Patterns Of Functional Traits Research Articles

Patterns and driving factors of functional traits of desert species with different elevational distributions in the Tibetan Plateau and adjacent areas

Variations in functional traits serve as measures of plants’ ability to adapt to environment. Exploring the patterns of functional traits of desert plants along elevational gradients is helpful to understand the responses and adaptation strategies of species to changing environments. However, it is unknown whether the relationship between functional traits and elevation is affected by differences in the species’ elevational distributions (elevation preference and species’ range). Importantly, most researches have concerned with differences in mean trait values and ignored intraspecific trait variation. Here, we measured functional traits of desert plants along a wide elevational gradient in the Tibetan Plateau and adjacent areas and explored functional trait patterns over elevation in species with different elevational distributions. We decomposed trait variation and further investigated characterizations of intraspecific variation. Ultimately, the main drivers of trait variation were identified using redundancy analysis. We found that species’ elevational distributions significantly influenced the relationship of functional traits such as plant height, leaf dry matter content, leaf thickness, leaf nitrogen and carbon content with elevation. Species with a lower elevational preference showed greater trait variation than species with a higher elevational preference, suggesting that species that prefer high elevation are more conservative facing environmental changes. We provide evidence that interspecific trait variation in leaf thickness and leaf carbon content decreased with increasing species’ range, indicating that increased variations in resistance traits within species make greater responsiveness to environmental changes, enabling species a wider range. Elevation, temperature and precipitation were the main drivers of trait variation in species with a low elevational preference, while the effect of precipitation on trait variation in species with a high elevational preference was not significant. This study sheds new insights on how plants with different elevational distributions regulate their ecological strategies to cope with changing environments.

Functional trait patterns: investigating variation-covariation relationships and the importance of intraspecific variability along distinct vegetation types

Functional trait patterns: investigating variation-covariation relationships and the importance of intraspecific variability along distinct vegetation types

Satellite hyperspectral imagery reveals scale dependence of functional diversity patterns in a Qinghai-Tibetan alpine meadow

Knowing how functional diversity varies across environmental gradients is crucial in investigating biodiversity formation and community assembly processes. The majority of studies concerning functional diversity are based on one fixed plot size, resulting in weakened sensitivity of the spatial patterns to sampling resolution. This weakness may obscure the true mechanisms behind community assemblage. In this study, we utilized hyperspectral imagery collected by Orbita hyperspectral satellites (OHS) to explore the spatial distribution patterns of functional traits and diversity in alpine meadows at four sampling radii (25 m, 50 m, 100 m, 200 m). We examined how functional traits and their diversity responded to variations in climatic and soil conditions at different sampling resolutions. Our findings revealed a significant influence of solar radiation and soil depth on the patterns of functional traits in alpine meadows. Scale dependency was evident in the functional richness (FRic), functional evenness (FEve), and functional dispersion (FDis) of different traits, indicated by a notable difference from the null model. In the presence of stronger soil nutrient and water limitation, chlorophyll a content (CAC), specific leaf area (SLA), leaf thickness (LT), and plant height (Height) exhibited increased clustering and convergence at larger sampling resolutions, illustrating environmental filtering in habitat patch assembly in the alpine meadow. For the first time, this study explores scale dependency in functional diversity patterns in alpine meadows using satellite-based hyperspectral imagery. It unveils the environmental filtering effect of soil nutrient limitation on shaping vegetation patch structures at a landscape level from a remote sensing perspective. The study underscores the significance of accounting for sampling resolution in future related research.

The Secchi disk depth to water depth ratio affects morphological traits of submerged macrophytes: Development patterns and ecological implications

Water clarity, represented by Secchi disk depth (SD), and water depth (WD) alter bottom light availability, and SD/WD is critical for morphological trait development of submerged macrophytes in freshwater ecosystems. However, the underlying mechanism and trait development patterns of submerged macrophytes to a decreasing SD/WD gradient remains largely unknown. Here, we performed a 42-day mesocosm experiment with the erect type submerged macrophyte, Hydrilla verticillata, along a decreasing SD/WD gradient to study the relationship of morphological trait development with light availability, to determine the critical SD/WD at which changes in the development of morphological traits occur, and to gain insights into the potential mechanism involved. The results indicate that most of the morphological traits, including biomass, relative growth rate, number of clonal propagules, and the root/shoot ratio decreased with a decrease in the SD/WD ratio. Conversely, plant height and shoot increment rate increased with a decrease in the SD/WD ratio. Principal component analysis indicated that the SD/WD ratio is critical in determining the growth, stability, and reproduction of H. verticillata, and that only SD/WD ratios ≥ 0.45 and ≥0.55 ensured growth ability and stability, respectively. Possible development patterns of functional traits in relation to SD/WD reduction were investigated, and patterns of key traits of H. verticillata were distinct from those of Vallisneria natans, indicating different strategies for the adaptation to conditions of decreasing light availability. These results highlight the role of adaptive changes in morphology, resource allocation and life strategies for the maintenance of growth, stability and resilience of submerged macrophytes in low light conditions. Our present study provides a basis from which we could enhance our understanding of the critical transition mechanisms involved in morphological trait development in response to bottom light availability.

Relationships between Environmental Factors and Functional Traits of Macrophyte Assemblages in Running Waters of Greece

The analysis of plant trait composition has raised significant interest among freshwater ecologists as a complementary approach for assessing the effects of environmental change on ecosystem functions. In this study, we investigated patterns of functional traits of the aquatic macrophyte assemblages of 74 lotic ecosystems of Greece, and we identified associations between species traits and environmental variables (hydromorphological and physicochemical parameters) through testing the hypothesis that the environmental features determine the spatial structure of traits. We allocated 12 traits to a total of 39 hydrophyte species, and we conducted RLQ and fourth corner analysis to explore relationships between species, trait composition, and environmental gradients. Based on the results of the RLQ, a hierarchical cluster analysis was conducted to identify groups of plants that share common trait characteristics. Plants were discriminated into five discrete groups based mostly on their life form (e.g., free-floating, rooted submerged etc.) and their ecological preference for nitrogen levels. Hydromorphological parameters had a higher contribution than physicochemical variables in explaining the total variance of the trait data, with water abstraction, channel substrate, and hydrologic alteration being the most important. Our analysis did not reveal significant bivariate relationships between single traits and environmental parameters, although the five groups of macrophyte assemblages appeared to associate with certain environmental gradients. Free-floating and emergent plants were related to higher concentrations of nutrients, whereas rooted submerged plants were related to higher oxygen concentration and increased pH. In addition, free-floating plants were highly associated with metrics of hydromorphological change. Our findings showed clear discrimination of macrophytes based on their functional composition and association of traits with environmental gradients. Thus, further research could explore whether macrophyte functional groups can serve as indicators of environmental change and the overall ecosystem health.

The change pattern of CSR ecological strategy of trees and seedlings during different succession stages in tropical lowland rainforests

Monitoring changes to growth-survival strategies is beneficial during plant growth and development to understand the dynamics of community succession. We measured key leaf traits and calculated competition, stress-tolerance, and ruderals ecological strategy scores for trees and seedlings in different successional stages in tropical lowland rain forests. We analyzed functional trait patterns and CSR strategies with plant growth and development through the different succession stages. We found that trees used strategies that were shifted from S/CS and CS strategies to CS/CSR strategies along the succession. However, seedlings maintained the use of the S/CSR strategy. Seedlings showed lower leaf dry matter content, higher specific leaf area, and their leaf area was relatively conservative. We also observed that the functional traits of seedlings and large trees showed basically consistent changes through each succession stage. Using the standard deviation of C-, S-, and R-scores, we found that the ecological strategy width of trees is smaller, while seedlings have a wider range of ecological strategies. Together, this information can be used to define plant succession changes with functional plant trait changes using different CSR ecological strategies in tropical rainforests that are a threated due to human activities. The research results provide scientific basis for understanding the strategic change of plant growth and predicting the direction of forest function succession, and also provide theoretical support for the management of tropical lowland rainforest in China.

Bryophyte assembly rules across scales

Abstract Understanding how species assemble into communities is a central issue in community ecology. So far, most studies have focused on the assembly mechanisms of vascular plant communities, while the role of deterministic (environmental filtering and biotic interactions) and stochastic (e.g. dispersal limitation) processes structuring bryophyte assemblages remains poorly understood. To evaluate how different assembly processes shape bryophyte communities in mountain streams, we examined functional trait patterns across spatial scales and along environmental gradients. To do so, we sampled 754 microhabitat plots (0.25 m2) nested within 165 sites (100‐m long stream segments) and 13 sub‐basins, located in the northwest and central‐west of Portugal. At each spatial scale, observed functional diversity indices (Functional Richness and Rao's quadratic entropy) were compared to random expectations derived from null models, followed by the analysis of changes in functional trait patterns along environmental gradients by fitting a series of generalized additive mixed models. At local scales (site and microhabitat plot), coexisting species tended to be more functionally similar than expected, suggesting the prevalence of environmental filtering effects. In contrast, no significant deviations from random expectations were detected at the broadest spatial scale (sub‐basin), indicating the prevalence of stochastic processes. We found contrasting assembly processes along environmental gradients: environmental filtering prevailed in stressful environments, while competitive interactions were more important in favourable conditions. Synthesis. Our results highlight the role of environmental filtering in bryophyte community assembly at fine spatial scales, emphasizing the importance of measuring environmental conditions at the same spatial scales where biotic interactions take place. In line with the stress‐dominance hypothesis, the relative importance of environmental filtering increased with abiotic stress. Thus, analysing functional trait patterns across different spatial scales and environmental gradients may contribute to a better understanding of the mechanisms underlying community assembly.

Irrigated urban trees exhibit greater functional trait plasticity compared to natural stands.

Urbanization creates novel ecosystems comprised of species assemblages and environments with no natural analogue. Moreover, irrigation can alter plant function compared to non-irrigated systems. However, the capacity of irrigation to alter functional trait patterns across multiple species is unknown but may be important for the dynamics of urban ecosystems. We evaluated the hypothesis that urban irrigation influences plasticity in functional traits by measuring carbon-gain and water-use traits of 30 tree species planted in Southern California, USA spanning a coastal-to-desert gradient. Tree species respond to irrigation through increasing the carbon-gain trait relationship of leaf nitrogen per specific leaf area compared to their native habitat. Moreover, most species shift to a water-use strategy of greater water loss through stomata when planted in irrigated desert-like environments compared to coastal environments, implying that irrigated species capitalize on increased water availability to cool their leaves in extreme heat and high evaporative demand conditions. Therefore, irrigated urban environments increase the plasticity of trait responses compared to native ecosystems, allowing for novel response to climatic variation. Our results indicate that trees grown in water-resource-rich urban ecosystems can alter their functional traits plasticity beyond those measured in native ecosystems, which can lead to plant trait dynamics with no natural analogue.

Understanding global and regional patterns of termite diversity and regional functional traits.

Our understanding of broad-scale biodiversity and functional trait patterns is largely based on plants, and relatively little information is available on soil arthropods. Here, we investigated the distribution of termite diversity globally and morphological traits and diversity across China. Our analyses showed increasing termite species richness with decreasing latitude at both the globally, and within-China. In addition, we detected obvious latitudinal trends in the mean community value of termite morphological traits on average, with body size and leg length decreasing with increasing latitude. Furthermore, temperature, NDVI and water variables were the most important drivers controlling the variation in termite richness, and temperature and soil properties were key drivers of the geographic distribution of termite morphological traits. Our global termite richness map is one of the first high resolution maps for any arthropod group and especially given the functional importance of termites, our work provides a useful baseline for further ecological analysis.

Examining the relative influence of dispersal and competition on co-occurrence and functional trait patterns in response to disturbance

Disturbance gradients are particularly useful for understanding the relative influences of competition and dispersal. Shortly after disturbance, plant composition should be influenced more strongly by dispersal than competition; over time, this should reverse, with competition becoming more important. As such, we predicted that plant functional traits associated with high dispersal ability would be over-represented shortly after a disturbance event occurs, while those associated with high competitive ability would have increased representation as time progresses. Additionally, it has been suggested that competitive interactions may contribute to negative co-occurrence patterns; if this is the case, negative co-occurrence patterns should also increase as time-since-disturbance increases. Here, we examine how functional trait and co-occurrence patterns change over time following a herbicide-based disturbance, compared to undisturbed vegetation, in a temperate, old-field grassland dominated by herbaceous perennials. In our study system, negative co-occurrence patterns were most pronounced in disturbed plots one year after herbicide application, consistent with several lines of evidence that dispersal can strongly impact both composition and co-occurrence patterns. Over three years post-disturbance, co-occurrence patterns in disturbed plots decreased, becoming more similar to control plots. This pattern is inconsistent with the expectation that competition contributes to negative co-occurrence patterns, at least over three growing seasons. More pronounced negative co-occurrence patterns were associated with higher species evenness among plots. Functional traits related to increased dispersal (mean seed mass, and proportion of stoloniferous/rhizomatous species) and competitive ability (mean species height, and mean specific leaf area) did not differ significantly across treatments, with the exception of mean height in the third-year post-disturbance; however, the overall trajectory of this trait was inconsistent with theoretical expectations. Overall, co-occurrence patterns changed across the gradient of time-since disturbance, but not as expected; functional trait patterns (trait means, functional diversity measures) were not responsive to our experimental disturbance gradient.

"Realistic strategies" and neutral processes drive the community assembly based on leaf functional traits in a subtropical evergreen broad-leaved forest.

Neutral‐theory‐based stochastic and niche‐theory‐based determinative processes are commonly used to explain the mechanisms of natural community assembly. However, considerable uncertainty remains regarding the relative importance of different ecological processes in shaping forest communities. Functional traits and phylogeny provide important information about plant environmental adaptation strategies and evolutionary history and promise a better mechanistic and predictive understanding of community assembly. Based on nine leaf functional traits and phylogenetic data of 18 dominant species in a Lithocarpus glaber–Cyclobalanopsis glauca evergreen broad‐leaved forest, we analyzed the variation in traits, explored the influence of phylogeny and environment on leaf traits, and distinguished the relative effects of spatial and environmental variables on functional traits and phylogenetic compositions. The results showed the following: (i) Leaf traits had moderate intraspecific variation, and significant interspecific variation existed especially among life forms. (ii) Significant phylogenetic signals were detected only in leaf thickness and leaf area. The correlations among traits both supported “the leaf economics spectrum” at the species and community levels, and the relationships significantly increased or only a little change after removing the phylogenetic influence, which showed a lack of consistency between the leaf functional trait patterns and phylogenetic patterns. We infer the coexistent species tended to adopt “realism” to adapt to their habitats. (iii) Soil total potassium and phosphorus content, altitude, aspect, and convexity were the most critical environmental factors affecting functional traits and phylogenetic composition. Total environmental and spatial variables explained 63.38% of the variation in functional trait composition and 47.96% of the variation in phylogenetic structures. Meanwhile, the contribution of pure spatial factors was significantly higher than that of the pure environment. Stochastic processes played dominant roles in driving community functional trait assembly, but determinative processes such as environmental filtering had a stronger effect on shaping community phylogenetic structure at a fine scale.

CSR Ecological Strategies and Functional Traits of the Co-Existing Species along the Succession in the Tropical Lowland Rain Forest

Trait-based approaches to calculate ecological strategy is important for understanding forest succession dynamics. However, the functional traits and ecological strategy change during succession remain poorly understood. We measured key leaf traits and calculated scores for CSR ecological strategy for 13 co-existing species in different successional stages in tropical lowland rain forests. We analyzed the patterns of functional traits and CSR strategies varied along the succession. The relationship between CSR strategy and environmental factors was examined. Our research results are as follows: (1) In older plots, LDMC was generally lower and SLA was generally higher than younger plots with the succession, the functional traits of the successional co-existing tree species changed, and SLA and LDMC showed significant differences. (2) The co-existing tree species’ strategies shifted from S/CS and CS strategies to CS/CSR and CS strategies along the succession. (3) Ecological strategies are linked to different combinations of environmental factors across the four successional stages. Our study suggests that the co-existing tree species in different succession stages of tropical lowland rain forests have a high degree of resistance and a conservative ecological strategy, which is significantly related to canopy openness, soil water content, and soil nutrients.

藏东木本植物群落功能性状分布与环境的关系

PDF HTML阅读 XML下载 导出引用 引用提醒 藏东木本植物群落功能性状分布与环境的关系 DOI: 10.5846/stxb202205071265 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 科技部第二次青藏高原综合科学考察研究（2019QZKK0301）；国家自然科学基金（31860123，31560153） Functional traits of woody plants along the environmental gradients in eastern Tibet Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:研究植物群落功能性状间的相关关系及其对环境变化的响应，能够有效揭示植物功能性状的权衡模式及其对环境的适应策略。藏东昌都地区位于横断山脉西北部，复杂气候地貌孕育了丰富的植物资源，是青藏高原森林灌丛生态系统主要组分和国际生物多样性保护的热点地区。以藏东森林灌丛群落优势木本植物为研究对象，在大量野外调查基础上，采用相关分析、主成分分析、线性回归和方差分析等方法，研究了该区域植物功能性状间的相关关系、功能性状对环境变量的响应规律以及功能性状的变异来源。结果表明：（1）藏东木本植物表现出适应高寒环境的性状权衡模式，即：比叶面积、叶体积较小而叶干物质含量较大，叶磷含量和叶钾含量协同变化；（2）海拔和气候变量共同驱动着藏东木本植物功能性状的变化，并且藏东木本植物倾向于采取"高投入-慢回报"提高御寒能力的保守型适应策略；（3）海拔是影响藏东植物功能性状变异最显著的环境变量，种间变异在藏东植物群落功能性状随环境变化中起主要作用。研究结果揭示了藏东木本植物功能性状的权衡模式及其对高寒环境的适应策略，有助于加深对藏东自然植物资源分布规律和生态功能的认识，为区域生态系统功能和生物多样性保护提供科学依据。 Abstract:Examining the relationships between functional traits of plant communities and their responses to environmental changes can effectively reveal the trade-off patterns of plant functional traits and their adaptation strategies to the environment. The Qamdo region is located in the northwest of the Hengduan Mountains in eastern Tibet. The complex climate and topography have fostered an abundance of plant resources. It is the main component of the Qinghai-Tibet Plateau forest and shrub ecosystem and a hot spot for international biodiversity conservation. Based on a large number of field investigations, we tested the correlation between plant functional traits, the variation of functional traits with environmental variables, and the sources of variation in functional traits of the dominant woody plants in the forest and shrub community of eastern Tibet using correlation analysis, principal component analysis (PCA), linear regression, and variance analysis. The results showed that:(1) The woody plants in eastern Tibet exhibited a trade-off pattern of adaptation to the high cold environment, characterized by a small specific leaf area (SLA) and leaf volume (LV), a high leaf dry matter content (LDMC), and a synergetic variation between leaf phosphorus content (LNC) and leaf potassium content (LKC). (2) Elevation and climate variables are the primary drivers of variation in functional traits of woody plants in eastern Tibet, and woody plants in eastern Tibet tend to adopt a conservative adaptation strategy of "high input-slow return" to improve their cold resistance. (3) Elevation is the most significant environmental variable influencing the variation of plant functional traits in eastern Tibet. The interspecific variation explains the majority of the total variation in functional traits with the environment in eastern Tibet. The results of this study reveal the trade-off patterns of functional traits of woody plants in eastern Tibet and their adaptation strategies to the high cold environment, which contributes to a better understanding of the distribution pattern and ecological function of natural plant resources in eastern Tibet, and provides a scientific basis for regional ecosystem functional and biodiversity protection. 参考文献 相似文献 引证文献

Phylogenetic conservatism explains why plants are more likely to produce fleshy fruits in the tropics.

Plant functional traits often show strong latitudinal trends. To explain these trends, studies have often focused on environmental variables, correlations with other traits that themselves show latitudinal trends, and phylogenetic conservatism. However, few studies have systematically disentangled the relative contributions of these factors. Using a dataset consisting of 9,370 plant species from Southwest China, we investigated factors affecting fruit type (fleshy vs. dry): plant growth form, environmental constraints (summarized by climate region), and phylogenetic conservatism. Growth form and climate region are often cited in the literature as important explanations for the higher proportion of fleshy fruited species in the tropics. Nonetheless, in our analyses using partial R2 , growth form and climate region explained only 1.7% and 0.3%, respectively, of the variance in fruit type in a model including phylogeny, while phylogenetic conservatism explained 79.5%. Furthermore, phylogenetic conservatism was evenly distributed along the phylogeny, implying that fruit type reflects both ancient and recent phylogenetic relationships. Our findings illustrate the value of parsing out the contributions of explanatory variables and phylogeny to the variance in species' traits. Methods using phylogenies that calculate partial R2 give a more informative tool than traditional methods to explore the phylogenetic patterns of functional traits.

Effects of environmental factors on plant functional traits across different plant life forms in a temperate forest ecosystem

Plant functional traits have been shown to vary with environmental conditions. However, we lack empirical data on how plant functional traits of different plant life forms respond to environmental factors. We studied the influence of environmental conditions on the distribution of plant functional traits in a Quercus wutaishanica forest with the aim of exploring the patterns of functional traits across different life forms and determining the driving factors of functional trait variation at fine spatial scales. We collected data on environmental factors (soil nutrients and soil moisture, canopy variables, topography) of 70 20 m × 20 m plots. Leaves were harvested from 26 species (4 tree species, 7 shrub species and 15 herbaceous species), and community-weighted mean (CWM) trait values for leaf area (LA), leaf mass per unit area (LMA), leaf carbon content (LCC), leaf nitrogen content (LNC), leaf phosphorus content (LPC), and leaf potassium content (LKC) were calculated. We also measured the height (H) of plants. The importance of biotic and abiotic factors in controlling plant functional traits was quantitatively assessed using redundancy analysis (RCA). Regression was used to determine relationships between CWM trait values and environment variables. We found that plant functional traits varied with life forms of plants. LA, LMA and LCC of trees were greater than those of the understory, whereas LNC, LPC and LKC of herbaceous were greater than those of trees. Responses of plant functional traits to environmental factors varied with different life forms. The combined effect of canopy, topography and soil factors had a greater impact on plant functional traits in understory layer than tree layer. General linear models showed that openness is the main factor affecting various functional traits of undergrowth plants, and the relationship between the element content in leaves of herbaceous plants and environmental factors is greater than that of shrub plants. The strong correlation of plant functional traits and environmental factors at fine spatial scales indicates that Q. wutaishanica forests have high spatial variability. Considering the variation of traits in different life form of plants and their interactions with biotic factors, it provides further insights into ecological mechanisms of shaping plant communities and driving plant community dynamics.

A trait‐based approach across the native and invaded range to understand plant invasiveness and community impact

Alien plant species invasiveness and impact on diversity (i.e. species richness and composition) can be driven by the altered competitive interactions experienced by the invader in its invaded range compared to its native range. Trait‐based competition effects on invasiveness can be mediated through size‐asymmetric competition, i.e. a trait suit of the invader that drives competitive dominance, and through ‘niche differences', i.e. trait differentiation and thus minimized competition between invader and the invaded community. In terms of invasion impact, size‐asymmetric competition is expected to result in competitive exclusion of co‐occurring subordinate species, whereas ‘niche differences' might result in competitive exclusion of the most functionally similar co‐occurring species. Although observational work does not allow the full disentanglement of both trait‐based effects, it does allow to verify the occurrence of expected theoretical trait patters. In this study, we explored the trait‐based competition effects on invasiveness and diversity impact for Rosa rugosa in both its invaded range in Belgium and its native range in Japan, based on seven functional traits across 100 vegetation plots. Following the predictions for enhanced invasiveness, we found much lower functional overlap between R. rugosa and the co‐occurring species in the invaded range compared to the native range. This likely also explains the absence of diversity impact in its native range. Despite the absence of changes in species richness in the invaded range, the invader did strongly impact species composition of invaded communities. This impact occurred through strong shade tolerance responses, suggesting size‐asymmetric competition effects and cover loss of co‐occurring dominant species, next to exclusion of co‐occurring species most functionally similar to the invader; suggesting niche difference effects. In conclusion, this case‐study illustrates how exploring functional trait patterns across a species native and invaded range can help in understanding how trait‐based competition processes can affect invasiveness and community impact.

Competitors and ruderals go to town: plant community composition and function along an urbanisation gradient

Urbanisation is expected to function as a filter for plant species by changing the physiochemical environment, causing species turnover along an urbanisation gradient. Analyses of the functional traits of species characteristic of different urbanisation levels allow for comparisons across studies, irrespective of exact species composition. This study aims to examine how plant species and functional traits vary with urbanisation. An independent dataset obtained through the Global Biodiversity Information Facility was used to validate the identified indicator species. The study was performed in Trondheim, Norway. Indicator species of two different urbanisation levels were identified from a structured plot vegetation survey, and their functional traits were contrasted. The functional trait patterns were compared to patterns identified from an independent GBIF dataset. Changes in species composition along the urbanisation gradient identified a shift in environmental‐ and anthropogenic variables, filtering species with different functional traits. Indicators of urban areas displayed higher SLA, nitrogen affinity and disturbance tolerance than indicators from non‐urban areas. Not all functional trait differences observed between the indicator species from the vegetation survey were recognised in the independent dataset from GBIF. Nevertheless, the overall trends were consistent. Urbanisation favours species adhering to different trait syndromes than species outside of urban areas; disturbance‐over stress‐tolerance, and species adapted for rapid resource acquisition rather than species adapted for resource conservation.

吉林蛟河针阔混交林功能性状分布格局及其对地形因素的响应

森林群落的构建过程及其内在机制是生态学研究的热点问题。植物功能性状是指能够代表植物的生活史策略，反映植物对环境变化响应的一系列植物属性。通过植物功能性状的分布格局及其对环境因素的响应有助于推测群落的构建过程及其内在作用机制。以吉林蛟河21.12hm²温带针阔混交林样地为研究对象，采集并测量了样地内34种木本植物的6种不同的功能性状。以20m×20m的样方为研究单元，通过计算平均成对性状距离指数（mean pairwise trait distance；PW）和平均最近邻体性状距离指数（mean nearest neighbor trait distance；NN）来探讨群落中单个性状和综合性状的分布格局。同时结合地形因子采用回归分析探讨功能性状的分布格局对局域生境变化的响应。基于PW的结果显示：单个性状中除叶面积外，其余性状的分布格局均为聚集分布多于离散分布；基于NN的结果显示：除叶面积和最大树高外，其余性状的分布格局为聚集分布多于离散分布。此外，由6种单个性状组成的综合性状的分布格局同样为聚集分布多于离散分布。基于回归分析的结果显示：森林群落中功能性状的分布格局受到海拔、坡度和坡向等因素的显著影响，而凹凸度的影响则不显著。研究结果表明包括环境过滤和生物相互作用的非随机过程能够影响温带针阔混交林的群落构建过程，中性过程对该区域群落构建过程的影响不显著。;Understanding the mechanism and process of community assembly is a key issue in ecological research. Functional traits, which represent plant physiological, morphological, and phenological attributes, have decisive effects on plant growth, survival, reproduction and dispersal. Examining the spatial distribution pattern of plant functional traits and its response to local environmental variation is helpful to speculate the underlying processes and mechanisms that regulate community assembly. In this study, we explored the underlying mechanisms of community assembly using the dataset from a 21.12hm² temperate conifer and broad-leaved mixed forest plot in Jiaohe, Northeast China. Four topographic attributes, including elevation, convexity, slope, and aspect, were measured as local environmental factors. Six functional traits, namely leaf area, specific leaf area, leaf carbon content, leaf nitrogen content, leaf carbon to nitrogen ratio, and maximum tree height, were collected and measured for all 34 woody species that present in this temperate forest plot. Two functional structure indices, including the mean pair-wise trait distance (PW) and the mean nearest neighbor trait distance (NN), were used to explore the spatial distribution pattern of plant traits. Furthermore, regression analyses were used to investigate the response of trait patterns to environmental variation. Based on the results of PW, we found that, except for the leaf area traits, the remaining traits mainly showed the clumped spatial patterns. The results based on NN showed that, except for the leaf area and maximum tree height, the remaining traits presented the clumped spatial patterns. The results of regression analyses showed that the distribution patterns of functional traits were significantly affected by elevation, slope, and aspect. In contrast, convexity had no significant effect on trait distribution in this temperate forest community. Our results indicate that the non-random processes including environmental filtering and biological interactions played important roles in regulating forest community assembly, while the role of neutral process was not significant in this temperate conifer and broad-leaved mixed forest.

Leaf traits and canopy structure together explain canopy functional diversity: an airborne remote sensing approach.

Plant functional diversity is strongly connected to photosynthetic carbon assimilation in terrestrial ecosystems. However, many of the plant functional traits that regulate photosynthetic capacity, including foliar nitrogen concentration and leaf mass per area, vary significantly between and within plant functional types and vertically through forest canopies, resulting in considerable landscape-scale heterogeneity in three dimensions. Hyperspectral imagery has been used extensively to quantify functional traits across a range of ecosystems but is generally limited to providing information for top of canopy leaves only. On the other hand, lidar data can be used to retrieve the vertical structure of forest canopies. Because these data are rarely collected at the same time, there are unanswered questions about the effect of forest structure on the three -dimensional spatial patterns of functional traits across ecosystems. In the United States, the National Ecological Observatory Network's Airborne Observation Platform (NEON AOP) provides an opportunity to address this structure-function relationship by collecting lidar and hyperspectral data together across a variety of ecoregions. With a fusion of hyperspectral and lidar data from the NEON AOP and field-collected foliar trait data, we assessed the impacts of forest structure on spatial patterns of N. In addition, we examine the influence of abiotic gradients and management regimes on top-of-canopy percent N and total canopy N (i.e., the total amount of N [g/m2 ] within a forest canopy) at a NEON site consisting of a mosaic of open longleaf pine and dense broadleaf deciduous forests. Our resulting maps suggest that, in contrast to top of canopy values, total canopy N variation is dampened across this landscape resulting in relatively homogeneous spatial patterns. At the same time, we found that leaf functional diversity and canopy structural diversity showed distinct dendritic patterns related to the spatial distribution of plant functional types.

Functional traits of broad-leaved monocot herbs in the understory and forest edges of a Costa Rican rainforest.

Broad-leaved monocot herbs are widespread and dominant components of the shaded understories of wet neotropical forests. These understory habitats are characterized by light limitation and a constant threat of falling branches. Many shaded understory herb species have close relatives that occupy forest edges and gaps, where light availability is higher and defoliation threat is lower, creating an opportunity for comparative analysis of functional traits in order to better understand the evolutionary adaptations associated with this habitat transition. We documented ecological, morphological and ecophysiological traits of multiple herb species in six monocot families from each of these two habitats in the wet tropical rainforest at the La Selva Biological Station, Costa Rica. We found that a mixture of phylogenetic canalization and ecological selection for specific habitats helped explain patterns of functional traits. Understory herbs were significantly shorter and had smaller leaves than forest edge species. Although the mean number of leaves per plant and specific leaf area did not differ between the two groups, the larger leaf size of forest edge species gave them more than three times the mean plant leaf area. Measures of leaf water content and nitrogen content varied within both groups and mean values were not significantly different. Despite the high leaf nitrogen contents, the maximum photosynthetic rates of understory herbs were quite low. Measures of δ13C as an analog of water use efficiency found significantly lower (more negative) values in understory herbs compared to forest edge species. Clonality was strongly developed in several species but did not show strong phylogenetic patterns. This study highlights many functional traits that differ between broad-leaved monocot species characteristic of understory and forest edge habitats, as well as traits that vary primarily by phylogenetic relatedness. Overall, plant functional traits do not provide a simple explanation for the relative differences in abundance for individual understory and forest edge species with some occurring in great abundance while others are relatively rare.