不同生活型被子植物功能性状与基因组大小的关系

基因组大小在被子植物物种之间存在着巨大的变异, 但目前对不同生活型被子植物功能性状与基因组大小的关系缺乏统一的认识。本研究基于被子植物245科2,226属11,215个物种的基因组大小数据, 探讨了不同生活型物种种子重量、最大植株高度和叶片氮、磷含量4个功能性状与基因组大小之间的关系。结果表明, 被子植物最大植株高度和种子重量与基因组大小间的关系在草本和木本植物中存在显著差异。草本植物最大植株高度与基因组大小的关系不显著, 但种子重量与其呈极显著的正相关关系。木本植物最大植株高度与基因组大小显著负相关, 但种子重量与其关系不显著。木本植物叶片氮含量与基因组大小呈显著正相关, 但其他生活型植物的叶片氮、磷含量与基因组大小均无显著相关性。本研究表明被子植物功能性状与基因组大小的相关性在不同生活型间存在差异, 这为深入研究植物多种功能性状和植物生活型与基因组大小的权衡关系在植物演化和生态适应中的作用提供了重要依据。     

植物功能性状对土壤保持的影响研究述评

植被对土壤保持具有重要的影响,但是从植物功能性状的角度总结评述植被对土壤保持影响的研究并不多见。总结评述了植物地上功能性状、地下功能性状对土壤保持功能的影响以及植物地上、地下功能性状的关系,认为:(1)植被地上部分功能性状对土壤保持的作用主要体现在对溅蚀、面蚀的影响及间接改变土壤理化性质等方面,其功能性状指标主要包括叶面积、叶长、叶宽、枝数、植被高度等;(2)植被地下部分功能性状对土壤保持的作用主要体现在固持土壤、提高土壤抗剪切强度、提高土壤抗侵蚀能力、增强土壤渗透性,植物根系固持土壤与根系抗拉能力密切相关,植物根系土壤的物理和水文性质,与细根比例、根长密度、根表面积等性状密切相关;(3)可以通过植物地上部分功能性状间接反映地下部分功能性状,但是现有研究多为定性认识;(4)在植物功能性状对土壤保持的研究中亟待加强植被地上地下功能性状的长期定位监测,深化植被功能性状尤其是根系特征与土壤保持的作用机理,加强植被地上部分、地下部分功能性状的定量表达,建立植被功能性状与土壤保持功能的定量关系,实现植被功能性状与土壤保持功能特征的动态链接。     

天坑森林植物群落叶功能性状、物种多样性和功能多样性特征

以天坑内部-边缘-外部森林植物群落为研究对象,通过调查植物的群落结构、叶功能性状,探究天坑内外森林植物群落叶功能性状、物种多样性和功能多样性变化特征及其内在关联,为深入了解负地形森林生态系统的功能和恢复退化喀斯特地区的植被提供一定参考。研究结果如下：（1）比叶面积（SLA: 198.75 cm2/g)）、叶面积（LA: 42.70 cm2）、叶磷含量（LPC: 1.70 g/kg）和叶钾含量（LKC: 10.27 g/kg）在天坑内部最高,叶组织密度（LTD: 0.32 g/cm3）和叶干物质含量（LDMC: 0.41 g/g）在天坑外部最高,天坑内外森林均易受到磷限制,表明随天坑内部-边缘-外部生境变化,植物对环境的适应机制和生存策略发生了部分调整,物种的防御策略增强,生长投入策略减弱。（2）Shannon-Wiener指数（2.82）、Simpson指数（0.92）和Pielou’s均匀度指数（0.87）均以天坑外部最高,功能丰富度（1.05）、功能离散度（1.88）和Rao’s二次熵（4.52）以天坑内部最高,表明随天坑内部-边缘-外部生境的变化,植物功能性状的差异减少,物种分布及其功能性状分布总体上更为均匀、物种数量增多。（3）物种多样性指数之间、功能多样性指数之间存在较强的相关性,表明物种多样性指数之间、功能多样性指数之间存在不同的制约关系。（4）叶功能性状与物种多样性、功能多样性的相关性强,物种多样性和功能多样性之间相关性较弱,表明叶性状对生态学过程的变化较为敏感,叶功能性状与物种多样性之间存在较强的耦合关系。     

Changes in species composition,diversity and biomass of herbaceous plant traits due to N amendment in a dry tropical environment of India

Aim European and North American studies have suggested that nitrogen (N) depositions reduce plant diversity and increase primary productivity due to changes in plant traits. To predict the vegetation response to future global change, experimental validations from other regions are widely needed. We assessed the effects of N treatment by urea fertilization on the diversity and biomass of the herbaceous plant traits (HPTs) in a dry tropical environment of India.Methods Diversity and biomass of different HPTs were determined on the basis of data collected in year 2010, from 135, 1 m × 1 m plots distributed over 15 locations. The plots were treated with urea fertilizer in different doses (Control, 60kgNha^-1 yr^-1 and 120kg N ha^-1 yr^-1) since 1st January 2007. The plots were ordinated and data were subjected to appropriate statistical analyses.Important findings Correspondence analysis (CA) suggested uniqueness of species composition due to N amendment. Species number and biomass of the trait categories varied due to N fertilization and traits. All studied trait categories (except N-fixers) yielded maximum mean species number at moderate level of N fertilization. Different levels of N fertilization exhibited different species diversity–primary productivity (D-P) relationships. Further, study showed reduction in plant diversity due to increase in biomass at high rates of N addition.Conclusions Tall, erect, non N-fixers, annuals, grasses HPTs were favoured by N enrichment. N dose above 60kg enhanced the biomass of fast growing, erect, annuals, non N-fixers, nitrophilic HPTs. The changes in traits with N addition, especially the increase in annuals and grasses and decrease in typically N-rich N-fixers, have implications for sustainable cattle production.     

伏牛山自然保护区森林生态系统草本植物功能群的分类

伏牛山国家级自然保护区是中国东部森林样带中的亚热带和暖温带的结合点,随着环境梯度(海拔)的变化,林下植物优势种变化明显.草本植物对环境的反应较为敏感,能较好的反映出植被与环境的动态关系.采用群落学调查方法,对伏牛山南北坡的植被进行调查.以X2检验为基础,结合联结系数AC和共同出现百分率PC来测定草本层优势种间的联结性,根据优势种间的联系性及其在海拔梯度上的变化异同,以优势种为主体划分伏牛山自然保护区林下草本植物功能群.研究结果表明,以优势种为主体对森林生态系统草本植物进行功能群划分可行性高,有较强的代表性.对草本优势种共划分了7组植物功能群:Ⅰ"伴人型",Ⅱ"高山型",Ⅲ"阴湿型",Ⅳ"耐旱型",Ⅴ"林隙型",Ⅵ"基础型",Ⅶ"原始型".每一组都有其特定的分布区域和形态特征,较好了反应出环境与植被的动态关系,为今后森林生态系统研究和植物功能群划分寻找新的思路.     

伊洛河河岸带生态系统草本植物功能群划分

植物功能群是对环境有相同响应和对主要生态系统过程有相似作用的组合。伊洛河是黄河中游南岸的一条重要水系,其河岸带生态系统不同生境类型中草本植物优势种变化明显,能较好地反映出植被与环境的动态关系。根据调查结果,结合出现次数和重要值,选取27种优势种进行种间联结及相关性分析。以$2检验为基础,结合联结系数AC和共同出现百分率PC来测定草本层优势种间的联结性,根据优势种间的联结性及其在不同生境中的变化异同,以优势种为主体划分伊洛河河岸带生态系统中草本植物功能群。结果表明,对27种草本植物优势种共划分了5组功能群:"广布型"、"湿生型"、"中旱生型"、"农田逃逸型"和"入侵型"。表明以优势种为主体对伊洛河河岸带生态系统草本植物进行功能群划分可行性高,有较强的代表性。同一功能群物种间表现出显著正联结性,一起出现在同一生境下的几率较大,在长期的生长演化过程中,能够适应相似的资源环境且对干扰有相似的响应。伊洛河河岸带生态系统由于长期的自然和人为干扰,加上外来物种的入侵,河岸带生态系统的生物多样性和生态安全面临着严峻的挑战。     

Below- and aboveground traits explain local abundance,and regional,continental and global occurrence frequencies of grassland plants

Plants vary widely in how common or rare they are, but whether commonness of species is associated with functional traits is still debated. This might partly be because commonness can be measured at different spatial scales, and because most studies focus solely on aboveground functional traits. We measured five root traits and seed mass on 241 central European grassland species, and extracted their specific leaf area, height, mycorrhizal status and bud-bank size from databases. Then we tested if trait values are associated with commonness at seven spatial scales, ranging from abundance in 16-m² grassland plots, via regional and European-wide occurrence frequencies, to worldwide naturalization success. At every spatial scale, commonness was associated with at least three traits. The traits explained the greatest proportions of variance for abundance in grassland plots (42%) and naturalization success (41%) and the least for occurrence frequencies in Europe and the Mediterranean (2%). Low root tissue density characterized common species at every scale, whereas other traits showed directional changes depending on the scale. We also found that many of the effects had significant non-linear effects, in most cases with the highest commonness-metric value at intermediate trait values. Across scales, belowground traits explained overall more variance in species commonness (19.4%) than aboveground traits (12.6%). The changes we found in the relationships between traits and commonness, when going from one spatial scale to another, could at least partly explain the maintenance of trait variation in nature. Most importantly, our study shows that within grasslands, belowground traits are at least as important as aboveground traits for species commonness. Therefore, belowground traits should be more frequently considered in studies on plant functional ecology.     

Effect of geographical range size on plant functional traits and the relationships between plant,soil and climate in Chinese grasslands

Aim Our aim was to address the potential effect of the geographical range size of species on the relationships between plant traits, soil and climate in Chinese grasslands. Previous analyses tended to examine plant–environment relationships across many species while ignoring that species with different range sizes may respond differently to the environment. Here we hypothesized that leaf traits of narrow‐ranging species would be more strongly correlated with soil and climatic variables than those of wide‐ranging species. Location Chinese grasslands. Methods Data on leaf traits, including nitrogen and phosphorus concentrations, carbon/nitrogen ratio, nitrogen/phosphorus ratio and specific leaf area, as well as species range sizes for 208 species distributed across 178 sites in Chinese grasslands were collected. Soil and climate information for each study site was also gathered. The effects of range size on leaf traits were tested using one‐way ANOVA. Correlations between leaf traits, soil and climate were calculated for all species pooled together and for species partitioned into range size quartiles, from the first (narrowest‐ ranging 25%) to the fourth (widest‐ranging 25%). Results Narrow‐ranging species tended to occur at high altitude with lower temperature but higher soil nutrient concentrations compared with wide‐ranging species. No direct link between leaf traits and species range sizes was detected. However, patterns of leaf–soil nutrient relationships changed significantly across levels of range size. Narrow‐ranging species tended to be more sensitive to variation in soil nutrient availability than wide‐ranging species, resulting in a shift from a positive leaf–soil nutrient relationship for narrow‐ranging plants to no relationship for wide‐ranging plants. Species responses to climatic variables were unrelated to their range sizes. Main conclusions The close relationship between leaf and soil nutrients indicates a specialization of narrow‐ranging species to particular habitats whereas wide‐ranging species may be able to better withstand changes in environment such as soil fertility over a large area.     

Evolutionary change in seed size among some legume species: The effects of phylogeny

The importance of phylogenetic effects in controlling seed size variation at the macroevolutionary levels was examined using species of a well-defined, monophyletic family, the Leguminosae. A nested ANOVA was used to separate variance components at the various taxonomic levels such as subfamily, genus, and subgenus. Statistical significance was found at most of the taxonomic levels examined, which suggests that phylogeny as shown by the accepted taxonomy of the family, exerted a substantial influence over seed size variation. Thus, there appears to be a characteristic mean seed size for each genus and subgenus. The overall positive correlation between plant height and seed size was interpreted as a scaling of seed size to plant height. When the effect of plant height was controlled, the amount of variance changed to some extent across taxonomic levels, though resulting in no change in statistical significance at various taxonomic levels. This results indicate that phylogenetic effects in seed size variation among congeneric or consubgeneric groupings were largely independent of allometric effects. The patterns of variance components and intraclass correlation coefficients for seed size differed to some extent among subfamilies. The difference in those patterns among taxa will reflect evolutionary change more closely with larger sample sizes. A simple inverse relationship between seed size and number per fruit among related legume species was difficult to generalize. This was perhaps due to phylogenetic constraints on seed size and/or seed number (or ovule number). These results demonstrate that phylogeny and plant height affect seed size variation among related species.     

Ecological traits influence the phylogenetic structure of bird species co‐occurrences worldwide

The extent to which species’ ecological and phylogenetic relatedness shape their co‐occurrence patterns at large spatial scales remains poorly understood. By quantifying phylogenetic assemblage structure within geographic ranges of >8000 bird species, we show that global co‐occurrence patterns are linked – after accounting for regional effects – to key ecological traits reflecting diet, mobility, body size and climatic preference. We found that co‐occurrences of carnivorous, migratory and cold‐climate species are phylogenetically clustered, whereas nectarivores, herbivores, frugivores and invertebrate eaters tend to be more phylogenetically overdispersed. Preference for open or forested habitats appeared to be independent from the level of phylogenetic clustering. Our results advocate for an extension of the tropical niche conservatism hypothesis to incorporate ecological and life‐history traits beyond the climatic niche. They further offer a novel species‐oriented perspective on how biogeographic and evolutionary legacies interact with ecological traits to shape global patterns of species coexistence in birds.     

基于知识图谱的植物功能性状与环境研究前沿态势分析

为系统了解国际上植物功能性状与环境的研究进展,该研究基于Web of Science数据来源,采用Web of Science数据库分析工具和Thomson Data Analysis(TDA)进行数据清理和统计分析,并利用Ucinet和Netdraw、Excel等软件进行可视化作图。结果表明:(1)近26年来,植物功能性状与环境研究论文数量呈持续稳步增长态势,尤其近9年来呈加速增长态势。(2)近9年来,研究主题主要围绕比叶面积、叶面积(指数)、光合作用(性能)、叶厚度、叶形态、叶氮含量、叶绿素、叶绿素荧光、比根长等功能指标,及光照、温度、水(水分利用效率、干旱等)、肥(氮、磷为主)、CO2等环境因子展开;化学计量学在该领域应用广泛。(3)2009—2017年间,欧美等发达国家是该领域研究的主要力量。美国发文数量和文献质量均为世界领先。中国在该领域的发文量居第二位,仅次于美国,但文献篇均被引和H指数较低。中国科学院发文量以绝对优势居第一位,但文献质量有待进一步提升。(4)该领域载文量Top10期刊8种为JCR分区Q1区、2种为Q2区。其中,Plant and Soil和Plant Ecology载文量分居第一位和第二位。(5) Top10高被引论文发表于8种期刊,其第一作者分别来自美国、荷兰、加拿大、德国和法国。     

内蒙古草原不同基因组大小植物对氮水添加的响应

被子植物基因组大小的种间差异巨大,约为2400倍.基因组大小与植物从细胞核到个体水平的一系列性状密切相关,进而影响植物对环境变化的响应.作为水分和养分共同限制的生态系统,内蒙古草原植物群落对氮素、水分有效性变化的响应具有明显的种间差异,这种差异可能与种间基因组大小不同有关.本研究利用流式细胞术测定了内蒙古典型草原水分、氮素添加实验平台植物的基因组大小,研究了不同基因组大小植物地上净初级生产力(ANPP)和物种丰富度对水分、氮素添加及其交互作用的响应.结果表明:基因组大小显著影响了不同植物ANPP对水分的响应,小基因组植物ANPP对氮水添加响应更敏感,加水和氮水共同添加显著增加了小基因组植物ANPP,而大基因组植物ANPP对所有处理响应均不显著.加氮对大小基因组植物ANPP都无显著影响.大小基因组植物的物种丰富度对氮水添加的响应也均不显著.基因组大小影响内蒙古草原不同植物ANPP对水分增加的响应.作为植物细胞核水平上十分稳定且种间差异巨大的物种性状,将基因组大小引入生态学研究将对全球变化背景下生态系统结构与功能变化研究起到重要作用.     

喀斯特森林不同演替阶段植物群落物种多样性、功能性状、化学计量及其关联

探讨森林植物群落物种多样性、功能性状与化学计量特征及其内在关联,有助于构建结构-性状-功能的研究脉络,深入理解生态系统的过程与功能,为群落结构优化配置和调控提供科学依据。以贵州喀斯特高原峡谷区森林草灌、灌木、灌乔和乔木4个演替阶段的植物群落为对象,通过群落学调查和植物功能性状、生态化学计量测度,研究其物种多样性、功能性状和化学计量特征及其互作关系。结果表明:(1)乔木阶段的Shannon-Wiener指数与Pielou均匀度指数均为最高,依次达8.62、2.41,表明伴随着群落演替,物种分布的均匀程度增加。(2)植物群落物种多样性指数之间仅Margalef丰富度指数与Simpson优势度指数未呈显著相关(-0.644),其余均为显著或极显著相关关系,表明物种多样性指数之间存在较强的促进或抑制作用。(3)叶片厚度与其余指标,以及群落物种多样性指数与功能性状、化学计量之间均未呈显著相关,比叶面积(SLA)仅与土壤N∶P呈显著正相关(0.742),表明群落物种多样性、功能性状和生态化学计量特征之间的相关性较弱。(4)SLA为灌木阶段的272.13 cm2/g为最大,δ13C值在演替后期略高,草灌、灌木阶段倾向于受N、P共同限制,说明随演替进展,植物的适应策略和资源利用对策等均发生了一定的调整,表明植物和环境之间存在较强的协变关系。(5)该区森林培育时,应构建完整的乔木、灌木和草本层片,提高生态系统对养分矿化、转化和循环等的自调控能力。     

不同纬度植物群落系统发育与功能性状结构研究

研究植物群落系统发育和功能性状结构有助于了解植物多样性维持机制及物种间的亲缘关系。甘肃省地理环境复杂,显著而多变的气候梯度形成了区域植被和环境差异,丰富了栖息地类型,具有显著的纵向连通性和纬度隔离性,以甘肃省典型纬度梯度植物群落为研究对象,通过对其进行群落学调查和功能性状测定,计算净亲缘关系指数(Net relatedness index, NRI)和平均成对性状距离(Mean pairwise trait distance, PW)来分析植物群落系统发育结构和功能性状格局对不同纬度的响应。结果表明：(1) Shannon-Weiner多样性指数,物种丰富度,谱系α多样性指数表现出随纬度增加而显著降低的变化趋势(P<0.05),Pielou均匀度指数随纬度的升高没有显著的变化趋势;(2)系统发育结构在高、低纬度上趋于发散状态(NRI<0),在中纬度上又表现出聚集(NRI>0)的谱系结构,表明种间竞争作用减弱,环境过滤作用逐渐增强,随纬度继续升高相似性限制作用在物种聚集过程中占优势;而群落的功能性状结构随着纬度增加表现出与谱系结构相反的状态,因此植物群落的系统发育和功能...     

Strong phylogenetic inertia on genome size and transposable element content among 26 species of flies

While the evolutionary mechanisms driving eukaryote genome size evolution are still debated, repeated element content appears to be crucial. Here, we reconstructed the phylogeny and identified repeats in the genome of 26 Drosophila exhibiting a twofold variation in genome size. The content in transposable elements (TEs) is highly correlated to genome size evolution among these closely related species. We detected a strong phylogenetic signal on the evolution of both genome size and TE content, and a genome contraction in the Drosophila melanogaster subgroup.     

Similarity of plant functional traits and aggregation pattern in a subtropical forest

The distribution of species and communities in relation to environmental heterogeneity is a central focus in ecology. Co‐occurrence of species with similar functional traits is an indication that communities are determined in part by environmental filters. However, few studies have been designed to test how functional traits are selectively filtered by environmental conditions at local scales. Exploring the relationship between soil characteristics and plant traits is a step toward understanding the filtering hypothesis in determining plant distribution at local scale. Toward this end, we mapped all individual trees (diameter >1 cm) in a one‐ha subtropical forest of China in 2007 and 2015. We measured topographic and detailed soil properties within the field site, as well as plant leaf functional traits and demographic rates of the seven most common tree species. A second one‐ha study plot was established in 2015, to test and validate the general patterns that were drawn from first plot. We found that variation in species distribution at local scale can be explained by soil heterogeneity and plant functional traits. (From first plot). (1) Species dominant in habitats with high soil ammonium nitrogen and total phosphorus tended to have high specific leaf area (SLA) and relative growth rate (RGR). (2) Species dominant in low‐fertility habitats tended to have high leaf dry matter content (LDMC), ratio of chlorophyll a and b (ratioab), and leaf thickness (LT). The hypothesis that functional traits are selected in part by environmental filters and determine plant distribution at local scale was confirmed by the data of the first plot and a second regional site showed similar species distribution patterns.     

践踏干扰对碧塔海高寒草甸植被茎叶性状、物种多样性和功能多样性的影响

高寒草甸具有重要的生态服务功能,然而固有脆弱性使其极易遭受气候变化和人为干扰等多重因素的影响。作为滇西北旅游资源中重要的组分之一,高寒草甸吸引了大批游客前往开展徒步旅行活动,但伴随着的践踏干扰作用会不可避免地对高寒草甸生态系统带来负面影响。然而,目前关注践踏干扰对滇西北高寒草甸植被的影响,特别是植被功能性状和功能多样性如何发生变化方面的研究还十分欠缺。以云南省香格里拉市碧塔海自然保护区内的典型高寒草甸生态系统为研究对象,采用实验践踏的方式(一共5种不同强度的践踏处理)来模拟旅游活动对草甸植被的干扰作用,并以草甸植被的茎叶性状特征为切入点,重点探讨践踏干扰对茎叶性状的平均大小和变异程度的影响,以及物种丰富度(以物种形态分类为基础)和功能丰富度(以功能性状为基础)之间的关系。研究结果显示,随着践踏强度的增加,植株高度和叶片大小的平均值,而不是茎叶性状的变异程度,出现明显下降趋势。此外,物种丰富度和功能丰富度均随践踏强度的增强而减小,且两者之间呈现显著正相关关系。然而,较之轻度践踏实验组,重度践踏实验组中的功能均匀度和功能分离度水平均有所增加,表明践踏干扰可能会在短期内打破优势种对资源的绝对占有格局和减少物种间的生态位重叠程度。尽管高寒草甸对人类践踏活动有一定的承受能力,但气候变化和人为干扰等多重因素势必会改变和影响高寒草甸群落的结构和功能可持续性,这也对高寒草甸的保护与管理工作提出了更加紧迫的要求。