Prior studies of a broad array of seed plants have reported strong correlations among leaf life span, specific leaf area, nitrogen concentration, and carbon assimilation rates, which have been interpreted as evidence of coordinated leaf physiological strategies. However, it is not known whether these relationships reflect patterns of evolutionary convergence, or whether they are due to contrasting characteristics of major seed plant lineages. We reevaluated a published data set for these seven traits measured in over 100 species, using phylogenetic independent contrasts calculated over a range of alternative seed plant phylogenies derived from recent molecular systematic analyses. In general, pairwise correlations among these seven traits were similar with and without consideration of phylogeny, and results were robust over a range of alternative phylogenies. We also evaluated relationships between these seven traits and lamina area, another important aspect of leaf function, and found moderate correlations with specific leaf area (0.64), mass-based photosynthesis (0.54), area-based nitrogen (-0.56), and leaf life span (-0.42). However, several of these correlations were markedly reduced using independent contrasts; for example, the correlation between leaf life span and lamina area was reduced to close to zero. This change reflects the large differences in both these traits between conifers and angiosperms and the absence of a relationship between the traits within these groups. This analysis illustrates that most interspecific relationships among leaf functional traits, considered across a broad range of seed plant taxa, reflect significant patterns of correlated evolutionary change, lending further support to the adaptive interpretation of these relationships.

Summary 1. Functional traits are increasingly used to investigate community structure, ecosystem functioning or to classify species into functional groups. These functional traits are expected to be variable between and within species. Intraspecific functional variability is supposed to influence and modulate species responses to environmental changes and their effects on their environment. However, this hypothesis remains poorly tested and species are mostly described by mean trait values without any consideration of variability in individual trait values. 2. In this study, we quantify the extent of intraspecific plant functional trait variability, its spatial structure and its response to environmental factors. Using a sampling design structured along two direct and orthogonal climatic gradients in an alpine valley, we quantified and analysed the intraspecific variability for three functional traits (height, leaf dry matter content and leaf nitrogen content) measured on sixteen plant species with contrasting life histories. 3. Results showed a large variability of traits within species with large discrepancies between functional traits and species. This variability did not appear to be structured within populations. Between populations, the overall variability was partly explained by the selected gradients. Despite the strong effects of temperature and radiation on trait intraspecific variability, the response curves of traits along gradients were partly idiosyncratic. 4. Synthesis . Giving a comprehensive quantification of intraspecific functional variability through the analysis of an original data set, we report new evidence that using a single trait value to describe a given species can hide large functional variation for this species along environmental gradients. These findings suggest that intraspecific functional variability should be a concern for ecologists and its recognition opens new opportunities to better understand and predict ecological patterns in a changing environment. Further analyses are, however, required to compare inter- and intraspecific variability.

Abstract Wood performs several essential functions in plants, including mechanically supporting aboveground tissue, storing water and other resources, and transporting sap. Woody tissues are likely to face physiological, structural and defensive trade-offs. How a plant optimizes among these competing functions can have major ecological implications, which have been under-appreciated by ecologists compared to the focus they have given to leaf function. To draw together our current understanding of wood function, we identify and collate data on the major wood functional traits, including the largest wood density database to date (8412 taxa), mechanical strength measures and anatomical features, as well as clade-specific features such as secondary chemistry. We then show how wood traits are related to one another, highlighting functional trade-offs, and to ecological and demographic plant features (growth form, growth rate, latitude, ecological setting). We suggest that, similar to the manifold that tree species leaf traits cluster around the 'leaf economics spectrum', a similar 'wood economics spectrum' may be defined. We then discuss the biogeography, evolution and biogeochemistry of the spectrum, and conclude by pointing out the major gaps in our current knowledge of wood functional traits.

以宁夏中部干旱带35种植物9种叶性状为研究对象,分析其变异特征、相关性以及不同科、功能类群间的关系,探讨该地区植物对环境的适应性,为该地区生态系统植被的恢复和重建提供理论依据。结果表明,叶性状特征存在种间差异,按照变异系数,可划分为3类:高变异系数(叶片厚度和叶片单位面积吸水量)、中变异系数(叶片含水量增加率、叶组织密度、叶片肉质化程度和比叶面积)和低变异系数(叶绿素含量、叶片干物质含量和叶片水分饱和亏)。一年生植物叶组织密度、叶绿素含量和叶片干物质含量的平均值极显著低于多年生植物,而比叶面积则极显著的高于多年生植物。叶组织密度、叶片厚度、叶片肉质化程度、叶片干物质含量和叶片单位面积吸水量在不同科类群之间存在极显著差异,而比叶面积、叶片水分饱和亏、叶绿素含量和叶片含水量增加率之间则差异不显著。因此,可以将叶组织密度、叶片厚度、叶片肉质化程度、叶片干物质含量和叶片单位面积吸水量用作不同科类群植物间相比较的研究因子。

以宁夏中部干旱带35种植物9种叶性状为研究对象,分析其变异特征、相关性以及不同科、功能类群间的关系,探讨该地区植物对环境的适应性,为该地区生态系统植被的恢复和重建提供理论依据。结果表明,叶性状特征存在种间差异,按照变异系数,可划分为3类:高变异系数(叶片厚度和叶片单位面积吸水量)、中变异系数(叶片含水量增加率、叶组织密度、叶片肉质化程度和比叶面积)和低变异系数(叶绿素含量、叶片干物质含量和叶片水分饱和亏)。一年生植物叶组织密度、叶绿素含量和叶片干物质含量的平均值极显著低于多年生植物,而比叶面积则极显著的高于多年生植物。叶组织密度、叶片厚度、叶片肉质化程度、叶片干物质含量和叶片单位面积吸水量在不同科类群之间存在极显著差异,而比叶面积、叶片水分饱和亏、叶绿素含量和叶片含水量增加率之间则差异不显著。因此,可以将叶组织密度、叶片厚度、叶片肉质化程度、叶片干物质含量和叶片单位面积吸水量用作不同科类群植物间相比较的研究因子。

叶功能性状体现了植物为获得最大化碳收获所采取的生存适应策略。本文研究了粤东89种常见植物叶功能性状包括叶面积(LA)、比叶面积(SLA)、叶干物质含量(LDMC)、叶氮含量(LNC)的变异特征及其与科类群、生活史属性和生境的关系。89种植物的LA、SLA、LDMC、LNC平均值分别为20.59 cm2、300.149 cm2·g-1、0.2213 g·g-1、2.55%;变异幅度依次是:LA(145.06%)SLA(97.21%)LDMC(36.40%)LNC(27%)。LMDC与SLA呈极显著负相关关系(P0.001)。不同科类群间SLA、LDMC差异显著(P0.05),禾本科植物LDMC最大(0.359 g·g-1)、SLA最小(163.749 cm2·g-1),伞形科植物LDMC最小(0.136 g·g-1)、SLA最大(1091.42 cm2·g-1);藤本和灌木LA显著大于草本植物(P0.01);科类群能解释LA、SLA、LDMC和LNC变异的26.3%、30.2%、40.9%和13.8%,其次是植物高度和生活型;科类群、植物高度和生活型三者交互作用能解释LA、SLA、LDMC、LNC变异的82.5%、80.9%、79.4%和56.7%;植物分布区、原产地及生境对叶性状均无显著影响(P0.05)。粤东89种植物叶性状的种间变异主要受物种系统发育史和生活史特征的影响。

叶功能性状体现了植物为获得最大化碳收获所采取的生存适应策略。本文研究了粤东89种常见植物叶功能性状包括叶面积(LA)、比叶面积(SLA)、叶干物质含量(LDMC)、叶氮含量(LNC)的变异特征及其与科类群、生活史属性和生境的关系。89种植物的LA、SLA、LDMC、LNC平均值分别为20.59 cm2、300.149 cm2·g-1、0.2213 g·g-1、2.55%;变异幅度依次是:LA(145.06%)SLA(97.21%)LDMC(36.40%)LNC(27%)。LMDC与SLA呈极显著负相关关系(P0.001)。不同科类群间SLA、LDMC差异显著(P0.05),禾本科植物LDMC最大(0.359 g·g-1)、SLA最小(163.749 cm2·g-1),伞形科植物LDMC最小(0.136 g·g-1)、SLA最大(1091.42 cm2·g-1);藤本和灌木LA显著大于草本植物(P0.01);科类群能解释LA、SLA、LDMC和LNC变异的26.3%、30.2%、40.9%和13.8%,其次是植物高度和生活型;科类群、植物高度和生活型三者交互作用能解释LA、SLA、LDMC、LNC变异的82.5%、80.9%、79.4%和56.7%;植物分布区、原产地及生境对叶性状均无显著影响(P0.05)。粤东89种植物叶性状的种间变异主要受物种系统发育史和生活史特征的影响。

Summary 1 There is limited understanding of patterns of variation that exist among root traits of different species, especially under field conditions. We contrasted 11 fast- and slow-growing species paired within five evolutionary lineages to investigate whether root traits associated with soil resource acquisition were related to species potential growth rate. 2 Measurements of root morphology, architecture, nitrogen and phenolic concentration, respiration and phosphorus uptake were taken on fine, non-woody roots sampled from forest stands in central Pennsylvania, USA. 3 Across all five contrasts, roots of fast-growing species generally had higher specific root length, smaller diameters, greater degree of branching, and lower phenolic concentrations than those of slow-growing species. This suggests differences in potential soil exploration and root defences among species differing in potential growth rate. 4 There were no significant differences between fast- and slow-growing species in root tissue density, respiration or P uptake. Lack of root physiological differences between species differing in growth rate contrasted with previous research on chamber-grown seedlings. 5 These results imply that, while roots of fast-growing species may be constructed for more rapid soil exploration and shorter life span than those of slow-growing species, root physiology is either more closely tied to overall plant physiology, which is more similar among mature trees, or masked by variation in soil microsites, root age or interactions with mycorrhizal fungi.

Uncertainties regarding the relationships between leaf and root traits have impeded an integrated understanding of plant evolution and the efficient parameterization of ecosystem models. We measured key root and leaf traits of grasses from 77 sites in four grassland regions of the world (New Zealand, Australia, South Africa, North America). Within each region, the relationships among leaf traits paralleled those among root traits. Plants with low root or leaf N concentrations had roots or leaves with high tissue density, high lignin concentrations, low amount of mass that was soluble in a neutral detergent solution, large diameter/thickness, and were less enriched in15N. Yet, whether comparing plants within a region or among all four regions, there was little relationship between root traits and leaf traits, except for a positive relationship between root and leaf N concentration and between root and leaf 15N. At the global scale, factors such as soil freezing and the type of nutrient limitation appear to determine relationships among leaves and roots. C4grasses not only had lower leaf N concentrations than C3grasses but also lower root N concentrations. When compared at the same root N concentration, C4grasses had greater leaf N concentrations than C3grasses.

Abstract Question: A set of easily-measured (‘soft’) plant traits has been identified as potentially useful predictors of ecosystem functioning in previous studies. Here we aimed to discover whether the screening techniques remain operational in widely contrasted circumstances, to test for the existence of axes of variation in the particular sets of traits, and to test for their links with ‘harder’ traits of proven importance to ecosystem functioning. Location: central-western Argentina, central England, northern upland Iran, and north-eastern Spain. Recurrent patterns of ecological specialization: Through ordination of a matrix of 640 vascular plant taxa by 12 standardized traits, we detected similar patterns of specialization in the four floras. The first PCA axis was identified as an axis of resource capture, usage and release. PCA axis 2 appeared to be a size-related axis. Individual PCA for each country showed that the same traits remained valuable as predictors of resource capture and utilization in all of them, despite their major differences in climate, biogeography and land-use. The results were not significantly driven by particular taxa: the main traits determining PCA axis 1 were very similar in eudicotyledons and monocotyledons and Asteraceae, Fabaceae and Poaceae. Links between recurrent suites of ‘soft’ traits and ‘hard’ traits: The validity of PCA axis 1 as a key predictor of resource capture and utilization was tested by comparisons between this axis and values of more rigorously established predictors (‘hard’ traits) for the floras of Argentina and England. PCA axis 1 was correlated with variation in relative growth rate, leaf nitrogen content, and litter decomposition rate. It also coincided with palatability to model generalist herbivores. Therefore, location on PCA axis 1 can be linked to major ecosystem processes in those habitats where the plants are dominant. Conclusion: We confirm the existence at the global scale of a major axis of evolutionary specialization, previously recognised in several local floras. This axis reflects a fundamental trade-off between rapid acquisition of resources and conservation of resources within well-protected tissues. These major trends of specialization were maintained across different environmental situations (including differences in the proximate causes of low productivity, i.e. drought or mineral nutrient deficiency). The trends were also consistent across floras and major phylogenetic groups, and were linked with traits directly relevant to ecosystem processes.

Abstract Earth is home to a remarkable diversity of plant forms and life histories, yet comparatively few essential trait combinations have proved evolutionarily viable in today's terrestrial biosphere. By analysing worldwide variation in six major traits critical to growth, survival and reproduction within the largest sample of vascular plant species ever compiled, we found that occupancy of six-dimensional trait space is strongly concentrated, indicating coordination and trade-offs. Three-quarters of trait variation is captured in a two-dimensional global spectrum of plant form and function. One major dimension within this plane reflects the size of whole plants and their parts; the other represents the leaf economics spectrum, which balances leaf construction costs against growth potential. The global plant trait spectrum provides a backdrop for elucidating constraints on evolution, for functionally qualifying species and ecosystems, and for improving models that predict future vegetation based on continuous variation in plant form and function.

Root turnover is important to the global carbon budget as well as to nutrient cycling in ecosystems and to the success of individual plants. Our ability to predict the effects of environmental change on root turnover is limited by the difficulty of measuring root dynamics, but emerging evidence suggests that roots, like leaves, possess suites of interrelated traits that are linked to their life span. In graminoids, high tissue density has been linked to increased root longevity. Other studies have found root longevity to be positively correlated with mycorrhizal colonization and negatively correlated with nitrogen concentration, root maintenance respiration and specific root length. Among fruit trees, apple roots (which are of relatively small diameter, low tissue density and have little lignification of the exodermis) have much shorter life spans than the roots of citrus, which have opposite traits. Likewise, within the branched network of the fine root system, the finest roots with no daughter roots tend to have higher N concentrations, faster maintenance respiration, higher specific root length and shorter life spans than secondary and tertiary roots that bear daughter roots. Mycorrhizal colonization can enhance root longevity by diverse mechanisms, including enhanced tolerance of drying soil and enhanced defence against root pathogens. Many variables involved in building roots might affect root longevity, including root diameter, tissue density, N concentration, mycorrhizal fungal colonization and accumulation of secondary phenolic compounds. These root traits are highly plastic and are strongly affected by resource supply (CO 2 , N, P and water). Therefore the response of root longevity to altered resource availability associated with climate change can be estimated by considering how changes in resource availability affect root construction and physiology. A cost benefit approach to predicting root longevity assumes that a plant maintains a root only until the efficiency of resource acquisition is maximized. Using an efficiency model, we show that reduced tissue Nconcentration and reduced root maintenance respiration, both of which are predicted to result from elevated CO 2 , should lead to slightly longer root life spans. Complex interactions with soil biota and shifts in plant defences against root herbivory and parasitism, which are not included in the present efficiency model, might alter the effects of future climate change on root longevity in unpredicted ways.

ABSTRACT Delayed seed germination (‘dispersal in time’), as a component of a plant’s germination strategy, was studied in dicotyledoneous species of a temperate rainforest flora in Chiloé Island (42°30′S), southern Chile. The objective of this investigation was to assess, for this temperate rainforest flora, what proportion of interspecific variation in the time of seed germination—measured in days since the onset of seed dispersal in space—could be attributed to the plants’ historical and phylogenetic background and what proportion was associated with life history and ecological attributes such as seed mass, life form, dispersal syndromes and dispersal periods. To characterise germination times for 44 species from Chiloé forests (n = 150 seeds sowed per species in laboratory assays), we computed the mean germination time (GT), in days since sowing, for all seeds germinated of each species. Seeds were taken from the plants at the onset of dispersal and germinated in Petri dishes at 10/20°C. Considering all species, GTs varied between 3 and 385 days and presented an L-shaped frequency distribution. One-way ANOVAs measured the effects of each factor across all other variables. Two-way ANOVAs were used to assess significant interactions between factors. Multifactorial ANOVAs were used to evaluate the independent effects of each of six historical, phylogenetic and ecological factors on GT and to detect associations between factors. In one-way ANOVAs, phylogenetic grouping (at or above order) explained 12% of the variance in GT; dispersal period (summer v. mainly autumn dissemination of ripe seeds), biogeographic element (endemic, austral, neotropical or cosmopolitan) and dispersal syndrome (fleshy v. dry propagules) explained 7, 6 and 5% of the variance in GT, respectively. The factors life form (trees, shrub and woody vines combined, herbs and non-woody epiphytes) and seed mass (light v. heavy) explained the 4 and 2% of the variance in GT, respectively. Taxa related to Ranunculales presented the longest mean GT (148 days). Endozoochorous species had a more delayed germination than species with other dispersal syndromes. Herbs and non-woody epiphyte species showed mean GT (41 days) significantly shorter than trees and shrubs plus woody vines combined (86 and 85 days, respectively). All interactions in two-way ANOVAs were significant. Multifactorial ANOVAs revealed that the three major factors contributing to differences in GT in this temperate rainforest flora were phylogenetic relatedness, dispersal syndromes and life form (7, 6 and 6% of the interspecific variation, respectively). In this analysis, biogeographic element, dispersal period and seed mass were not significantly related to GT. For the factors examined, failure-time analysis, which takes into account all viable seeds not germinating in laboratory assays, confirmed results from multifactorial ANOVAs.

Summary 6168 Specific leaf area (leaf area to dry mass ratio), leaf dry matter content (leaf dry mass to saturated fresh mass ratio) and leaf nitrogen concentration (LNC) have been proposed as indicators of plant resource use in data bases of plant functional traits. 6168 We tested whether species ranking based on these traits was repeatable by studying spatio-temporal variations in specific leaf area and leaf dry matter content of water-saturated leaves (SLA SAT and LDMC SAT ), as well as in LNC, for 57 herbaceous and woody species (or subsets thereof) growing under the Mediterranean climate of southern France. 6168 Interseason and intersite variations were more pronounced than interannual variations, but species ranking for a given trait remained mostly consistent in space and time. Classifications based on LDMC SAT were generally more repeatable across years and sites, whereas those based on SLA SAT were more stable over seasons. LNC usually gave the least repeatable classifications. 6168 Species rankings were not completely similar for the three traits. Discussion of reproducibility, ease of trait measurement, as well as trait–function relationships led us to propose that measurements of the leaf traits, SLA SAT and/or LDMC SAT , were the most suitable in large screening programmes.

论文以江西省武夷山自然保护区黄岗山黄山松天然林为研究对象,根据黄山松实际的分布情况,共设置1200m、1400m、1600m、1800m、2000m五个海拔梯度,对黄山松细根生物量、碳(C)、氮(N)、磷(P)、碳氮比(C:N)、比根长(SRL)、比根面积(SRA)、根组织密度(RTD)、细根平均直径(AvgDiam)与海拔梯度、季节变化、土壤养分及比叶面积的关系进行了研究。主要研究结果如下：(1)不同海拔黄山松细根生物量存在显著差异,其中1800m样地的黄山松细根平均生物量最高(222.63g/m2),而2000m样地细根的生物量的最少(118.3 g/m2)；黄山松细根生物量在1200m-2000m海拔梯度上出现了先降低后增加再降低的趋势；各海拔梯度上黄山松细根生物量在6月和9月要高于12月和3月,但各季节间差异不显著(P0.05)。(2)黄山松细根功能性状存在显著的海拔梯度差异：各海拔黄山松细根SRL在829.21g/cm-1128.05g/cm之间变动,其中2000m海拔梯度SRL最低而1600m最高。除1400m和1600m外,其余海拔3月、6月、9月的黄山松细根SRL显著高于12月(P0.05)。SRA在不同海拔间具有显著差异(P0.05),其中,1800m最低(234.11g/cm2),1600m最高(330.97g/cm2),各海拔梯度9月黄山松细根SRA显著高于12月(P0.05)；RTD在不同海拔间也具有显著差异,表现为2000m最高(0.21g/cm3),而1600m最低(0.14g/cm2)；各海拔间黄山松细根AvgDiam差异显著,在1.13mm-0.86mm之间变动,在1200m和1800m海拔在12月和其他月份间存在显著差异(P0.05)；SRL和SRA随海拔梯度变化出现了先增加后减少的趋势,RTD随海拔梯度变化出现了先降低后升高再降低的过程(3)细根生物量、SRL、SRA、RTD、AvgDiam之间存在密切相关关系,其中,细根生物量与SRL、SRA极显著负相关(P0.01),与RTD极显著正相关(P0.01),SRL和SRA极显著正相关(P0.01),SRA与RTD极显著负相关(P0.01)。(4)黄山松细根平均C、N、P、C:N、N:P分别为488.89mg/g、9.29mg/g、0.39mg/g、54.53%与24.55%。双因素方差分析表明,海拔梯度、季节、海拔梯度季节对细根C、N、P、C:N、N:P影响均达到极显著水平(P0.01)。细根C含量与N含量极显著正相关(P0.01),与C:N极显著负相关(P0.01), C、C:N和P含量之间并无显著的相关关系(P0.05)。(5)土壤C与细根C、P、N:P之间无显著相关关系(P0.05),但与细根的N存在显著的正相关关系(P0.05)；土壤N与细根C、P之间不存在显著的相关关系(P0.05),与细根N、C:N的关系密切,对细根N、C:N变异的解释分别达到27%和26%；土壤P与细根C、N、C:N之间无显著相关关系,但与细根P、N:P间有显著相关关系(P0.05)；土壤C:N与细根C、N、C:N之间没有显著的相关关系(P0.05),与细根P、N:P呈显著的相关关系(P0.05)；土壤C、N、P、CN和pH与SRL、SRA、RTD、AvgDiam之间无显著相关关系(P0.05)(6)细根C、C:N与SRR显著负相关(P0.05),细根N、P、N:P与SRR无显著相关关系；SRR与RTD、AvgDiam存在显著的相关关系(P0.05),但与SRA、 SRL无显著相关关系；黄山松细根和叶功能性状表现出不同程度的联系,细根N、N:P与叶N、P、C:N都存在显著相关关系,细根N对叶N、P、C:N变异的解释分别达到33%、22%、35%；SLA与SRL、SRA、RTD、AvgDiam都不存在显著相关关系(P0.05)。

论文以江西省武夷山自然保护区黄岗山黄山松天然林为研究对象,根据黄山松实际的分布情况,共设置1200m、1400m、1600m、1800m、2000m五个海拔梯度,对黄山松细根生物量、碳(C)、氮(N)、磷(P)、碳氮比(C:N)、比根长(SRL)、比根面积(SRA)、根组织密度(RTD)、细根平均直径(AvgDiam)与海拔梯度、季节变化、土壤养分及比叶面积的关系进行了研究。主要研究结果如下：(1)不同海拔黄山松细根生物量存在显著差异,其中1800m样地的黄山松细根平均生物量最高(222.63g/m2),而2000m样地细根的生物量的最少(118.3 g/m2)；黄山松细根生物量在1200m-2000m海拔梯度上出现了先降低后增加再降低的趋势；各海拔梯度上黄山松细根生物量在6月和9月要高于12月和3月,但各季节间差异不显著(P0.05)。(2)黄山松细根功能性状存在显著的海拔梯度差异：各海拔黄山松细根SRL在829.21g/cm-1128.05g/cm之间变动,其中2000m海拔梯度SRL最低而1600m最高。除1400m和1600m外,其余海拔3月、6月、9月的黄山松细根SRL显著高于12月(P0.05)。SRA在不同海拔间具有显著差异(P0.05),其中,1800m最低(234.11g/cm2),1600m最高(330.97g/cm2),各海拔梯度9月黄山松细根SRA显著高于12月(P0.05)；RTD在不同海拔间也具有显著差异,表现为2000m最高(0.21g/cm3),而1600m最低(0.14g/cm2)；各海拔间黄山松细根AvgDiam差异显著,在1.13mm-0.86mm之间变动,在1200m和1800m海拔在12月和其他月份间存在显著差异(P0.05)；SRL和SRA随海拔梯度变化出现了先增加后减少的趋势,RTD随海拔梯度变化出现了先降低后升高再降低的过程(3)细根生物量、SRL、SRA、RTD、AvgDiam之间存在密切相关关系,其中,细根生物量与SRL、SRA极显著负相关(P0.01),与RTD极显著正相关(P0.01),SRL和SRA极显著正相关(P0.01),SRA与RTD极显著负相关(P0.01)。(4)黄山松细根平均C、N、P、C:N、N:P分别为488.89mg/g、9.29mg/g、0.39mg/g、54.53%与24.55%。双因素方差分析表明,海拔梯度、季节、海拔梯度季节对细根C、N、P、C:N、N:P影响均达到极显著水平(P0.01)。细根C含量与N含量极显著正相关(P0.01),与C:N极显著负相关(P0.01), C、C:N和P含量之间并无显著的相关关系(P0.05)。(5)土壤C与细根C、P、N:P之间无显著相关关系(P0.05),但与细根的N存在显著的正相关关系(P0.05)；土壤N与细根C、P之间不存在显著的相关关系(P0.05),与细根N、C:N的关系密切,对细根N、C:N变异的解释分别达到27%和26%；土壤P与细根C、N、C:N之间无显著相关关系,但与细根P、N:P间有显著相关关系(P0.05)；土壤C:N与细根C、N、C:N之间没有显著的相关关系(P0.05),与细根P、N:P呈显著的相关关系(P0.05)；土壤C、N、P、CN和pH与SRL、SRA、RTD、AvgDiam之间无显著相关关系(P0.05)(6)细根C、C:N与SRR显著负相关(P0.05),细根N、P、N:P与SRR无显著相关关系；SRR与RTD、AvgDiam存在显著的相关关系(P0.05),但与SRA、 SRL无显著相关关系；黄山松细根和叶功能性状表现出不同程度的联系,细根N、N:P与叶N、P、C:N都存在显著相关关系,细根N对叶N、P、C:N变异的解释分别达到33%、22%、35%；SLA与SRL、SRA、RTD、AvgDiam都不存在显著相关关系(P0.05)。

我国西南喀斯特地区生态脆弱,石漠化问题严重,植被恢复/重建的难度极大。为此,近年来开展了许多基础性研究,以求为石漠化治理提供科技支撑。该文概略介绍了该地区喀斯特生境的特点,回顾和评述了喀斯特生境中植物适应性、植物种群、植物群落和生态系统生态学方面取得的主要研究进展,并结合石漠化综合治理的现状,提出了喀斯特植物生态学研究的几点期望。

我国西南喀斯特地区生态脆弱,石漠化问题严重,植被恢复/重建的难度极大。为此,近年来开展了许多基础性研究,以求为石漠化治理提供科技支撑。该文概略介绍了该地区喀斯特生境的特点,回顾和评述了喀斯特生境中植物适应性、植物种群、植物群落和生态系统生态学方面取得的主要研究进展,并结合石漠化综合治理的现状,提出了喀斯特植物生态学研究的几点期望。

Abstract Plant biomass and nutrient allocation explicitly links the evolved strategies of plant species to the material and energy cycles of ecosystems. Allocation of nitrogen (N) and phosphorus (P) is of particular interest because N and P play pivotal roles in many aspects of plant biology, and their availability frequently limits plant growth. Here we present a comparative scaling analysis of a global data compilation detailing the N and P contents of leaves, stems, roots, and reproductive structures of 1,287 species in 152 seed plant families. We find that P and N contents (as well as N : P) are generally highly correlated both within and across organs and that differences exist between woody and herbaceous taxa. Between plant organs, the quantitative form of the scaling relationship changes systematically, depending on whether the organs considered are primarily structural (i.e., stems, roots) or metabolically active (i.e., leaves, reproductive structures). While we find significant phylogenetic signals in the data, similar scaling relationships occur in independently evolving plant lineages, which implies that both the contingencies of evolutionary history and some degree of environmental convergence have led to a common set of rules that constrain the partitioning of nutrients among plant organs.

Summary Root, stem and leaf traits are thought to be functionally coordinated to maximize the efficiency of acquiring and using limited resources. However, evidence is mixed for consistent whole-plant trait coordination among woody plants, and we lack a clear understanding of the adaptive value of root traits along soil resource gradients. If fine roots are the below-ground analogue to leaves, then low specific root length (SRL) and high tissue density should be common on infertile soil. Here, we test the prediction that root, stem and leaf traits and relative growth rate respond in unison with soil fertility gradients. We measured fine root, stem and leaf traits and relative growth rate on individual seedlings of 66 tree species grown in controlled conditions. Our objectives were (i) to determine whether multiple root traits align with growth rate, leaf and stem traits and with each other and (ii) to quantify the relationships between community-weighted mean root traits and two strong soil fertility gradients that differed in spatial extent and community composition. At the species level, fast growth rates were associated with low root and stem tissue density and high specific leaf area. SRL and root diameter were not clearly related to growth rate and loaded on a separate principal component from the plant economic spectrum. At the community level, growth rate was positively related to soil fertility, and root tissue density (RTD) and branching were negatively related to soil fertility. SRL was negatively related and root diameter was positively related to soil fertility on the large-scale gradient that included ectomycorrhizal angiosperms. Synthesis . Root, stem and leaf tissue traits of tree seedlings are coordinated and influence fitness along soil fertility gradients. RTD responds in unison with above-ground traits to soil fertility gradients; however, root traits are multidimensional because SRL is orthogonal to the plant economic spectrum. In contrast to leaves, trees are not constrained in the way they construct fine roots: plants can construct high or low SRL roots of any tissue density. High RTD is the most consistent below-ground trait that reflects adaptation to infertile soil.

Plants are multifaceted organisms that have evolved numerous solutions to the problem of establishing, growing and reproducing with limited resources. The intrinsic dimensionality of plant traits is the minimum number of independent axes of variation that adequately describes the functional variation among plants and is therefore a fundamental quantity in comparative plant ecology. Given the large number of functional traits that are measured on plants, the dimensionality of plant form and function is potentially vast.A variety of linear and nonlinear methods were used to estimate the intrinsic dimensionality of three large trait data sets. The results of these analyses indicate that while the dimensionality of plant traits is generally larger than we have admitted in the past, it does not exceed six in the most comprehensive data set.The dimensionality of plant form and function is a blessing, not a curse. The higher the intrinsic dimension of traits in an analysis, the more easily our models will be able to accurately discriminate species in trait space and therefore be able to predict species distributions and abundances. Recent analyses indicate that the ability to predict community composition increases rapidly with additional traits, but reaches a plateau after four to eight traits.Synthesis. There appears to be a tractable upper limit to the dimensionality of plant traits. To optimize research efficiency for advancing our understanding of trait-based community assembly, ecologists should minimize the number of traits while maximizing the number of dimensions, because including multiple correlated traits does not yield dividends and including more than eight traits leads to diminishing returns. It is recommended to measure traits from multiple organs whenever possible, especially leaf, stem, root and flowering traits, given their consistent performance in explaining community assembly across different ecosystems.

以重庆石灰岩地区15种常绿木本植物和14种落叶木本植物为研究对象,对两种生活型植物叶片衰老前后叶干物质含量（LDMC）、比叶面积（SLA）和叶片厚度（LT）进行了比较,并采用不同的计算方法（单位质量叶片养分含量、单位面积叶片养分含量）分析了两类植物叶片衰老前后养分含量及再吸收特征,最后对养分再吸收效率与其他叶性状因子之间的关系进行了相关分析。结果表明：常绿植物成熟叶LDMC、LT及衰老叶LT显著低于落叶植物,落叶植物成熟叶和衰老叶SLA均显著高于常绿植物（P〈0.05）;基于单位质量叶片计算的养分含量,常绿植物成熟和衰老叶N、P量均低于落叶植物,而基于单位面积叶片计算的N、P含量则表现出相反的趋势;基于不同方法计算的N、P再吸收效率差异不明显,其中常绿植物基于单位质量叶片养分含量计算的N、P平均再吸收效率为39.42%、43.79%,落叶植物的为24.08%、33.59%;常绿和落叶植物N、P再吸收效率与LDMC、SLA、LT和成熟叶N、P含量之间没有显著相关性,但与衰老叶养分含量存在显著负相关（P〈0.05）。研究发现,无论是常绿植物还是落叶植物,衰老叶N、P含量均较低,表明石灰岩地区植物具有较高的养分再吸收程度。

以重庆石灰岩地区15种常绿木本植物和14种落叶木本植物为研究对象,对两种生活型植物叶片衰老前后叶干物质含量（LDMC）、比叶面积（SLA）和叶片厚度（LT）进行了比较,并采用不同的计算方法（单位质量叶片养分含量、单位面积叶片养分含量）分析了两类植物叶片衰老前后养分含量及再吸收特征,最后对养分再吸收效率与其他叶性状因子之间的关系进行了相关分析。结果表明：常绿植物成熟叶LDMC、LT及衰老叶LT显著低于落叶植物,落叶植物成熟叶和衰老叶SLA均显著高于常绿植物（P〈0.05）;基于单位质量叶片计算的养分含量,常绿植物成熟和衰老叶N、P量均低于落叶植物,而基于单位面积叶片计算的N、P含量则表现出相反的趋势;基于不同方法计算的N、P再吸收效率差异不明显,其中常绿植物基于单位质量叶片养分含量计算的N、P平均再吸收效率为39.42%、43.79%,落叶植物的为24.08%、33.59%;常绿和落叶植物N、P再吸收效率与LDMC、SLA、LT和成熟叶N、P含量之间没有显著相关性,但与衰老叶养分含量存在显著负相关（P〈0.05）。研究发现,无论是常绿植物还是落叶植物,衰老叶N、P含量均较低,表明石灰岩地区植物具有较高的养分再吸收程度。

为探讨生长在喀斯特石灰岩山地植物叶片性状适应特征,在重庆中梁山海石公园选取乔、灌、草三种生活型植物共30种,分别测定其叶干质量(mLDMC)、比叶面积(SLA)、叶pH、叶碳质量(mLCC)、叶氮质量(mLNC)和叶碳氮比等六个叶片性状因子.结果表明:不同叶片性状因子变异系数不同,其中,植物mLDMC、SLA和mLNC变异较大,分别为28.7%,50.8%和21.4%;mLDMC和SLA在不同生活型植物中存在显著差异,与乔木和灌木相比,草本具有较低的mLDMC和较大的SLA,而乔木和灌木在两者之间差异不显著;所有叶片性状因子中,植物mLDMC和SLA呈显著负相关,其他因子间没有显著相关性.可见,mLDMC和SLA是植物资源利用分类轴上划分植物类群的最佳指标,石灰岩地区不同生活型植物叶片性状不同,这是植物和环境相互选择综合作用的结果.

为探讨生长在喀斯特石灰岩山地植物叶片性状适应特征,在重庆中梁山海石公园选取乔、灌、草三种生活型植物共30种,分别测定其叶干质量(mLDMC)、比叶面积(SLA)、叶pH、叶碳质量(mLCC)、叶氮质量(mLNC)和叶碳氮比等六个叶片性状因子.结果表明:不同叶片性状因子变异系数不同,其中,植物mLDMC、SLA和mLNC变异较大,分别为28.7%,50.8%和21.4%;mLDMC和SLA在不同生活型植物中存在显著差异,与乔木和灌木相比,草本具有较低的mLDMC和较大的SLA,而乔木和灌木在两者之间差异不显著;所有叶片性状因子中,植物mLDMC和SLA呈显著负相关,其他因子间没有显著相关性.可见,mLDMC和SLA是植物资源利用分类轴上划分植物类群的最佳指标,石灰岩地区不同生活型植物叶片性状不同,这是植物和环境相互选择综合作用的结果.

Abstract The biomass of a secondary evergreen and deciduous broad-leaved mixed forest was comprehensively inventoried in a permanent 2 ha plot in southwestern China. Biomass models, sub-sampling, soil pit method, and published data were utilized to determine the biomass of all components. Results showed that the total biomass of the forest was 158.1 Mg ha-1; the total biomass included the major aboveground (137.7 Mg ha-1) and belowground (20.3 Mg ha-1) biomass components of vascular plants as well as the minor biomass components of bryophytes (0.078 Mg ha-1) and lichens (0.043 Mg ha-1). The necromass was 17.6 Mg ha-1 and included woody debris (9.0 Mg ha-1) and litter (8.6 Mg ha-1). The spatial pattern of the aboveground biomass was determined by the spatial distribution of dominant trees with large diameter, tall height, and dense wood. The belowground biomass differed in terms of root diameter and decreased with increasing soil depth. The belowground biomass in each soil pit in local habitats was not related to the spatial distribution of woody plants and soil pit depth. The karst forest presented lower biomass compared than the nonkarst forests in the subtropical zone. Biomass carbon in the karst terrains would increase substantially if degraded karst vegetation could be successfully restored to the forest. Comprehensive site-based biomass inventory of karst vegetation will contribute not only to provide data for benchmarking global and regional vegetation and carbon models but also for regional carbon inventory and vegetation restoration. 2016, Finnish Society of Forest Science. All rights reserved.

选择桂林尧山14种常见植物为研究对象,通过测定其叶干质量(DW)、叶面积(AR)、叶干物质含量(LDMC)、叶厚度(TH)和比叶面积(SLA)等叶片性状因子,探讨不同植物适应土山生境所表现出的叶性状特征.结果表明:14种常见植物的5个叶性状因子之间存在显著差异.Pearson相关性分析表明,DW与LDMC、AR、TH呈显著的正相关关系.DW与SLA呈显著的负相关关系;LDMC与AR、TH、SLA呈显著的负相关关系;AR与TH、SLA呈显著的正相关关系,TH与SLA呈显著的负相关关系.5个叶性状因子中,反映叶片性状权重的大小依次为:AR＞LDMC＞TH＞DW＞SLA.与桂林岩溶石山相比,作为土山的桂林尧山生境植物具有相对较小的DW、LDMC、AR、TH和相对较大的SLA,研究结果较好地反映了植物适应土山和石山不同生境的策略.

选择桂林尧山14种常见植物为研究对象,通过测定其叶干质量(DW)、叶面积(AR)、叶干物质含量(LDMC)、叶厚度(TH)和比叶面积(SLA)等叶片性状因子,探讨不同植物适应土山生境所表现出的叶性状特征.结果表明:14种常见植物的5个叶性状因子之间存在显著差异.Pearson相关性分析表明,DW与LDMC、AR、TH呈显著的正相关关系.DW与SLA呈显著的负相关关系;LDMC与AR、TH、SLA呈显著的负相关关系;AR与TH、SLA呈显著的正相关关系,TH与SLA呈显著的负相关关系.5个叶性状因子中,反映叶片性状权重的大小依次为:AR＞LDMC＞TH＞DW＞SLA.与桂林岩溶石山相比,作为土山的桂林尧山生境植物具有相对较小的DW、LDMC、AR、TH和相对较大的SLA,研究结果较好地反映了植物适应土山和石山不同生境的策略.

植物性状反映了植物对生长环境的响应和适应，将环境、植物个体和生态系统结构、过程与功能联系起来（所谓的“植物功能性状”）。该文介绍了植物功能性状的分类体系，综述了国内外植物功能性状与气候（包括气温、降水、光照）、地理空间变异（包括地形地貌、生态梯度、海拔）、营养、干扰（包括火灾、放牧、生物入侵、土地利用）等环境因素，以及与生态系统功能之间关系的研究进展，探讨了全球变化（气候变化和CO2浓度升高）对个体和群落植物功能性状的影响。植物功能性状的研究已经取得很多成果，并应用于全球变化、古植被恢复和古气候定量重建、环境监测与评价、生态保护和恢复等研究中，但大尺度、多生境因子下的植物功能性状研究仍有待于加强，同时需要改进性状的测量手段；我国的植物功能性状研究还需要更加 明朗化和系统化。

植物性状反映了植物对生长环境的响应和适应，将环境、植物个体和生态系统结构、过程与功能联系起来（所谓的“植物功能性状”）。该文介绍了植物功能性状的分类体系，综述了国内外植物功能性状与气候（包括气温、降水、光照）、地理空间变异（包括地形地貌、生态梯度、海拔）、营养、干扰（包括火灾、放牧、生物入侵、土地利用）等环境因素，以及与生态系统功能之间关系的研究进展，探讨了全球变化（气候变化和CO2浓度升高）对个体和群落植物功能性状的影响。植物功能性状的研究已经取得很多成果，并应用于全球变化、古植被恢复和古气候定量重建、环境监测与评价、生态保护和恢复等研究中，但大尺度、多生境因子下的植物功能性状研究仍有待于加强，同时需要改进性状的测量手段；我国的植物功能性状研究还需要更加 明朗化和系统化。

Abstract 1. Plant phenotypic diversity is shaped by the interplay of trade-offs and constraints in evolution. Closely integrated groups of traits (i.e. trait dimensions) are used to classify plant phenotypic diversity into plant strategies, but we do not know the degree of interdependence among trait dimensions. To assess how selection has shaped the phenotypic space, we examine whether trait dimensions are independent. 2. We gathered data on saplings of 24 locally coexisting tree species in a temperate forest, and examined the correlation structure of 20 leaf, branch, stem and root traits. These traits fall into three well-established trait dimensions (the leaf economic spectrum, the wood spectrum, and Corner Rules) that characterize vital plant functions: resource acquisition, sap transport, mechanical support and canopy architecture. Using ordinations, network analyses and Mantel tests, we tested whether the sapling phenotype of these tree species is organized along independent trait dimensions. 3. Across species, the sapling phenotype is not structured into clear trait dimensions. The trait relationships defining the trait dimensions are weak and do not dominate the correlation structure of the sapling phenotype as a whole. Instead traits from the three commonly recognized trait dimensions are organized into an integrated trait network. The effect of phylogeny on trait correlations is minimal. 4. Our results indicate that trait dimensions apparent in broad-based interspecific surveys do not hold up among locally coexisting species. Furthermore, architectural traits appear central to the phenotypic network, suggesting a pivotal role for branching architecture in linking resource acquisition, mechanical support and hydraulic functions. 5. Synthesis. Our study indicates that local and global patterns of phenotypic integration differ and calls into question the use of trait dimensions at local scales. We propose that a network approach to assessing plant function more effectively reflects the multiple trade-offs and constraints shaping the phenotype in locally co-occurring species.

In mountainous areas of southwestern China, especially Guizhou province, continuous, broadly distributed karst landscapes with harsh and fragile habitats often lead to land degradation. Research indicates that vegetation located in karst terrains has low aboveground biomass and land degradation that reduces vegetation biomass, but belowground biomass measurements are rarely reported. Using the soil pit method, we investigated the root biomass of karst vegetation in five land cover types: grassland, grass–scrub tussock, thorn–scrub shrubland, scrub–tree forest, and mixed evergreen and deciduous forest in Maolan, southern Guizhou province, growing in two different soil-rich and rock-dominated habitats. The results show that roots in karst vegetation, especially the coarse roots, and roots in rocky habitats are mostly distributed in the topsoil layers (89 % on the surface up to 20 cm depth). The total root biomass in all habitats of all vegetation degradation periods is 18.77 Mg ha611, in which roots in rocky habitat have higher biomass than in earthy habitat, and coarse root biomass is larger than medium and fine root biomass. The root biomass of mixed evergreen and deciduous forest in karst habitat (35.83 Mg ha611) is not greater than that of most typical, non-karst evergreen broad-leaved forests in subtropical regions of China, but the ratio of root to aboveground biomass in karst forest (0.37) is significantly greater than the mean ratio (0.26 ± 0.07) of subtropical evergreen forests. Vegetation restoration in degraded karst terrain will significantly increase the belowground carbon stock, forming a potential regional carbon sink.

Leaf dry mass per unit area (LMA) is a product of leaf thickness (T) and of density (D). Greater T is associated with greater foliar photosynthetic rates per unit area because of accumulation of photosynthetic compounds; greater D results in decreased foliage photosynthetic potentials per unit dry mass because of lower concentrations of assimilative leaf compounds and decreases in intercellular transfer conductance to CO2. To understand the considerable variation in T and D at the global scale, literature data were analyzed for 558 broad-leaved and 39 needle-leaved shrubs and trees from 182 geographical locations distributed over all major earth biomes with woody vegetation. Site climatic data were interpolated from long-term world climatologies (monthly precipitation, surface temperature) or modeled using the Canadian Climate Center Model (monthly global solar radiation). Influences of total annual precipitation (WT), precipitation of the driest month (Wmin), monthly mean precipitation of the three driest months in the year (W3 min), highest monthly precipitation (Wmax), precipitation index ([Wmax- Wmin]/WT), mean, minimum, and maximum annual monthly temperatures, and daily annual mean global solar radiation (R) on LMA, D, and T were tested by simple and multiple linear and log-linear regression analyses. In broad-leaved species, LMA and T increased with increasing R and mean temperature and scaled weakly and negatively with precipitation variables, but D was negatively related only to precipitation. Similar relationships were also detected in needle-leaved species, except that, in multiple regression analysis, precipitation did not significantly influence leaf thickness, and R was positively related to D. Given that increases in LMA and T are compatible with enhanced photosynthetic capacities per unit leaf area, but also with greater costs for construction of unit surface area, positive effects of solar irradiance and surface temperature on these variables are indicative of shorter leaf pay-back times in conditions of higher irradiance and temperature allowing construction of leaves with higher photosynthetic potential. To gain insight into the scaling of leaf density with site aridity, correlations of D with the leaf elastic modulus close to full turgor ( ) and with the leaf osmotic potentials ( ) at full and zero turgor were analyzed. Both low , which is compatible with low leaf water potential, and high , which permits large adjustment of leaf water potential with small changes in leaf water content, may facilitate water uptake from drying soil. Leaf elastic modulus was independent of T and was weakly related to LMA; but there were close positive associations of with D and leaf dry to fresh mass ratio, which is an estimate of apoplastic leaf fraction. Consequently, changes in D bring about modifications in leaf elasticity and allow tolerance of water limitations. Across all the data, and the estimates of were negatively related. However, given that varied only fourfold, but 10-fold, I conclude that osmotic adjustment of leaf water relations is inherently limited, and that elastic adjustment resulting from changes in leaf structure may be a more important and general way for plants to adapt to water-limited environments.

Changes in plant growth, photosynthetic gas exchange, chlorophyll fluorescence and stem diameter of soybean [Glycine max (L.) Merr.] plants under drought stress were studied. Total plant dry mass was reduced by 30% compared to well-watered control plants. Leaf water potential was slightly decreased by water stress. Water stress induced daytime shrinkage and reduced night-time expansion of stem. Photosynthetic rate, stomatal conductance and transpiration rate were significantly declined by water stress, while the intercellular CO2 concentration was changed only slightly at the initiation of stress treatment. The maximum photochemical efficiency of photosystem 2 and apparent photosynthetic electron transport rate were not changed by water stress..

Variation in plant functional traits results from evolutionary and environmental drivers that operate at a variety of different scales, which makes it a challenge to differentiate among them. In this article we describe patterns of functional trait variation and trait correlations within and among habitats in relation to several environmental and trade-off axes. We then ask whether such patterns reflect natural selection and can be considered plant strategies. In so doing we highlight evidence that demonstrates that (1) patterns of trait variation across resource and environmental gradients (light, water, nutrients, and temperature) probably reflect adaptation, (2) plant trait variation typically involves multiple-correlated traits that arise because of inevitable trade-offs among traits and across levels of whole-plant integration and that must be understood from a whole-plant perspective, and (3) such adaptation may be globally generalizable for like conditions; i. e., the set of traits (collections of traits in syndromes) of taxa can be considered as "plant strategies." [References: 166]

Abstract Recent studies have shown that accounting for intraspecific trait variation (ITV) may better address major questions in community ecology. However, a general picture of the relative extent of ITV compared to interspecific trait variation in plant communities is still missing. Here, we conducted a meta-analysis of the relative extent of ITV within and among plant communities worldwide, using a data set encompassing 629 communities (plots) and 36 functional traits. Overall, ITV accounted for 25% of the total trait variation within communities and 32% of the total trait variation among communities on average. The relative extent of ITV tended to be greater for whole-plant (e.g. plant height) vs. organ-level traits and for leaf chemical (e.g. leaf N and P concentration) vs. leaf morphological (e.g. leaf area and thickness) traits. The relative amount of ITV decreased with increasing species richness and spatial extent, but did not vary with plant growth form or climate. These results highlight global patterns in the relative importance of ITV in plant communities, providing practical guidelines for when researchers should include ITV in trait-based community and ecosystem studies. 2015 John Wiley & Sons Ltd/CNRS.

The adaptation of plant species to their biotic and abiotic environment is manifested in their traits. Suites of correlated functional traits may reflect fundamental tradeoffs and general plant strategies and hence represent trait spectra along which plant species can vary according to their respective strategies. However, the functional interpretation of these trait spectra requires the inspection of their relation to plant performance. We employed principle coordinate analysis (PCoA) to quantify fundamental whole-plant trait spectra based on 23 traits for 305 North American woody species that span boreal to subtropical climates. We related the major axes of PCoA to five measures of plant performance (i.e., growth rate, and tolerance to drought, shade, water-logging and fire) for all species and separately for gymnosperms and angiosperms. Across all species a unified gymnosperm-angiosperm trait spectrum (wood density, seed mass, rooting habit) is identified, which is correlated with drought tolerance. Apart from this, leaf type and specific leaf area (SLA) strongly separate gymnosperms from angiosperms. For gymnosperms, one trait spectrum emerges (seed mass, rooting habit), which is positively correlated with drought tolerance and inversely with shade tolerance, reflecting a tradeoff between these two strategies due to opposing trait characteristics. Angiosperms are functionally more diverse. The trait spectra related to drought tolerance and shade tolerance are decoupled and three distinct strategies emerge: high drought tolerance (low SLA, dense wood, heavy seeds, taproot), high shade tolerance (high SLA, shallow roots, high toxicity, opposite arranged leaves), and fast growth/stress intolerance (large maximum heights, soft wood, light seeds, high seed spread rate). In summary, our approach reveals that complex suits of traits and potential tradeoffs underlie fundamental performance strategies in forests. Studies relying on small sets of plant traits may not be able to reveal such underlying strategies. Read More: http://www.esajournals.org/doi/abs/10.1890/ES13-00143.1

Summary Plant functional types (PFTs) aggregate the variety of plant species into a small number of functionally different classes. We examined to what extent plant traits, which reflect species’ functional adaptations, can capture functional differences between predefined PFTs and which traits optimally describe these differences. We applied Gaussian kernel density estimation to determine probability density functions for individual PFTs in an n -dimensional trait space and compared predicted PFTs with observed PFTs. All possible combinations of 1–6 traits from a database with 18 different traits (total of 1802287 species) were tested. A variety of trait sets had approximately similar performance, and 4–5 traits were sufficient to classify up to 85% of the species into PFTs correctly, whereas this was 80% for a bioclimatically defined tree PFT classification. Well-performing trait sets included combinations of correlated traits that are considered functionally redundant within a single plant strategy. This analysis quantitatively demonstrates how structural differences between PFTs are reflected in functional differences described by particular traits. Differentiation between PFTs is possible despite large overlap in plant strategies and traits, showing that PFTs are differently positioned in multidimensional trait space. This study therefore provides the foundation for important applications for predictive ecology.

Abstract Despite being recognized as a promoter of diversity and a condition for local coexistence decades ago, the importance of intraspecific variance has been neglected over time in community ecology. Recently, there has been a new emphasis on intraspecific variability. Indeed, recent developments in trait-based community ecology have underlined the need to integrate variation at both the intraspecific as well as interspecific level. We introduce new T-statistics ('T' for trait), based on the comparison of intraspecific and interspecific variances of functional traits across organizational levels, to operationally incorporate intraspecific variability into community ecology theory. We show that a focus on the distribution of traits at local and regional scales combined with original analytical tools can provide unique insights into the primary forces structuring communities. Copyright 2011 Elsevier Ltd. All rights reserved.

Abstract Great uncertainty exists in the global exchange of carbon between the atmosphere and the terrestrial biosphere. An important source of this uncertainty lies in the dependency of photosynthesis on the maximum rate of carboxylation ( V cmax) and the maximum rate of electron transport ( J max). Understanding and making accurate prediction of C fluxes thus requires accurate characterization of these rates and their relationship with plant nutrient status over large geographic scales. Plant nutrient status is indicated by the traits: leaf nitrogen (N), leaf phosphorus (P), and specific leaf area (SLA). Correlations between V cmax and J max and leaf nitrogen (N) are typically derived from local to global scales, while correlations with leaf phosphorus (P) and specific leaf area (SLA) have typically been derived at a local scale. Thus, there is no global-scale relationship between V cmax and J max and P or SLA limiting the ability of global-scale carbon flux models do not account for P or SLA. We gathered published data from 24 studies to reveal global relationships of V cmax and J max with leaf N, P, and SLA. V cmax was strongly related to leaf N, and increasing leaf P substantially increased the sensitivity of V cmax to leaf N. J max was strongly related to V cmax, and neither leaf N, P, or SLA had a substantial impact on the relationship. Although more data are needed to expand the applicability of the relationship, we show leaf P is a globally important determinant of photosynthetic rates. In a model of photosynthesis, we showed that at high leaf N (3 gm 2), increasing leaf P from 0.05 to 0.22 gm 2 nearly doubled assimilation rates. Finally, we show that plants may employ a conservative strategy of J max to V cmax coordination that restricts photoinhibition when carboxylation is limiting at the expense of maximizing photosynthetic rates when light is limiting.

An important aim of plant ecology is to identify leading dimensions of ecological variation among species and to understand the basis for them. Dimensions that can readily be measured would be especially useful, because they might offer a path towards improved worldwide synthesis across the thousands of field experiments and ecophysiological studies that use just a few species each. Four dimensions are reviewed here. The leaf mass per area-leaf lifespan (LMA-LL) dimension expresses slow turnover of plant parts (at high LMA and long LL), long nutrient residence times, and slow response to favorable growth conditions. The seed mass-seed output (SM-SO) dimension is an important predictor of dispersal to establishment opportunities (seed output) and of establishment success in the face of hazards (seed mass). The LMA-LL and SM-SO dimensions are each underpinned by a single, comprehensible tradeoff, and their consequences are fairly well understood. The leaf size-twig size (LS-TS) spectrum has obvious consequences for the texture of canopies, but the costs and benefits of large versus small leaf and twig size are poorly understood. The height dimension has universally been seen as ecologically important and included in ecological strategy schemes. Nevertheless, height includes several tradeoffs and adaptive elements, which ideally should be treated separately. Each of these four dimensions varies at the scales of climate zones and of site types within landscapes. This variation can be interpreted as adaptation to the physical environment. Each dimension also varies widely among coexisting species. Most likely this within-site variation arises because the ecological opportunities for each species depend strongly on which other species are present, in other words, because the set of species at a site is a stable mixture of strategies.

There is a spectrum from species with narrow, frequently branched twigs carrying small leaves and other appendages, to species with thick twigs carrying large leaves and appendages. Here we investigate the allometry of this spectrum and its relationship to two other important spectra of ecological variation between species, the seed mass-seed output spectrum and the specific leaf area-leaf lifespan spectrum. Our main dataset covered 33 woody dicotyledonous species in sclerophyll fire-prone vegetation on low nutrient soil at 1,200 mm annual rainfall near Sydney, Australia. These were phylogenetically selected to contribute 32 evolutionary divergences. Two smaller datasets, from 390 mm annual rainfall, were also examined to assess generality of cross-species patterns. There was two to three orders of magnitude variation in twig cross-sectional area, individual leaf size and total leaf area supported on a twig across the study species. As expected, species with thicker twigs had larger leaves and branched less often than species with thin twigs. Total leaf area supported on a twig was mainly driven by leaf size rather than by the number of leaves. Total leaf area was strongly correlated with twig cross-section area, both across present-day species and across evolutionary divergences. The common log-log slope of 1.45 was significantly steeper than 1. Thus on average, species with tenfold larger leaves supported about threefold more leaf area per twig cross-section, which must have considerable implications for other aspects of water relations. Species at the low rainfall site on loamy sand supported about half as much leaf area, at a given twig cross-section, as species at the low rainfall site on light clay, or at the high rainfall site. Within sites, leaf and twig size were positively correlated with seed mass, and negatively correlated with specific leaf area. Identifying and understanding leading spectra of ecological variation among species is an important challeng

Abstract The tissue traits and architectures of plant species are important for land-plant ecology in two ways. First, they control ecosystem processes and define habitat and resources for other taxa; thus, they are a high priority for understanding the ecosystem at a site. Second, knowledge of trait costs and benefits offers the most promising path to understanding how vegetation properties change along physical geography gradients. There exists an informal shortlist of plant traits that are thought to be most informative. Here, we summarize recent research on correlations and tradeoffs surrounding some traits that are prospects for the shortlist. By extending the list and by developing better models for how traits influence species distributions and interactions, a strong foundation of basic ecology can be established, with many practical applications.

A key element of most recently proposed plant strategy schemes is an axis of resource capture, usage and availability. In the search for a simple, robust plant trait (or traits) that will allow plants to be located on this axis, specific leaf area is one of the leading contenders. Using a large new unpublished database, we examine the variability of specific leaf area and other leaf traits, the relationships between them, and their ability to predict position on the resource use axis. Specific leaf area is found to suffer from a number of drawbacks; it is both very variable between replicates and much influenced by leaf thickness. Leaf dry-matter content (sometimes referred to as tissue density) is much less variable, largely independent of leaf thickness and a better predictor of location on an axis of resource capture, usage and availability. However, it is not clear how useful dry matter content will be outside northwest Europe, and in particular in dry climates with many succulents.

Global data sets provide strong evidence of convergence for leaf structure with leaf longevity such that species having thick leaves, low specific leaf area, low mass-based nitrogen concentrations, and low photosynthetic rates typically exhibit long leaf life span. Leaf longevity and corresponding leaf structure have also been widely linked to plant potential growth rate, plant competition, and nutrient cycling. We hypothesized that selection forces leading to variation in leaf longevity and leaf structure have acted simultaneously and in similar directions on the longevity and structure of the finest root orders. Our four-year study investigated the links between root and leaf life span and root and leaf structure among 11 north-temperate tree species in a common garden in central Poland. Study species included the hardwoods Acer pseudoplatanus L., Acer platanoides L., Fagus sylvatica L., Quercus robur L., and Tilia cordata Mill.; and the conifers Abies alba Mill., Larix decidua Mill., Picea abies (L.) Karst., Pinus nigra Arnold, Pinus sylvestris L., and Pseudotsuga menziesii (Mirbel) Franco. Leaf life span, estimated by phenological observations and needle cohort measurements, ranged from 0.5 to 8 yr among species. Median fine-root life span, estimated using minirhizotron images of individual roots, ranged from 0.5 to 2.5 yr among species. Root life span was not correlated with leaf life span, but specific root length was significantly correlated with specific leaf area. Root nitrogen: carbon ratio was negatively correlated with root longevity, which corroborates previous research that has suggested a trade-off between organ life span and higher organ N concentrations. Specific traits such as thickened outer tangential walls of the exodermis were better predictors of long-lived roots than tissue density or specific root length, which have been correlated with life span in previous studies. Although theories linking organ structure and function suggest that similar root and leaf traits should be linked to life span and that root and leaf life span should be positively correlated, our results suggest that tissue structure and longevity aboveground (leaves) can contrast markedly with that belowground (roots).

61 Background and Aims When ecologically important plant traits are correlated they may be said to constitute an ecological 'strategy' dimension. Through identifying these dimensions and understanding their inter-relationships we gain insight into why particular trait combinations are favoured over others and into the implications of trait differences among species. Here we investigated relationships among several traits, and thus the strategy dimensions they represented, across 2134 woody species from seven Neotropical forests. 61 Methods Six traits were studied: specific leaf area (SLA), the average size of leaves, seed and fruit, typical maximum plant height, and wood density (WD). Trait relationships were quantified across species at each individual forest as well as across the dataset as a whole. 'Phylogenetic' analyses were used to test for correlations among evolutionary trait-divergences and to ascertain whether interspecific relationships were biased by strong taxonomic patterning in the traits. 61 Key Results The interspecific and phylogenetic analyses yielded congruent results. Seed and fruit size were expected, and confirmed, to be tightly related. As expected, plant height was correlated with each of seed and fruit size, albeit weakly. Weak support was found for an expected positive relationship between leaf and fruit size. The prediction that SLA and WD would be negatively correlated was not supported. Otherwise the traits were predicted to be largely unrelated, being representatives of putatively independent strategy dimensions. This was indeed the case, although WD was consistently, negatively related to leaf size. 61 Conclusions The dimensions represented by SLA, seed/fruit size and leaf size were essentially independent and thus conveyed largely independent information about plant strategies. To a lesser extent the same was true for plant height and WD. Our tentative explanation for negative WD-leaf size relationships, now also known from other habitats, is that the traits are indirectly linked via plant hydraulics.

Bringing together leaf trait data spanning 2,548 species and 175 sites we describe, for the first time at global scale, a universal spectrum of leaf economics consisting of key chemical, structural and physiological properties. The spectrum runs from quick to slow return on investments of nutrients and dry mass in leaves, and operates largely independently of growth form, plant functional type or biome. Categories along the spectrum would, in general, describe leaf economic variation at the global scale better than plant functional types, because functional types overlap substantially in their leaf traits. Overall, modulation of leaf traits and trait relationships by climate is surprisingly modest, although some striking and significant patterns can be seen. Reliable quantification of the leaf economics spectrum and its interaction with climate will prove valuable for modelling nutrient fluxes and vegetation boundaries under changing land-use and climate.

探究叶片性状的空间变异性和环境关联性有助于我们理解植物对环境的适应策略和群落建构机制.该研究以浙江 天童5 hrn2大型动态样地所有胸径≥1 cm的木本植物为对象,测定了20 253株个体的单叶面积、比叶面积和叶片干物质含量,土壤总氮、总磷、总碳、pH值、体积含水率、容重和腐殖质,以及海拔、坡度和凹凸度等;并用地统计学 等方法分析了叶片性状的空间变异性及其与环境因子的相关性.结果表明:1)单叶面积的空间变异最大,比叶面积次之,叶片干物质含量最小.三者在 0-5.16m空间范围内表现出较弱的空间自相关,其半变异函数的最优模型分别为高斯模型、指数模型和指数模型.2)叶片性状空间变异具有方向性,单叶面 积空间变异在东北-西南方向上最大,在西北-东南方向上最小;比叶面积和叶片干物质含量的空间变异均在西北-东南方向最大,在东北-西南方向最小.3)单 叶面积与地形因子显著负相关(r=-0.12,p＜0.000 1);比叶面积与土壤养分显著负相关(r=-0.16,p＜0.000 1),叶片干物质含量与土壤养分显著正相关(r=0.13,p＜0.000 1).4)东北-西南方向上,地形因子对单叶面积、比叶面积和叶片干物质含量空间变异的影响大于土壤养分;西北-东南方向上,地形因子对单叶面积空间变异 的影响相对较大,而土壤养分对比叶面积和叶片干物质含量空间变异的影响较大.总之,在研究样地内,植物叶片性状随空间距离和方向存在很大的变异性,叶片性 状与地形因子、土壤养分的关联性间接表明了环境过滤对群落构建的影响.

探究叶片性状的空间变异性和环境关联性有助于我们理解植物对环境的适应策略和群落建构机制.该研究以浙江 天童5 hrn2大型动态样地所有胸径≥1 cm的木本植物为对象,测定了20 253株个体的单叶面积、比叶面积和叶片干物质含量,土壤总氮、总磷、总碳、pH值、体积含水率、容重和腐殖质,以及海拔、坡度和凹凸度等;并用地统计学 等方法分析了叶片性状的空间变异性及其与环境因子的相关性.结果表明:1)单叶面积的空间变异最大,比叶面积次之,叶片干物质含量最小.三者在 0-5.16m空间范围内表现出较弱的空间自相关,其半变异函数的最优模型分别为高斯模型、指数模型和指数模型.2)叶片性状空间变异具有方向性,单叶面 积空间变异在东北-西南方向上最大,在西北-东南方向上最小;比叶面积和叶片干物质含量的空间变异均在西北-东南方向最大,在东北-西南方向最小.3)单 叶面积与地形因子显著负相关(r=-0.12,p＜0.000 1);比叶面积与土壤养分显著负相关(r=-0.16,p＜0.000 1),叶片干物质含量与土壤养分显著正相关(r=0.13,p＜0.000 1).4)东北-西南方向上,地形因子对单叶面积、比叶面积和叶片干物质含量空间变异的影响大于土壤养分;西北-东南方向上,地形因子对单叶面积空间变异 的影响相对较大,而土壤养分对比叶面积和叶片干物质含量空间变异的影响较大.总之,在研究样地内,植物叶片性状随空间距离和方向存在很大的变异性,叶片性 状与地形因子、土壤养分的关联性间接表明了环境过滤对群落构建的影响.

羊草(Leymus chinensis)是我国北方典型草原群落的主要建群种和优势种,由于长期的过度放牧,羊草草原生态系统的结构和功能严重退化。养分添加作为恢复草地生态系统的一种管理措施,其应用目前还处于实验性研究阶段。关于羊草的地上-地下功能性状对养分添加,尤其是P添加的响应研究较少,相关机制尚不十分清楚。为此,该文以羊草为研究对象,通过温室栽培进行N(50,100,250 mg N·kg–1)和P(5,10,25 mg P·kg–1)各3个水平的养分添加实验,研究羊草的地上-地下功能性状对N、P添加的响应及适应机制。主要研究结果表明:1)羊草的地上生物量和总生物量主要受N添加的影响,N添加显著提高了羊草的地上生物量,而地下生物量主要受P添加的影响,尤其在中N和高N水平,P添加显著降低了羊草的地下生物量。羊草的根冠比受N、P添加的共同影响,随着N、P添加梯度加大,根冠比显著降低,N、P添加促进了羊草生物量向地上部分的分配和N、P向叶片的分配。2)在低N和高N水平,羊草对P添加的响应与适应机制不同。低N水平,羊草主要通过增加光合速率和比根长(SRL),提高光合能力和根系对N的获取能力促进地上部分的生长,而根系对P的吸收有利于地下部分的生长;在高N水平,P添加对羊草的个体生长无明显促进作用,甚至地下生物量明显受到P素抑制,羊草主要通过保持较高的比叶面积(SLA)和SRL,提高对光资源的截获能力和根系对N的获取和吸收能力,维持地上部分的生长。3)相对于地上性状,P添加对羊草的地下性状影响更大,羊草的SLA与SRL呈较弱的正相关关系,表明叶片与根系在资源获取和利用方面具有相对独立性。

羊草(Leymus chinensis)是我国北方典型草原群落的主要建群种和优势种,由于长期的过度放牧,羊草草原生态系统的结构和功能严重退化。养分添加作为恢复草地生态系统的一种管理措施,其应用目前还处于实验性研究阶段。关于羊草的地上-地下功能性状对养分添加,尤其是P添加的响应研究较少,相关机制尚不十分清楚。为此,该文以羊草为研究对象,通过温室栽培进行N(50,100,250 mg N·kg–1)和P(5,10,25 mg P·kg–1)各3个水平的养分添加实验,研究羊草的地上-地下功能性状对N、P添加的响应及适应机制。主要研究结果表明:1)羊草的地上生物量和总生物量主要受N添加的影响,N添加显著提高了羊草的地上生物量,而地下生物量主要受P添加的影响,尤其在中N和高N水平,P添加显著降低了羊草的地下生物量。羊草的根冠比受N、P添加的共同影响,随着N、P添加梯度加大,根冠比显著降低,N、P添加促进了羊草生物量向地上部分的分配和N、P向叶片的分配。2)在低N和高N水平,羊草对P添加的响应与适应机制不同。低N水平,羊草主要通过增加光合速率和比根长(SRL),提高光合能力和根系对N的获取能力促进地上部分的生长,而根系对P的吸收有利于地下部分的生长;在高N水平,P添加对羊草的个体生长无明显促进作用,甚至地下生物量明显受到P素抑制,羊草主要通过保持较高的比叶面积(SLA)和SRL,提高对光资源的截获能力和根系对N的获取和吸收能力,维持地上部分的生长。3)相对于地上性状,P添加对羊草的地下性状影响更大,羊草的SLA与SRL呈较弱的正相关关系,表明叶片与根系在资源获取和利用方面具有相对独立性。

Spatial patterns and interspecific associations of plant species in forests are important for revealing how species interact with each other and with the environment, and hence have important implications for optimal forest management and restoration in degraded forest ecosystems. In this paper, the O -ring statistics were used to characterize the spatial patterns and interspecific associations of eight dominant tree species in two 1-ha old-growth karst forest plots in Maolan National Natural Reserve, southwestern China. We found that most of the eight dominant tree species in two forests were continuously regenerating populations. Six species ( Platycarya longipes , Acer wangchii , Clausena dunniana , Castanopsis carlesii var. spinulosa , Distylium myricoides , and Rhododendron latoucheae ) exhibited significant aggregations at the majority of scales while others ( Celtis biondii and Cyclobalanopsis myrsinaefolia ) showed a random distribution pattern at most scales. Negative association was a dominant pattern for most species pairs in the two plots, while positive associations were found at most scales for only two species pairs ( Platycarya – Clausena and Castanopsis – Rhododendron ). Results also indicated that the two main factors of habitat complexity and heterogeneity—the elevation and rock-bareness rate—play important roles in determining spatial distribution patterns and interspecific associations of tree species in karst forests of Maolan. Thus, the observed spatial patterns among the eight tree species are influenced by habitat heterogeneity in the context of karst topographical variations. The partitioning of habitat niches contributes to the promoting species coexistence in species-rich karst forests. The differences of species features in spatial patterns and associations should be paid more attention when planning forest management and developing restoration strategies.