Plant Functional Traits

This study examined the patterns of plant functional trait variation in relation to geomorphology, disturbance and a suite of other environmental factors in the riparian margin of the Upper Hunter River, New South Wales, Australia. Vegetation was surveyed on three geomorphic surfaces (point bar, bench and bank) along a 5.5-km stretch of the Upper Hunter River. Functional traits relating to plant growth and reproduction were collected for the identified species. anova and principal components analysis were used to compare the trait assemblages of species associated with each geomorphic unit. Pearson's correlation coefficients were used to investigate trait variation with respect to environmental variables. There were clear differences in the plant functional trait assemblages associated with the three geomorphic units. Generally the point bar was associated with species that were herbaceous, with small seed mass, a short stature and a high specific leaf area (SLA). Conversely, the bench was associated with grasses that had unassisted seed dispersal and intermediate seed mass and SLA, while species on the bank had tall stature, large seed mass, a high SLA and a perennial life cycle. Variation along the primary gradient of plant functional trait composition was most strongly related to disturbance frequency and to a lesser extent soil nutrients and the proportion of clay and silt, while variation along the secondary gradient was associated with variation in substrate texture as well as soil nutrients.

Abstract. Links between plant traits and the environment, i.e. sets of plant attributes consistently associated with certain environmental conditions, are the consequence of the filtering effect of climatic, disturbance and biotic conditions. These filters determine which components of a species pool are assembled into local communities. We aimed at testing for consistent association between plant traits and climatic conditions along a steep regional gradient, divided into 13 climatically homogeneous sectors, in central-western Argentina. We analyzed 19 vegetative and regeneration traits of the 100 most abundant species along the gradient. For each trait, we tested for homogeneity of frequencies of different categories between sectors and the regional species pool, using the χ2 statistic. We rejected H0 in 71% of the pair-wise comparisons, which strongly suggests a ‘filtering effect’ of climatic factors on key plant functions. Vegetative traits were filtered more often than regeneration traits. Specific leaf area, life span, ramification, canopy height, leaf weight ratio, carbon investment into support tissue and pollination mode were the traits showing differences in the largest number of pair-wise comparisons.This is probably the first attempt to detect, on a quantitative, statistically conservative basis, consistent linkages between climatic factors and numerous plant traits, over a broad spectrum of environmental conditions and plant growth forms. We discuss the advantages and limitations of this approach in predicting vegetation structure and functioning under present environmental conditions, and those expected for the next century as a consequence of global change.

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration , biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this develop...

Ce rapport traite de la comparaison des traits foliaires (SLA, LDMC et surface foliaire) d’une quarantaine d’espèces indigènes et endémiques sur l’île de La Réunion entre deux forêts tropicales humides le long d’un gradient altitudinal (150 et 1600 m). Il traite également d’essais de reproduction d’une vingtaine d’espèces indigènes menacées par la dégradation de leurs milieux naturels dans le but de maitriser leur multiplication et permettre leur insertion dans un ou plusieurs systèmes économiques. Il traite enfin de la mise en place de haies antiérosives à l’aide d’espèces indigènes. La comparaison des traits foliaires a mis en évidence la dominance de l’espèce sur la variation des traits mesurés et les différentes stratégies mises en place par ces espèces. Le processus de multiplication montre la diversité des techniques de multiplication nécessaires entre les espèces à multiplier ainsi que l’ampleur de la tache qu’il reste a accomplir pour maitriser la reproduction de l’ensemble des espèces menacées de l’ile (165 selon l’UICN). Un modèle de haie endémique à été proposé et met en avant un exemple concret d’agroécologie. Ce rapport montre enfin l’intérêt de rassembler et d’organiser l’ensemble des acteurs liés à la protection de l’environnement.
tropical rain forest, native vegetation, endemic, exotic, plant functional traits, plant strategy, degraded environment, endangered species, reproduction methods, erosion, runoff, water quality, hedges.

Research has delivered convincing findings on the effect of biodiversity on ecosystem functioning and humankind. Indeed, ecosystems provide provisioning, regulating, supporting, and cultural services. The global value of annual ecosystem services of grasslands and rangelands is about US$ 232 ha−1 year−1. Nevertheless, the precise evaluation of biodiversity benefits remains challenging. This issue is due to valuation methods, subjective assumptions, and complexity of drivers of plant community dynamics. Here, we review the primary factors that influence plant diversity of permanent grasslands, and we describe underlying processes. These factors must indeed be identified to focus policies meant to preserve and restore plant diversity and to advise farmers about efficient decision rules. We show that plant dynamics of permanent grasslands cannot be explained simply by agricultural management rules, e.g., grazing, fertilization, and mowing, implemented at the field scale. The configuration of the surrounding landscape, e.g., landscape heterogeneity, habitat fragmentation, and connectivity, acts as a species filter that defines the regional species pool and controls seed flow. The regional species pool often contains higher species richness in a heterogeneous landscape, because of a higher diversity of suitable habitats. This regional pool could be a major species sources for permanent grasslands according to the seed flow. We discuss the need to consider all of these factors to understand plant species composition of permanent grasslands and the necessity to study plant communities using both taxonomic and functional approaches. In order to report this integrative approach, we propose a conceptual model based on three ecological challenges—dispersal, establishment, and persistence—that are considered to act as filters on plant diversity, and a graphical representation of the complexity of such studies due to the interaction effects between plant dispersal abilities, forage productivity, disturbances induced by farming practices, and landscape heterogeneity on plant diversity. Last, we discuss the ability of farmers to manage each factor and the necessity of such study in the improvement of the current agro-environment schemes efficiency for farmland biodiversity restoration or preservation.

Abiotic ecosystem properties together with plant species interaction create differences in structural and physiological traits among plant species. Certain plant traits cause a spatial and temporal variation in canopy reflectance that enables the differentiation of plant functional types, using earth observation data. However , it often remains unclear which traits drive the differences in reflectance between plant functional types, since the spectral regions in which electromagnetic radiation is influenced by certain plant traits are often overlapping. The present study aims to assess the relative (statistical) contributions of plant traits to the separability of plant functional groups using their reflectance. We apply the radiative transfer model PROSAIL to simulate optical canopy reflectance of 38 herbaceous plant species based on field-measured traits such as leaf area index, leaf inclination distribution, chlorophyll content, carotenoid content, water and dry matter content. These traits of the selected grassland species were measured in an outdoor plant experiment. The 38 species differed in growth form and strategy types according to Grime 0 s CSR model and hence represented a broad range of plant functioning. We determined the relative (statistical) contribution of each plant trait for separating plant functional groups via reflec-tance. Therein we used a separation into growth forms, that is graminoids and herbs, and into CSR strategy types. Our results show that the relative contribution of plant traits to differentiate between the examined plant functional types (PFT) groups using canopy reflectance depends on the PFT scheme applied. Plant traits describing the canopy structure were more important in this regard than leaf traits. Accordingly, leaf area index (LAI) and leaf inclination showed consistently high importance for separating the examined PFT groups. This indicates that the role of canopy structure for spectrally differentiating PFT might have been underestimated.

Plant dispersal syndromes are allocated based on diaspore morphology and used to predict the dominant mechanisms of dispersal. Many authors assume that only angiosperms with endozoochory, epizoochory or anemochory syndromes have a longdistance dispersal (LDD) mechanism. Too much faith is often placed in classical syndromes to explain historical dispersal events and to predict future ones. What is usually recorded as the 'endozoochory syndrome' is in reality a 'frugivory syndrome' and this has often diverted attention from endozoochory by non-frugivores (e.g. waterbirds and large herbivores) that disperse a broad range of angiosperms, for which they likely provide the maximum dispersal distances. Neither the endozoochory nor the epizoochory syndromes provide helpful predictions of which plants non-frugivores disperse, or by which mechanism. We combined data from previous studies to show that only 4% of European plant species dispersed by ungulate endozoochory belong to the corresponding syndrome, compared to 36% for ungulate epizoochory and 8% for endozoochory by migratory ducks. In contrast, the proportions of these species that are assigned to an 'unassisted syndrome' are 37, 31 and 28%, respectively. Since allocated syndromes do not adequately account for zoochory, empirical studies often fail to find the expected relationship between syndromes and LDD events such as those underlying the colonization of islands or latitudinal migration rates. We need full incorporation of existing zoochory data into dispersal databases, and more empirical research into the relationship between plant traits and the frequency and effectiveness of different dispersal mechanisms (paying attention to unexpected vectors). Acknowledging the broad role of non-frugivores in facilitating LDD is crucial to improve predictions of the consequences of global change, such as how plant distributions respond to climate change, and how alien plants spread. Networks of dispersal interactions between these vertebrates and plants are a vital but understudied part of the Web of Life.

Wet tropical forests of the world are continuously subjected to human disturbance processes,
which  generate  changes  in  ecosystem  properties  which  in  turn  has  implications  for  the
provision  of  ecosystem  services.  In  this  sense,  the  main  objective  of  this  study  was  to
determine the impacts of human disturbance in the functional diversity of wet tropical forests
of Costa Rica, and its implications for the provision of ecosystem services of carbon fixation
and storage (carbon) and water regulation ecosystem (water). To address this research interest
species belonging to 75% of the basal area of these forests (forest without intervention, low
impact  managed forest,  high impact  managed forest  and secondary forest) were selected in
four  study  periods.  Traits  were  measured  to  carbon  service,  leaf  dry  matter  content,  leaf
content of nitrogen and phosphorus, wood density, growth rate, to  water service; texture of
bark, leaf texture, angle of branch, capacity load of epiphytes and crown density, and finally
traits used in both services, leaf area, specific leaf area, leaf tensile strength, maximum height
and leaf phenology. 
First  we  determined  the  diversity  and  functional  composition  of  the  forests  studied  by  the
weighted  community  mean  (WCM),  functional  diversity  indices  (FDI)  and  multivariate
analysis for grouping into plant functional types (PFT). Second we determined the impacts of
human  disturbance  in  the  functional  diversity  and  its  implications  for  the  provision  of
ecosystem services  carbon and water through the changes of the basal area and biomass of
functional types. It showed that communities with greater taxonomic richness values reported
higher rates of functional diversity and that species locally called "rare" that occupied niches
later as forests recover from disturbance will be occupied by species functionally similar to
those already present. Multivariate analysis determined the 110 species in four plant functional
types  through  the  interaction  of  traits  within  the  spectrum  of  species  "acquisitive"  and
"conservative"  for  the  carbon  services  "conservative  upper-canopy"  (Ic),  “acquisitive
emerging" (IIc), “acquisitive lower-canopy” (IIIc) and "palms” (IVc), the same way for water
service identified  four functional types in the spectrum of species"interceptor"and “catcher"
according  to  performance  in  the  interception  and  collection  of  rainwater,  "catcher  canopy-
upper" (Ia), "interceptor" (IIa), "mid-canopy-catcher” (IIIa) and "emerging interceptor” (IVa).
The  weighted  average  mean  showed:  for  the  carbon  service  the  secondary  forests  was dominated for "acquisitives" species, while in primary forests especially in the forest without
intervention had a greater presence of species "conservative", and likewise for water service,
there  was  a  greater  presence  of  “catcher”  species  in  secondary  forest,  whereas  in  primary
forests increased presence of "interceptor." 
Human  disturbance  caused  changes  in  the  diversity  and  functional  composition  of  these
forests, just as that generated changes in biomass and carbon stored in the "palms" (IVc) and
"conservative upper-canopy” (Ic) while the other two functional types were not affected. For
water service, human disturbance generated changes in the four functional types but with more
intensity in the "emerging-catcher" that are quite similar to the "conservative upper-canopy."
Significantly,  both  basal  area  and  aboveground  biomass  of  these  functional  types  are  in  a
process of recovery, especially in secondary forest, followed by managed forests, while in the
woods  without  intervention  remains  stable,  even  showing  a  slight  tendency  to  decline,
indicating that even without human intervention there is a substantial loss of biomass. It also
became evident that some functional types are more sensitive than others, information of great
importance for the differential management of these forests, although these results should be
validated with further studies at higher spatial and temporal scale.

† Background and Aims Global environmental change will affect non-native plant invasions, with profound potential impacts on native plant populations, communities and ecosystems. In this context, we review plant functional traits, particularly those that drive invader abundance (invasiveness) and impacts, as well as the integration of these traits across multiple ecological scales, and as a basis for restoration and management.
† Scope We review the concepts and terminology surrounding functional traits and how functional traits influence processes at the individual level. We explore how phenotypic plasticity may lead to rapid evolution of novel traits facilitating invasiveness in changing environments and then ‘scale up’ to evaluate the relative importance of demographic traits and their links to invasion rates. We then suggest a functional trait framework for assessing per capita effects and, ultimately, impacts of invasive plants on plant communities and ecosystems. Lastly, we focus on the role of functional trait-based approaches in invasive species management and restoration in the context of rapid, global environmental change.
†Conclusions To understand how the abundance and impacts of invasive plants will respond to rapid environmental changes it is essential to link trait-based responses of invaders to changes in community and ecosystem properties. To do so requires a comprehensive effort that considers dynamic environmental controls and a targeted approach to understand key functional traits driving both invader abundance and impacts. If we are to
predict future invasions, manage those at hand and use restoration technology to mitigate invasive species impacts, future research must focus on functional traits that promote invasiveness and invader impacts under changing conditions, and integrate major factors driving invasions from individual to ecosystem levels.

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration , biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.

Recent syntheses demonstrate that functional composition more often controls ecosystem functioning than does species diversity. Functional trait approaches thus provide a framework to identify biotic mechanisms relevant to ecosystem service delivery. Many ecosystem functions rely on interactions between primary producers and other trophic levels (consumers, detritivores, predators). However, the mechanisms through which these interactions influence ecosystem functioning are still poorly understood. Overlap between traits underlying organisms' response to environment, and traits determining their effects on ecosystem processes, may enhance predictability of ecosystem functioning. This, however, has only been confirmed in a small number of plant-based studies. We present a new conceptual framework which builds on this ‘Holy Grail’ hypothesis by considering functional composition at multiple trophic levels. This framework contributes to the fundamental understanding of complex dyna...

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration , biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this develop...