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| 1 | On the combined effect of soil fertility and topography on tree growth in subtropical forest ecosystems—a study from SE China显示文摘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 China.Methods Geomorphometric terrain analyses were carried out at a spatial resolution of 5×5 m.Soil 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 attributes.All plots were classified into geomorphological units.Analyses of variance and linear regressions were applied to all terrain,soil fertility and tree growth attributes.Important 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 experiment.This explains the concurrently increasing CEC and SOC stocks downslope,in hollows and in valleys.However,colluvial,carbon-rich sediments are missing widely due to the convexity of the footslopes caused by uplift and removal of eroded sediments by adjacent waterways.The results showed that soil fertility is mainly influenced by topography.Monte-Carlo flow accumulation(MCCA),curvature,slope and aspect significantly affected soil fertility.Furthermore,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 leaching.This geomorphological effect of soil fertility is most pronounced in the topsoil and decreases when considering the subsoil down to 50 cm depth.Few 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 roles.Nevertheless,soil acidity and a high proportion of Al on the exchange complex affected tree height even after only 1-2 years growth.Hence,our study showed that forest nutrition is coupled to a recycling of litter nutrients,and does not only depend on subsequent supply of nutrients from the mineral soil.Besides soil fertility,topography affected tree height.We found that especially MCCA as indicator of water availability affected tree growth at small-scale,as well as aspect.Overall,our synthesis on the interrelation between fertility,topography and tree growth in a subtropical forest ecosystem in SE China showed that topographic heterogeneity lead to ecological gradients across geomorphological positions.In this respect,small-scale soil-plant interactions in a young forest can serve as a driver for the future development of vegetation and biodiversity control on soil fertility.In addition,it shows that terrain attributes should be accounted for in ecological research. | 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 | 2017 | Journal of Plant Ecology2017，10，1： | 22 |
| 2 | Interspecific and intraspecific variation in specific root length drives aboveground biodiversity effects in young experimental forest stands显示文摘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 partitioning.Our 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 variation.Methods 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 2009.We 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 effects.Important 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. | Wensheng Bu Bernhard Schmid Xiaojuan Liu Ying Li Werner Härdtle Goddert von Oheimb Yu Liang Zhenkai Sun Yuanyuan Huang Helge Bruelheide Keping Ma | 2017 | Journal of Plant Ecology2017，10，1： | 18 |
| 3 | Positive effects of tree species richness on fine-root production in a subtropical forest in SE-China显示文摘Aims Fine roots play an important role in the biogeochemical cycles of terrestrial ecosystems and are vital for understanding forest ecosystem functioning and services.Higher plant species diversity has been largely reported to increase aboveground community biomass,but how biodiversity affects fine-root production and the related mechanisms in forests remain unclear.In this study,we aim to answer two questions:(i)does fine-root production increase with tree species richness?(ii)Can this effect be explained by niche complementarity among species?Methods We analyzed data from a large forest biodiversity experiment(BEF-China)with 5-year-old trees.Fine-root growth was measured as standing biomass and annual fine-root regrowth was estimated using ingrowth cores.Moreover,relative yield was calculated to test whether over-or under-yielding occurred when mixtures were compared with the average monoculture of the species included in the mixtures.We calculated functional diversity for fine-root(≤2 mm in diameter)traits by Rao’s quadratic entropy index for each species mixture.The effects of manipulated tree species richness and identity on fine-root traits were analyzed with linear mixed-effects models.Mixed models were also used to test the relationships between tree species richness and fine-root standing biomass,annual regrowth and vertical heterogeneity.Important Findings Fine roots of more than one species were found in half of the soil cores in mixtures indicating that belowground interactions in these young forest stands occurred much earlier than canopy closure.We found significant differences among species in fine-root traits such as diameter and specific root length(SRL),which suggested different resource-use strategies and niche partitioning among species.Mean fine-root diameter of species ranged from 0.31 to 0.74 mm,mean SRL ranged from 12.43 m·g^(−1)to 70.22 m·g^(−1)and mean vertical distribution indexβranged from 0.68 to 0.93.There was a significant positive relationship between species richness and the evenness of the vertical distribution of fine-root standing biomass.Moreover,marginally significant positive relationships existed between species richness and standing biomass as well as annual regrowth of fine roots.Relative yields and Rao’s quadratic entropy index were both not significantly affected by species richness.However,the relative yield of fine-root standing biomass was marginally correlated with Rao’s quadratic entropy index,implying that belowground niche complementarity between species does contribute to diversity effects.In conclusion,our study showed positive effects of species richness on the filling of soil volume by fine roots in the studied experimental forest communities.This has positive effects on fine-root standing biomass and may also lead to increased aboveground biomass. | Zhenkai Sun Xiaojuan Liu Bernhard Schmid Helge Bruelheide Wensheng Bu Keping Ma | 2017 | Journal of Plant Ecology2017，10，1： | 14 |
| 4 | Leaf area increases with species richness in young experimental stands of subtropical trees显示文摘Aims Most biodiversity-ecosystem functioning research has been carried out in grassland ecosystems,and little is known about whether forest ecosystems,in particular outside the temperate zone,respond similarly.Here,we tested whether productivity,assessed as leaf area index(LAI),increases with species richness in young experimental stands of subtropical trees,whether this response is similar for early-season leaf area(which is dominated by evergreens)and seasonal leaf area increase(which is dominated by deciduous species),and whether responses saturate at high species richness.Methods We used a planted tree biodiversity experiment in south-east China to test our hypotheses.LAI was determined three times by digital hemispheric photography in 144 plots that had been planted with 400 trees each,forming communities with 1,2,4,8 or 16 tree species.Important Findings LAI increased significantly with tree species richness in the fifth year of stand establishment.Similar,but weaker,statistically non-significant trends were observed 1 year before.We did not observe leaf area overyielding and the presence of particularly productive and unproductive species explained large amounts of variation in leaf area,suggesting that selection-type effects contributed substantially to the biodiversity effects we found in this early phase of stand establishment.Effects sizes were moderate to large and comparable in magnitude to the ones reported for grassland ecosystems.Subtropical(and tropical)forests harbor substantial parts of global net primary production and are critical for the Earth’s carbon and hydrological cycle,and our results suggest that tree diversity critically supports these ecosystem services. | Siyi Peng Bernhard Schmid Josephine Haase Pascal A.Niklaus | 2017 | Journal of Plant Ecology2017，10，1： | 13 |
| 5 | Seasonal characteristics and determinants of tree growth in a Chinese subtropical forest显示文摘Aims To quantify the seasonal differences in effects of leaf habit,species identity,initial diameter,neighborhood interaction and stand environment on tree absolute diameter growth rates in a subtropical forest in China.Methods We used man-made dendrometer bands to record radial increments of all trees with diameter at breast height(DBH)≥5 cm and height≥3 m within 25 comparative study plots(30×30 m for each)of the‘Biodiversity-Ecosystem Functioning Experiment China’(BEF-China)in the Gutianshan National Nature Reserve,Zhejiang Province,China.We measured stem circumferences twice a year from 2011 to 2014 to calculate absolute diameter growth rate of a warm and wet season(WWS,April to September)and a dry and cold season(DCS,October to the next March)for each individual tree:annual growth(GR_(year)),growth during the WWS(GR_(WWS))and growth during the DCS(GR_(DCS)).We firstly tested the differences in growth rates between different seasons using paired t-tests with Bonferroni correction.Then we applied linear mixed models to explore the effects of leaf habit,species identity,initial diameter,neighborhood interaction(indicated by richness,density and total basal area of all neighboring trees within a radius of 5 m around target trees),stand age and topography(elevation,slope and aspect)on tree growth rates of the two different seasons in three deciduous and 14 evergreen species.Important Findings GR_(year),GR_(WWS)and GR_(DCS)varied between 0.04-0.50 cm year^(−1)(mean=0.21),0.03-0.46 cm season^(−1)(mean=0.18)and 0.01-0.05 cm season^(−1)(mean=0.03)across the 17 species,respectively.GR_(WWS)was significantly higher than GR_(DCS)for all species.Growth rates of faster growing species tended to have larger absolute differences between the WWS and DCS.Tree growth rates of both seasons and of the year(GR_(year),GR_(WWS)and GR_(DCS))varied significantly among leaf habit and species,and increased allometrically with initial diameter,decreased with stand age,but were not significantly related to topography and neighborhood richness or density.GR_(WWS)decreased with neighborhood total basal area,while GR_(DCS)did not.In conclusion,species might the temporally complementary,contributing to plot growth at different times of the year. | Xiulian Chi Qiang Guo Jingyun Fang Bernhard Schmid Zhiyao Tang | 2017 | Journal of Plant Ecology2017，10，1： | 11 |
| 6 | Species-specific effects of genetic diversity and species diversity of experimental communities on early tree performance显示文摘Aims Changing biodiversity can affect ecosystem functioning.However,the role of genetic diversity within species,relative to the one of species diversity,has hardly been addressed.Methods To address the effects of both genetic diversity and species diversity during the important stage of early tree life,we used eight seed families(SF)taken from each of 12 evergreen and deciduous tree species of subtropical forest to perform a factorial experiment.We established 264 communities of 16 trees each.Each community had a species diversity of either one or four species and a genetic diversity of either one,two or four SF per species.We measured plant survival,growth rate,final biomass and herbivory 20 months after sowing.Important Findings Species differed from each other in biomass,growth rate,herbivory and survival(P<0.001).Deciduous species tended to have much higher biomass(P<0.1)and experienced higher herbivory(P<0.05)than evergreen species.Species diversity affected the performance of different species differently(species diversity by species interaction,P<0.001 for all variables but survival).Biomass differed between SF and increasing genetic diversity from one to two,and from two to four,SF per species increased biomass for some species and decreased it for others(P<0.001).Our study showed pronounced species-specific responses of early tree performance to species diversity and less pronounced responses to genetic diversity.These species-specific responses suggest feedbacks of species diversity and genetic diversity on future species composition. | Xueqin Zeng Walter Durka Markus Fischer | 2017 | Journal of Plant Ecology2017，10，1： | 8 |
| 7 | Impact of tree diversity and environmental conditions on the survival of shrub species in a forest biodiversity experiment in subtropical China显示文摘Aims Although shrubs are an important component of forests,their role has not yet been considered in forest biodiversity experiments.In the biodiversity-ecosystem functioning(BEF)experiment with subtropical tree species in south-east China(BEF-China),we factorially combined tree with shrub species-diversity treatments.Here,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 characteristics.Methods 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 planting.Shrub survival was analyzed with generalized linear mixed effects models at the level of individuals and with variance partitioning at the plot level.Random 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,respectively.Irrespective 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 mortality.In contrast,neither tree nor shrub richness affected shrub survival at this early stage of the experiment.Among the biotic predictors,only herb layer species richness and cover of the dominant fern species(Dicranopteris pedata)affected shrub survival.Overall,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 species diversity(species richness and identity)and herb layer characteristics contributed much less.Thus,in this early stage of the experiment the biotic interactions among shrubs and between shrubs and trees have not yet overruled the impact of abiotic environmental factors. | 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 | 2017 | Journal of Plant Ecology2017，10，1： | 7 |
| 8 | 林下引入耐阴树种功能性状特征及其与生长的关系显示文摘植物功能性状之间的协调性揭示了其适应特定生境的主要策略,而植物早期生长与功能性状可能具有很大关联性。为探讨林下引入耐阴树种的根、茎、叶功能性状协调性及其与生长的关系,研究了杉木人工林林下引入5种常绿阔叶树种(洒金叶珊瑚、杨桐、蚊母树、栀子和海桐)的生长率(树高和地径相对增长率)以及27个根茎叶形态、生理性状指标。结果表明:(1)由主成分分析(Principal component analysis,PCA)可知耐阴树种种间根茎功能性状关联更紧密。此外,种间根、茎性状的变异系数均小于叶面积;(2)耐阴树种种间和种内关键性状与生长率网络关联性差异较大。在种间水平上,生长率与大部分叶性状显著正相关,与根茎性状多为显著负相关;在种内水平上,关键性状与生长率关系网更加复杂;(3)树高相对增长率是种间和种内关系网中心性最高的生长率指标。种间中心性最高的性状指标是叶面积;叶、茎生物量占比和根干物质含量是种内中心性最高的性状指标。但只有叶面积与树高相对增长率在种间和种内均显著正相关,因此,叶面积更适合作为指示林下耐阴树种生长率变化的性状。总体上,耐阴树种叶性状对生长率的调控要强于根茎性状,其中引入较大叶面积的常绿阔叶树种可能更有利于杉木纯林的人促更新和高效复层林的构建。 | 徐海东 查美琴 成向荣 汤胜 周恒发 虞木奎 | 2020 | 生态学报2020，40，19： | 6 |
| 9 | Tree diversity and nectar composition affect arthropod visitors on extrafloral nectaries in a diversity experiment显示文摘Aims Plants with extrafloral nectaries(EFNs)are common in tropical and subtropical habitats and,despite many other arthropods also forage for EFN,most studies solely focused on the defense mutualisms between EFN plants and ants.This study aims at a quantitative assessment of the entire arthropod community that visits EFN trees to compare visitor communities between different tree species to disentangle the mechanisms that may drive EFN visitor community composition.We also test for tree diversity effects on EFN visitors,as it is unknown if local tree species richness relates to the abundance and species richness of arthropods foraging for EFN.Methods We sampled EFN-visiting arthropods in the experimental tree species richness gradient of the BEF-China Experiment,the currently largest forest diversity experiment in the world,and tested if tree species richness affects EFN visitors and if visitor community composition differs between EFN tree species.In a second step,we analyzed the EFN of Ailanthus altissima and Triadica cochinchinensis,the two EFN tree species with highest visitor abundance,for sugars and amino acids(AA)to test if tree species-specific differences in nectar chemistry translate to differing visitor communities.Lastly,we conducted a choice experiment using different artificial nectar solutions to test if nectar quality affects foraging decisions of ants,the most frequent EFN visitors in our study sites.Important Findings EFN trees in young successional forests in subtropical South-East China are visited by a diverse assemblage of arthropods including ants,beetles,flies,and spiders.Albeit ants accounted for about 75%of all individuals,non-ant visitors were by far more species rich.Visitor abundance and species richness declined with increasing tree species richness,suggesting a resource dilution effect,because plots with more tree species had proportionally less EFN tree individuals and thus lower nectar availability.Ailanthus altissima and T.cochinchinensis were visited by different arthropods and their nectar had species-specific AA composition and sugar concentration,indicating that differences in visitors may,at least partly,be explained by differences in nectar chemistry.These findings are supported by the choice experiment,in which artificial nectars containing sugar solutions supplemented with essential AAs attracted more ants than pure sugar solutions or sugar solutions supplemented with non-essential AAs.Our results improve the understanding of the complex ecology of EFN trees,a plant life form that might be crucial for understanding how tree diversity influences patterns of tree growth in young successional tropical and subtropical forests. | Michael Staab Joel Methorst Jan Peters Nico Blüthgen Alexandra-Maria Klein | 2017 | Journal of Plant Ecology2017，10，1： | 6 |
| 10 | Asymmetric competition for light varies across functional groups显示文摘Aims Asymmetric competition for light may depress the growth rates(GRs)to different extents for different-sized tree individuals.Various responses of different functional groups to light availability result that tree individuals of different functional groups may experience different competition intensities,e.g.canopy and deciduous species grow faster and demand more light than understory and evergreen species.In this study,we estimated the effects of asymmetric competition for light using individual GRs and explored the effects of asymmetric competition on growth among different functional groups(e.g.canopy vs.understory species and deciduous vs.evergreen species).Methods We measured growth in circumference to determine the radial increments of a total of 2233 stems with diameter at breast height≥5.0 cm in a permanent plot(140×80 m^(2))located in a typical evergreen and deciduous broadleaved mixed forest on Mt Shennongjia,China.All of the measurements were carried out at~6-month intervals every April and October from 2012 to 2014,and biomass of each individual was calculated based on its diameter and species-specific allometry.We then calculated GRs of annual biomass growth(growth between October and the next October).Considering the hypothesis that asymmetric competition for light among trees of different sizes may result in a steeper allometric growth curve with increasing tree size,we further divided the sampled trees into different subsets according to their height,at intervals of 1 m,and then fitted the scaling relationship between the logarithm of the biomass GR(logGR)and the logarithm of diameter(logD)for each height class using standardized major axis regression.Finally,we used simple linear regression to test whether the scaling exponent was related to tree height.The above analyses were conducted for the annual growth of all tree species,canopy species,understory vs.treelets species and deciduous vs.evergreen species.Important findings We observed a concave curve for the relationship between logGR and logD with an increase in the scaling exponent between logGR and logD with increasing tree height.This pattern held for the annual growth of canopy species and deciduous species but not for the annual growth of understory species,treelets or evergreen species.These results suggest that asymmetric competition for light is more important in regulating the GRs of the fast-growing species,such as canopy species and deciduous species,than those of shade-tolerant species,such as understory species,treelets and evergreen species. | Qiang Guo Xiulian Chi Zongqiang Xie Zhiyao Tang | 2017 | Journal of Plant Ecology2017，10，1： | 5 |
| 11 | Limited tree richness effects on herb layer composition,richness and productivity in experimental forest stands显示文摘Aims In forests,the herbaceous understory vegetation plays an important role for ecosystem functioning as it represents a significant component of total aboveground productivity.In addition,the herb layer contributes to overall forest species richness and controls tree species regeneration.Vice versa,trees in the overstory control understory herb and shrub growth through competition for resources.Using an experimental forest plantation with manipulated tree richness,we asked to which degree tree species richness and identity affect herb layer composition,richness and productivity and how these relationships across strata change with abiotic environmental conditions and competition intensity.Methods In the context of the Biodiversity-Ecosystem Functioning project in subtropical China(BEF-China),we made use of the integrated BEFmod experiment arranged along a tree species richness gradient at two sites,with additional subplot treatments of phosphorus addition,herb layer weeding and no weeding.We recorded the understory vegetation and determined herb layer biomass production on a total of 201 subplots.Important Findings We found only minor effects of tree layer richness on herb layer species composition and no significant effect on herb layer richness or productivity yet.However,there were strong tree layer identity effects on all response variables,which were partly explained by differences in leaf area index and by a high share of woody species both in total herb layer species richness and biomass.There were strong treatment effects,which were largest in the‘no weeding’treatment but we did not find any treatment×tree layer richness interaction in herb layer responses.Thus,these effects are mainly explained by increased competition intensity within the herb layer in the absence of weeding.Despite the young age of the experiment,the interactions between tree species identity,tree richness and the herb layer did already emerge and can be expected to become stronger with ongoing runtime of the experiment. | Markus S.Germany Helge Bruelheide Alexandra Erfmeier | 2017 | Journal of Plant Ecology2017，10，1： | 4 |
| 12 | Heritability of early growth traits and their plasticity in 14 woody species of Chinese subtropical forest显示文摘Aims Genetic variation in plant traits represents the raw material for future adaptive evolution.Its extent can be estimated as heritability based on the performance of experimental plants of known relatedness,such as maternal half-sib seed families.While there is considerable heritability information for herbaceous plants and commercially important trees,little is known for woody species of natural subtropical forest.Moreover,it is open whether heritability is higher for species with r-or K-strategies,for more common species with larger distribution ranges than for rarer ones,or for populations closer to the centres of distributional ranges.Methods For 14 woody species in Chinese subtropical forest,we collected 13-38 maternal seed families,assessed seed size,grew replicates of each seed family in one more and one less benign nursery environment and measured stem diameter and plant height after 7 months.Important findings For the different species,plants grew 1.8-8.1 times taller in the more benign environment.For all 14 species,variation between seed families(and thus heritability)was significant(with very few exceptions at the P<0.001 level)for seed size and for stem diameter and plant height in both nurseries.Moreover,significant seed family by nursery interactions for stem diameter and plant height for all species(P<0.001)indicated significant heritability for plasticity in these traits.Multiple regression analysis suggests that heritabilities were higher for species with higher age at reproduction and higher wood density(traits indicating a K strategy)but also for species with higher specific leaf area(a trait rather indicating an r strategy).Furthermore,heritabilities were higher for species with larger range sizes,while there was no significant relationship between heritabilities and the distance of the study area to the range margins of our study species.In conclusion,the detected large heritability estimates suggest considerable potential for the evolution of plant performance and its plasticity for trees of subtropical forest.Moreover,our study shows that the simple method of comparing plants of different maternal seed families is valuable to address evolutionary ecological questions for so far understudied species. | Xueqin Zeng Walter Durka Erik Welk Markus Fischer | 2017 | Journal of Plant Ecology2017，10，1： | 4 |
| 13 | Biodiversity-ecosystem functioning research in Chinese subtropical forests显示文摘Worldwide,forests provide habitat for a large diversity of plants,animals and microbes.At the same time,forest ecosystems are essential providers of multiple ecosystem services important for human well-being.However,the relationship between biodiversity and ecosystem functioning has only been little researched in forests and therefore its role for the functioning of forest ecosystems and their services is not yet understood.If results from comparable studies in other ecosystems are considered(e.g.Balvanera et al.2006),it is conceivable that diverse forests would,for example,grow faster,produce more biomass,store more carbon and better maintain soil fertility and plant-insect interactions and functional stability than less diverse forests or monoculture tree plantations.The hypothesis that biodiversity increases and stabilizes interactions and functions is the common theme of the papers in the present issue of the Journal of Plant Ecology. | Keping Ma Jin-Sheng He Helge Bruelheide Alexandra-Maria Klein Xiaojuan Liu Bernhard Schmid | 2017 | Journal of Plant Ecology2017，10，1： | 3 |
| 14 | Preservation of nucleic acids by freeze-drying for next generation sequencing analyses of soil microbial communities显示文摘Aims Soil sample preservation is a challenging aspect in molecular studies on soil microbial communities.The demands for specialized sample storage equipment,chemicals and standardized protocols for nucleic acid extraction often require sample processing in a home laboratory that can be continents apart from sampling sites.Standard sampling procedures,especially when dealing with RNA,comprise immediate snap freezing of soils in liquid nitrogen and storage at−80℃until further processing.For these instances,organizing a reliable cooling chain to transport hundreds of soil samples between continents is very costly,if possible at all.In this study we tested the effect of soil sample preservation by freeze-drying with subsequent short-term storage at 4℃or ambient temperatures compared to−80℃freezing by comparative barcoding analyses of soil microbial communities.Methods Two grassland soil samples were collected in Central Germany in the Biodiversity Exploratory Hainich-Dün.Samples were freeze-dried or stored at−80℃as controls.Freeze-dried samples were stored at 4℃or ambient temperature.Investigated storage times for both storage temperatures were 1 and 7 days.Total DNA and RNA were extracted and bacterial and arbuscular mycorrhizal(AM)fungal communities were analyzed by amplicon 454 pyrosequencing of the 16S(V4-V5 variable region)and 18S(NS31-AM1 fragment)of ribosomal RNA(rRNA)marker genes,respectively.Important Findings Bacterial communities were sufficiently well preserved at the rDNA and rRNA level although storage effects showed as slightly decreased alpha diversity indices for the prolonged storage of freeze-dried samples for 7 days.AM fungal communities could be studied without significant changes at the rDNA and rRNA level.Our results suggest that proper sampling design followed by immediate freeze-drying of soil samples enables short-term transportation of soil samples across continents. | Christina Weißbecker François Buscot Tesfaye Wubet | 2017 | Journal of Plant Ecology2017，10，1： | 1 |
| 15 | Morphological characteristics of tree crowns of Cunninghamia lanceolata var. Luotian显示文摘The structural characteristics of the tree crowns of Cunninghamia lanceolata var. Luotian(herein, Luotian), a natural variety of C. lanceolata(Chinese-fir, herein Lanceolata) in China, were analyzed using trunk and branch measurements and biomass determinations. Samples from two typical cultivated varietal populations were collected, including twenty-six 15–23-year-old trees of Luotian from a plantation, and nine 16–23-year-old trees of Lanceolata. Our results show that Luotian and Lanceolata samples differed significantly in crown structure, morphological indices, and biomass:(1) the oldest live branches on Luotian trees were 5–6 years old and 8–11 years old on Lanceolata. The ages of the live branches were not affected by the ages of the Luotian trees, while live branch ages increased with ages of Lanceolata trees;(2) the maximumbranching order of Luotian was level two. Compared to Lanceolata, the average number of first-order lateral branches(i.e., branches emerging from the trunk) and the number of first-order lateral branch whorls per sample tree were 12.9% and 32.2% lower, respectively, in Luotian.However, the average number of branches within a single whorl was 21.8% greater in Luotian;the average number of branch whorls at crown height was 51.1% greater. Thus,the Luotian variety has thicker branches;(3) the average lateral branch angles in Luotian and Lanceolata sample trees were 105.2° and 61.4°, respectively. The branch angles in 53.0% of lateral branches on Luotian ranged from105° to 135°, but 30° to 90° in 96% of the lateral branches on Lanceolata. Within the same crown layer, the average branch angle was 1.6–2.2 times greater in Luotian, and the angle was directly proportional to crown thickness;(4) the average base diameter and branch length on Luotian were1.3 cm and 75.8 cm, respectively, and 1.6 cm and112.2 cm for Lanceolata. For individual trees, branch growth differed significantly(p < 0.01) between Luotian and Lanceolata. However, the lateral branches grew at a similar rate among Luotian trees of different ages;(5) the average height to the lowest live branch on Luotian was128.3% greater than on Lanceolata, resulting in a significant difference(p < 0.01) in crown size. Compared to the crowns on Lanceolata, the Luotian crowns were 45.3%higher and 41.1% wider, and the surface area, volume, and growth of the crown were 27.0%, 11.4%, and 2.4 times greater than for Lanceolata, respectively;and,(6) the biomass of Luotian and Lanceolata sample trees also differed significantly. The mean crown, branch, and leaf biomass for Luotian was 40.0%, 25.2%, and 54.1% of those for Lanceolata, respectively. However, the leaf biomass in each layer of the Luotian crown was higher thanthat of Lanceolata, and leaf biomass increased with crown thickness. | Yezhou Xu Chaoqun Du Guowei Huang Zhenfang Li Xiangyang Xu Jingjin Zheng Chu Wu | 2020 | Journal of Forestry Research2020，31，3： | 0 |
| 16 | 神木天坑不同小生境木本植物叶功能性状的差异与关联显示文摘为进一步探讨天坑生境下木本植物的生存策略,该研究以神木天坑不同小生境(底部、坑腰和边缘)的木本植物为对象,选取叶厚度、叶组织密度、叶面积等10个叶功能性状指标,运用单因素方差分析和相关性分析等方法,分析了天坑木本植物叶功能性状的变异特征以及小生境对木本植物叶功能性状的影响。结果表明:(1)在神木天坑木本植物10个叶功能性状中,叶面积变异系数最大(113.9%),叶碳含量变异系数最小(10.5%)。(2)天坑边缘、坑腰的乔木叶组织密度显著高于底部(P<0.05),天坑底部乔木、灌木的叶钾含量显著高于边缘(P<0.05),3种小生境中木质藤本未出现显著差异(P>0.05)。(3)不同小生境叶功能性状相关性存在一定差异,从天坑底部到边缘小生境,叶厚度与叶面积逐渐呈极显著正相关;主成分分析结果显示叶组织密度(-0.833)、叶钾含量(0.782)、叶干物质含量(-0.647)贡献较大,是神木天坑不同小生境木本植物叶功能性状的主要指标。综上认为,叶功能性状之间普遍关联,天坑木本植物通过对叶功能性状的权衡来适应不同小生境。该研究结果为了解植物对特殊生境的适应机制以及天坑植被的保护提供了理论指导。 | 余林兰 罗奕杏 薛跃规 安小菲 黄贵 刘昕宇 陈铭 | 2023 | 广西植物2023，43，3： | 0 |
| 17 | Effects of thinning on the understory light environment of different stands and the photosynthetic performance and growth of the reforestation species Phoebe bournei显示文摘Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in south China(a Cryptomeria japonica plantation,a Quercus acutissima plantation,and a mixed stand of both)and three thinning intensities to determine the best understory light environ-ment for 3-year-old Phoebe bournei seedlings.The canopy structure,understory light environment,and photosynthe-sis and growth indicators were assessed following thin-ning.Thinning improved canopy structure and understory light availability of each stand;species composition was the reason for differences in the understory light environ-ment.Under the same thinning intensity,the mixed stand had the greatest light radiation and most balanced spectral composition.P.bournei photosynthesis and growth were closely related to the light environment;all three stands required heavy thinning to create an effective and sustained understory light environment.In a suitable understory light environment,the efficiency of light interception,absorption,and use by seedlings was enhanced,resulting in a higher carbon assimilation the main limiting factor was stomatal conductance.As a shade-avoidance signal,red/far-red radia-tion is a critical factor driving changes in photosynthesis and growth of P.bournei seedlings,and a reduction increased light absorption and use capacity and height:diameter ratios.The growth advantage transformed from diameter to height,enabling seedlings to access more light.Our findings suggest that the regeneration of shade-tolerant species such as P.bournei could be enhanced if a targeted approach to thinning based on stand type was adopted. | Shicheng Su Nianqing Jin Xiaoli Wei | 2024 | Journal of Forestry Research2024，35，1： | 0 |
| 18 | 亚热带森林生物多样性与生态系统功能实验研究基地(BEF-China)研究进展显示文摘生物多样性与生态系统功能的关系(BEF)及其内在机制是当前生物多样性研究领域的热点问题。长期以来,以草地生态系统为主的BEF研究积累了大量研究成果,而基于森林生态系统的相关研究则相对较少。亚热带森林生物多样性与生态系统功能实验研究基地(BEF-China)是目前包含树种最多、涉及多样性水平最高的大型森林控制实验样地。该文总结了基于BEF-China平台的研究进展,特别是生物多样性对生态系统生产力、养分循环以及多营养级相互作用关系等方面的影响,并提出了未来BEF-China的研究应注重高通量测序和遥感等新兴技术的应用,在生物多样性的多维度、生态系统的多种组分与多种功能以及BEF研究的多种尺度等交叉方向上持续开展深入研究。针对BEF-China研究成果的梳理有助于理解驱动亚热带森林生物多样性与生态系统功能关系的内在机理,为生物多样性保护和生态修复提供科学依据。 | 李珊 刘晓娟 马克平 | 2023 | 广西植物2023，43，8： | 0 |
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