Leaf Functional Traits Research Articles

Coordination of economics and hydraulic traits shapes the adaptive strategies of tree species in two forest communities with distinct water regimes.

Species distribution is strongly driven by local resource availability, while the coordination and trade-offs among plant functional traits can reveal their adaptive strategies and community assembly in environments of different resource availability. Plant economics and hydraulic traits play fundamental roles in plant environmental adaptation; however, how these key functional traits contribute to the formation of different adaptive strategies to shape community assembly in different environments remains largely unknown. Here, we assess the role of coordinated carbon economics and hydraulic strategies in shaping tree adaptation in environments with two distinct water regimes. We analyzed 20 leaf, stem and root functional traits related to plant economics and hydraulics for 10 tree species from a dry sandy land community and 10 tree species from a neighboring wet valley community. We found an economics spectrum that is coordinated with hydraulic traits, conveying a trade-off between stress tolerance associated with high tissue construction cost and resource acquisition efficiency. Trees in the dry sandy land community adopted a more conservative strategy, characterized by denser tissues, greater dry matter contents, lower carbon assimilation rates, higher leaf drought tolerance, narrower conduits, and larger Huber values, than trees from the valley. The functional coordination across organs was not detected in the sandy land forest, while the coupling of leaf economics and stem hydraulics occurred in the valley forest. Moreover, the trait network was looser in the sandy land forest compared to that in the valley forest. From sandy land to valley forests, the hub traits shifted from root diameter to stem vulnerability index and vessel diameter. Our results demonstrate that the coupled carbon and water related functional traits have played important roles in shaping the adaptive strategies of forest communities with distinct water regimes.

Patterns of Change in Plant Leaf Functional Traits Along an Altitudinal Gradient in a Karst Climax Community

Exploring the changes in plant leaf functional traits in response to altitude across various altitudinal gradients of climax communities in karst regions can elucidate the characteristics of survival strategy adaptations among plant communities. This understanding may also reveal the growth dynamics and driving factors of climax communities in unique habitats. In this study, we examined nine climax communities located in the karst region of Southwest China, categorizing them into three distinct altitude gradients: low-, middle-, and high-altitude communities. By integrating species characteristics and community structure, we analyzed the patterns of change in leaf functional traits among plant communities at different altitudinal gradients and the relationships between these functional traits and environmental factors across the varying altitudes. The results indicated the following: (1) There was a significant difference in the specific leaf area (SLA) of the community as altitude increased, with a gradual decrease observed. The traits exhibiting higher coefficients of variation (CVs) in the leaves of the karst vertex community included the leaf carbon-to-nitrogen ratio (LCN), leaf area (LA), and leaf dry matter content (LDMC). Additionally, the environmental factors with higher CVs included soil organic carbon (SOC), soil phosphorus content (SPC), and the soil carbon-to-phosphorus ratio (SCP). (2) Soil organic carbon content (SOC), total nitrogen content (SNC), carbon-to-phosphorus ratio (SCP), and nitrogen-to-phosphorus ratio (SNP) demonstrated significant differences with increasing altitude. (3) The primary environmental factors influencing plant communities in karst areas included soil nitrogen content (SNC), mean annual temperature (NJW), soil organic carbon content (SOC), soil phosphorus content (SPC), soil water content (SWC), and mean annual precipitation (NJS). Our results indicated that the variation in leaf functional traits with altitude in karst climax communities was inconsistent. Among these traits, the specific leaf area (SLA) showed the most significant variation, and karst climax communities appeared to adapt to environmental changes by regulating traits such as leaf area (LA), leaf dry matter content (LDMC), and leaf carbon-to-nitrogen ratio (LCN). Soil organic carbon (SOC) and soil phosphorus content (SPC) are key factors contributing to habitat heterogeneity in the karst region. The karst climax communities are influenced by both soil and climatic factors along the altitudinal gradient. As altitude increases, these communities tend to adopt a life strategy. Furthermore, high-altitude terminal communities in karst areas are more susceptible to environmental filtering, while low-altitude areas are more affected by limitations in similarity.

Leaf functional traits, insect herbivory, and fungal damage on early Eocene leaf compression fossils, Dolus Hill, Wyoming.

In the fossil record, herbivory and fungal damage can be directly measured. Though herbivory is commonly recorded, only rarely has it been examined with fungal damage and through the lens of functional plant traits. Here, we introduce, date, and use a new well-preserved fossil flora to understand relationships between fungal damage, insect feeding, and leaf traits during a hothouse interval. We constrained the age of Dolus Hill using uranium-lead radioisotopic dating of zircons from tuffaceous sandstone. We identified 611 eudicot leaf fossils, quantified insect feeding and fungal damage, and measured leaf traits on appropriate fossils. Generalized linear models, beta regressions, and Fisher's exact test were applied to elucidate relationships between damage and leaf traits. Dolus Hill was dated to 52.22 ± 0.21 (95% confidence) million years ago and has 18 eudicot morphospecies. Insect damage occurred on 82% of leaves, and 27% had fungal damage. Leaf mass per area had no relationship with any damage metric; leaf vein density had a positive relationship with the number of damage types on a leaf. Percentage area damaged and fungal damage were not affected by these leaf traits. Fungal and insect feeding damage significantly co-occurred. The leaf fossils at the Dolus Hill from the Early Eocene Climatic Optimum provide new insight into plant-fungus interactions and the utility of certain plant trait metrics in the fossil record. These insights will enhance our understanding of plant-fungus-insect interactions within the regime of current rapid climate change.

Reprogramming of Metabolome and Transcriptome Shaped the Elevational Adaptation of Quercus variabilis by Regulating Leaf Functional Traits.

Exploring how plants adapt to environmental changes is key to plant survive and protection under accelerating climate change. Quercus variabilis is widely distributed in China with high economic and ecological value, yet its elevational adaptation mechanism remains unclear. Here, we investigated the leaf functional traits, metabolome and transcriptome of Q. variabilis along an elevational gradient (800-1400 m) in Mt. Li, China. Results showed that leaves at higher elevations became smaller, narrower, thicker, with smaller and denser stomata, and maintained higher levels of nitrogen, soluble sugar, total phenol, lignin and soluble sugar-to-starch ratio. With increasing elevation, Q. variabilis underwent a metabolic shift from being dominated by primary metabolism to secondary metabolism, and 1300 m could be identified as the transition point. Particularly, phenylpropanoid metabolism and its metabolites (flavonoids and phenolic acids) played crucial roles in its adaptation to elevations. Moreover, 24 hub transcription factors (TFs) were screened through WGCNA and verified by RT-qPCR. Environmental factors not only directly influenced leaf functional traits, but also affected metabolite accumulation through TF-mediated gene expression, which in turn influenced leaf functional traits. This study highlights that integrating plant functional traits, metabolome and transcriptome simultaneously provides novel insights into the mechanisms for shaping plants' adaptability.

Different responses of canopy and shrub leaves to canopy nitrogen and water addition in warm temperate forest.

Understanding the effects of nitrogen deposition and increased rainfall on plants is critical for maintaining forest ecosystem services. Although previous studies primarily examined the effects of environmental changes on leaf functional traits, the underlying physiological and metabolic processes associated with these traits remain poorly understood and warrant further investigation. To address this knowledge gap, we evaluated the influence of canopy nitrogen (25 kg ha-1 yr-1) and water (30% of the local precipitation) addition on leaf functional traits, diversity, and associated physiological and metabolic processes in the dominant species of tree and shrub layers. Only the interaction between nitrogen and water significantly reduced the functional richness (FRic) of the community. The other treatments had no notable effects on functional diversity. Importantly, the physiological processes of trees and shrubs showed different regulatory strategies. In addition, there were significant changes in 29 metabolic pathways of the tree, whereas only 18 metabolic pathways were significantly altered in shrub. Among the identified metabolic pathways, four were annotated multiple times, with amino acid metabolism being the most active. These regulatory processes enable the leaves to withstand external disturbances and maintain their relative stability under changing environmental conditions. The study findings underscore the limitations of previous research, which often relied on the direct application of treatments to the understory and so failed to accurately assess the effects of nitrogen and water on leaf functional traits. Future studies should adopt canopy-level nitrogen and water addition to better simulate the impacts of global environmental change.

Community-level foliar stable carbon isotope is dominantly influenced by leaf functional traits in dry Inner Mongolia steppes

Foliar stable carbon isotope is an excellent indicator of plant water use efficiency, providing crucial insights into vegetation dynamics under climate change. However, in arid and semiarid grassland ecosystems, the factors driving variations in community-level foliar stable carbon isotope remain unclear. Here, we combined community-weighted mean foliar stable carbon isotope from 399 sampling sites across three grassland types in Inner Mongolia with environmental factors and leaf traits to reveal the mechanisms driving variations in community-level foliar carbon isotopes. We examined the impact of environmental factors (climate and soil factors) and leaf traits on community-level foliar stable carbon isotope. Our results show that community-level foliar stable carbon isotope variations are predominantly influenced by environmental factors in meadow and typical steppes but by leaf traits in desert steppe. These findings clarify divergent regulatory mechanisms of carbon-water balance in different grasslands, providing critical insights for predicting ecosystem responses to environmental changes.

Impacts of elevated temperature and CO2 concentration on carbon metabolism in an endangered carnation: Consequences for biomass allocation and flowering.

Impacts of elevated temperature and CO2 concentration on carbon metabolism in an endangered carnation: Consequences for biomass allocation and flowering.

Climate warming increases the invasiveness of the exotic Spartina alterniflora in a coastal salt marsh: Implications for invasion management.

Spartina alterniflora is a major invasive C4 grass in coastal wetlands worldwide. It spreads rapidly through both clonal growth and sexual reproduction, causing significant negative impacts on the ecological functions of coastal wetland ecosystems. A key question is whether climate warming will affect its invasiveness and how adaptive management strategies can be developed to address the anticipated climate warming. In this study, open-top chambers (OTCs) were used to elevate temperature (+1.5°C) throughout the entire growing season for two years (2019-2020), we measured the leaf gas exchange, leaf and plant growth functional traits, as well as clonal and sexual reproduction traits of S. alterniflora under the warming and ambient (control) conditions. The results showed that (1) Compared to the control, warming significantly increased shoot biomass of S. alterniflora through both physiological and phenotypic changes in the middle and later periods of the growing season (p<0.05); (2) Warming did not affect clonal shoots (p>0.05), but it increased the shoot biomass allocation to spikes, resulting in higher spike biomass and seed production (both number and weight) compared to the control (p<0.05); (3) Warming induced alterations in seed morphology and mass distribution, leading to an increase in seed floating time (p<0.05), while the weight of the endosperm and embryo remained unaffected, and no differences in seed germination were observed (p>0.05). We concluded that climate warming affected shoot biomass through both physiological and phenotypic modifications and influenced reproductive traits by altering resource allocation to organs and seed composition. The invasiveness of S. alterniflora should increase due to increased shoot biomass, higher seed production, and longer seed floating times. Implementing cutting measures at the early flowering stage is recommended to mitigate the effects of anticipated climate warming.

Soil nutrients and leaf area index interact with species and structural diversity to buffer mangrove productivity against salinity

The comparative roles of species and structural diversity in mitigating the impacts of salinity were evaluated.Greater diversity contributes to mitigating salinity impacts by interacting with nutrients and leaf functional trait.Nutrients and leaf functional trait (leaf area) significantly influenced the effects of salinity on mangrove growth.Future growth models should incorporate functional traits and nutrient availability to improve predictions of mangrove growth under saline conditions.Mangroves show a biogenic response to adjust sea-level rise by accumulating sediment and carbon (vertical soil accretion), reshaping their structure and composition to minimize the effects. Additionally, the often-overlooked factors of soil nutrient availability, functional traits, and stand structure can alter the mangrove diversity-salinity-productivity link. However, how these multiple drivers interplay to maintain growth against salinity still needs to be better understood. Considering all these, we answered two questions: (QI) How do species diversity and structural heterogeneity modulate growth vs. salinity relationships? (QII) To what extent can structural heterogeneity and species diversity create optimal conditions by minimizing the adverse effects of salinity while concurrently maximizing forest growth? To comprehensively understand the interplay between structural and species diversity, nutrient availability, functional traits, and rising salinity, we examined a dataset from 60 permanent plots established in the Sundarbans mangrove forest in Bangladesh. Our results indicated that species diversity less directly contributed to forest growth than structural heterogeneity, nutrient availability (N, P, and K), and leaf area index. While forest structural and species diversity alone is unlikely to optimize growth, incorporating nutrients into the models showed a slight improvement in buffering against salinity. However, when nutrients were combined with the leaf area index, the models indicated a much stronger enhancement in the forest’s resilience to salinity through interactions with these factors, allowing continued growth. In conclusion, our study highlights the relative contributions of species and structural diversity to mangrove growth under stress and the potential roles of nutrients and functional traits. These findings are valuable for forest growth modelling, informing conservation and management strategies for mangroves, particularly in coastal plantations facing environmental changes.

Leaf dry mass per unit area and leaf pigments underlying the higher stomatal conductance of deciduous species relative to evergreen species in Dendrobium

BackgroundLeaf stomatal conductance is an important indicator of photosynthetic capacity. However, stomatal conductance is poorly quantified and rarely explored in the context of the leaf functional traits for epiphytes, particularly when it comes to herbaceous species with different leaf habits (deciduous vs. deciduous species). Here, we investigated leaf stomatal conductance, leaf dry mass per unit area, leaf thickness, stomatal density, abaxial epidermal cell size and pigment contents in 23 Dendrobium evergreen and deciduous species from a greenhouse. Our main objectives were to compare differences in all measured traits between evergreen and deciduous species, and to determine the relationships of leaf stomatal conductance with leaf functional traits and leaf pigments.ResultsThe results showed that the evergreen species of Dendrobium had thicker leaves and higher leaf dry mass per unit area, whereas deciduous species had higher leaf stomatal conductance and higher leaf chlorophyll contents. Leaf stomatal conductance had a negative correlation with leaf thickness, and dry mass per unit area, but a positive correlation with leaf pigment contents. There was a negative correlation between pigment contents and leaf dry mass per unit area.ConclusionThe results reveal the clear differences in leaf stomatal conductance, leaf functional traits and leaf pigments between deciduous and evergreen Dendrobium species, with the form groups showing trait values indicative of less investments in structural components and of more investments in photosynthetic carbon gain. Furthermore, leaf dry mass per unit area and leaf pigments play an important role in shaping leaf stomatal conductance.

Temporal constraints on leaf-level trait plasticity for next-generation land surface models.

Dynamic global vegetation models (DGVMs) are essential for quantifying the role of terrestrial ecosystems in the Earth's climate system, but struggle with uncertainty and complexity. Eco-evolutionary optimality (EEO) theory provides a promising approach to improve DGVMs based on the premise that leaf carbon gain is optimized with resource costs. However, the timescales at which plant traits can adjust to environmental changes are not yet systematically incorporated in EEO-based models. Our aims were to identify temporal constraints on key leaf photosynthetic and leaf functional traits, and develop a conceptual framework for incorporation of temporal leaf trait dynamics in EEO-based models. We reviewed scientific literature on temporal responses of leaf traits associated with stomata and hydraulics, photosynthetic biochemistry, and morphology and lifespan. Subsequent response times were categorized from fast to slow considering physiological, phenotypical (acclimation), and evolutionary (adaptation) mechanisms. We constructed a conceptual framework including several key leaf traits identified from the literature review. We considered temporal separation of dynamics in the leaf interior to atmospheric CO2 concentration (ci:ca) from the optimal ci:ca ratio χ(optimal), and dynamics in stomatal conductance within the constraint of the anatomical maximum stomatal conductance (gsmax). A proof-of-concept was provided by modelling temporally-separated responses in these trait combinations to CO2 and humidity. We identified 15 leaf traits crucial for EEO-based modelling and determined their response mechanisms and timescales. Physiological and phenotypical response mechanisms were considered most relevant for modelling EEO-based trait dynamics, while evolutionary constraints limit response ranges. Our conceptual framework demonstrated an approach to separate near-instantaneous physiological responses in ci:ca from week-scale phenotypic responses in χ(optimal), and to separate minute-scale physiological responses in stomatal conductance from annual-scale phenotypic responses in gsmax. We highlight an opportunity to constrain leaf trait dynamics in EEO-based models based on physiological, phenotypical and evolutionary response mechanisms.

Leaf biomechanical traits predict litter decomposability

Abstract Leaf biomechanical strength is important not only in plant defence strategies but also in “after‐life” effects—determining leaf‐litter decomposability. It is a composite metric that can be evaluated by fracturing a leaf using multiple methods. However, such after‐life effects have not been systematically evaluated. We assessed 40 leaf functional traits, including 12 biomechanical traits measured through three standard tests (i.e. punch, tensile and shearing tests) and categorized as fracture length‐, fracture area‐ or mass‐based traits, to predict leaf‐litter decomposition dynamics among 186 species from diverse functional groups. Categorized as fracture length‐based traits, they outcompeted fracture area‐ and mass‐based traits in predicting decomposition rates, with “force to punch” emerging as the best predictor, followed by “work to shear”. After incorporating all studied traits into a multidimensional trait space, the first principal component axis accounted for 44.3% of the total variation in decomposition rates, whereas excluding biomechanical traits reduced the variation explained to 31.6%. The leaf's inherent resistance properties independently influenced litter decomposability beyond tissue density and lamina thickness, rendering leaf mass per area an incomplete proxy for biomechanical traits. Additionally, using the tensile force for leaves with parallel veins would underestimate leaf‐litter decomposition rates. In contrast, focusing on punch force and shearing work as principal biomechanical traits offers a promising research avenue for an improved understanding of how leaf decomposability is determined. Synthesis. Our results provide the first evaluation of leaf biomechanical traits from three standard physical resistance tests as predictors of leaf‐litter decomposability. These biomechanical traits complement chemical, structural and morphological traits and should be more effectively integrated into existing models to enhance our comprehension of the leaf‐litter decomposition process.

Study on synergistic change strategies of leaf functional traits of common garden plants along the urban-rural gradient-Suzhou, China.

The study of changes in landscape plant responses along the urban-rural gradient can better inform plant allocation strategies to mitigate the ecological risks associated with rapid urban development. This study focused on the trait changes of 10 common garden plants along the urban-rural gradient in Suzhou, selecting 12 leaf functional traits for the investigation to provide a quantitative basis for decision-making and landscape plant management practices. The results showed that: (1) six leaf functional traits, including specific leaf area (SLA), stomatal conductance (Gs), transpiration rate (Tr), leaf nitrogen content per unit of mass (Nmass), leaf potassium content per unit of mass (Kmass), and stomatal size (SS), differed significantly along the urban-rural gradient; (2) the variability and variance characteristics of leaf functional traits varied along the urban-rural gradient among different plants and growth forms; (3) the synergistic changes in leaf functional traits of different garden plants, driven by the urban-rural, differed, which can be further explored to understand plant adaptive strategies in various environments and guide garden plant selection.

Interacting effects of crop domestication and soil resources on leaf and root functional traits.

Domestication altered wheat leaf functional trait expression, and soil amendments altered root trait expression. These alterations shape crop suitability to stressed environments, and informs variety selection for agronomic conditions. Crop traits have been altered through domestication, resulting in syndromes that assist modern crops in contending with environmental constraints. Yet, we have limited understanding of how domestication has shaped the ability of crops to alter leaf and root functional traits for optimal performance under contemporary agronomic conditions, such as water limitation and organic amendments. We used a greenhouse pot experiment that included a wild progenitor of wheat (Aegilops tauschii), three domesticated wheat (Triticum aestivum) varieties (Watkins, Red Fife and Marquis), and three modern wheat varieties (developed from 1969 to 2016) to assess the effects of domestication on crop functional traits under water limitation and under organic and inorganic soil amendments, and to evaluate how this trait expression moderates rhizosphere soil conditions. Leaf functional trait expression varied significantly across wheat domestication classes, with these differences being almost independent of soil amendment or watering treatments. The wild progenitor expressed resource conservative leaf trait values, with low water use efficiency and stomatal conductance. Root trait expression was influenced by both soil amendment and watering treatment, with all wheat lineages expressing acquisitive traits, e.g., higher specific root length and lower root diameter, under organic amendments. Soil amendments and watering treatments impacted rhizosphere conditions, including microbial diversity and acid phosphatase activity, and domestication class impacted fungal diversity. Broadly, domestication altered the expression of wheat leaf functional traits, and soil amendments altered the expression of wheat root functional traits. These alterations in trait expression and rhizosphere soil response shape crop suitability to drought-prone or nutrient stressed environments, and should be considered when selecting varieties for hybridization for contemporary agronomic conditions.

Leaf trait networks of subtropical woody plants weaken along an elevation gradient

Leaf trait networks of subtropical woody plants weaken along an elevation gradient

Woody encroachment and leaf functional traits of ground-layer savanna species

Woody encroachment and leaf functional traits of ground-layer savanna species

Leaf metabolomic traits decipher the invasiveness of Alternanthera philoxeroides in urban wetlands.

Leaf metabolomic traits decipher the invasiveness of Alternanthera philoxeroides in urban wetlands.

Adaptive strategies in plant life forms: assessing the variations in leaf ecological stoichiometry and functional traits

Adaptive strategies in plant life forms: assessing the variations in leaf ecological stoichiometry and functional traits

Simplification of woody plant trait networks among communities along a climatic aridity gradient

Abstract Plant ecological strategies are shaped by numerous functional traits and their trade‐offs. Trait network analysis enables testing hypotheses for the shifting of trait correlation architecture across communities differing in climate and productivity. We built plant trait networks (PTNs) for 118 species within six communities across an aridity gradient, from forest to semi‐desert across the California Floristic Province, based on 34 leaf and wood functional traits, representing hydraulic and photosynthetic function, structure, economics and size. We developed hypotheses for the association of PTN parameters with climate and ecosystem properties, based on theory for the adaptation of species to low resource/stressful environments versus higher resource availability environments with greater potential niche differentiation. Thus, we hypothesized that across community PTNs, trait network connectivity (i.e., the degree that traits are intercorrelated) and network complexity (i.e., the number of trait modules, and the degree of trait integration among modules) would be lower for communities adapted to arid climates and higher for communities adapted to greater water availability, similarly to trends expected for phylogenetic diversity, functional richness and productivity. Further, within given PTNs, we hypothesized that traits would vary strongly in their network connectivity and that the traits most centrally connected within PTNs would be those with the least across‐species variation. Across communities from more arid to wetter climates, PTN architecture varied from less to more interconnected and complex, in association with functional richness, but PTN architecture was independent of phylogenetic diversity and ecosystem productivity. Within the community PTNs, traits with lower species variation were more interconnected. Synthesis. The responsiveness of PTN architecture to climate highlights how a wide range of traits contributes to physiological and ecological strategies with an architecture that varies among plant communities. Communities in more arid environments show a lower degree of phenotypic integration, consistent with lesser niche differentiation. Our study extends the usefulness of PTNs as an approach to quantify tradeoffs among multiple traits, providing connectivity and complexity parameters as tools that clarify plant environmental adaptation and patterns of trait associations that would influence species distributions, community assembly, and ecosystem resilience in response to climate change.

Network Architecture of Leaf Trait Correlations Has Shifted Following Crop Domestication.

Domestication of crops with the goal of improving yield has led to spectacular shifts in phenotypic traits and their correlation patterns. However, it is relatively unknown whether domestication has driven variation in the architecture of trait correlation networks to optimise carbon return on construction cost along the leaf economics spectrum (LES). Here, we compiled a data set of leaf functional, biochemical, and anatomical traits of 54 wild and cultivated crops. We found that crops tended to be located at the acquisitive end of global LES, typically having low leaf mass per area (LMA), high photosynthetic rate per mass, and high leaf nitrogen and phosphorus content per mass. Architectural changes in trait networks (module number, hub traits, and number of correlations) aligned with the notion of a divergent domestication syndrome due to artificial selection for faster growth and higher yield in high-resource agricultural fields. Domestication has increased the carbon return on resource investment via selecting trait combinations including higher photosynthesis, greater leaf area and LMA. We highlight that strategy-shifts towards faster photosynthetic return on investments in leaves have been coordinated with divergent trait correlation, which has important implications for understanding patterns of trait covariation under crop domestication.