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Shifts of forest types and their dominant species with different leaf and anatomical traits along the altitudinal gradient. From low to high elevation, there are different forest types involving various dominant leaf types with adaptive anatomical structures. Plants had the adaptive changes in leaf anatomical traits along the environmental gradient, first with thin leaves and low anatomical trait values at the broadleaved forests (deciduous broadleaved forest and birch forest), and then with thick leaves and high anatomical trait values at the coniferous forests (fir forest and larch forest). At the high altitude, the dominant species include evergreen conifers and deciduous conifers showing differently adaptive strategies that the the evergreen conifers had higher trait values than the deciduous conifers.
Source publication
As important indicators of leaf traits, leaf anatomical traits are sensitive and adaptable to environmental changes. However, how leaf anatomical traits at species and community levels vary along the altitudinal gradients is still unclear. In this study, a total of 60 woody plants from four typical vegetation zones along the 2000 m-elevation gradie...
Contexts in source publication
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... are more obvious trends of trait variations along the latitudinal gradient at community level than that at species level. These results suggested that species-level J o u r n a l P r e -p r o o f community-level traits. The dominant species in the community can best adapt to the local environment and have close relationship with the environment (Fig. 4). However, the simple substitution of species mean traits for community-level traits may undermine or cancel the influence of the dominant species and lead to erroneous results ( Garnier et al. 2004). On the contrary, the CWM values integrate the data of community structure and species information, which can better explain the response ...
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... first and then decrease along the altitudinal gradient. Specifically, ET c , PT c , ST c , and LT c reached the maximum value in fir forest, while PST reached the maximum value in fir forest birch forest ( Fig. 1f-j). This is the result that the community traits were affected by different vegetation under the vertical environmental gradient (Fig. 4). In terms of the tends of ET c , PT c , ST c , and LT c , from low elevation to high elevation, the environment gradually became colder, and the plant community changed from deciduous broadleaf forest (with thin leaves and low anatomical trait values) to evergreen coniferous forest (with thick leaves and high anatomical trait values), ...
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... and low anatomical trait values) to evergreen coniferous forest (with thick leaves and high anatomical trait values), resulting in an increasing trend towards leaf anatomical traits. When the elevation is more than 3000 m, deciduous conifers, L. potaninii var. chinensis is the dominant species, shedding leaves to resist the cold environment (Fig. 4), thus compared with evergreen coniferous forest, leaf anatomical traits decreased at the community level. Similar to the previous studies, PFTs involving various leaf types with different leaf lifespans represent different adaptive strategies in plants ( Reich et al. 2007;Werden et al. 2017). The tend of PST along the altitudinal ...
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... deciduous conifers reduce their construction investment which may help them to produce more photosynthetic products during a short growing period (Gower & Richards 1990;Tian et al. 2016). In the present study, the environmental, especially climatic changes along the altitudinal gradient lead to the shift of the dominant species within communities (Fig. 4). These dominant species with different leaf types and leaf lifespans resulted in the elevation variation pattern of leaf anatomical traits at the community ...
Citations
... A paraffin-embedding method was used to analyze the leaves' anatomical structure. We followed the method of Liu et al. for obtaining leaf cross-sections [33], with minor modifications. Briefly, after fixing, all leaf samples were dehydrated in a series of graded ethanol solutions (70%, 85%, 95%, and anhydrous ethanol), immersed and embedded in paraffin wax (melting point 58 °C), and naturally dried in the shade for at least two weeks. ...
... Typically, a diverse array of genetic mechanisms underlie speciation, particularly the emergence of ploidy variations [9,52]. In addition, divergent natural selection, including abiotic and biotic factors, may serve as a crucial determinant of phenotypic and geographic differentiation [5,21,22,[26][27][28][29][30][31]33,53]. The results of the RDA reveal a positive association between the distribution of the B. macrostachya complex and habitat altitude level, as well as soil total P concentration ( Figure 4). ...
Leaf functional traits reflect species’ adaptive strategies and habitat requirements. Examining intra-specific variations and their underlying drivers can aid in comprehending species differentiation and adaptation. Here, we investigated the leaf functional traits of Buddleja macrostachya tetraploids and octaploids across 18 sites in the Sino-Himalayan region. The habitat environmental variables were also recorded. In this study, leaf functional traits showed a considerable differentiation in both tetraploid and octaploid B. macrostachya. Redundancy analysis (RDA) revealed that the octaploid cytotypes displayed higher specific leaf area, leaf total nitrogen and phosphorus concentrations, water-use efficiency, and light-use efficiency in contrast to the tetraploid plants. These functional leaf traits exhibited different plasticity levels in both taxa. A positive link was found between habitat altitude and soil total P concentration and the geographic distribution of the B. macrostachya complex, using RDA and Pearson’s correlation. Our findings suggest that both tetraploid and octaploid B. macrostachya exhibited divergent ecological strategies, conservative and acquisitive strategies, respectively. The ecological adaptability of species within the B. macrostachya complex is enhanced by the combination of divergent ecological strategies and high phenotypic plasticity of distinct key ecological traits. Furthermore, abiotic environmental factors influenced the allopatric geographic distribution pattern of the B. macrostachya complex in the Sino-Himalayan region.
... The main anatomical features of leaves are epidermis, mesophyll, and vascular system [36], and differences in those structures can indicate adaptations to specific environments [37,38]. For example, changes in epidermis thickness can protect leaf tissues against adverse factors and also adjust leaf moisture level and preserve heat [39]. Palisade tissue is the main site of photosynthesis and regulates leaf photosynthetic efficiency by changes in porosity [40]. ...
... Spongy tissues with large intercellular spaces can increase gas change. Differences in palisade and sponge tissues can indirectly reflect environmental water status, and thus, the ratio of palisade tissue thickness to sponge tissue thickness (P/S) can reflect leaf resource-use strategies in different habitats [39]. Generally, the higher the P/S ratio reflects the higher the photosynthetic utilization efficiency, which may be one important reason why plants can resist drought stress. ...
... Palisade tissue is the main site of photosynthesis, and large cellular spaces in sponge tissue increase gas exchange [34,36]. In this study, the QSH plants had well-developed palisade tissue and sponge tissue, which increased the number of chloroplasts and CO 2 diffusion rate, compensating for the short photosynthesis period on the plateau [39,52,64]. The P/S ratio was greater than one and indicated that QSH plants were typical drought-resistant plants. ...
Background
With the dramatic uplift of the Qinghai–Tibet Plateau (QTP) and the increase in altitude in the Pliocene, the environment became dry and cold, thermophilous plants that originally inhabited ancient subtropical forest essentially disappeared. However, Quercus sect. Heterobalanus (QSH) have gradually become dominant or constructive species distributed on harsh sites in the Hengduan Mountains range in southeastern QTP, Southwest China. Ecological stoichiometry reveals the survival strategies plants adopt to adapt to changing environment by quantifying the proportions and relationships of elements in plants. Simultaneously, as the most sensitive organs of plants to their environment, the structure of leaves reflects of the long-term adaptability of plants to their surrounding environments. Therefore, ecological adaptation mechanisms related to ecological stoichiometry and leaf anatomical structure of QSH were explored. In this study, stoichiometric characteristics were determined by measuring leaf carbon (C), nitrogen (N), and phosphorus (P) contents, and morphological adaptations were determined by examining leaf anatomical traits with microscopy.
Results
Different QSH life forms and species had different nutrient allocation strategies. Leaves of QSH plants had higher C and P and lower N contents and higher N and lower P utilization efficiencies. According to an N: P ratio threshold, the growth of QSH species was limited by N, except that of Q. aquifolioides and Q. longispica, which was limited by both N and P. Although stoichiometric homeostasis of C, N, and P and C: N, C: P, and N: P ratios differed slightly across life forms and species, the overall degree of homeostasis was strong, with strictly homeostatic, homeostatic, and weakly homeostatic regulation. In addition, QSH leaves had compound epidermis, thick cuticle, developed palisade tissue and spongy tissue. However, leaves were relatively thin overall, possibly due to leaf leathering and lignification, which is strategy to resist stress from UV radiation, drought, and frost. Furthermore, contents of C, N, and P and stoichiometric ratios were significantly correlated with leaf anatomical traits.
Conclusions
QSH adapt to the plateau environment by adjusting the content and utilization efficiencies of C, N, and P elements. Strong stoichiometric homeostasis of QSH was likely a strategy to mitigate nutrient limitation. The unique leaf structure of the compound epidermis, thick cuticle, well-developed palisade tissue and spongy tissue is another adaptive mechanism for QSH to survive in the plateau environment. The anatomical adaptations and nutrient utilization strategies of QSH may have coevolved during long-term succession over millions of years.
... Variations of leaf anatomy with habitats suggest that plants can adapt to environmental changes by adjusting the proportions of leaf tissues [19,20]. Previous studies indicated that leaf epidermis and mesophyll thickness show significant geographic patterns at the species and community levels [21][22][23]. Thickening of the leaves, mesophyll, and epidermis might limit gas exchange but reduce water loss and increase water retention [8,24,25]. Water losses are also greatly affected by stomata characteristics, and stomata density is more plastic in response to water stress than stomata size. ...
... Although speciesand community-level PCA results indicated different anatomical traits, the overall strategy pointed to a similar finding. At the species level, the thickening of leaf tissues reflected hydraulic safety strategy, and the decrease in stem VS reduced the efficiency of water transport, all of which referred to high drought tolerance characteristics [21][22][23][24][25]. We found that both the total leaf area and the single leaf area contributed higher on the second cardinal axis, but the contribution rate of the total leaf area was higher, which may be the characteristic of small and dense leaves of this strategy, which further improved the protective ability of leaves [4]. ...
... Although species-and community-level PCA results indicated different anatomical traits, the overall strategy pointed to a similar finding. The thickening of leaf tissue suggested the shift of leaves to a more drought-tolerant hydraulic security strategy [21][22][23][24][25]. The trend of change in SD and SL was consistent at the species and community level, and the leaves not only improved certain protection ability, but also ensured certain physiological activities. ...
Background
Water stress seriously affects the survival of plants in natural ecosystems. Plant resistance to water stress relies on adaptive strategies, which are mainly based on plant anatomy with following relevant functions: (1) increase in water uptake and storage; (2) reduction of water loss; and (3) mechanical reinforcement of tissues. We measured 15 leaf-stem anatomical traits of five dominant shrub species from 12 community plots in the eastern Qaidam Basin to explore adaptive strategies based on plant leaf-stem anatomy at species and community levels. and their relationship with environmental stresses were tested.
Results
Results showed that the combination of leaf-stem anatomical traits formed three types of adaptive strategies with the drought tolerance of leaf and stem taken as two coordinate axes. Three types of water stress were caused by environmental factors in the eastern Qaidam Basin, and the established adaptive strategy triangle could be well explained by these environmental stresses. The interpretation of the strategic triangle was as follows: (1) exploitative plant strategy, in which leaf and stem adopt the hydraulic efficiency strategy and safety strategy, respectively. This strategy is mostly applied to plants in sandy desert (i.e., Nitraria tangutorum, and Artemisia sphaerocephala) which is mainly influenced by drought stress; (2) stable plant strategy, in which both leaf/assimilation branches and stem adopt hydraulic safety strategy. This strategy is mostly applied to plants in salty desert (i.e., Kalidium foliatum and Haloxylon ammodendron) which aridity has little effect on them; and (3) opportunistic plant strategy, in which leaf and stem adopt hydraulic safety strategy and water transport efficiency strategy. This strategy is mostly applied to plants in multiple habitats (i.e., Sympegma regelii) which is mainly affected by coldness stress.
Conclusion
The proposed adaptive strategy system could provide a basis for elucidating the ecological adaptation mechanism of desert woody plants and the scientific management of natural vegetation in the Qinghai-Tibet Plateau.
... En las características de hoja, la variabilidad observada fue similar a lo reportado en otras especies de Ardisia (Lascurain et al., 2010;Ahammed et al., 2019;Nuraliev et al., 2020), y se considera que las condiciones ambientales del hábitat de desarrollo de las plantas son factores determinantes en la variabilidad (Khadivi-Khub, 2014). Entre estos factores ambientales la altitud, humedad y luminosidad, tienen un papel importante con la interacción del genotipo sobre las características de las hojas (Liu et al., 2021). En este estudio probablemente la altitud pudo ser un factor determinante en la expresión de la variabilidad morfológica de la hoja. ...
... En este estudio probablemente la altitud pudo ser un factor determinante en la expresión de la variabilidad morfológica de la hoja. Liu et al. (2021) mencionan que las variables anatómicas de grosor de epidermis, grosor de tejido empalizado y esponjoso de las hojas tienden a una disminución a lo largo de un gradiente altitudinal (Tabla 1). Con relación a las variables del fruto, los resultados de este estudio son comparables con lo reportado por otros autores (Lascurain et al., 2010;Jun y Nian-He, 2012;Ahmmed et al., 2019), quienes encontraron diámetros de fruto de 6 a 8 mm; de 6 a 10 mm y de 4 a 9 mm, respectivamente. ...
Background. Ardisia compressa Kunth, is a wild species native from tropical evergreen forests of Mexico, it produces fruits with phytochemical, ecological and dietary potencial. Its fruits are appreciated by people from local communities. However, in Mexico there are no studies that allow knowing the state of its phenotypic diversity. Objective. Characterize the morphological diversity of A. compressa populations from Chiapas state, Mexico. Methodology. Ninety individuals of nine wild populations of A. compressa were evaluated using 45 morphological traits (16 qualitative and 29 quantitative). The qualitative data were subjected to descriptive analysis and quantitative data were used in an analysis of variance (ANOVA) and finally the qualitative and quantitative data were analyzed simultaneously by means of a multivariate analysis with the Ward-MLM Method. Results. The qualitative traits showed phenotypic variability in the characteristics of leaf and fruit color. The quantitative data showed significant differences (P≤ 0.05) in all traits evaluated. The results of the principal component analysis (PCA) and cluster analysis (UPGMA) grouped the populations into three morphological groups differentiated by the similarity of the morphological traits of the populations and not by their geographical origin. Implications. The results in this study should be considered to implementing strategies of plant production and conservation of A. compressa. Conclusion. A wide phenotypic variability was found organized into three morphological groups defined base on characteristics of tree height, number of fruits, number of flowers and ratio of length to thickness leaf. The quantitative traits allowed us to observe the greatest morphological variability in the populations of A. compressa.
... The region belongs to a warm temperate climate, with mean annual temperature ranging from 0.02 to 13.27 °C and mean annual precipitation of 656-855 mm. Due to the heterogeneity of climatic and soil conditions, different forest vegetation types have formed, including deciduous broadleaf forest (800-2300 m), temperate birch forest (2300-2800 m), fir forests (2800-3015 m) and larch forest (3150-3400 m) (Tang and Fang 2006;Wang et al. 2020;Liu et al. 2021) (Table S1). ...
Aims
Although the variation in absorptive root traits at the species level and driving factors has received a lot of attention, it is still unknown how community-level root traits vary along the environmental gradients.
Methods
In this study, absorptive fine roots of 69 woody plants from four forest vegetation on the northern slope of Taibai Mountain were collected, and four root traits (including morphological and chemical traits) were measured.
Results
At the species level, absorptive root traits, except root nitrogen concentration (RNC), did not change along altitudinal gradients. A large proportion of variation in root diameter (RD), specific root length (SRL) and root tissue density (RTD) was attributed to phylogenetic taxonomy (clade, 39.47-60.72%). Differently, community-level absorptive roots at birch forest exhibited thinner RDc and lesser RNCc but longer SRLc and greater RTDc than other altitudes, which were mainly influenced by the climatic (aridity index) and soil factors (soil available P and nitrate concentration). Moreover, unlike root economic space, community-level root traits were divided into the morphological (including RDc, SRLc and RTDc) and chemical (including RNCc) dimensions.
Conclusions
Our results indicate that the response of community-level root traits to climatic and soil factors is more significant compared to species-level root traits. Future studies should incorporate community-level root traits into global vegetation distribution models.
... LMA responds to environmental parameters such as solar irradiance, temperature, precipitation and, by extension, site aridity (Niinemets 2001; see also Grubb et al. 2015). It is also clear that the relative extent of tissue types comprising leaves varies with environmental factors, such as elevation (Liu et al. 2021), temperature, aridity and soil nutrient availability (Tian et al. 2016). Some size-related traits, particularly involving leaf venation (vein length per unit leaf area) are involved in determining hydraulic conductance and thus influence physiological traits involved in the leaf economics spectrum, such as mass-based photosynthetic rates and stomatal conductance (Sack et al. ...
Plant functioning depends on variation in resource economics traits (acquisition vs. conservation) and the size of plants and their parts (the ‘global spectrum of plant form and function’). The anatomical basis of single traits (e.g., leaf mass per area; LMA) is generally understood, but little is known regarding the relationship between anatomical trade-offs and ecological strategies (representing integrated suites of traits). We hypothesised correlations between the relative extent of leaf tissue types and Grime’s Competitor Stress-tolerator Ruderal (CSR) strategies, principally a trade-off between structural (mechanical/fibro-vascular) vs. photosynthetic (chlorenchyma and intercellular airspace; ICAS) tissues, for ecologically contrasting herbaceous angiosperms in northern Italy. Specifically, that in the lamina portion, the trade-off represents the economics spectrum (S-R selection), but in the midvein portion, it reflects the mechanical constraints inherent to supporting large leaves (i.e., varies with C-selection). We used microscopy and image analysis to determine the relative cross-sectional area of tissues from transverse leaf sections (lamina and midvein portions) of angiosperms of contrasting CSR strategies. Principal components analysis (PCA) determined that the main trade-off (PCA1) was between mechanical/fibro-vascular tissues vs. ICAS/epidermis/chlorenchyma, but that this was associated with the economics spectrum (R- to S-selection) in the lamina, and with size (C-selection) for the midvein. A secondary trade-off in both lamina and midvein portions involved ICAS (i.e., the internal gas diffusion pathway) vs. chlorenchyma/epidermis (light capture), associated with S- to R-selection, respectively. Our results confirm the expectation that ecological strategy variation has a basis in underlying trade-offs between tissues with contrasting metabolic/architectural (i.e., economics/size-related) roles.
... Eighteen dominant species in this community belonging to 10 families, including Fagaceae, Theaceae, Anacardiaceae, Pinaceae, and Taxodiaceae (Table 1), exhibited significantly different phylogeny background and thus may help them coexist through the coordination of functional traits. In addition, needle-leaf trees are generally thought to be better adapted to cold or nutrient-poor environments than broad-leaf trees Liu, Chen, et al., 2021;. With an increase in water stress, plants tend to exhibit xerophytic leaves with a thicker leaf structure (Guerfel et al., 2009; TA B L E 4 Pearson's correlation coefficients (lower diagonal) and phylogenetically independent contrasts (PIC, upper diagonal) among nine leaf functional traits for all species. ...
... This result was consistent with those of previous studies that showed larger SLA and thinner leaves of broad-leaved trees than those of coniferous trees (Tian et al., 2016). Furthermore, the LN content of evergreen species was significantly lower than that of deciduous species because the generation cost of leaves was related to seasonal variation; leading to different adaptive strategies of evergreen and deciduous trees based on the variation of traits to adverse environments (Liu, Chen, et al., 2021;. In summary, the variations in leaf F I G U R E 5 Variation partitioning of phylogenetic and functional traits structures (adjusted R 2 × 100%) in the effects of different response variables at the community level. ...
... Therefore, compared with the leaf chemical traits, the formation and development of structural traits were more affected by genetic differences, which is consistent with the results of Cao et al. (2013). In Numerous studies have indicated that phylogeny has a significant effect on the functional trait composition and that the relationships among traits are generally weakened after removing phylogeny (Cadotte et al., 2019;Liu, Chen, et al., 2021;Wang et al., 2020). This study also found that the traits of coexisting species in the community had a phylogenetic structure; however, only a few leaf traits (LA and LT) showed strongly phylogenetic signals. ...
Neutral‐theory‐based stochastic and niche‐theory‐based determinative processes are commonly used to explain the mechanisms of natural community assembly. However, considerable uncertainty remains regarding the relative importance of different ecological processes in shaping forest communities. Functional traits and phylogeny provide important information about plant environmental adaptation strategies and evolutionary history and promise a better mechanistic and predictive understanding of community assembly. Based on nine leaf functional traits and phylogenetic data of 18 dominant species in a Lithocarpus glaber–Cyclobalanopsis glauca evergreen broad‐leaved forest, we analyzed the variation in traits, explored the influence of phylogeny and environment on leaf traits, and distinguished the relative effects of spatial and environmental variables on functional traits and phylogenetic compositions. The results showed the following: (i) Leaf traits had moderate intraspecific variation, and significant interspecific variation existed especially among life forms. (ii) Significant phylogenetic signals were detected only in leaf thickness and leaf area. The correlations among traits both supported “the leaf economics spectrum” at the species and community levels, and the relationships significantly increased or only a little change after removing the phylogenetic influence, which showed a lack of consistency between the leaf functional trait patterns and phylogenetic patterns. We infer the coexistent species tended to adopt “realism” to adapt to their habitats. (iii) Soil total potassium and phosphorus content, altitude, aspect, and convexity were the most critical environmental factors affecting functional traits and phylogenetic composition. Total environmental and spatial variables explained 63.38% of the variation in functional trait composition and 47.96% of the variation in phylogenetic structures. Meanwhile, the contribution of pure spatial factors was significantly higher than that of the pure environment. Stochastic processes played dominant roles in driving community functional trait assembly, but determinative processes such as environmental filtering had a stronger effect on shaping community phylogenetic structure at a fine scale. We infer the coexistent species tended to adopt “realism” to adapt to their habitats.Neutral‐ theory‐based stochastic processes played dominant roles in driving community functional trait assembly, but niche‐theory‐based determinative processes such as environmental filtering had a stronger effect on shaping community phylogenetic structure at a fine scale.
... As important indicators of leaf traits, leaf anatomical traits change along environmental gradients, suggesting that plants can adapt to environmental changes by adjusting the ratios of leaf anatomical structure (Chen et al., 2010;Aguraijuja et al., 2015). Studies have reported that leaf epidermis and mesophyll traits exhibited significant geographical patterns at the species and community levels Lin et al., 2021;Liu et al., 2021). For example, the palisade mesophyll to leaf thickness ratio increased with increasing temperature and precipitation, while the spongy mesophyll to leaf thickness ratio decreased (He et al., 2018.) ...
... In addition to environmental factors, plant phylogeny and plant functional type (PFT) involving plant growth form (trees, shrubs, herbs) and life form (deciduous, evergreen; coniferous, broad-leaved), may play important roles in the variation in leaf traits (Song et al., 2016;Li et al., 2017;He et al., 2018;Zheng et al., 2019;Sun et al., 2021). Previous studies have reported that phylogeny influences leaf epidermis, mesophyll and vein traits across elevation gradients even more significantly than that of environmental factors (Wang et al., 2020;Liu et al., 2021). Meanwhile, PFTs captured significant differences in leaf traits (Kröber et al., 2015;Wang et al., 2016;Werden et al., 2017), overtaking the impacts of climatic variables at global scales (Reich et al., 2007). ...
... Our study not only focused on the patterns of leaf epidermis and mesophyll traits that have been widely investigated before (Tian et al., 2016;He et al., 2018;Liu et al., 2020;Lin et al., 2021;Liu et al., 2021), but also showed that leaf midrib and vascular traits exhibited similar latitudinal patterns and were more remarkable. With increasing latitude (decreasing MAT and MAP or increasing SOC, TN and TP), all leaf midrib and vascular traits (MT, VBD, MVD and VD) tended to decrease significantly ( Fig. 4e − h, 5). ...
Leaf anatomical traits are responsive to environmental factors and thus highly plastic in their development and biochemical function. However, how they vary across large geographical scales and the main driving factors remain unclear, especially for forest plants. Here, by combining field sampling with plant semi-thin sectioning methods, eight anatomical traits (including leaf epidermis and mesophyll traits, leaf midrib and vascular traits) that can fully reflect leaf structure were measured in 60 plant species inhabiting eight forests in eastern China, and their geographical patterns and possible determinants were explored. Our results showed that leaf anatomical traits varied significantly among different plant functional types (PFTs), and phylogeny had a negligible effect on them. At the species level, leaf anatomical traits exhibited significant geographical patterns, and the thickness of leaf tissues tended to increase from boreal to tropical forests. Compared to leaf epidermis and mesophyll traits, leaf midrib and vascular traits showed similar and more significant geographical patterns. Moreover, the spatial variations in leaf anatomical traits were mainly determined by the shifts in PFTs, while climate and soil nutrient availability had relatively marginal effects. Our findings emphasized that leaf anatomical trait coordination could reflect the resource trade-off and utilization strategies of plants, which is expected to improve our understanding of the responses and adaptation mechanisms of plants to environmental changes.
... Reduced intercellular airspace is known to reduce mesophyll conductance to internal CO 2 diffusion, limiting photosynthetic rates (see Ye et al. (2020) and references therein). It is also clear that the relative extent of tissue types comprising leaves varies with environmental factors, such as elevation (Liu et al. 2021). However internal anatomical variation has not been placed in the context of the wider 'global spectrum' trade-off between economics and size. ...
Plant functioning depends on variation in resource economics traits (acquisition vs. conservation) and the size of plants and their parts (the ‘global spectrum of plant form and function’). The anatomical basis of single traits (e.g., leaf mass per area; LMA) is understood, but little is known regarding the relationship between anatomical trade-offs and ecological strategies (suites of traits). We hypothesised correlations between the relative extent of leaf tissue types and Grime’s Competitor Stress-tolerator Ruderal (CSR) strategies, principally a trade-off between structural (mechanical/fibro-vascular) vs. photosynthetic (chlorenchyma and intercellular airspace; ICAS) tissues, for ecologically-contrasting herbaceous angiosperms in northern Italy. Specifically, that in the lamina portion the trade-off represents the economics spectrum (S-R selection), but in the mid-vein portion it reflects the mechanical constraints inherent to large leaves (varies with C-selection). We used microscopy and image analysis to determine the relative cross-sectional area of tissues from transverse leaf sections (lamina and midvein portions) of angiosperms of contrasting CSR strategies. Principal components analysis (PCA) determined that the main spectrum was that of economics (S-R selection) characterised by a mechanical/ICAS vs. chlorenchyma/epidermis trade-off in the midvein, but contrary to expectations ICAS and chlorenchyma did not trade-off in the lamina. The secondary axis involved a trade-off between larger leaved competitors with extensive mechanical/fibrovascular tissue and small-leaved species (S and R-selected) with proportionally greater ICAS, chlorenchyma and epidermis. Our results confirm the expectation that ecological strategy variation has a basis in underlying trade-offs between tissues with contrasting physiological and structural roles.
