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Stand dynamics of the drought-affected floodplain forests of Araguaia River,Brazilian Amazon

Forest Ecosystems 2017年第3期4卷 201-210页

作者： Jürgen Homeier Dariusz Kurzatkowski Christoph Leuschner plant Ecology Albrecht von Haller Institute for Plant Sciences University of Goettingen

Background： The floodplain forests of Araguaia River, a clear-water river in the southeastern Amazon（Tocantins State, Brazil）, are characterized by seasonal flooding up to 3.5 m height, low nutrient levels in the water, and seasonal drought periods of 4–5 ***： We studied the forest dynamics（tree diameter growth, tree mortality and recruitment） of this unique forest ecosystem over a 5-year period by repeated censuses in 12 permanent plots established along a flooding ***： The cumulative basal area in the plots increased by 0.84（±0.45） m^2·ha^-1·yr^-1（mean ±SD） in the annual y-flooded（AF） plots in lower terrain and by 0.69（±1.00） m^2·ha^-1·yr^-1 in the higher non-annual y flooded（NAF） plots, corresponding to an aboveground biomass increase of 0.81（±0.57） and 0.69（±1.58） Mg·ha^-1·yr^-1 in the AF and NAF plots, indicating a recent carbon sink in the biomass. Mean diameter growth rate was 1.8（±0.44） mm·yr^-1 in the AF and 2.0（±0.56） mm·yr^-1 in the NAF plots（corresponding to a coarse wood production of 1.53（±1.29） and 2.02（±0.52） Mg·ha^-1·yr^-1）,indicating no flooding effect on radial growth. Mean mortality rates in the 5-year period were 1.9（±0.37）·yr^-1 in the AF plots and 1.8（±0.87）%·yr^-1 in the NAF plots with no differences along the flooding gradient. Highest mortalities were registered in the AF plots for the 10–20 cm dbh class（2.4%·yr^-1）, likely as a consequence of flooding,and in the NAF plots for the 40–50 cm dbh class（3.0%·yr^-1）, probably mainly caused by ENSO-related ***： We conclude that these drought-affected tropical floodplain forests have a lower standing biomass and aboveground productivity than central Amazonian floodplain forests in more humid climates, and the imprint of the flooding gradient on stand dynamics is relatively weak, which may result from the lower flooding height and the interaction of flooding with low nutrient supply and periodic drought.

关键词： Amazon Diameter growth Dry season Flooding regime Mortality rate Productivity Tree recruitment

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Equations for estimating the above-ground biomass of Larix sibirica in the forest-steppe of Mongolia

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Journal of Forestry Research 2013年第3期24卷 431-437页

作者： Purevragchaa Battulga Jamsran Tsogtbaatar Choimaa Dulamsuren Markus Hauck institute of Geoecology Mongolian Academy of Sciences Chingeltei District Department of plant Ecology Albrecht von Haller Institute of Plant Sciences Georg August University of Gttingen

Biomass functions were established to estimate above-ground biomass of Siberian larch （Larix sibirica） in the Altai Mountains of Mon- golia. The functions are based on biomass sampling of trees from 18 different sites, which represent the driest locations within the natural range ofL. sibirica. The best performing regression model was found for the equations y = （D2 H）/（a＋bD） for stem biomass, y = aDb for branch biomass, and y=aDb Hc for needle biomass, where D is the stem diameter at breast height and H is the tree height. The robustness of the biomass functions is assessed by comparison with equations which had been previously published from a plantation in Iceland. There, y=aDb Hc was found to be the most significant model for stem and total above-ground biomasses. Applying the equations from Iceland for estimating the above-ground biomass of trees from Mongolia resulted in the underesti- mation of the biomass in large-diameter trees and the overestimation of the biomass in thin trees. The underestimation of thick-stemmed trees is probably attributable to the higher wood density, which has to be ex- pected under the ultracontinental climate of Mongolia compared to the euoceanic climate of Iceland. The overestimation of the biomass in trees with low stem diameter is probably due to the high density of young growth in the not systematically managed forests of the Mongolian Altai Mountains, which inhibits branching, whereas the plantations in Iceland are likely to have been planted in lower densities.

关键词： allometry biomass functions Central Asia forest-steppe Siberian larch

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Phylogenetic biogeography and taxonomy of disjunctly distributed bryophytes

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Journal of Systematics and Evolution 2009年第5期47卷 497-508页

作者： Jochen HEINRICHS Jrn HENTSCHEL Kathrin FELDBERG Andrea BOMBOSCH Harald SCHNEIDER Department of Systematic Botany Albrecht von Haller Institute of Plant SciencesGeorg-August-University Botany Department Natural History Museum

More than 200 research papers on the molecular phylogeny and phylogenetic biogeography of bryophytes have been published since the beginning of this *** papers corroborated assumptions of a complex genetic structure of morphologically circumscribed bryophytes,and raised reservations against many morphologically justified species concepts,especially within the ***,many molecular studies allowed for corrections and modifications of morphological classification *** studies reported that the phylogenetic structure of disjunctly distributed bryophyte species reflects their geographical ranges rather than morphological *** data led to new appraisals of distribution ranges and allowed for the reconstruction of refugia and migration *** ranges of bryophytes are often caused by dispersal rather than geographical *** distribution patterns of disjunct bryophytes are likely formed by processes such as short distance dispersal,rare long distance dispersal events,extinction,recolonization and diversification.

关键词： bryophytes cryptic speciation disjunctions divergence time estimates Diversity Arrays Technology DNA sequence variation isozymes molecular phylogeny.

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Response of tree-ring width to climate warming and selective logging in larch forests of the Mongolian Altai

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Journal of plant Ecology 2014年第1期7卷 24-38页

作者： Choimaa Dulamsuren Mookhor Khishigjargal Christoph Leuschner Markus Hauck Department of plant Ecology Albrecht von Haller Institute of Plant SciencesGeorg August University of GöttingenUntere Karspüle 237073 GöttingenGermany

Aims The Mongolian Altai is an old settlement area,which is populated by pastoral nomads since 2000–3000 *** in this region(at ca.2300 m a.s.l.)are highly fragmented and border on steppe and alpine grasslands,which are used for mobile livestock *** climate in Central Asia is warming to levels clearly above the global average,which affects the ***,the transition from planned to market economy and the decollectivization of livestock 20 years ago has strongly changed land use practices in Mongolia,especially resulting in an increase in recent logging *** were interested in the question how climate warming and selective logging influence the annual stem growth and the stand *** The impact of climate and land use by the pastoral nomads on the annual stem increment of more than 1800 trees of Siberian larch(Larix sibirica)was *** groups of trees with divergent growth trends depending on the social position and stand history were identified by non-metric multidimensional scaling and analysis of ***-term trends in the annual stem increment were analyzed by establishing separate regional growth curves for trees of different age *** Findings Instrumental climate data substantiate an increase of temperature by 2.1°C since 1940 at constant *** benefit from the increased ***–response analysis revealed that radial stem increment was promoted by the temperature in early summer,but also high precipitation in spring and in the year before tree-ring *** dynamics is also strongly influenced by anthropogenic *** addition to the natural forest dynamics,logging resulted in divergent growth trends within given age classes and habitats(forest interior and forest edge);overall,22 groups of trees with different characteristics in the annual radial stem increment were identified.A tree-ring series-based reconstruction of logging inten

关键词： climate change forest management forest-steppe ecotones Central Asia Larix sibirica

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Soil carbon and nutrient stocks under Scots pine plantations in comparison to European beech forests: a paired-plot study across forests with different management history and precipitation regimes

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Forest Ecosystems 2021年第3期8卷 628-643页

作者： Marco Diers Robert Weigel Heike Culmsee Christoph Leuschner plant Ecology Albrecht-von-Haller-Institute for Plant SciencesUniversity of GoettingenUntere Karspuele 237073 GoettingenGermany Centre of Biodiversity and Sustainable Land Use(CBL) University of GoettingenBuesgenweg 137077 GoettingenGermany

Background:Organic carbon stored in forest soils(SOC)represents an important element of the global C *** is thought that the C storage capacity of the stable pool can be enhanced by increasing forest productivity,but empirical evidence in support of this assumption from forests differing in tree species and productivity,while stocking on similar substrate,is ***:We determined the stocks of SOC and macro-nutrients(nitrogen,phosphorus,calcium,potassium and magnesium)in nine paired European beech/Scots pine stands on similar Pleistocene sandy substrates across a precipitation gradient(560–820mm∙yr−1)in northern Germany and explored the influence of tree species,forest history,climate,and soil pH on SOC and nutrient ***:While the organic layer stored on average about 80%more C under pine than beech,the pools of SOC and total N in the total profile(organic layer plus mineral soil measured to 60 cm and extrapolated to 100 cm)were greater under pine by about 40%and 20%,*** contrasts with a higher annual production of foliar litter and a much higher fine root biomass in beech stands,indicating that soil C sequestration is unrelated to the production of leaf litter and fine roots in these stands on Pleistocene sandy *** pools of available P and basic cations tended to be higher under *** precipitation nor temperature influenced the SOC pool,whereas tree species was a key *** extended data set(which included additional pine stands established more recently on former agricultural soil)revealed that,besides tree species identity,forest continuity is an important factor determining the SOC and nutrient pools of these ***:We conclude that tree species identity can exert a considerable influence on the stocks of SOC and macronutrients,which may be unrelated to productivity but closely linked to species-specific forest management histories,thus masking weaker climate and soil chemistry effects on pool sizes

关键词： Basic cations Fagus sylvatica Forest history Nitrogen Paired plots Pinus sylvestris Productivity effect Soil organic carbon Tree species effect

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Microtopography causes small-scale variation in harvest and forage quality of high-yielding silage grassland in northern Germany

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Grassland Research 2024年第1期3卷 33-42页

作者： Angelika Mroncz Johannes Isselstein Martin Komainda Christoph Leuschner Department of plant Ecology Albrecht von Haller Institute for Plant SciencesUniversity of GoettingenGöttingenGermany Department of Crop sciences Grassland ScienceUniversity of GoettingenGöttingenGermany

Background:Local sward dieback,especially in grasslands on peat soil,in response to the extreme 2018/2019 drought demonstrates climate vulnerability of intensive grasslands in northern Central ***:We explore the inﬂuence of microtopography,that is,the within-ﬁeld mosaic of depressions and elevated patches,on soil volumetric moisture content,standing biomass and biomass crude protein(CP)andﬁbre content in intensively managed grassland on peat soil in a moist year(2021)and a dry year(2022)for quantifying small-scale spatial heterogeneity within aﬁ***:We found high within-ﬁeld variation in soil moisture,biomass and forage quality and a moisture dependence of productivity that was stronger in the dry *** ranged from 10%to 25%within aﬁeld,being lower in moist depressions than elevated patches in the wet(but not in the dry)***:The moister depressions help to limit the overall productivity decline in dry summers,whereas,in moist summers,the higher dry patches produce more protein-rich forage than the depressions,where productivity is higher but quality is *** recommend adapting grassland management to this heterogeneity through spatially differentiated management regimes in order to better cope with an increasingly drier and more variable climate.

关键词： biomass map dairy farming drought elevation differences protein content silage grassland soil

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Functional Cooperativity of Enzymes of Phosphoinositide Conversion According to Synergistic Effects on Pectin Secretion in Tobacco Pollen Tubes

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Molecular plant 2010年第5期3卷 870-881页

作者： Till Ischebeck Linh Hai Vu Xu Jin Irene Stenzel Christian Lofke Ingo Heilmann Department of plant Biochemistry Albrecht-von-Haller-lnstitute for Plant Sciences Georg-August-University Gottingen Justus-von-Liebig-Weg 11 37077 Guttingen Germany Present address: Center for Biochemistry Cologne University Joseph-Stelzmann-Straβe 52 50931 Cologne Germany Present address: Department of Forest Botany Georg-August-University Gottingen Busgenweg 2 37077 Gottingen Germany Present address: Department of plant Cell Biology Albrecht-von-Haller-lnstitute for Plant Sciences Georg-August-University Gottingen Untere Karspule 2 37073 Gottingen Germany

The Arabidopsis phosphoinositide kinases PI4Kβ1 and PIP5K5 have been implicated in the control of directional vesicle trafficking underlying polar tip growth in pollen tubes. PI4Kβ1 and PIP5K5 catalyze key consecutive steps of phosphoinositide conversion, and it appears obvious that phosphatidylinositol-4-phosphate formed by PI4Kβ1 might act as a substrate for phosphatidylinositol-4,5-bisphosphate formation by PIP5K5. However, this hypothesis has not been experimentally addressed and distinct localization patterns of PI4Kβ1, PIP5K5, and also PI-synthases （PIS） generating phosphatidylinositol suggest additional complexity. Here, the synergistic functionality of enzymes of phosphoinositide conversion was assessed. In tobacco and Arabidopsis pollen tubes, phosphoinositides influence the apical secretion of pectin, and increased pectin deposition results in characteristic morphological alterations. Catalytically active and dominant negative variants of PI4Kβ1 and PIP5K5 were systematically co-expressed in tobacco pollen tubes and the incidence of morphologies related to enhanced pectin secretion was evaluated. The data support a proposed functional interplay of PI4Kβ1 and PIP5K5 at the trans-Golgi network, mediating directional vesicle trafficking. Co-expression experiments additionally including PIS isoforms, PIS1 or PIS2, indicate that pectin secretion is synergistically mediated by PI4Kβ1 and PIPSK5 acting on Ptdlns formed by PIS2 rather than PIS1. Possible ramifications for the preferential channeling of phosphoinositide intermediates between particular isoforms of PI pathway enzymes are discussed.

关键词： Phosphatidylinositol synthase phosphatidylinositol 4-kinase phosphatidylinositol-4-phosphate 5-kinase cooperativity pectin secretion pollen tubes.

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Vitality variation and population structure of a riparian forest in the lower reaches of the Tarim River,NW China

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Journal of Forestry Research 2018年第3期29卷 742-753页

作者： Maierdang Keyimu Umut Halik Florian Betz Choimaa Dulamsuren Key Laboratory of Oasis Ecology College of Resources and Environmental ScienceXinjiang UniversityUrumqi 830046China Faculty of Mathematics and Geography Catholic University of Eichstatt-Ingolstadt85072 EichstattGermany Department of plant Ecology and Ecosystems Research Albrecht von Haller Institute for Plant SciencesGeorg August University of Gottingen37073 GottingenGermany

Since 2000, the Chinese government has implemented emergency water diversion measures to restore the damaged riparian forest ecosystem with dominant tree species Euphrat poplar(Populus euphratica Oliv.)at the lower reaches of the Tarim River. In the present study, comparative analysis of variations in the vitality of P. euphratica trees were made using 2005 and 2010 data to illustrate the revitalization process of riparian forest. Poplar trees within 300 m of the riverbed were positively revitalized, while the vitality of trees farther than 300 m from the river decreased. Population structure was studied to demonstrate the development of poplar community. In the first belt, the class structure for the diameter at breast height(DBH) of P. euphratica fit a logistic model, and the 2nd, 3rd and 4th belt curve fittings were close to a Gaussian model; in other plots they were bimodal. Cluster analysis of the composition of the DBH class of poplar trees demonstrated that those within 16–36 cm DBH were the most abundant(58.49% of total) in study area, under 16 cm of DBH were second(31.36%), and trees >40 cm DBH were the least abundant(10.15%). More than 80% of the trees were young and medium-sized, which means that the poplar forest community in the vicinity of the lower Tarim River is at a stable developmental stage. The abundance of juvenile trees of P. euphratica in the first and second measuring belts was 12.13% in 2005 and increased to 25.52% in 2010, which means that the emergency water transfer had a positive impact on the generation of young P. euphratica trees in the vicinity of the river.

关键词： Lower Tarim River Riparian forest ecosystem Populus euphratica Vitality Population structure Diameter at breast height

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Phosphoinositide and Inositolpolyphosphate Signalling in Defense Responses of Arabidopsis thaliana Challenged by Mechanical Wounding

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Molecular plant 2008年第2期1卷 249-261页

作者： Alina Mosblech Sabine Konig Irene Stenzel Peter Grzeganek Ivo Feussner Ingo Heilmann Department of plant Biochemistry Albrecht-yon-Hailer-Institute for Plant Sciences Georg-August-University G6ttingen Justus-von-Liebig-Weg 1137077 G6ttingen Germany

Various biochemical signals are implicated in Arabidopsis wound signalling, including jasmonic acid （JA）, salicylic acid, auxin, and Ca^2＋. Here, we report on cross-talk of phytohormones with phosphoinositide signals not previously implicated in plant wound responses. Within 30 min of mechanical wounding of Arabidopsis rosette-leaves, the levels of the lipid-derived soluble inositolpolyphosphate, inositol 1,4,5-trisphosphate （InsP3）, increased four to five-fold. Concom- itantly, the precursor lipids, phosphatidylinositol 4,5-bisphosphate, phosphatidylinositol 4-phosphate and phosphatidylinositol transiently depleted, followed by re-synthesis after 30-60 min of stimulation. Increased InsP3 levels with wounding coincided with JA increases over the first hours of stimulation. In dde2-2-mutant plants deficient in JA biosynthesis, no InsP3 increase was observed upon wounding, indicating that JA was required for InsP3 formation, and InsP3 levels increased in wild-type plants challenged with sorbitol, increasing endogenous JA levels. In InsP 5-ptase plants with attenuated phosphoinositide signalling, the induction of wounding-inducible genes was diminished compared with wildtype plants, suggesting a role for phosphoinositide signalling in mediating plant wound responses. The gene-expression patterns suggest that phosphoinositides contribute to both JA-dependent and JA-independent aspects of wound signalling. Weight gain of Plutella xylostella caterpillars feeding on InsP 5-ptase plants was increased compared with that of caterpillars feeding on wild-type plants. The ecophysiological relevance of phosphoinositide signals in plant defense responses to herbivory is discussed in light of recent findings of inositolpolyphosphate involvement in phytohormone-receptor function.

关键词： Phosphoinositide and Inositolpolyphosphate Signalling Arabidopsis Mechanical Wounding

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DNA Damage-Induced Transcription of Transposable Elements and Long Non-coding RNAs in Arabidopsis Is Rare and ATM-Dependent

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Molecular plant 2016年第8期9卷 1142-1155页

作者： Zhenxing Wang Rainer Schwacke Reinhard Kunze institute of Biology - Applied Genetics Dahlem Centre of Plant Sciences - DCPS Freie Universit~t Berlin Albrecht-Thaler-Weg 6 14195 Berlin Germany Forschungszentrum JQlich GmbH Institute of Bio- and Geosciences Plant Sciences (IBG-2) 52425 JQlich Germany

Induction and mobilization of transposable elements （TEs） following DNA damage or other stresses has been reported in prokaryotes and eukaryotes. Recently it was discovered that eukaryotic TEs are frequently associated with long non-coding RNAs （IncRNAs）, many of which are also upregulated by stress. Yet, it is unknown whether DNA damage-induced transcriptional activation of TEs and IncRNAs occurs sporadically or is a synchronized, genome-wide response. Here we investigated the transcriptome of Arabidopsis wild- type （WT） and ataxia telangiectasia mutated （atm） mutant plants 3 h after induction of DNA damage. In WT, expression of 5.2% of the protein-coding genes is 〉 2-fold changed, whereas in atm plants, only 2.6% of these genes are regulated, and the response of genes associated with DNA repair, replication, and cell cy- cle is largely lost. In contrast, only less than 0.6% of TEs and IncRNAs respond to DNA damage in WT plants, and the regulation of 〉95% of them is ATM-dependent. The ATM-downstream factors BRCA1, DRM1, JMJ30, AGO2, and the ATM-independent AGO4 participate in the regulation of individual TEs and IncRNAs. Remarkably, protein-coding genes located adjacent to DNA damage-responsive TEs and IncRNAs are frequently coexpressed, which is consistent with the hypothesis that TEs and IncRNAs located close to genes commonly function as controlling elements.

关键词： Arabidopsis thaliana ataxia telangiectasia mutated DNA damage response transposable element,long non-coding RNA

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