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How competitive is the‘pioneer-climax’tree species Nothofagus alpina in pristine temperate forests of Chile?

Journal of Plant Ecology 2019年第1期12卷 144-156页

作者： Rebekka Bögelein Cecilia APérez philipp schäferand frank m.thomas Faculty of Regional and Environmental Sciences GeobotanyUniversity of TrierBehringstraße 2154296 TrierGermany Present address:Thünen-Institut Institut für WaldökosystemeAlfred-Möller-Straße 116225 EberswaldeGermany Departamento de Ecología de Ecosistemas Instituto de Ecología y Biodiversidad(IEB)Alameda 340SantiagoChile

Aims Nothofagus species are constitutive elements of the temperate forests along the Southern Andes *** deciduous Nothofagus alpina is a fast-growing,but long-lived opportunistic pioneer spe-cies(‘pioneer-climax species’)and co-occurs with the evergreen *** tested whether *** is competitively superior to *** in mature stands and whether intra-specific competition in *** is stronger than inter-specific competition with *** In a pristine old-growth forest in South-Central Chile,we compared the growth of *** trees in pure stands and in mixture with *** to the growth of *** and calculated compe-tition *** related growth variables to climate data and weather *** Findings In ***,juvenile basal area increment was signifi-cantly higher in pure than in mixed *** to our hypothesis,*** exhibited larger radial stem increments than *** in the most recent 40 *** the most recent two decades,this was caused by high growth rates of large *** *** both Nothofagus species,stem growth was negatively related to temperature,but *** responded more sensitively to weather conditions than *** ***,stem increment was negatively related to the intensity of competition,but the size of the competition effects on this species was similar in pure and mixed ***,compared to ***,the‘pioneer-climax species’concept is even more appropriate for *** with its relatively high growth rates even in the early stages of its life.

关键词： competition index dendroecology growth-competition relationship pointer year productivity tree-ring analysis

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Growth of the tropical Pinus kesiya as influenced by climate and nutrient availability along an elevational gradient

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Journal of Plant Ecology 2020年第1期13卷 97-106页

作者： Le Tuan Ho Raimund schneider frank m.thomas Department of Geobotany University of TrierFaculty of Regional and Environmental SciencesBehringstraße 2154296 TrierGermany Department of Forest Resources management Faculty of ForestryNong Lam University HCMCThu Duc DistrictHo Chi Minh CityVietnam Department of Soil Science University of TrierFaculty of Regional and Environmental SciencesBehringstraße 2154296 TrierGermany

Aims In contrast to temperate regions,the reasons for growth reductions of individual tree species along elevational gradients in tropical mountain ranges are poorly known,especially for tropical *** aimed at testing whether climatic or edaphic conditions are responsible for the reduced growth of Pinus kesiya,a widely distributed pine species of southern and south-eastern Asia,at higher *** We analysed the stem diameter increment and the isotope discrimination against ^(13)C(△^(13)C)in tree rings of *** along an elevational gradient of~900 to~2000 m *** the mountain ranges of South-Central Vietnam,and related growth to△^(13)C and to climatic and edaphic *** findings We found no consistent correlation patterns between the basal area increment(BAI)of the trees and temperature or *** contrast,across the elevational gradient,we obtained significantly negative correlations of BAI with△^(13)C and with the C/N ratios and theδ^(15)N signature of the upper mineral *** was positively correlated with the concentrations of plant-available phosphorus(P_(a))and of“base”cations(calcium,magnesium,potassium)in the *** conclude that lower temperatures at higher elevations exert an indirect effect on tree growth by inducing higher C/N ratios and by reducing the rate of nitrogen(N)and P mineralization,which may be further hampered by lower concentrations of“base”cations(upon enhanced leaching by precipitation)and a negative feedback from low availability of mineralized N and P at higher *** results may be transferable to the uppermost growth limit of *** and to other montane regions of the species’occurrence.

关键词： dendroecology pine pointer year soil nutrient stable isotope

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Stand structure and productivity of Populus euphratica along a gradient of groundwater distances at the tarim River(NW china)

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Journal of Plant Ecology 2017年第5期10卷 753-764页

作者： frank m.thomas michael Jeschke Ximing Zhang Petra Lang Geobotany Faculty of Regional and Environmental SciencesUniversity of TrierBehringstraße 2154296 TrierGermany Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences40 South Beijing Road830011 UrumqiChina

Aims Along central-Asian rivers in arid regions,lowering of the ground-water level constitutes a major threat to the riparian forests,whose tree layers are dominated by Euphrates poplar(Populus euphratica).Some of these fragile ecosystems are supplied with additional(‘eco-logical’)water for protection and *** investigated interrelationships among groundwater distance,stand structure and above-ground wood production(at the tree and the stand level)in *** stands along a groundwater gradient(distances of 2.0-12.0 m)that also included a plot supplied with‘ecological water’.methods We measured the height,diameter at breast height and basal area of poplar trees and determined the annual above-ground wood production for the three most recent years on the basis of tree-ring analyses and allometric regressions at three sites at the upper,mid-dle and lower reaches of the tarim River,Xinjiang,NW *** Findingsthe distribution of age classes differed significantly among the plots:in accordance with their life histories,stands growing at a larger distance to the groundwater harboured a larger fraction of old trees(>80 years)and,in most cases,a smaller fraction of young trees(≤20 years).the annual above-ground wood production per ha was highest on a plot with a short groundwater distance(2.0 m;maxi-mum of the 3-year investigation period:3.0 t ha−1 a−1)and lowest,at a plot with a large distance to the water table(6.6 m;minimum:0.23 t ha^(−1)a^(−1)).However,the plot located close to the groundwater(and to the river)at the middle reaches exhibited a relatively large interannual variation in above-ground wood production,which can be attributed to interannual variations in the river *** the middle and the lower reaches,these interannual variations on plots with the most favourable water supply were even more obvious at the tree *** the fraction of mature trees(60-99 years old),no significant differences in above-ground wood production were

关键词： allometry ground water life history tree-age distribution tugai forest

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Weather or weathering?Growth of Nothofagus dombeyi on volcanic soils differing in nitrogen and phosphorus concentrations

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Journal of Plant Ecology 2016年第5期9卷 596-607页

作者： Christoph Walter Cecilia A.Pérez frank m.thomas Faculty of Regional and Environmental Sciences GeobotanyUniversity of TrierBehringstraße 2154296 TrierGermany Departamento de Ecología de Ecosistemas Instituto de Ecología y Biodiversidad(IEB)Alameda 340SantiagoChile

Aims We tested whether—in addition to weather conditions—the concentrations of nitrogen and phosphorus in the substrate have an effect on the radial stem increment of Nothofagus dombeyi trees in old-growth forest stands on volcanic soil at the western slopes of the Andes in South-Central *** We took soil samples and tree increment cores from five proximate sites(1000-1300 m a.s.l.)that are located in the volcanic region of the Conguillío National Park and differ in the age of the substrate(miocene—3500 years B.P.)and in its concentrations of nitrogen(N)and phosphorus(P).The soil samples were also analysed on their concentrations of other plant mineral nutrients,carbon(C)and nitrogen isotope ratios(δ^(15)N).Tree-ring widths and the stem basal area increment(BAI)were related to climate *** selected tree rings,the stable isotope ratios of carbon(δ^(13)C)and oxygen(δ^(18)O)were determined and related to growth and climate *** FindingsConsistent with theory,the soils on the oldest substrate showed the highest(least negative)δ^(15)N values,but mineral N was the only nutrient whose concentration exhibited a straightforward(increasing)relationship with increasing substrate *** BAI was largest on the soil with the highest concentration of plant-available *** contrast to BAI,tree-ring chronologies did not differ among the study ***,tree-ring chronologies and BAI exhibited significantly positive correlations with summer precipitation,and negative correlations,with summer(December)temperature.A negative correlation was found betweenδ^(13)C and precipitation anomalies in the growing season(November-march).We interpret the negative correlations between growth and temperature,and betweenδ^(13)C andδ^(18)O in the tree rings,as an impairment of net carbon assimilation by anomalously warm weather conditions during the growing *** conclude that the growth of *** is mainly affected by high temperature and low precipitation

关键词： Andisol annual ring dendroecology temperate broadleaf forest weather anomalies

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Regulation of the water status in three co-occurring phreatophytes at the southern fringe of the Taklamakan Desert

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Journal of Plant Ecology 2008年第4期1卷 227-235页

作者： frank m.thomas Andrea Foetzki Dirk Gries Helge Bruelheide Xiangyi Li Fanjiang Zeng Ximing Zhang Department of Plant Ecology Albrecht von Haller Institute for Plant SciencesGeorg-August-Universitat GottingenUntere Karspule 237073 GottingenGermany Present address:Department of Geobotany University of TrierBehringstraße 2154296 TrierGermany Eidgenossisches Institut fur Agrarokologie und Landwirtschaft Forschungsanstalt AgroscopeReckenholzstrasse 1918046 ZurichSwitzerland Institute of Geobotany and Botanical Garden Martin Luther University Halle-WittenbergAm Kirchtor 106108 Halle(Saale)Germany Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences40 South Beijing Road830011 UrumqiChina

Aims We investigated the regulation of the water status in three predominant perennial C3 phreatophytes(Alhagi sparsifolia,Populus euphratica,Tamarix ramosissima)at typical sites of their occurrence at the southern fringe of the hyperarid Taklamakan Desert(north-west China).methods In the foreland of the river oasis of Qira(Cele),we determined meteorological variables,plant biomass production,plant water potentials(WL)and the water flux through the *** calculated the hydraulic conductance on the flow path from the soil to the leaves(kSL)and tested the effects of kSL,WL and the leaf-to-air difference in the partial pressure of water vapour(Dw)on stomatal regulation using regression *** Findings Despite high values of plant water potential at the point of turgor loss,all plants sustained WL at levels that were high enough to maintain transpiration throughout the growing *** ***,stomatal resistance(rs;related to leaf area or leaf mass)was most closely correlated with kSL;whereas in ***,~70%of the variation in rs was explained by *** ***,leaf area-related rs was significantly correlated with WL and *** regulation mechanisms are in accordance with the growth patterns and the occurrence of the species in relation to their distance to the ground water.

关键词： aboveground growth extreme aridity stomatal conductance transpirational demand vapour pressure deficit

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Clones or no clones：genetic structure of riparian Populus euphratica forests in Central Asia

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Journal of Arid Land 2018年第5期10卷 750-766页

作者： Katja KRAmP thomas schmITT Petra LANG michael JEschKE philipp schAFERI Dustin KULANEK ZHANG Ximing YU Ruide frank m.thomas Senckenberg German Entomological Institute Eberswalder StraBe 90 Muncheberg 15374 Germany Department of Zoology Faculty Natural Sciences I Institute of Biology Martin Luther University Halle-Wittenberg Halle (SaMe) 06099 Germany Faculty of Regional and Environmental Sciences University of Trier Campus II BehringstraBe 21 Trier 54296 Germany Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China Sino-German Joint Research Center for the management of Ecosystems and Environmental Changes in Arid Lands (mEECAL) Urumqi 830011 China

many riparian（Tugai） forests growing along rivers in arid and hyper-arid regions of Central Asia are dominated by the Euphrates poplar（Populus euphratica）. Besides generative reproduction, which is only possible upon flooding events and at a distance to the groundwater of less than 2 m, this phreatophytic tree species also reproduces vegetatively by forming clones that can cover land surface areas of several hectares. Along a gradient of groundwater distances, we investigated whether the fraction of clones in P. euphratica stands（1） increases with increasing distance to the water table;（2） is higher if supplied with water via river cut-offs; and（3） approaches 100% at a short distance to the groundwater, but at high salt concentrations in the upper soil layers, which would prevent germination and establishment of seedlings. AFLP（Amplified Fragment Length Polymorphism） analyses were conducted on leaf samples taken from mature P. euphratica trees growing at the fringes of the Taklimakan Desert in stands with different distances（2–12 m） to the groundwater at two plots at the middle and the lower reaches of the Tarim River and in a stand close to Ebinur Lake, Xinjiang, China. Genetic diversity was large among plots, but considerably smaller within plots. We found the highest genetic diversity（caused by regeneration from seeds） at plots that have a short distance to the groundwater or are supplied with additional water. There was no significant relationship between groundwater distance and clonal fraction. All investigated trees at the saline Ebinur Lake site belonged to one single clone. Our results demonstrate that the genetic pattern of this widespread species is not easily predictable even over small distances as it is a result of a complex interplay of stand history and dispersal of propagules（pollen, seeds, and vegetative diaspores） by wind and water. In conservation and restoration schemes, P. euphratica stands with a high genetic diversity and stands that grow at

关键词： clonality floodplain forest ground water phreatophyte population genetics rejuvenation salinity

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Influence of groundwater depth on species composition and community structure in the transition zone of Cele oasis

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Journal of Arid Land 2010年第4期2卷 235-242页

作者： frank m. thomas Department of Geobotany University of Trier Behringstraβe 21 54296 Trier Germany

The paper analyzes the hypothesis that the distribution of dominant plant species and characteristics of plant communities are related to groundwater depth. The results showed that variations of groundwater depth impacted distributions and characteristics of dominant plant communities. However, besides groundwater depth, the community composition and species diversity were also influenced by physiognomy of the habitat. Based on the similarity coefficient, the differences between dominant plant communities were significant at different groundwater depths. Compared with other results relating to desert vegetation and groundwater depth, variations of community distribution were similar at the large spatial scale. However, in this extremely arid region, there were significant differences in community type and community succession when compared with other arid regions, especially in relationship to deep groundwater depth. With groundwater depth from deep to shallow, communities transformed with the sequence of Alhagi communities, Tamarix spp. communities, Populus communities, Phragmites communities, and Sophora communities. At groundwater depth of less than 6.0 m, the community type and composition changed, and the species diversity increased. Among these dominant species, Tamarix exhibited the biggest efficiency in resource utilization according to niche breadth, which means it possessed the best adaptability to environmental conditions at the oasis margins.

关键词： groundwater depth community characteristic niche breadth oases Taklamakan desert

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Influence of structural depth of laser-patterned steel surfaces on the solid lubricity of carbon nanoparticle coatings

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Friction 2023年第7期11卷 1276-1291页

作者： Timothy mACLUCAS Lukas DAUT philipp GRÜTZmACHER maria Agustina GUITAR Volker PRESSER Carsten GACHOT Sebastian SUAREZ frank mÜCKLICH Chair of Functional materials Saarland UniversitySaarbrücken 66123Germany Institute for Engineering Design and Product Development TU WienWien 1060Austria INm–Leibniz Institute for New materials Saarbrücken 66123Germany Department of materials Science&Engineering Saarland UniversitySaarbrücken 66123Germany Saarene-Saarland Center for Energy materials and Sustainability Saarbrücken 66123Germany

Carbon nanoparticle coatings on laser-patterned stainless-steel surfaces present a solid lubrication system where the pattern's recessions act as lubricant-retaining *** study investigates the influence of the structural depth of line patterns coated with multi-walled carbon nanotubes(CNTs)and carbon onions(COs)on their respective potential to reduce friction and *** laser interference patterning(DLIP)with a pulse duration of 12 ps is used to create line patterns with three different structural depths at a periodicity of 3.5μm on AISI 304 steel ***,electrophoretic deposition(EPD)is applied to form homogeneous carbon nanoparticle coatings on the patterned *** ball-on-disc experiments are conducted on the as-described surfaces with an alumina counter body at a load of 100 *** results show that the shallower the coated structure,the lower its coefficient of friction(COF),regardless of the particle ***,with a minimum of just below 0.20,CNTs reach lower COF values than COs over most of the testing *** resulting wear tracks are characterized by scanning electron microscopy,transmission electron microscopy,and energy-dispersive X-ray *** friction testing,the CNTs remain in contact,and the immediate proximity,whereas the CO coating is largely *** of structural depth,no oxidation occurs on CNT-coated surfaces,whereas minor oxidation is detected on CO-coated wear tracks.

关键词： solid lubricant coatings carbon nanotubes carbon onions direct laser interference patterning(DLIP)surface structuring electrophoretic deposition(EPD)

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Changes in higher order aberrations after central corneal regularization-a comparative two-year analysis of a semiautomated topography-guided photorefractive keratectomy combined with corneal cross-linking

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Eye and Vision 2020年第1期7卷 99-108页

作者： Katja C.Iselin philipp B.Baenninger Lucas m.Bachmann frank Bochmann michael A.Thiel Claude Kaufmann Department of Ophthalmology Lucerne Cantonal HospitalLucerneSwitzerland medignition Healthcare Innovations ZurichSwitzerland

Background:The optical quality in progressive keratoconus deteriorates due to ectasia and distortion of the corneal shape and *** corneal cross-linking(CXL)aims at stopping disease progression,“CXL-Plus”combines CXL with excimer laser ablation to improve visual *** Corneal Regularization(CCR)represents a therapeutic excimer laser modality specifically designed to smoothen the ectatic corneal shape and to reduce higher order aberrations(HOA).We set out to compare CXL-Plus,consisting of CXL combined with CCR,with CXL by itself for patients with progressive ***:Retrospective 2-year matched group analysis of patients who either underwent CXL-Plus(n=28)or CXL as a sole procedure(n=28)for progressive *** outcome parameters were HOA,visual function and tomographic results 12 and 24 months ***:After 12 months,the total HOA root mean square wavefront error was reduced from 0.79±0.30 to 0.40±0.19μm(CXL-Plus;pm 0.71±0.28 to 0.73±0.36μm(CXL;p=0.814).Uncorrected distance visual acuity improved from 0.70±0.35 to 0.36±0.29 logmAR(CXL-Plus;p=0.0002)and from 0.65±0.39 to 0.46±0.37 logmAR(CXL;p=0.067),translating to gains of three or more lines in 50%(CXL-Plus)and 36%(CXL)of *** steepest keratometry value(Kmax)regressed by 5.84 D(CXL-Plus;pmeters a statistically significant change could be shown between 12 and 24 ***:CXL-Plus in the form of a CCR reduces HOA and Kmax more effectively than CXL as a sole procedure.

关键词： Keratoconus Corneal cross-linking CXL-plus Photorefractive keratectomy Central corneal regularization Higher order aberrations Coma-like aberrations

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Prospective observational multicenter study to define a diagnostic algorithm for biliary candidiasis

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World Journal of Gastroenterology 2014年第34期20卷 12260-12268页

作者： philipp Lenz Franziska Eckelskemper thomas Erichsen Tim Lankisch Alexander Dechêne Gabriele Lubritz frank Lenze Torsten Beyna Hansjorg Ullerich Andre schmedt Dirk Domagk Department of medicine B University of MuensterD-48149 MuensterGermany Department of Gastroenterology Hepatology and EndocrinologyHannover Medical School30625 HannoverGermany Department of Gastroenterology and Hepatology University Hospital Essen45147 EssenGermany Institute of medical microbiology University Hospital MuensterD-48149 MuensterGermany

AIm:To develop an algorithm to improve the diagnosis and treatment of patients with biliary ***:We performed a prospective study of 127patients who underwent endoscopic retrograde cholangiopancreatography,for various biliary disorders,at 3 tertiary referral centers in Germany from July 2011through July 2012(***:NCT01109550).Bile,buccal,and stool samples were *** indicated,endoscopic transpapillary bile duct biopsies were performed to clarify the etiology of bile duct strictures and to prove invasive fungal ***:Candida species were detected in 38 of the 127 bile samples(29.9%).By multivariate analysis patients’age and previous endoscopic sphincterotomy were independent risk factors for biliary candidiasis(Pmmunosuppression(P=0.058)and recent long-term antibiotic therapy(>7 d)(P=0.089)tend to be at risk for biliary *** patient was negative in mycological culture of bile fluid but invasive biliary candidiasis was diagnosed *** Candida subspecies detected,36.7%were azole-resistant,such as C *** patients received anti-mycotic therapy,based on our *** these,3 had cancer with biliary tract involvement,2had secondary sclerosing cholangitis,1 had retroperitoneal fibrosis,and 5 had *** all patients contamination was ruled out by smears of the endoscope ***:Gastroenterologists should be aware of frequent candida colonization in patients with cholangitis and biliary *** suggested algorithm facilitates the further clinical management.

关键词： Cholangitis Biliary candidiasis Invasive fungal infection Biliary obstruction

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