Variation In Leaf Traits Research Articles

Photosynthetic characteristic and leaf traits variations along a natural light gradient in Acer campestre and Crataegus monogyna

Variations in leaf traits at anatomical, morphological and physiological level were assessed in Acer campestre L. and Crataegus monogyna Jacq. plants in a forest understory-gap-edge light gradient inside a broadleaf deciduous forest. The relative changes of the considered parameters monitored in the two species were compared in terms of intraspecific plasticity. Overall, both species were able to acclimatize to the natural light gradient with different light regime (i.e. low light, medium light and high light), through an integrated response at the three analyzed levels. However, some differences in intraspecific plasticity were detected related to the different shade-tolerance of these species. In particular, the investigated species showed significantly differences in plasticity at morphological level (i.e. leaf area and specific leaf area) with A. campestre having a greater morphological plasticity related to its greater shade-tolerance compared to C. monogyna. At the physiological level, differences in intraspecific plasticity have been identified for those parameters describing a higher drought susceptibility in high light regime (i.e. dark respiration rate, maximum PSII photochemical efficiency and actual quantum yield of photosynthesis) suggesting that A. campestre was less capable to acclimatize to these conditions, thus confirming the trade-off between drought and shade-tolerance.

Leaf trait variation is similar among genotypes of Eucalyptus camaldulensis from differing climates and arises in plastic responses to the seasons rather than water availability.

We used a widely distributed tree Eucalyptus camaldulensis subsp. camaldulensis to partition intraspecific variation in leaf functional traits to genotypic variation and phenotypic plasticity. We examined if genotypic variation is related to the climate of genotype provenance and whether phenotypic plasticity maintains performance in a changing environment. Ten genotypes from different climates were grown in a common garden under watering treatments reproducing the wettest and driest edges of the subspecies' distribution. We measured functional traits reflecting leaf metabolism and associated with growth (respiration rate, nitrogen and phosphorus concentrations, and leaf mass per area) and performance proxies (aboveground biomass and growth rate) each season over a year. Genotypic variation contributed substantially to the variation in aboveground biomass but much less in growth rate and leaf traits. Phenotypic plasticity was a large source of the variation in leaf traits and performance proxies and was greater among sampling dates than between watering treatments. The variation in leaf traits was weakly correlated to performance proxies, and both were unrelated to the climate of genotype provenance. Intraspecific variation in leaf traits arises similarly among genotypes in response to seasonal environmental variation, instead of long-term water availability or climate of genotype provenance.

Leaf trait variation and decomposition in short-rotation woody biomass crops under agroforestry management

The integration of trees into agricultural landscapes has a strong influence on plant-soil interactions, with major impacts on rates of nutrient cycling across multiple spatial scales. Shifts in abiotic conditions owing to agroforestry practices, such as changes in soil nutrient and microclimatic conditions, are commonly identified as primary mechanisms for these changes. Yet agroforestry systems are also likely to influence litter decomposition rates through their influence on morphological and chemical traits of crop leaves and residues. However, explicit evaluations of how agroforestry management results in intraspecific leaf trait plasticity, and how this variation then links with litter decomposition, remain sparse. Using a 30-year-old agroforestry system intercropped with short-rotation willow (Salix dasyclados), we i) examined the effects of agroforestry management (i.e. N2-fixing trees vs. non N2-fixing trees vs. monoculture) and distance from tree row on key crop (willow) leaf morphological (i.e. leaf area, specific-leaf area [SLA]) and chemical (leaf carbon (C) and nitrogen (N) concentration) traits, and then assessed ii) how this intraspecific leaf trait variability influenced decomposition rates. Willow leaves within agroforestry treatments exhibited significantly greater leaf area (p = 0.01), SLA (p = 0.002), and leaf N (p = 0.001) than willow leaves in monoculture. Following a 56-day incubation, willow leaves from agroforestry treatments did not decompose more quickly than those in the monoculture. Our results indicate high intraspecific variation in willow leaf traits owing to agroforestry management. However, intraspecific variation in willow leaf traits did not correspond to statistically significant differences in decomposition rates. We show that variation in willow traits near tree rows in agroforestry systems translates into limited variability in agroecosystems processes such as litter decomposition (as compared to monoculture arrangements). Our results have implications for optimal nutrient management in agroforestry systems.

Combined Analyses of Phenotype, Genotype and Climate Implicate Local Adaptation as a Driver of Diversity in Eucalyptus microcarpa (Grey Box)

Trees are a keystone species in many ecosystems and a critical component of ecological restoration. Understanding their capacity to respond to climate change is essential for conserving biodiversity and determining appropriate restoration seed sources. Patterns of local adaptation to climate between populations within a species can inform such conservation decisions and are often investigated from either a quantitative trait or molecular genetic basis. Here, we present findings from a combined analysis of phenotype (quantitative genetic analysis), genotype (single nucleotide polymorphism (SNP) trait associations), and climate associations. We draw on the strength of this combined approach to investigate pre-existing climate adaptation and its genetic basis in Eucalyptus microcarpa (Grey box), an important tree for ecological restoration in south-eastern Australia. Phenotypic data from a 26-year-old provenance trial demonstrated significant genetic variation in growth and leaf traits at both the family and provenance levels. Growth traits were only associated with temperature, whilst leaf traits were associated with temperature, precipitation and aridity. Genotyping of 40 putatively adaptive SNPs from previous genome-wide analyses identified 9 SNPs associated with these traits. Drawing on previous SNP–climate association results, several associations were identified between all three comparisons of phenotype, genotype and climate. By combining phenotypic with genomic analyses, these results corroborate genomic findings and enhance understanding of climate adaptation in E. microcarpa. We discuss the implication of these results for conservation management and restoration under climate change.

Different responses of leaf and root traits to changes in soil nutrient availability do not converge into a community-level plant economics spectrum

Spatial heterogeneity in soil can influence the distribution of plant communities because plants differ in their ability to acquire resources. In nutrient-poor soils, plants should bear traits that prioritize conservation of resources over growth, whereas the opposite is expected in nutrient-rich soils. A coordinated response to soil fertility, in which leaves and roots converge into the same strategy, would lead to a community-level plant economics spectrum (PEScom). Here, we examine how nutrient availability across different soil types shapes the functional structure of desert shrub communities and how much of this variation is explained by species turnover or intraspecific variability (ITV). We measured leaf and root traits of 16 shrub species in four sites with contrasting soil nutrient availability in the southern edge of the Atacama Desert. In leaves, changes in soil nutrient availability were associated with a leaf economics spectrum, shifting from communities with more acquisitive strategies to communities with more conservative strategies with increasing nutrient limitation. No such pattern of co-variation was observed for roots; thus, the relationship between above and below-ground traits did not fit the PEScom. Variation of leaf traits was mainly determined by species turnover, while for root traits it was determined equally by species turnover and ITV. The lack of a PEScom appears to be related to the co-limitation of multiple resources, which promotes different responses in root traits. We highlight the importance of incorporating leaf and root traits to understand how multiple resource limitation shapes plant ecological strategies.

Intraspecific trait variation and reversals of trait strategies across key climate gradients in native Hawaiian plants and non-native invaders.

Displacement of native plant species by non-native invaders may result from differences in their carbon economy, yet little is known regarding how variation in leaf traits influences native-invader dynamics across climate gradients. In Hawaii, one of the most heavily invaded biodiversity hotspots in the world, strong spatial variation in climate results from the complex topography, which underlies variation in traits that probably drives shifts in species interactions. Using one of the most comprehensive trait data sets for Hawaii to date (91 species and four islands), we determined the extent and sources of variation (climate, species and species origin) in leaf traits, and used mixed models to examine differences between natives and non-native invasives. We detected significant differences in trait means, such that invasives were more resource acquisitive than natives over most of the climate gradients. However, we also detected trait convergence and a rank reversal (natives more resource acquisitive than invasives) in a sub-set of conditions. There was significant intraspecific trait variation (ITV) in leaf traits of natives and invasives, although invasives expressed significantly greater ITV than natives in water loss and photosynthesis. Species accounted for more trait variation than did climate for invasives, while the reverse was true for natives. Incorporating this climate-driven trait variation significantly improved the fit of models that compared natives and invasives. Lastly, in invasives, ITV was most strongly explained by spatial heterogeneity in moisture, whereas solar energy explains more ITV in natives. Our results indicate that trait expression and ITV vary significantly between natives and invasives, and that this is mediated by climate. These findings suggest that although natives and invasives are functionally similar at the regional scale, invader success at local scales is contingent on climate.

Morphological differentiation among populations of Quercus elliptica Neé (Fagaceae) along an environmental gradient in Mexico and Central America

Background: Variation in leaf morphology is an important indicator of how plants respond to different environmental conditions. Leaf trait variation is associated with physiological responses of plants to gradients of humidity and temperature. 
 Objective: We analyzed the variation in the leaf morphological and functional traits of Quercus elliptica and its relationships with environmental and geographic variables across the distribution of this species to evaluate population differentiation using ecological niche models.
 Study species: Quercus elliptica Neé (Fagaceae).
 Study sites and dates: Plants were collected in diverse forest types between 350 and 2,400 m in elevation in Mexico and Central America during 2016 and 2017.
 Methods: We measured and analyzed the differentiation in morphological and functional traits of 4,017 leaves from 402 trees from 41 populations using univariate and multivariate analyses.
 Results: The leaf length and thickness and specific leaf area (SLA) of Q. elliptica were significantly correlated with the seasonality of temperature, precipitation, elevation and aridity. We identified two divergent morphological groups: (1) populations distributed along the Pacific coast with broad and thin elliptical leaves with high SLA values and inhabited humid forests at more than 1,200 m elevation, and (2) populations located along the Gulf of Mexico coast, and in southern Mexico and Central America with thicker, narrower leaves and lower SLA values and inhabited seasonal tropical forests in less than 1,200 m in elevation. 
 Conclusions: Climate and geographic barriers and the ecological niche models supported the population differentiation of Q. elliptica .

The Influence of Taxonomy and Environment on Leaf Trait Variation Along Tropical Abiotic Gradients

Abstract Deconstructing functional trait variation and co-variation across a wide range of environmental conditions should increase the mechanistic understanding of community assembly processes and improve current parameterization of dynamic vegetation models. Here, we present a study that deconstructs leaf trait variation and co-variation to iithin-species, taxonomic-interspecific, and plot-environment components comparing three tropical environmental gradients in Peru, Brazil and Ghana. We measured photosynthetic, chemical and structural leaf traits using a standardized sampling protocol, totalling more than 1,000 individuals belonging to 367 species sampled. Variation associated with the whole interspecific taxonomic component (species+genus+family) for most traits was relatively consistent across environmental gradients, but intra-specificwithin-species variation and the plot-environment variation was strongly dependent on the environmental gradient. Trait-trait co-variation was also strongly linked to the environmental gradient where the traits were measured, although some traits had consistent co-variation components irrespective of environmental gradient. Our results demonstrate that filtering along gradients is mostly expressed through trait intra- and interspecifictaxonomic variation, but that trait co-variation is strongly dependent on the local environment, and thus global trait co-variation relationships might not always apply at smaller scales.

Geographical variation in morphological leaf traits of <i>Huperzia serrata </i>(lycopodiaceae) from Vietnam

Morphological leaf traits can be used to assess adaptive responses of plants to environmental conditions. To assess how the representation of Huperzia serrata leaf traits, such as leaf length (LL), leaf width (LW) and leaf area (LA) response to changes in mean annual temperature (MAT), sunshine duration (SuH), mean annual precipitation (MAP), air humidity (Hu), intraspecific variation of the morphological leaf traits of the species was analyzed along a geographical gradient of Vietnam. The results showed that among the three populations at the three sites, leaf sizes increased with MAT and MAP. Huperzia serrata, climatic factors, morphological leaf traits, Vietnam.

Large‐Scale Geographical Variations and Climatic Controls on Crown Architecture Traits

AbstractCrown architecture is a critical component for a tree to interact with the ambient environment and to compete with neighbors. However, little is known regarding how climate variability may shape crown architecture traits across large geographical extents and whether crown architecture traits have coordinated variations with trunk and leaf traits to climate gradients. Here we used Quercus mongolica trees as an example, used the cutting‐edge terrestrial laser scanning technique to accurately characterize their crown architecture traits, and explored their variabilities along with environmental variability across large climate gradients in northern China. Our results showed that there are significant spatial variations in trunk, crown, and leaf traits even for the same genetic group across large environmental gradients. Tree height and leaf size had tight covariations with precipitation (|R|> 0.8, p < 0.01). We also observed coordinated variations among crown architecture traits related to canopy shape (e.g., primary branch insertion angle, chord length ratio), trunk traits (e.g., tree height), leaf traits (e.g., specific leaf area), and climate variability, highlighting there are likely fundamental evolutionary strategies regulating these covariations. With a projected drier and hotter climate scenario in this region, our results further suggest trees are expected to transit from a “tree shape” to a “shrub shape,” with large ecological and ecophysiological impacts on this region.

Scaling of petiole anatomies, mechanics and vasculatures with leaf size in the widespread Neotropical pioneer tree species Cecropia obtusa Trécul (Urticaceae).

Although the leaf economic spectrum has deepened our understanding of leaf trait variability, little is known about how leaf traits scale with leaf area. This uncertainty has resulted in the assumption that leaf traits should vary by keeping the same pace of variation with increases in leaf area across the leaf size range. We evaluated the scaling of morphological, tissue-surface and vascular traits with overall leaf area, and the functional significance of such scaling. We examined 1,271 leaves for morphological traits, and 124 leaves for anatomical and hydraulic traits, from 38 trees of Cecropia obtusa Trécul (Urticaceae) in French Guiana. Cecropia is a Neotropical genus of pioneer trees that can exhibit large laminas (0.4m2 for C. obtusa), with leaf size ranging by two orders of magnitude. We measured (i) tissue fractions within petioles and their second moment of area, (ii) theoretical xylem hydraulic efficiency of petioles and (iii) the extent of leaf vessel widening within the hydraulic path. We found that different scaling of morphological trait variability allows for optimisation of lamina display among larger leaves, especially the positive allometric relationship between lamina area and petiole cross-sectional area. Increasing the fraction of pith is a key factor that increases the geometrical effect of supportive tissues on mechanical rigidity and thereby increases carbon-use efficiency. We found that increasing xylem hydraulic efficiency with vessel size results in lower leaf lamina area: xylem ratios, which also results in potential carbon savings for large leaves. We found that the vessel widening is consistent with hydraulic optimisation models. Leaf size variability modifies scaling of leaf traits in this large-leaved species.

Variations in leaf economics spectrum traits for an evergreen coniferous species: Tree size dominates over environment factors

Abstract Many leaf traits strongly vary with tree size and environmental factors, but the importance of these factors to intraspecific variations of leaf traits in forest trees has rarely been simultaneously evaluated. We measured needle longevity and specific leaf area (SLA) and nitrogen (N) content of every needle age (0‐ to 4‐year old) for 65 individuals with 0.3–100 cm diameter at breast height (DBH) for an evergreen coniferous species, Pinus koraiensis Sieb. et Zucc., in Northeast China. We simultaneously evaluated the effects of tree size (DBH or tree height) and environment factors (light intensity, soil N content and water availability) on the needle longevity, SLA, foliage N content as well as the slopes of regressions of SLA and foliage N content against needle age. All of the studied leaf traits and slopes of regressions of SLA and foliage N content against needle age were significantly related to tree size. Tree height had a greater impact on SLA and area‐based leaf N content (Narea), whereas DBH was more important for needle longevity and mass‐based leaf N content (Nmass). The environment variables, light intensity, soil N content and water availability, were rather minor factors for trait variations compared with tree size. Significant influence of light intensity was found only on needle longevity, and soil N and water availability had no effects on the leaf traits. Our study clearly showed that tree size is an important driver of intraspecific variations in the key leaf traits of P. koraiensis in a natural forest. We also emphasize the importance of DBH or tree height varies depending on leaf traits, suggesting various mechanisms of size effects on the intraspecific variations in leaf traits. We suggest that ecological significance of leaf trait variations needs reconsideration incorporating tree size effect. A free Plain Language Summary can be found within the Supporting Information of this article.

Leaf herbivory modulates fruit trait correlations within individual plants

Plant performance is based on the relationship between resource acquisition and allocation to complete essential functions. Herbivory causes compromises in resource allocation that impact at the plant and within-plant (sub-individual) levels. This impacts fruit display traits which in turn affect reproductive success and seed dispersal. Because leaf damage affects resource allocation, herbivory should modulate the relationship between fruit display traits. We explore the relation between the level of leaf herbivory (mean damage and coefficient of variation) and fruit display traits in Vassobia breviflora (Solanaceae). According to trait function, we explore relationships between reproductive traits (seed number and weight), reward traits (sugar concentration, pulp weight), and relationships between reproductive and reward traits. We found no effect of herbivory on the correlation between reproductive traits, but an effect was found on the correlation between rewards traits. In conclusion, herbivory affects the correlation between fruit traits, and the magnitude and direction of the association between traits vary according to the magnitude and variation of the damage at the within-plant level. In evolutionary terms, our results suggest that within-plant variation in leaf traits would constitute a strategy to resolve allocation conflicts derived from damage and to maintain fruit display characteristics that favor the interaction with seed dispersers.

Temporal variations in leaf traits, chemical composition and in vitro true digestibility of four temperate fodder tree species

Context Many tree and shrub species are underestimated fodder resources due to insufficient knowledge about their potential feeding value, especially for goats. Aims The present work aimed at assessing productive and nutritional attributes of the foliage of the following four temperate tree species widespread in Europe: Acer pseudoplatanus, Fraxinus excelsior, Salix caprea and Sorbus aucuparia. Methods Leaf length and biomass, proximate composition, fatty acid profile, phenolic composition and in vitro true dry matter digestibility were determined along the vegetative season. Key results The leaf length of the four species was significantly related to leaf biomass and can be considered as a proficient proxy for estimating leaf biomass. The differences found among the species were remarkable, although weakly related to temporal changes, especially when considering fatty acid and phenolic compositions. Fraxinus excelsior sprouts were the most productive, with a mean biomass of 13.2 g dry matter (DM) per sprout at the end of the growing season. Its foliage showed also the lowest phenolic concentrations (average total extractable phenols of 11.25 g/kg DM), resulting in the highest digestibility values (average in vitro true dry matter digestibility of 56.5 g/kg DM). Digestibility of S. aucuparia was similar, but its lower polyunsaturated fatty acid concentration (average value of 62.13 g/kg DM) could reduce the interest for this species as a feeding resource for goat dairy products with healthy properties. The lower digestibility found for A. pseudoplatanus and S. caprea (average values of 43.3 and 46.2 g/kg DM, respectively) may be related to their higher phenolic concentrations (average total extractable phenols of 45.9 and 47.3 g/kg DM, respectively). Conclusions The four species could represent an appealing feedstuff for goat nutrition, due to the valuable and complementary nutritional characteristics of their foliage. Implications The use of the studied species as fodder resource may be particularly relevant during drought periods and in the late summer when herbage quality decreases, especially in terms of crude protein and fatty acid profile.

Divergent Strategies of Epiphytic Pteridophytes and Angiosperms Responding to Dry and Wet Seasons in a Tropical Cloud Forest

Epiphyte is a unique component of forest diversity vulnerable to changing environments. Characterizing variations in functional traits of epiphytes across dry and wet seasons can enhance our understanding their strategies to environments. We measured and assessed variations of 14 leaf functional traits responding to water conditions for epiphytic pteridophytes (EP) and epiphytic angiosperms (EA) across dry and wet seasons in a tropical cloud forest. Results showed that leaf dry weight (LDW) and stomatal length (SL) of EP were significantly higher than EA, while leaf water content (LWC) of EA was significantly higher than EP. The SL, stomatal density (SD), upper epidermis thickness (UET), lower epidermis thickness (LET), palisade tissue thickness (PT), spongy tissue thickness (ST), and leaf thickness (LT) of EP and EA were significantly higher in wet season than dry season. The variance of stomatal and anatomical traits explained by season types (0.24–0.78) was higher than plant groups (0.0–0.25), while the variance of LDW and LWC explained by plant groups (0.12–0.40) was higher than season types (0.0–0.29). Principal component analysis and correlation analyses showed that SL, stomatal index, UET, ST, LET, and LT were the key traits reflecting epiphyte adaptation to dry season, as well as that LWC and leaf density were the key traits in wet season. Our results suggest that the different taxonomic groups exhibit divergent strategies responding to water differences. Great variations in leaf traits to dry seasons are predicted that vascular epiphytes, especially pteridophytes, are prone to disappear with drought events.

Do patterns of intra-specific variability and community weighted-means of leaf traits correspond? An example from alpine plants

Intraspecific variability of the traits is usually less than interspecific, but directions of inter-and intraspecific variation along environmental gradients are not well studied. For 17 alpine species we test a hypothesis that the direction of intraspecific variation in leaf traits among different communities along an environmental gradient coincides consistently with community weighted mean (CWM) trait variation at the community level along the same gradient. We obtained two groups of leaf traits according to their response to CWM and topographic (snow depth and snow melt) gradients. For leaf mass and area intraspecific variation corresponded to CWM variation among communities. SLA, water content and leaf thickness patterns within species changed directly among communities according to the toposequence (snowmelt gradient). These results are well expressed for forbs, but mostly they were not significant for graminoids. For leaf area we obtained opposite response of forbs and graminoids to snowmelt gradient. Forbs increased, but graminoids decreased leaf area when snow depth increased. Intraspecific trait variation across natural gradients does not necessarily follow that for interspecific or community-level variation.

Variations of leaf and stem traits in relation to altitudinal distributions of 12 Fagaceae species of Mount Kinabalu, Borneo

Variations of leaf and stem traits in relation to altitudinal distributions of 12 Fagaceae species of Mount Kinabalu, Borneo

羌塘高原降水梯度植物叶片、根系性状变异和生态适应对策

羌塘高原降水梯度植物叶片、根系性状变异和生态适应对策

Geographical variation in morphological leaf traits of <i>Huperzia serrata </i>(lycopodiaceae) from Vietnam

Morphological leaf traits can be used to assess adaptive responses of plants to environmental conditions. To assess how the representation of Huperzia serrata leaf traits, such as leaf length (LL), leaf width (LW) and leaf area (LA) response to changes in mean annual temperature (MAT), sunshine duration (SuH), mean annual precipitation (MAP), air humidity (Hu), intraspecific variation of the morphological leaf traits of the species was analyzed along a geographical gradient of Vietnam. The results showed that among the three populations at the three sites, leaf sizes increased with MAT and MAP. Huperzia serrata, climatic factors, morphological leaf traits, Vietnam.

El papel de la evapotranspiración en la distribución funcional foliar de 28 especies del género Quercus de España y México

de la Riva, E.G., Arenas, M., Villar, R., Garcia-Oliva, F., Oyama, K. 2019. The role of evapotranspiration on the foliar functional distribution of 28 Quercus species from Mexico and Spain. Ecosistemas 28(3):199-207. Doi.: 10.7818/ECOS.1803 Quercus species represent the most important woody genus in the northern hemisphere, with broad environmental distribution in Spain and Mexico. Functional plant traits are commonly used as indicators of species diversification and environmental adaptations, and they allow us to better understand the morphological and physiological limitations of the species that restrict its evolution. The main objective of this study is to explore the spectrum of variation of Quercus genus, by analyzing the variation in five functional leaf traits of 28 Quercus species from Spain and Mexico along an environmental gradient of potential evapotranspiration. We found two major dimensions of functional variation: on one hand, the species are segregating along the humidity gradient according with the leaf economics spectrum. Therefore, we found species associated to a conservative use of resources in areas with higher evapotranspiration rate and acquisitive species in the areas with lower evapotranspiration. On the other hand, the leaf size is mainly determined by the geographical origin of the species. These results suggest that the evolutionary modifications within the same genus are related with the leaf traits variation, being humidity a key factor of functional trait variation within the Quercus genus. In addition, we would like to highlight that we do not find relationship between leaf longevity and leaf economic spectrum, which may be explained by the different evolutionary histories of the leaf habit in oaks between both countries.