Leaf Asymmetry Research Articles

Variability ofTilia cordataMill. by a complex of morphological and phenological features as a measure of environmental quality

The article presents the findings from a long-term study on the environmental quality of the city of Yoshkar-Ola, Russia, based on an analysis of the intra-population diversity ofTilia cordataMill. according to morphological and phenological indicators.Tilia cordataTrees have been studied at different stages of their ontogenesis, during the generative phase. The selected ecotopes differed in the degree of anthropogenic load – pollution from motor vehicles and industrial businesses. Heterogeneity of the ontogenetic groups ofTilia cordatawas established by morphological and phenological features using principal component analysis. The linear size has decreased, and the leaves’ area has shown a reduction, while damage to leaves caused by atmospheric toxicants has increased in the context of urban pollution. The index of fluctuating leaf asymmetry does not differ in trees from different ecotopes. The most informative indicators of the environmental state inT. cordataspecimens are morphometric - the size and number of structural components of buds and stems, and phenological - the timing and duration of phenophases. The medium-aged generative trees ofT. cordataare the most sensitive to environmental pollution.

APPLICATION OF FLUCTUATING ASYMMETRY METHODS FOR ENVIRONMENTAL MONITORING IN KAMIANSKE

The city of Kamianske has a hazardous environmental situation due to the long and intensive development of industry, whose enterprises emit large amounts of harmful substances into the atmosphere. Therefore, the implementation of continuous environmental monitoring for the city is an urgent task that can be solved by combining instrumental measurement methods with phytoindication methods. The aim of the study is to test the methods of phytoindication in the environmental monitoring system using the indicator of fluctuating asymmetry of the leaf blade of woody plants of the Populus canadensis species and to assess the quality of the environment, taking into account the functional zones of the urban system. A methodology for assessing the quality of the environment by the integral index of the fluctuating asymmetry of the leaf blade of Populus plants has been developed and an assessment scale with different gradient values has been proposed. The integral indicator of the fluctuating asymmetry of the leaf blades of Populus canadensi plants was calculated for 30 experimental plots covering all functional zones of Kamianske. It was determined that the quality of the environment within the industrial zones is characterised as critically polluted with unfavourable conditions for living organisms, which is confirmed by the integral index of fluctuating asymmetry 0,076¸0,104. Settlement areas are characterised as polluted, with an integral index of 0,063¸0,093. In recreational areas, the state of the environment is assessed by a conditional norm of 0,054¸0,066. The results of the average integral index of leaf asymmetry of Populus canadensi plants for a ten-year period for the city of Kamianske were compared, and the lower (0,038±0,002) and upper (0,106±0,003) limits of the index were determined. The dependence of the integral indicator on the volume of pollutant emissions into the atmosphere has been established, which is confirmed by high correlation coefficients r = 0,8¸0,9 at a significance level of p < 0,05. The modelled polynomial trends predict further growth of the integral indicator of fluctuating asymmetry depending on the increase in pollutant emissions.

How Important Are Functional and Developmental Constraints on Phenotypic Evolution? An Empirical Test with the Stomatal Anatomy of Flowering Plants.

AbstractQuantifying the relative contribution of functional and developmental constraints on phenotypic variation is a long-standing goal of macroevolution, but it is often difficult to distinguish different types of constraints. Alternatively, selection can limit phenotypic (co)variation if some trait combinations are generally maladaptive. The anatomy of leaves with stomata on both surfaces (amphistomatous) present a unique opportunity to test the importance of functional and developmental constraints on phenotypic evolution. The key insight is that stomata on each leaf surface encounter the same functional and developmental constraints but potentially different selective pressures because of leaf asymmetry in light capture, gas exchange, and other features. Independent evolution of stomatal traits on each surface imply that functional and developmental constraints alone likely do not explain trait covariance. Packing limits on how many stomata can fit into a finite epidermis and cell size-mediated developmental integration are hypothesized to constrain variation in stomatal anatomy. The simple geometry of the planar leaf surface and knowledge of stomatal development make it possible to derive equations for phenotypic (co)variance caused by these constraints and compare them with data. We analyzed evolutionary covariance between stomatal density and length in amphistomatous leaves from 236 phylogenetically independent contrasts using a robust Bayesian model. Stomatal anatomy on each surface diverges partially independently, meaning that packing limits and developmental integration are not sufficient to explain phenotypic (co)variation. Hence, (co)variation in ecologically important traits like stomata arises in part because there is a limited range of evolutionary optima. We show how it is possible to evaluate the contribution of different constraints by deriving expected patterns of (co)variance and testing them using similar but separate tissues, organs, or sexes.

Use of morphometric and phenological indicators of Betula pendula Roth for environmental health assessment

The article presents the results of long-term biomonitoring of the quality of the environmental of the city of Yoshkar-Ola (Russia) based on the analysis of morphological and phenological indicators of Betula pendula Roth. The authors studied Betula pendula trees at various stages of ontogenesis in the generative period. The authors also found out the heterogeneity of ontogenetic groups of trees by morphological and phenological characteristics in different ecotopes of the city, differing in the degree of pollution by industrial and transport emissions, using principal component analysis A decrease in the morphometric parameters of the Betula pendula leaf blade and leaf damage by phyllophagous insects do not always indicate a deterioration in the quality of the habitat. Moderate doses of atmospheric toxicants can accelerate the growth of B. pendula leaves. However, in conditions of urban pollution, the stability of B. pendula development is disrupted, which is manifested in an increase in the leaf asymmetry index. There are the most informative indicators of the state of the environment in individuals B. pendula: morphometric – an indicator of fluctuating asymmetry of leaves, phenological – the timing and duration of phenophases. The young generative trees of B. pendula are most sensitive to habitat pollution.

MONITORING THE STATE OF ENVIRONMENTAL SAFETY USING PHYTOINDICATION METHODS TO ENSURE SUSTAINABLE DEVELOPMENT OF A TECHNOLOGICALLY LOADED CITY

Ecological aspects of sustainable development have recently attracted the attention of scientists. The article is devoted to the control of ecological safety based on the study of the state of plantations in the city of Kremenchuk using the method of fluctuating leaf asymmetry as an indicator. The research was conducted in recreational, residential, transport and industrial areas. It was found that the condition of green areasin the city of Kremenchuk is heterogeneous and depends on the level of anthropogenic pressure. Plants growing near traffic routes and in industrial areas are much weaker than those growing in recreational areas.. The main indicator of plant condition in the study was the fluctuating asymmetry of the leaf blade of pyramidal poplar and hanging birch. It was found that the integral values of this indicator differ in different parts of the city with different intensities of anthropogenic impact, with the maximum values observed in industrial and traffic zones where there is an intense impact of pollutants. The results of the study confirm the unfavourable ecological condition of certain areas of the technologically loaded city of Kremenchuk, and also indicate the importance of environmental monitoring of pollution and development of measures to improve the condition of green areas. The results of the study can be used to improve the methodology and theory of ecological safety and urban environmental protection in order to preserve and restore plant populations in cities.

Identification of Pests and Diseases on Begonia Plants (Begonia sp) in Sewu Kembang Tourism Village, Karanganyar

Begonia (Begoniaceae) is one of the large genus in the Angiospermae group, with a distinctive leaf asymmetry. Begonias have considerable economic value and some Begonia plants have potential as medicinal plants and as vegetables. Pests and diseases are one of the problems in the development of Begonia cultivation. This study aims to identify and identify the types of pests and diseases that attack Begonia plants. The location of this research is in the area of ​​Sewu Kembang Tourism Park, Nglurah, Tawangmangu, Karanganyar Regency. This research was carried out from September 4 to October 3, 2021. This research was carried out for 30 days using 10 begonia plant samples. The tools used include a camera to take pictures and stationery to record data. The variables observed were pests and diseases that attack Begonia plants. In this study using direct observation and interviews with begonia plant owners. The data were analyzed by qualitative descriptive. The results of the study found 1 disease, namely nitrogen deficit and 2 pests, namely caterpillars and snails. Which causes damage to the leaves of the Begonia plant where the leaves of the Begonia plant are the attraction of the plant.

The assessment of Ishim ecological state dynamics by the method of fluctuating asymmetry

The paper presents data of the assessment of Ishim ecological state dynamics by the method of fluctuating asymmetry. The ecological state of the urban environment should ensure favorable living conditions for the population and a high quality of life. We assessed the degree of fluctuating asymmetry using the example of drooping birch ( Betula pendula ) leaves at 4 points of the city remote from each other (10 trees per 1 point, 100 leaves were selected from each tree). On the basis of morphometric measurements, an integral indicator was calculated, with the help of which the magnitude of asymmetry was estimated. The average values of fluctuating asymmetry of drooping birch leaves in all studied points of the city did not exceed the conditional norm. The ecological state of the city of Ishim can be assessed as favorable. In the dynamics of 11 years there was a deterioration of the ecological state of most districts in Ishim. In three observation areas, an increase in the index of fluctuating leaf asymmetry from 1,5 to 4 times was registered compared to 2010. The lowest indicators of leaf asymmetry were observed in the area of the park Berezovaya Roschya and in the area of the Prigorodny forest (Vankovka). The highest indicators of leaf asymmetry were observed in the area of the railway station. On the contrary, there was a significant improvement of the ecological state within the streets of Lunacharsky and Tolstoy in the city.

Seasonality and forest edge as drivers of Tradescantia zebrina Hort. ex Bosse invasion in the Atlantic Forest.

As a result of biodiversity and ecosystem service losses associated with biological invasions, there has been growing interest in basic and applied research on invasive species aiming to improve management strategies. Tradescantia zebrina is a herbaceous species increasingly reported as invasive in the understory of disturbed forest ecosystems. In this study, we assess the effect of spatial and seasonal variation on biological attributes of this species in the Atlantic Forest. To this end, we measured attributes of T. zebrina associated with plant growth and stress in the four seasons at the forest edge and in the forest interior of invaded sites in the Iguaçu National Park, Southern Brazil. The invasive plant had higher growth at the forest edge than in the forest interior and lower leaf asymmetry and herbivory in the winter than in the summer. Our findings suggest that the forest edge environment favours the growth of T. zebrina. This invasive species is highly competitive in the understory of semi-deciduous seasonal forests all over the year. Our study contributes to the management of T. zebrina by showing that the summer is the best season for controlling this species.

Qualitative and Quantitative Indicators of Foliar Mass of Woody Plants in Urban Greenspaces According to the Level of Air Pollution

The purpose of this study is to conduct a comparative analysis of the leaf fall timing and parameters of fluctuating leaf asymmetry among two commonly used plant species for street landscaping in Detroit city, namely, American elm and American ash. The study was completed between summer and fall for the year 2019 in and around Detroit, US. Phenological leaf fall timing of elm and ash was studied, and the fluctuating asymmetry index of their leaves was estimated within the city limits (80 trees of ash and 40 of elm) and outside the city (control site, 20 trees of each species). Leaf fall in city ash trees was recorded from November 1st to 4th and 5-8 days prior to the leaf fall in elms (p ≤ 0.01). Elm trees in the control group shed their leaves 10 days later compared to the city trees, i.e., on average, on November 25th (p ≤ 0.01). Ash trees in the control group shed their leaves earlier than the elm control group, on November 11th (p ≤ 0.001). In the city streets, the average fluctuating asymmetry ranged from 0.065 to 0.086 (point 1), from 0.049 to 0.078 (point 2) and from 0.063 to 0.082 (control site, near the highway).

Morphological Changes of Leaves of Birch (Betula pendula Roth) During the Growing Season in the Conditions of Petrochemical Pollution of the Environment

The authors analyze their data on birch leaves (Betula pendula Roth) during the growing season of 2019. Studies were conducted on the territory of the Ufa industrial center near oil refineries. Model birch trees grow on permanent plots. Ten leaves are numbered on the trees. Photographs of each plate were taken during the growing season (June-July-August-September). The integral indicator of the stability of leaf development was calculated according to five criteria: (1) the wide of the left and right halves of the leaf; (2) the length of the second vein from the base of the plate; (3) the distance between the grounds of the bottom of the first and second veins of the second-order of the leaf; (4) the distance between the ends of the first and second veins of the second-order of the plate; (5) the angle between the central vein and the second vein of the second order from the base of the leaf. The research shows that under conditions of the hydrocarbon type of environmental pollution, there are deviations in the morphological development of birch leaves. The authors show that an individual trajectory of morphological development is characteristic of leaves. The phenomenon of adaptive polymorphism of birch leaves is noted. Moreover, the morphological and functional features of the plate are inextricably linked. Leaf asymmetry indicators can be used to characterize the state of birch trees in urban conditions.

Developing a list of woody plants recommended for landscaping and reconstruction of Cheboksary green areas based on the assessment of the urban environment quality

The paper presents the results of research to assess the quality of the urban environment in the areas we have identified by the functional and economic significance of Cheboksary using a method of fluctuating asymmetry of Betula pendula Roth leaves and a scale of gas resistance of tree and shrub plants. The studies have showed that the integral indices of fluctuating asymmetry of Betula pendula leaf plates of all surveyed green planting objects vary from 0,038 to 0,054. The highest levels of asymmetry were found in the eastern and southern parts of the city, where the values of leaf asymmetry fluctuations range from 0,050 to 0,054. Based on an assessment of the quality of the urban environment the authors have developed recommendations to improve and expand the range of resistant woody plants to anthropogenic stress of Cheboksary. Depending on the nature of the urban environment and the degree of woody plants resistance to anthropogenic pollution, we offer a range of woody and shrub plants for landscaping, it contains 73 species. The recommended range of trees and shrubs for landscaping in the Central zone of Cheboksary is 68 species (asymmetry coefficient 0,040 to 0,044), in the Coastal and Suburban areas 62 species (asymmetry coefficient 0,046 to 0,049), in the Industrial zone 29 species (asymmetry coefficient 0,050 to 0,053).

Change of Leaf Trait Asymmetry Type in Tilia cordata Mill. and Betula pendula Roth under Air Pollution

Leaf fluctuating asymmetry (FA) is widely used as an environmental stress index, including pollution. Besides FA, leaf bilateral traits can have directional asymmetry (DA) and antisymmetry (AS), which are considered hereditary. Leaf FA transitioning to DA/AS or mixed asymmetry, under air pollution, has been insufficiently investigated. This study analysed leaf asymmetry types in Tilia cordata Mill. and Betula pendula Roth under traffic air pollution over several years. In addition, the relations of such transitions to pollution, and their effect on FA-integrated index, were studied. The asymmetry types of all studied leaf traits varied with air pollution increase, as well as in control trees in different years. T. cordata most often had FA transition to DA/mixed asymmetry, while B. pendula rarely had a mixed asymmetry and FA transitions to DA/AS were observed with the same frequency. Air pollution impacted FA transitions to other asymmetry types. In most cases their frequency changed non-monotonically that corresponded to hormesis and paradoxical effects. However, FA integrated index in studied trees did not depend on change of leaf asymmetry type. Thus, DA and AS in studied plants were not exclusively hereditary. Hence, the changes of leaf asymmetry type should be considered when using leaf FA in environment assessment.

Anatomy of leaf edges in Marantaceae in the Neotropics: the relationship between vernation and leaf asymmetry and contributions to the systematics of the family

AbstractMarantaceae consist of species with asymmetric leaves of two types: those with either a wider left or right half; this asymmetry is related, respectively, to clockwise or counterclockwise convolute vernation. In this study, we analysed whether anatomical differences in the leaf edges, i.e. the anatomical asymmetry, were related to the orientation of the convolute vernation and to the asymmetry of leaf morphology, and whether these differences supported the organization of the clades in the family. Transverse sections of the mid third of the leaf buds expanded to the height of the right and left edges of the blades were prepared for 19 species belonging to 11 genera, using cyto-histological techniques. Anatomical analyses of the blade edges revealed that there is a relationship between morphological asymmetry and anatomical asymmetry that has never before been ascribed to the family. The anatomical data support differences between the arrangements in two of the three Neotropical informal groups. In the Calathea clade, Calathea showed much more similarity with Goeppertia than with Ischnosiphon and Monotagma, since they are the only genera that do not present with anatomical asymmetry. In the Maranta clade, Ctenanthe, Saranthe and Stromanthe appear to be related to one another, as they share strong anatomical asymmetry and fibrous edges. These characteristics, however, are not observed in Myrosma, which in turn is more anatomically similar to Maranta.

Photosynthetic Efficiency is Higher in Asymmetric Leaves than in Symmetric Leaves of the Same Plant

Symmetry pervades nature, but asymmetry is also rather common. Deviations from genetically programmed symmetry are usually associated with internal or external developmental disturbances and may therefore be related to imperfections in physiological processes. In this study, we test the hypotheses that the photosynthetic efficiency of individual leaves of a plant is negatively related to their asymmetry. We measured chlorophyll fluorescence in leaves of three woody species (Betula pubescens, Populus tremula and Salix caprea) in early and late summer in two localities situated ca. 1000 km apart, and we quantified the asymmetry of these leaves by a multivariate measure based on the relative positions of several landmarks. Contrary to our expectation, we found that the photochemical efficiency of photosystem II was positively correlated with leaf fluctuating asymmetry; this effect was weak but consistent across the studied plant species, localities and seasons. Our finding adds to limited evidence that within-plant variation in leaf asymmetry is associated with variation in leaf physiology. Irrespective of the underlying mechanisms, which remain unknown, the results suggest that trees may benefit even more from their asymmetric leaves, at least in terms of photosynthesis, than they do from their more symmetric leaves.

The effect of low frequency electromagnetic fields on fluctuating asymmetry of woody plants

The paper analyzes the impact of environmental factors of physical and chemical nature on the stability of the development of three species of woody plants: common lilac, Siberian apple tree, birch tree. Determining the value of the fluctuating asymmetry index (FA) over the width of two halves of leaves was performed on plants growing in the suburban green area (control), in the suburban green area under high-voltage power lines of 220 kV (physical factor, experiment 1), as well as in the city of Krasnoyarsk in terms of air pollution by exhaust gases of cars (chemical factor, experiment 2). The values of the FA index of common lilac and Siberian apple tree, defined for the control variants, were 0.024 and 0.028, and calculated for experiments 1 and 2 were respectively equal to 0.032 and 0.039; 0.029 and 0.030. It is established that the response of common lilac and Siberian apple trees to the physical environmental factor - electromagnetic radiation of industrial frequency - which is expressed in the appearance of leaf asymmetry is stronger in comparison with the reaction to the chemical factor - exhaust gases of cars. It is shown that the value of the FA index of Siberian apple tree and common lilac can be a sensitive indicator when monitoring the anthropogenic load on the environment in the form of an alternating electromagnetic field of industrial frequency. The FA index of the birch tree, measured on the basis of the width of the right and left halves of the leaf, is less sensitive than in the case of the common lilac and the Siberian apple tree.

Taylor’s Power Law for Leaf Bilateral Symmetry

Leaf shape and symmetry is of interest because of the importance of leaves in photosynthesis. Recently, a novel method was proposed to measure the extent of bilateral symmetry in leaves in which a leaf was divided into left and right sides by a straight line through the leaf apex and base, and a number of equidistant strips were drawn perpendicular to the straight line to generate an equivalent number of differences in area between the left and right parts. These areal differences are the basis for a measure of leaf bilateral symmetry, which was then examined to see how well it follows Taylor’s power law (TPL) using three classes of plants, namely, 10 geographical populations of Parrotia subaequalis (H.T. Chang) R.M. Hao et H.T. Wei, 10 species of Bambusoideae, and 10 species of Rosaceae. The measure of bilateral symmetry followed TPL for a single species or for a class of closely related species. The estimate of the exponent of TPL for bamboo plants was significantly larger than for the dicotyledonous trees, but its goodness of fit was the best among the three classes of plants. The heterogeneity of light falling on branches and leaves due to above-ground architectural patterns is an important contributor to leaf asymmetry.

Patterns of herbivore damage, developmental stability, morphological and biochemical traits in female and male Mercurialis perennis in contrasting light habitats

Light environments can influence variation in plant morphology, development and susceptibility to herbivores. Our research interest was to investigate the patterns of herbivore damage and developmental stability in dioecious understory forb Mercurialis perennis in contrasting light habitats, located at 1700 m a.s.l. on Mt. Kopaonik. Male and female plants from two light habitats, open (a sun-exposed field) and shaded (a spruce forest) were examined with respect to: herbivore damage (percentage of leaf area loss), fluctuating asymetry (FA) as a measurement of developmental stability, plant morphological and, specifically, leaf size traits, as well as biochemical traits relating to nutritional quality and defence, taking into account the possible presence of intersexual differences. Our results show that herbivore damage was significantly higher in open habitat, as well as one out of four univariate FA indices and the multivariate index. Morphological and biochemical traits, apart from defensive compounds, had higher values in the shade, pointing to sun-exposed habitat being more stressful for this species. Intersexual differences were observed for foliar damage, defensive compounds (phenolics and tannins), all leaf size traits, total leaf area, and protein content. Contrasting light habitats affected most of the analysed traits. Both foliar damage and FA were higher in a more stressful habitat; within habitats, no positive correlations were found. Herbivore damage was significantly male biased in open habitat. The analysis of intersexual differences in developmental stability measured by leaf asymmetry levels provided no evidence that female plants were more sensitive to environmental stress.

Leaf morphology of progenies in Q. suber, Q. ilex, and their hybrids using multivariate and geometric morphometric analysis

Abstract: The genus Quercus is known for the occurrence of frequent hybridization events between species. Although this phenomenon is not common among holm oak (Q. ilex) and cork oak (Q. suber), these species can hybridize when they coexist in mixed stands. The result of hybridization is a viable hybrid progeny with very heterogeneous leaf morphology. Literature concerning the leaf morphology of suber-ilex hybrid seedlings is scarce, and non-existent from a quantitative point of view. In the case of the leaf morphology of hybrids and their progeny, it has been observed a high frequency of leaves with fluctuating asymmetry or developmental abnormalities, which can have a marked effect on fitness. In this work, we have characterized seedlings’ leaf morphology corresponding to two- and four-year-old half-sib progenies of holm oak, cork oak and their hybrids. For this purpose, three to ten leaves of each individual were collected, and two methodologies were used for analysis. Firstly, we used a classic morphological analysis of twelve variables that were reduced using multivariate techniques. On the other hand, shape of the leaves was thoroughly analyzed by geometric morphometric analysis methods. The extent of fluctuating asymmetry and the presence of developmental abnormalities of seedlings were analyzed calculating an asymmetry index. The results indicate that thickness is the most discriminating trait between species, and that the hybrid progenies do not show a third different phenotype compared to the parental species. However, half-siblings tend to show similar leaf morphology between them, depending on the genetic adscription of the parents. While fluctuating asymmetry was found in half-sib progenies of the parental species and the hybrids, a significant proportion of hybrid half-sibs showed strong leaf asymmetry, probably due to modifications of the epigenetic systems that control leaf development at the shoot apical meristems and leaf primordia.

How many leaves are enough? The influence of sample size on estimates of plant developmental instability and leaf asymmetry

One issue in studies of leaf asymmetry is the lack of standardization of sample sizes for estimating the different types of leaf asymmetry, namely fluctuating asymmetry (FA –, differences in leaf sides around zero, normally distributed data), directional asymmetry (DA – one leaf side is substantially larger than the other) and antisymmetry (AS – both right-and left-sidedness; bimodal data). FA is the only parameter regarded as a biomarker of stress and it is used consistently for population monitoring. Here we investigated whether leaf samples of different sizes showed different asymmetries (FA, DA or AS) in three unrelated plant species (Miconia fallax, Solanum lycocarpum and Bauhinia brevipes). We hypothesized that larger samples would show FA, as substantial side differences would be buffered and so that the sample would display differences in leaf sides around zero (i.e., FA). The results were highly dependent on both sample size and plant species. Larger samples did not consistently display FA, but they did provide leaf asymmetry values close to zero, which is a prerequisite of FA. AS was pervasive, but detailed exploration of histograms revealed that none of the data sets had a bimodal distribution and most curves were leptokurtic. On this basis, we suggest that kurtosis tests in combination with histograms should be given preference over normality tests as a method to evaluate potential AS. We conclude that at this time it is still not possible to give a rule-of-thumb for sample sizes for this type of investigation, and that graphical representations of data should be used to classify the asymmetry types more accurately. We suggest that the statistical tests used to examine FA should be reconsidered and that graphs such as histograms can be more informative than p-values when it comes to distinguishing between types of leaf asymmetry.

Fluctuating asymmetry, leaf thickness and herbivory in Tibouchina granulosa: an altitudinal gradient analysis

Gradient of stressful conditions affect plant physiological and morphological traits. Previous studies have shown that plants located at higher altitudes might exhibit higher levels of both fluctuating asymmetry and leaf thickness. Although it is expected that higher fluctuating asymmetry levels should be accompanied by higher leaf consumption by herbivores, lower herbivory could be expected for elevated leaf thickness. Aiming to investigate this contradiction our objective was to determine the effects of altitude on fluctuating asymmetry and leaf thickness, and evaluate the importance of these two morphological traits on herbivory levels of Tibouchina granulosa Cogn. (Melastomatecea) in Brazilian Atlantic Forest. The study was conducted in southern Brazil, along a continuous altitudinal gradient raging from 1275 to 1950 m, where we measured fluctuating asymmetry, leaf thickness and herbivory from leaves of 29 individuals of T. granulosa. There was a positive effect of altitude on both fluctuating asymmetry and leaf thickness but only fluctuating asymmetry was related to herbivore. Our results suggest that as altitude increases plants face more stressful conditions, leading to higher fluctuating asymmetry. This may lead to a higher nutritional quality of leaves and herbivores may use leaf asymmetry as a cue for plant quality. The lack of a relationship between leaf thickness and herbivory gives us evidence that, in the studied location, leaf thickness is not primarily used as plant defense and probably has other functions related, for example, to water, solar radiation, and nutrient stresses. These results may be considered a baseline for the understanding on how altitudinal stress and potential herbivory pressure influence plant populations.