Functional divergence drives the prevalence of low‐abundance species in bat assemblages

Variation in leaf functional traits along environmental gradients can reveal how vascular epiphytes respond to broad‐ and small‐scale environmental gradients. Along elevational gradients, both temperature and precipitation likely play an important role as drivers of leaf trait variation, but these traits may also respond to small‐scale changes in light, temperature and humidity along the vertical environmental gradient within forest canopies. However, the relative importance of broad‐ and small‐scale environmental gradients as drivers of variation in leaf functional traits of vascular epiphytes is poorly understood. Here, we examined variation in morphological and chemical leaf traits of 102 vascular epiphyte species spanning two environmental gradients along Cofre de Perote mountain in Mexico: (i) a broad‐scale environmental gradient approximated by elevation as well as by species' lower and upper elevational limits, and (ii) small‐scale environmental gradients using the relative height of attachment of an epiphyte on a host tree as a proxy for variation in environmental conditions within the forest canopy. We also assessed whether variation in morphological and chemical leaf traits along these gradients was consistent across photosynthetic pathways (CAM and C3). Broad‐ and small‐scale environmental gradients explained more variation in chemical traits (marginal R2: 11%–89%) than in morphological traits (marginal R2: 2%–31%). For example, leaf carbon isotope signatures (δ13C), which reflects water‐use efficiency, varied systematically across both environmental gradients, suggesting a decrease in water‐use efficiency with increasing lower and upper elevational limits and an increase in water‐use efficiency with relative height of attachment. The influence of lower and upper elevational limits on trait variation differed between photosynthetic pathways, except for leaf dry matter content and leaf nitrogen‐to‐phosphorus ratio. Contrary to our expectations, broad‐ and small‐scale environmental gradients explained minimal variation in morphological leaf traits, suggesting that environmental conditions do not constrain morphological leaf trait values of vascular epiphytes. Our findings suggest that assessing multiple drivers of leaf trait variation among photosynthetic pathways is key for disentangling the mechanisms underlying responses of vascular epiphytes to environmental conditions. Read the free Plain Language Summary for this article on the Journal blog.

A major goal in plant science is overcoming the recalcitrance of plant biomass to cellulose extraction, to enable efficient production of cellulosic biofuel. We have started to understand the genetic basis of some important traits such as cell wall chemistry, but we do not know anything about the key structural and functional traits such as wood anatomy that greatly affect plant biomass recalcitrance. Furthermore, biofuel feedstocks have to be adapted to varied environmental conditions to ensure high productivity in plantations, but little is known about the molecular mechanisms underlying local adaptation. With the advancement in sequencing and genotyping technologies, association genetics has emerged as a powerful approach for unraveling complex traits in plants, thereby linking the natural variation present in the phenotype with the underlying genotype. Furthermore, the integration of phenotypic, genomic and environmental data has great premise for understanding plant adaptation in the face of climate change. Because of its rapid growth, hybrid vigor, broad geographic distribution, transformation potential, and the availability of tremendous genetic resources and wide phenotypic variation, Populus is a highly desirable genus for biofuel production and other wood products. My dissertation research uses an association genetics approach focused on important anatomical, morphological and physiological traits to address three key questions: (1) What genetic mechanisms underlie variation in morphological and physiological traits in P. trichocarpa? (2) What are the factors affecting local adaptation in P. trichocarpa and what is the relative contribution of climate and geography variables to population structure? (3) What genes or genomic regions are associated with variation in important functional and structural traits that can be targeted to enhance productivity and reduce recalcitrance of woody bioenergy feedstocks? My research will enhance understanding of the biology of Populus trichocarpa by determining the genetic basis of key agronomic traits such as vessel size and density, leaf area, and stomatal density that affect overall performance under field conditions using genome-wide association study (GWAS). Understanding the genetic basis of these traits is key for developing Populus as a biomass feedstock for biofuel production. Furthermore, morphological and structural traits are often tightly correlated with physiological performance. Therefore, another aspect of this study is to unravel the genetic basis of key physiological traits such as leaf chlorophyll content, carbon isotope composition and leaf water potential, and their correlation with morphological traits. This will aid in better understanding of stress tolerance and the overall biology of this species. Furthermore, by

Functional trait divergence underpins many biological invasions, yet its role in native- invasive fish interactions remains poorly understood. Invasive species significantly threaten the native biodiversity by disrupting the functional structure of aquatic communities. The widespread expansion of the invasive gibel carp ( Carassius gibelio ) throughout the European freshwater systems has potentially led to notable decline of the native crucian carp ( Carassius carassius ), yet the specific functional trait mechanisms driving this shift remains unclear. To address this unexplored aspect, we aimed to study the detailed morphometric measurements with a standardized functional trait approach to in order to understand whether divergence in the key morpho- functional ecological traits gives the invasive gibel carp a competitive edge. Samples for both native crucian carp and invasive gibel carp were collected across five sympatric pond systems in Czech Republic, wherein we quantified fourteen morpho-functional traits related to feeding and locomotion in both the species. Our analysis revealed that gibel carp consistently exhibited higher gut length ratios and larger oral gape surfaces than crucian carp, reflecting broader digestive capabilities and an increased ability to exploit diverse food resources, particularly plant and detrital material. Gibel carp also displayed significantly hightened values for the fin morphological traits, including pectoral fin aspect ratio and fin surface to body size ratio, suggesting enhanced maneuverability and habitat access. On the other hand, certain traits such as eye position and body shape showed substantial overlap between the two Carassius species, indicating convergence in certain ecological functions. The observed divergence in feeding and locomotory traits under sympatric conditions indicates that the invasion success of gibel carp is closely associated with increased trophic flexibility and resource acquisition. These functional trait advantages likely underpin rapid population growth and heightened competitive pressure on the native crucian carp population, which continues to decline in the invaded habitats. Our findings therefore, underscore the importance of trait-based analysis for elucidating the ecological processes underlying invasion and highlight the urgent need for targeted conservation actions to protect the critically endangered native crucian carp population.

Intracanopy variation in leaf morphology and physiology in dominant shrubs of Florida’s xeric uplands

Emerging Patterns of Microbial Functional Traits.

Composition, structure and diversity of phyllostomid bat assemblages in different successional stages of a tropical dry forest

Plant communities can influence the structure of soil microbial communities through the combined effects of the quality and quantity of plant‐derived resources. However, the specific mechanisms underlying these effects remain poorly understood. We sampled soil bacterial and fungal communities, as well as plant biomass and functional traits, across nine temperate grassland sites in northern China. We explored how plant community characteristics, including biomass and functional diversity along conservation and collaboration gradients, shape the growth strategies, diversity and composition of soil microbial communities. Our results revealed a coupling of strategies between plant and soil fungal communities. Plant communities dominated by ‘fast‐growing’ or ‘do‐it‐yourself’ strategy species provide readily decomposable carbon sources, which increased fungal diversity and the copiotroph/oligotroph ratio but decreased bacterial diversity. Functional divergence in plant traits along the collaboration gradient positively influenced the copiotroph/oligotroph ratio of fungi but negatively affected that of bacteria, possibly because bacteria are less competitive for limited nutrients. Plant functional composition had a stronger influence on fungal community composition than on bacterial communities, reflecting fungi's greater reliance on symbiosis with plants. These findings underscore the importance of different aspects of plant functional diversity, including functional divergence and community‐weighted mean associated with plant resource acquisition strategies, in shaping soil microbial communities and provide a novel perspective for exploring plant–microbe interactions at the community level. Read the free Plain Language Summary for this article on the Journal blog.

Research over the past decade has shown that quantifying spatial variation in ecosystem properties is an effective approach to investigating the effects of environmental change on ecosystems. Yet, current consensus among scientists is that we need a better understanding of short‐ and long‐term (temporal) variation in ecosystem properties to plan effective ecosystem management and predict future ecologies.Trait‐based approaches can be used to reconstruct ecosystem properties from long‐term ecological records and contribute significantly to developing understandings of ecosystem change over decadal to millennial time‐scales.Here, we synthesise current trait‐based approaches and explore how organisms' functional traits (FTs) can be scaled across time and space. We propose a framework for reconstructing long‐term variation in ecosystems by means of analysing FTs derived from palaeoecological datasets. We then summarise challenges that must be overcome to reconcile trait‐based approaches with palaeo‐datasets. Finally, we discuss the benefits and limitations of trait‐based reconstructions of ecosystem temporal dynamics and suggest future directions for research.Reconstructing environmental properties through time vis‐à‐vis FTs can be separated into two parts. The first is to record trait data for organisms present in modern ecosystems, and the second is to reconstruct temporal variability in FTs from palaeoecological datasets, capturing changes in trait composition over time. Translating palaeoecological datasets into FTs is challenging due to taphonomic, taxonomic and chronological uncertainties, as well as uniformitarian assumptions. Explicitly identifying and addressing these challenges is important to effectively calculate changes in FT through time.Palaeo‐trait research offers insights into questions related to short‐ and long‐term ecosystem functioning, environmental change and extinction and community assembly rules across time. As work in this area matures, we expect that trait‐based approaches integrating palaeoecology and neo‐ecology will improve understanding of past ecologies and provide a deeper insight of their implications for present‐day and future ecosystem management and conservation.Read the freePlain Language Summaryfor this article on the Journal blog.

Studies of community assembly often explore the role of niche selection in limiting the diversity of functional traits (underdispersion) or increasing the diversity of functional traits (overdispersion) within local communities. While these patterns have primarily been explored with morphological functional traits related to environmental tolerances and resource acquisition, plant metabolomics may provide an additional functional dimension of community assembly to expand our understanding of how niche selection changes along environmental gradients. Here, we examine how the functional diversity of leaf secondary metabolites and traditional morphological plant traits changes along local environmental gradients in three temperate forest ecosystems across North America. Specifically, we asked whether co‐occurring tree species exhibit local‐scale over‐ or underdispersion of metabolomic and morphological traits, and whether differences in trait dispersion among local communities are associated with environmental gradients of soil resources and topography. Across tree species, we find that most metabolomic traits are not correlated with morphological traits, adding a unique dimension to functional trait space. Within forest plots, metabolomic traits tended to be overdispersed while morphological traits tended to be underdispersed. Additionally, local environmental gradients had site‐specific effects on metabolomic and morphological trait dispersion patterns. Taken together, these results show that different suites of traits can result in contrasting patterns of functional diversity along environmental gradients and suggest that multiple community assembly mechanisms operate simultaneously to structure functional diversity in temperate forest ecosystems.

Differing ecological conditions are considered drivers of directional selection among or between populations, resulting in ecological speciation. In particular, divergence of phenotypes in differing habitats, or convergence of phenotypes in similar habitats, can be the result of directional selection. Accordingly, species of dwarf chameleons (Bradypodion) that occur in structurally similar habitats tend to converge on a similar phenotype. Conversely, dwarf chameleons from contrasting habitats have been shown to diverge in phenotype. Thus, ecological speciation appears to be a mechanism for diversification in this genus. Using a combination of morphological (functional and ornamental traits) and population genetic analyses (microsatellite loci), we examined whether three closely related Bradypodion lineages have diverged for these dimensions. We assess whether habitats differ in structure for features related to divergence in morphological traits or whether convergence of traits corresponds to similarity in habitat structure. We find that the three taxa differ significantly at a population genetic level, but some allele sharing suggests incomplete lineage sorting or gene flow. Differences among taxa for functional traits related to gripping of branches (e.g., distal limb size [hands/feet]) can be explained by the perch diameters used by chameleons, whereas the degree of ornamentation differs among taxa in different habitats but is convergent for those in similar habitats. These outcomes are congruent with an ecological model of speciation, with taxa having diverged genetically but showing phenotypic convergence when in similar habitats and divergence when in different habitats.

BackgroundGossypium raimondii Ulbr is a diploid wild cotton (2n = 26, D5D5) that originated in west-central Peru of South America and possesses desirable characteristics that are absent in the Upland cotton G. hirsutum. Many beneficial genes were lost from G. hirsutum in the process of domestication, leading to a narrowed genetic base and greater vulnerability to biotic and abiotic stresses. This genetic base can be expanded through distant hybridization using the superior genes of G. raimondii.ResultsIn this study, putative hexaploid F1 plants of G. hirsutum - G. raimondii were generated by interspecific hybridization. Analysis of its mitotic metaphase plates revealed the presence of 78 chromosomes, with each of the six chromosome-specific fluorescence in situ hybridization (FISH) probes (3D5, 5D5, 6D5, 7D5, 9D5, and 10D5) of G. raimondii exhibiting bright and distinct signals on its respective pair of chromosomes. Then, the fertile hexaploid F1 plants were continuously backcrossed with G. hirsutum and a set of G. hirsutum - G. raimondii monosomic alien addition lines (MAALs) were developed using SSR markers in successive backcrosses and self-crossing from BC2F1 to BC4F2. These MAALs were confirmed by chromosome-specific anchored SSRs and FISH. This set of MAALs exhibited abundant variation in morphological traits, agronomic characteristics, yield, and fiber quality traits, as well as in drought and salt resistance at seedling stage. Notably, MAAL_9D5 and MAAL_10D5 demonstrated excellent fiber length (FL), fiber uniformity (FU), fiber strength (FS), micronaire value, and fiber elongation (FE); At seeding stage, MAAL_8D5, MAAL9D5, MAAL_10D5, MAAL_12D5, and MAAL_13D5 showed salt resistance potential; while MAAL_1D5, MAAL_3D5, MAAL_4D5, MAAL_7D5, MAAL_8D5, MAAL_12D5, and MAAL_13D5 exhibited drought resistance potential. These MAALs will provide important genetic bridge materials for gene transfer from G. raimondii as well as for the study of Gossypium species genomes and their evolution.ConclusionsA set of Gossypium hirsutum - Gossypium raimondii MAALs were developed and they showed abundant variation in morphological, agronomic, yield, and fiber quality traits, as well as in drought and salt resistance at seedling stage.

Functional traits and functional diversity measures are increasingly being used to examine land use effects on biodiversity and community assembly rules. Morphological traits are often used directly as functional traits. However, behavioral characteristics are more difficult to measure. Establishing methods to derive behavioral traits from morphological measurements is necessary to facilitate their inclusion in functional diversity analyses. We collected morphometric data from over 1,700 individuals of 12 species of dung beetle to establish whether morphological measurements can be used as predictors of behavioral traits. We also compared morphology among individuals collected from different land uses (primary forest, logged forest, and oil palm plantation) to identify whether intraspecific differences in morphology vary among land use types. We show that leg and eye measurements can be used to predict dung beetle nesting behavior and period of activity and we used this information to confirm the previously unresolved nesting behavior for Synapsis ritsemae. We found intraspecific differences in morphological traits across different land use types. Phenotypic plasticity was found for traits associated with dispersal (wing aspect ratio and wing loading) and reproductive capacity (abdomen size). The ability to predict behavioral functional traits from morphology is useful where the behavior of individuals cannot be directly observed, especially in tropical environments where the ecology of many species is poorly understood. In addition, we provide evidence that land use change can cause phenotypic plasticity in tropical dung beetle species. Our results reinforce recent calls for intraspecific variation in traits to receive more attention within community ecology.

The aim of this study was to evaluate morphological and functional malocclusion trait changes in 3- to 12-year-old children and to determine whether such functional traits at the 3, 4, and 5 years of age correlated with malocclusion severity score at 12 years of age. Two hundred and sixty-seven children (132 boys, 135 girls) were randomly selected for a follow-up study from a previous cohort of 560 subjects. Functional and morphological traits were clinically assessed. Five functional malocclusion traits: mouth breathing, atypical swallowing, thumb, pacifier sucking, and bottle feeding were assessed and evaluated. Intra-arch assessment involved measurements of incisor crowding, rotation of incisors, and axial inclination of the teeth. For inter-arch measurements, overbite, anterior open bite, overjet, reverse overjet, anterior crossbite, and buccal segment relationships were recorded. The weighted sum of recorded occlusal traits thus represented the total malocclusion severity score. The median morphological malocclusion severity score was almost the same at 3 and 12 years of age, while functional malocclusion decreased. Sucking habits (finger- or dummy-sucking, bottle feeding) until 5 years of age were statistically significantly correlated with an atypical swallowing pattern from 6 to 9 years (Spearman r = 0.178, P = 0.017), which in turn was statistically significantly correlated with the morphological malocclusion severity score (Spearman r = 0.185, P = 0.042) at 12 years of age. At an early age, the morphological severity score is related to the stage of dental development, while at a later period, malocclusion severity score is also the result of incorrect orofacial functions at an early stage of dental development.

Leaves and absorptive roots (i.e., first‐order root) are above‐ and belowground plant organs related to resource acquisition; however, it is controversy over whether these two sets of functional traits vary in a coordinated manner. Here, we examined the relationships between analogous above‐ and belowground traits, including chemical (tissue C and N concentrations) and morphological traits (thickness and diameter, specific leaf area and root length, and tissue density) of 154 species sampling from eight subtropical and temperate forests. Our results showed that N concentrations of leaves and absorptive roots were positively correlated independent of phylogeny and plant growth forms, whereas morphological traits between above‐ and belowground organs varied independently. These results indicate that, different from plant economics spectrum theory, there is a complex integration of diverse adaptive strategies of plant species to above‐ and belowground environments, with convergent adaptation in nutrient traits but divergence in morphological traits across plant organs. Our results offer a new perspective for understanding the resource capture strategies of plants in adaptation to heterogeneous environments, and stress the importance of phylogenetic consideration in the discussion of cross‐species trait relationships.

Summary Understanding how environmental factors drive plant community assembly remains a major challenge in community ecology. The strength of different assembly processes along environmental gradients, such as environmental filtering and functional niche differentiation, can be quantified by analysing trait distributions in communities. While environmental filtering affects species occurrence among communities, functional divergence or convergence is strongly related to species abundances within communities, which few studies have taken into account. We examine the trait‐mediated effect of these two processes along a stress‐resource gradient. We measured species abundances and the distributions of eight traits related to vegetative and regenerative phases in plant communities along a gradient of soil depth and resource availability in Mediterranean rangelands. We quantified environmental filtering, defined as a local restriction of trait range, and trait divergence, based on abundance‐weighted trait variance, using a two‐step approach with specifically designed null models. Communities presented a clear functional response to the soil gradient, as evidenced by strong trends in community‐weighted trait means. We detected environmental filtering of different traits at both ends of the gradient, suggesting that, contrary to widespread expectations, trait filtering may not necessarily be the result of abiotic filtering under harsh conditions but could likely also result from biotic interactions in productive habitats. We found marked shifts in trait abundance distributions within communities along the gradient. Vegetative traits (e.g. leaf dry matter content) diverged on shallow soils, reflecting the coexistence of distinct water‐ and nutrient‐use strategies in these constrained habitats and converged with increasing soil resource availability. By contrast, regenerative traits (e.g. seed mass) tended to diverge towards deeper soils, while plant reproductive heights diverged all along the gradient. Synthesis: Our study highlights how the combination of abundance data with traits capturing different functional niches is critical to the detection of complex functional responses of plant communities to environmental gradients. We demonstrate that patterns of trait divergence and filtering are strongly contingent on both trait and environment such that there can be no expectation of a simple trend of increasing or decreasing functional divergence along a gradient of resource availability.