor 106120 HalleGermany Key Laboratory of Speciality Plant Resources of Jiangxi Province Jingdezhen University838 Cidu AvenueJingdezhenJiangxi 333000China Faculty of Sustainability Institute of EcologyLeuphana University LüneburgScharnhorststr 121335 LüneburgGermany College of Life and Environmental Sciences Wenzhou UniversityWenzhouZhejiang 325035China Institute of Biological and Environmental Sciences University of Aberdeen23 St Machar DriveAberdeen AB243UUUK Institute for Ecosystem Research GeobotanyKiel UniversityOlshausenstr 7524118 KielGermany German Centre for Integrative Biodiversity Research(iDiv)halle-Jena-Leipzig Deutscher Platz 5e04103 LeipzigGermany State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of Sciences20 NanxincunXiangshanBeijing 100093China Institute of Evolutionary Biology and Environmental Studies University of ZürichWinterthurerstr 1908057 ZürichSwitzerland Department of Geosciences Chair of Soil Science and GeomorphologyEberhard Karls University TübingenRümelinstraße19-23D-72070 TübingenGermany Technische Universität Dresden Institute of General Ecology and Environmental ProtectionPienner Straße 701737 TharandtGermany Key Laboratory of Biodiversity and Biogeography Kunming Institute of BotanyCAS KunmingKunming 650201China

Aims Although shrubs are an important component of forests,their role has not yet been considered in forest biodiversity *** the biodiversity-ecosystem functioning(BEF)experiment with subtropical tree species in south-east China(BEF-China),we factorially combined tree with shrub species-diversity ***,we tested the hypotheses that shrub survival differs between the 10 planted shrub species,with lower survival rates of late-than early-successional species and is affected by environmental conditions,such as topography and top soil characteristics,as well as by biotic factors,represented by tree,shrub and herb layer *** We analyzed the survival of 42000 shrub individuals in 105 plots varying in tree and shrub species richness of the BEF-China project four years after *** survival was analyzed with generalized linear mixed effects models at the level of individuals and with variance partitioning at the plot *** intercept and random slope models of different explanatory variables were compared with respect to the Bayesian Information Criterion(BIC).Important Findings Survival rates differed largely between the 10 shrub species,ranging from 26%to 91%for Ardisia crenata and Distylium buxifolium,*** of species identity,single abiotic factors explained up to 5%of species survival,with a negative effect of altitude and slope inclination and a positive effect of the topsoil carbon to nitrogen ratio,which pointed to drought as the major cause of shrub *** contrast,neither tree nor shrub richness affected shrub survival at this early stage of the *** the biotic predictors,only herb layer species richness and cover of the dominant fern species(Dicranopteris pedata)affected shrub ***,our models that included all variables could explain about 65%in shrub survival,with environmental variables being most influential,followed by shrub species identity,while tree speci

关键词： BEF-China biodiversity-ecosystem functioning experiment forest herb layer plant survival shrub species richness

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On the combined effect of soil fertility and topography on tree growth in subtropical forest ecosystems—a study from SE China

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Journal of Plant Ecology 2017年第1期10卷 111-127页

作者： Thomas Scholten Philipp Goebes Peter Kühn Steffen Seitz Thorsten Assmann Jürgen Bauhus helge Bruelheide Francois Buscot Alexandra Erfmeier Markus Fischer werner härdtle Jin-Sheng he Keping Ma Pascal A.Niklaus Michael Scherer-Lorenzen Bernhard Schmid Xuezheng Shi Zhengshan Song Goddert von Oheimb Christian Wirth Tesfaye Wubet Karsten Schmidt Department of Geosciences Soil Science and GeomorphologyUniversity of TübingenRümelinstraße 19-2372070 TübingenGermany Institute of Ecology Leuphana University LüneburgScharnhorststr.121335 LüneburgGermany Faculty of Forest and Environmental Sciences SilvicultureUniversity of FreiburgTennenbacherstraße 479085 Freiburg im BreisgauGermany Institute of Biology/Geobotany and Botanical Garden Martin Luther University Halle WittenbergAm Kirchtor 106108 HalleGermany German Centre for Integrative Biodiversity Research(iDiv)halle-Jena-Leipzig Deutscher Platz 5e04103 LeipzigGermany helmholtz Centre for Environmental Research UFZ Theodor-Lieser-Straße 406120 HalleGermany Department of Plant Sciences University of BernAltenbergrain 213013 BernSwitzerland Peking University No.5 Yiheyuan RoadHaidian DistrictBeijing 100871China Institute of Botany Chinese Academy of SciencesNo.20 NanxincunXiangshanBeijing 100093China Institute of Evolutionary Biology and Environmental Studies University of ZürichWinterthurerstrasse 1908057 ZürichSwitzerland Faculty of Biology Department of GeobotanyUniversity of FreiburgSchänzlestraße 179104 FreiburgGermany Institute of Soil Science Chinese Academy of SciencesNo.71 East Beijing RoadNanjingChina TU Dresden Biodiversity and Nature ConservationPienner Straße 701737 TharandtGermany Department of Systematic Botany and Functional Biodiversity University of LeipzigJohannisallee 2104103 LeipzigGermany

Aims The aim of our research was to understand small-scale effects of topography and soil fertility on tree growth in a forest biodiversity and ecosystem functioning(BEF)experiment in subtropical SE *** Geomorphometric terrain analyses were carried out at a spatial resolution of 5×5 *** samples of different depth increments and data on tree height were collected from a total of 566 plots(667 m2 each).The soils were analyzed for carbon(soil organic carbon[SOC]),nitrogen,acidity,cation exchange capacity(CEC),exchangeable cations and base saturation as soil fertility *** plots were classified into geomorphological *** of variance and linear regressions were applied to all terrain,soil fertility and tree growth *** Findings In general,young and shallow soils and relatively small differences in stable soil properties suggest that soil erosion has truncated the soils to a large extent over the whole area of the *** explains the concurrently increasing CEC and SOC stocks downslope,in hollows and in ***,colluvial,carbon-rich sediments are missing widely due to the convexity of the footslopes caused by uplift and removal of eroded sediments by adjacent *** results showed that soil fertility is mainly influenced by ***-Carlo flow accumulation(MCCA),curvature,slope and aspect significantly affected soil ***,soil fertility was affected by the different geomorphological positions on the experimental sites with ridge and spur positions showing lower exchangeable base cation contents,especially potassium(K),due to *** geomorphological effect of soil fertility is most pronounced in the topsoil and decreases when considering the subsoil down to 50 cm *** soil fertility attributes affect tree height after 1-2 years of growth,among which C stocks proved to be most important while ph_(KCl)and CEC only played minor ***,soil acidity and a hig

关键词： soil fertility topography soil erosion matter transport biodiversity DSM carbon stocks tree forest BEF-China China

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Quenching Simulation of PM Coated Tools

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材料热处理学报 2004年第05B期25卷 752-757页

作者： Axel htter werner Theisen Christoph Broeckmann Chair of Materials Technology Ruhr University Bochum GermanyChair of Materials Technology Ruhr University Bochum GermanyKoppern Entwicklungs-GmbH Hattingen Germany

hIP cladding is a powder metallurgical coating technique used in the production of wear parts and tools. In many cases the composite components consist of carbide-free hot-work steel as base material and wear resistant carbide-rich PM cold-work steel as coating material. To ensure operativeness a heat treatment matched to the substrate and coating material is required. Dissimilar phase transformation behaviour and different thermal expansion coefficients of layer and substrate entail inner stresses affecting the transformation kinetics in turn. In order to get a deeper insight into these effects Finite Element simulation tools are used. On the one hand, the transient heat conduction problem of the quenching process has to be solved. Non-linear boundary conditions and phase transformation of both, substrate and layer are considered. On the other hand, the mechanical response is calculated. The overall aim of the investigation is an improvement of common heat treatment techniques used for hIP cladded wear parts.

关键词：数值模拟淬火 hIP包覆磨损工具钢

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Integrated photonic systems based on transformation optics enabled gradient index devices

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Light(Science & Applications) 2012年第1期1卷 11-16页

作者： Qi Wu Jeremiah P Turpin Douglas h werner The Pennsylvania State University Department of Electrical EngineeringUniversity ParkPA 16802USA

Integrated photonics is expected to play an increasingly important role in optical communications,imaging,computing and sensing with the promise for significant reduction in the cost and weight of these *** advancement of this technology is critically dependent on an ability to develop compact and reliable optical components and facilitate their integration on a common *** we reveal,with the utility of the emerging transformation optics technique,that functional components composed of planar gradient index materials can be designed and readily integrated into photonic *** unprecedented design flexibility of transformation optics allows for the creation of a number of novel devices,such as a light source collimator,waveguide adapters and a waveguide crossing,which have broad applications in integrated photonic chips and are compatible with current fabrication *** the finite-difference time-domain method,we perform full-wave numerical simulations to demonstrate their superior optical performance and efficient integration with other components in an on-chip photonic *** components only require spatially-varying dielectric materials with no magnetic properties,facilitating low-loss,broadband operation in an integrated photonic environment.

关键词： gradient index material integrated photonic system quasi-conformal mapping transformation optics

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Drosophila, destroying angels, and deathcaps! Oh my! A review of mycotoxin tolerance in the genus Drosophila

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Frontiers in Biology 2018年第2期13卷 91-102页

作者： Clare h. Scott Chialvo Thomas werner Department of Biologtcal Sciences University of Alabama Tuscaloosa Alabama USA Department of Biological Sciences Michigan Technological University Houghton Michigan USA

BACKGROUND： Evolutionary novelties, be they morphological or biochemical, fascinate both scientists and non-scientists alike. These types of adaptations can significantly impact the biodiversity of the organisms in which they occur. While much work has been invested in the evolution of novel morphological traits, substantially less is known about the evolution of biochemical adaptations. METhODS： In this review, we present the results of literature searches relating to one such biochemical adaptation： α- amanitin tolerance/resistance in the genus Drosophila. RESULTS： Amatoxins, including α-amanitin, are one of several toxin classes found in Amanita mushrooms. They act by binding to RNA polymerase Ⅱ and inhibiting RNA transcription. Although these toxins are lethal to most eukaryotic organisms, 17 mushroom-feeding Drosophila species are tolerant of natural concentrations of amatoxins and can develop in toxic mushrooms. The use of toxic mushrooms allows these species to avoid infection by parasitic nematodes and lowers competition. Their amatoxin tolerance is not due to mutations that would inhibit α-amanitin from binding to RNA polymerase Ⅱ. Furthermore, the mushroom-feeding flies are able to detoxify the other toxin classes that occur in their mushroom hosts. In addition, resistance has evolved independently in several D. melanogaster strains. Only one of the strains exhibits resistance due to mutations in the target of the toxin. CONCLUSIONS： Given our current understanding of the evolutionary relationships among the mushroom-feeding flies, it appears that amatoxin tolerance evolved multiple times. Furthermore, independent lines of evidence suggest that multiple mechanisms confer α-amanitin tolerance/resistance in Drosophila.

关键词： Drosophila mushroom-feeding biochemical adaptations mushroom toxins cyclopeptides α-amanitin

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Exact orbital-free kinetic energy functional for general many-electron systems

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Frontiers of physics 2020年第2期15卷 87-92页

作者： Thomas Pope werner hofer School of Natural and Environmental Sciences Newcastle UniversityNewcastle NE17RUUnited Kingdom School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China

The exact form of the kinetic energy functional has remained elusive in orbital-free models of density functional theory(DFT).This has been the main stumbling block for the development of a general-purpose framework on this ***,we show that on the basis of a two-density model,which represents many-electron systems by mass density and spin density components,we can derive the exact form of such a *** exact functional is shown to contain previously suggested functionals to some extent,with the notable exception of the Thomas-Fermi kinetic energy functional.

关键词： condensed matter density functional theory(DFT) extended electrons

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Solving the dark-matter problem through dynamic interactions

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Frontiers of physics 2015年第6期10卷 1-5页

作者： werner A. hofer School of Mathematics and Statistics Newcastle University Newcastle upon Tyne NE1 7R U UK

Owing to the renewed interest in dark matter after the upgrade of the large hadron collider and its dedication to dark-matter research, it is timely to reassess the whole problem. Considering dark matter is one way to reconcile the discrepancy between the velocity of matter in the outer regions of galaxies and the observed galactic mass. Thus far, no credible candidate for dark matter has been identified. here, we develop a model accounting for observations by rotations and interactions between rotating objects analogous to magnetic fields and interactions with moving charges. The magnitude of these fields is described by a fundamental constant on the order of 10^-41kg^-1. The same interactions can be observed in the solar system, where they lead to small changes in planetary orbits.

关键词： galactic rotation curves dark matter solar system perihelion of Mercury nodes of Venus

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Uncertainty relations for general phase spaces

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Frontiers of physics 2016年第3期11卷 51-60页

作者： Reinhard F. werner Institut fiir Theoretische Physik Leibniz Universitiit Hannover Germany

We describe a setup for obtain!ing uncertainty relations for arbitrary pairs of observables related by a Fourier transform. The physical examples discussed here are the standard position and momentum, number and angle, finite qudit systems, and strings of qubits for quantum information applications. The uncertainty relations allow for an arbitrary choice of metric for the outcome distance, and the choice of an exponent distinguishing, e.g., absolute and root mean square deviations. The emphasis of this article is on developing a unified treatment, in which one observable takes on values in an arbitrary locally compact Abelian group and the other in the dual group. In all cases, the phase space symmetry implies the eciuality of measurement and preparation uncertainty bounds. There is also a straightforward method for determining the optimal bounds.

关键词： uncertainty relations phase space measurement uncertainty

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