Patterns of morphological leaf traits among pteridophytes along humidity and temperature gradients in the Bolivian Andes

2007 ◽  
Vol 34 (11) ◽  
pp. 963 ◽  
Author(s):  
Michael Kessler ◽  
Yvonne Siorak ◽  
Meike Wunderlich ◽  
Caroline Wegner

Macroecological patterns of leaf traits can be used to assess adaptive responses of plants to environmental stress. Here we present the first such study on a large number of fern species (403) along gradients of elevation (temperature) and humidity. To assess how the representation of traits such as degree of lamina dissection, leaf length, leaf mass per area (LMA), trichome density, venation density, stomatal density, and of adaptive strategies such as poikilohydry vary at the community and species levels in response to changes in humidity and temperature in the Bolivian Andes, we (1) compared whole pteridophyte communities at 14 sites, and (2) analysed intraspecific variation of the morphological traits of 17 fern species along an elevational gradient at 1700–3400 m in humid forest. Among the fern communities of the 14 sites, leaf length decreased with elevation and aridity, LMA increased with elevation, and trichome density and venation density increased with aridity. The study of intraspecific variation among 17 species showed an increase of stomatal density with elevation in six of 11 species (filmy ferns lacked stomata), an increase of specific weight in 15 species, a decrease of trichome density in seven of 10 species (other species lacked hairs), and a decrease of venation density in seven of 10 cases. Some of these trends can be interpreted adaptively: leaf thickness appears to increase in situations with low nutrient availability rather than with low water availability, whereas a dense cover of scales or hairs serves as a protection against insolation or as a vehicle for the absorption of water in poikilohydric species. In arid areas, trichome density increased with elevation, while it decreased with elevation in cloudy and humid regions. For most traits, variation was more pronounced at the community than at the species level, except for stomatal density, which varied much more strongly within than between species. Several of these morphological and anatomical characters can be used to infer palaeoclimatic conditions based on fossil pteridophyte floras.

2014 ◽  
Vol 66 (2) ◽  
pp. 615-627
Author(s):  
J. Kołodziejek

The morphological, anatomical and biochemical traits of the leaves of yellow foxglove (Digitalis grandiflora Mill.) from two microhabitats, forest interior (full shade under oak canopy) and forest edge (half shade near shrubs), were studied. The microhabitats differed in the mean levels of available light, but did not differ in soil moisture. The mean level of light in the forest edge microhabitat was significantly higher than in the forest interior. Multivariate ANOVA was used to test the effects of microhabitat. Comparison of the available light with soil moisture revealed that both factors significantly influenced the morphological and anatomical variables of D. grandiflora. Leaf area, mass, leaf mass per area (LMA), surface area per unit dry mass (SLA), density and thickness varied greatly between leaves exposed to different light regimes. Leaves that developed in the shade were larger and thinner and had a greater SLA than those that developed in the half shade. In contrast, at higher light irradiances, at the forest edge, leaves tended to be thicker, with higher LMA and density. Stomatal density was higher in the half-shade leaves than in the full-shade ones. LMA was correlated with leaf area and mass and to a lesser extent with thickness and density in the forest edge microsite. The considerable variations in leaf density and thickness recorded here confirm the very high variation in cell size and amounts of structural tissue within species. The leaf plasticity index (PI) was the highest for the morphological leaf traits as compared to the anatomical and biochemical ones. The nitrogen content was higher in the ?half-shade leaves? than in the ?shade leaves?. Denser leaves corresponded to lower nitrogen (N) contents. The leaves of plants from the forest edge had more potassium (K) than leaves of plants from the forest interior on an area basis but not on a dry mass basis; the reverse was true for phosphorus.


2019 ◽  
Vol 46 (7) ◽  
pp. 649
Author(s):  
C. Korgiopoulou ◽  
P. Bresta ◽  
D. Nikolopoulos ◽  
G. Karabourniotis

In dioecious species, sex-related adaptive strategies, influenced by natural and sexual selection, allow each sex to meet the specific demands of reproduction. Differences in ecophysiological traits between males and females may rely on innate differences in secondary sex traits such as structural and functional leaf traits. We tested structural sexual leaf dimorphism in Pistacia vera L. and the intersexual differences in sun–shade acclimation processes expected from the different adaptive strategies of males and females. Fifteen structural and functional leaf traits were compared in 50-year-old trees between females with low fruit load and males under sun and shade conditions. Despite the low additional energy investment in reproduction in females, remarkable sex effects in leaf structure and function were observed. Male trees had smaller leaves with significantly lower total conducting petiole area (TCA) and higher stomatal density, water use efficiency and concentration of phenolic compounds; females had larger leaves with greater thickness, leaf mass per area, TCA and maximum photosynthetic capacity per area (Amax,a). The higher Amax,a and stomatal conductance of female leaves were associated with their ~20-fold higher TCA compared with male trees. Females seem to invest more in high xylem efficiency and rates of C gain; males invest more in defence-protection. Sun–shade plastic responses were sex- and trait-specific, but the plasticity assessment indicated that both sexes have evolved an almost equal degree of phenotypic plasticity that allows them to perform optimally under varying environmental conditions. However, the trait-specific differences indicate that each sex displays a different strategy of optimisation.


Author(s):  
Hammad A Khan ◽  
Yukiko Nakamura ◽  
Robert T Furbank ◽  
John R Evans

Abstract A growing number of leaf traits can be estimated from hyperspectral reflectance data. These include structural and compositional traits, such as leaf mass per area (LMA) and nitrogen and chlorophyll content, but also physiological traits such a Rubisco carboxylation activity, electron transport rate, and respiration rate. Since physiological traits vary with leaf temperature, how does this impact on predictions made from reflectance measurements? We investigated this with two wheat varieties, by repeatedly measuring each leaf through a sequence of temperatures imposed by varying the air temperature in a growth room. Leaf temperatures ranging from 20 °C to 35 °C did not alter the estimated Rubisco capacity normalized to 25 °C (Vcmax25), or chlorophyll or nitrogen contents per unit leaf area. Models estimating LMA and Vcmax25/N were both slightly influenced by leaf temperature: estimated LMA increased by 0.27% °C–1 and Vcmax25/N increased by 0.46% °C–1. A model estimating Rubisco activity closely followed variation associated with leaf temperature. Reflectance spectra change with leaf temperature and therefore contain a temperature signal.


2012 ◽  
Vol 36 (1) ◽  
pp. 07-16 ◽  
Author(s):  
Miguel Angelo Branco Camargo ◽  
Ricardo Antonio Marenco

Crabwood (Carapa guianensis Aubl.) is a fast growing tree species with many uses among Amazonian local communities. The main objective of this study was to assess the effect of seasonal rainfall pattern on growth rates, and seasonal and diurnal changes in leaf gas exchange and leaf water potential (ΨL) in crabwood. To assess the effect of rainfall seasonality on growth and physiological leaf traits an experiment was conducted in Manaus, AM (03º 05' 30" S, 59º 59' 35" S). In this experiment, six 6-m tall plants were used to assess photosynthetic traits and ΨL. In a second experiment the effect of growth irradiance on stomatal density (S D), size (S S) and leaf thickness was assessed in 0.8-m tall saplings. Stomatal conductance (g s) and light-saturated photosynthesis (Amax) were higher in the wet season, and between 09:00 and 15:00 h. However, no effect of rainfall seasonality was found on ΨL and potential photosynthesis (CO2-saturated). ΨL declined from -0.3 MPa early in the morning to -0.75 MPa after midday. It increased in the afternoon but did not reach full recovery at sunset. Growth rates of crabwood were high, and similar in both seasons (2 mm month-1). Leaf thickness and S D were 19% and 47% higher in sun than in shade plants, whereas the opposite was true for S S. We conclude that ΨL greatly affects carbon assimilation of crabwood by reducing g s at noon, although this effect is not reflected on growth rates indicating that other factors offset the effect of g s on Amax.


2016 ◽  
Vol 9 (11) ◽  
pp. 4227-4255 ◽  
Author(s):  
Bradley O. Christoffersen ◽  
Manuel Gloor ◽  
Sophie Fauset ◽  
Nikolaos M. Fyllas ◽  
David R. Galbraith ◽  
...  

Abstract. Forest ecosystem models based on heuristic water stress functions poorly predict tropical forest response to drought partly because they do not capture the diversity of hydraulic traits (including variation in tree size) observed in tropical forests. We developed a continuous porous media approach to modeling plant hydraulics in which all parameters of the constitutive equations are biologically interpretable and measurable plant hydraulic traits (e.g., turgor loss point πtlp, bulk elastic modulus ε, hydraulic capacitance Cft, xylem hydraulic conductivity ks,max, water potential at 50 % loss of conductivity for both xylem (P50,x) and stomata (P50,gs), and the leaf : sapwood area ratio Al : As). We embedded this plant hydraulics model within a trait forest simulator (TFS) that models light environments of individual trees and their upper boundary conditions (transpiration), as well as providing a means for parameterizing variation in hydraulic traits among individuals. We synthesized literature and existing databases to parameterize all hydraulic traits as a function of stem and leaf traits, including wood density (WD), leaf mass per area (LMA), and photosynthetic capacity (Amax), and evaluated the coupled model (called TFS v.1-Hydro) predictions, against observed diurnal and seasonal variability in stem and leaf water potential as well as stand-scaled sap flux. Our hydraulic trait synthesis revealed coordination among leaf and xylem hydraulic traits and statistically significant relationships of most hydraulic traits with more easily measured plant traits. Using the most informative empirical trait–trait relationships derived from this synthesis, TFS v.1-Hydro successfully captured individual variation in leaf and stem water potential due to increasing tree size and light environment, with model representation of hydraulic architecture and plant traits exerting primary and secondary controls, respectively, on the fidelity of model predictions. The plant hydraulics model made substantial improvements to simulations of total ecosystem transpiration. Remaining uncertainties and limitations of the trait paradigm for plant hydraulics modeling are highlighted.


2008 ◽  
Vol 24 (2) ◽  
pp. 121-133 ◽  
Author(s):  
Satomi Shiodera ◽  
Joeni S. Rahajoe ◽  
Takashi Kohyama

Abstract:The relationship between leaf longevity and other leaf traits was compared among different life-form categories (trees, herbs, climbers and epiphytes) of 101 plant species in a tropical montane forest on Mt. Halimun, West Java, Indonesia. We applied the Cox proportional hazards regression to estimate the leaf longevity of each species from 30 mo of census data. We examined whether estimated longevity was explained by either species life-form categories, taxonomic groupings (eudicots, monocots, magnoliids and chloranthales, and ferns) or such leaf traits as leaf area, leaf mass per area (LMA), mass-based leaf nitrogen, penetrometer reading, condensed-tannin-free total phenolics and condensed tannin. There was a wide-ranged interspecific variation in leaf longevity, mostly 10–50 mo, similarly across life-form categories. LMA showed a strong positive influence on leaf longevity. We found that relationships between leaf longevity and some leaf traits were different among various life forms. Trees tended to have high LMA, while climbers tended to have low LMA at the same leaf longevity. We hypothesize that such difference among life forms reflects shoot architecture characteristics. Multi-shoot trees with branching architecture need to have self-supporting leaves, whereas semi-epiphytic climbers can maintain relatively low biomass investment to leaves hanging or relying upon the mechanical support from host plants.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1638
Author(s):  
Seong-Min Kim ◽  
Yeong Deuk Jo ◽  
Jae-In Chun ◽  
Jin-Baek Kim ◽  
Jin-Ho Kang

Compared to the studies on acute irradiation of seeds, fewer studies have reported on the chronic irradiation of seedlings, especially in fruit-bearing vegetables. We examined the effects of chronic gamma irradiation on tomato (Solanum lycopersicum ‘Micro-Tom’) seedlings exposed to gamma rays (50, 100, 150, and 200 Gy) for 4 weeks. As the total dose of gamma rays increased, leaf length, trichome density, and seed number were reduced in the irradiated seedlings (M1). Additionally, a change in fruit shape was observed. Chronic gamma irradiation reduced the expression of two trichome-related genes and affected the expression levels of 11 reactive oxygen species (ROS)-related genes. We examined the transmittance of these effects using M2 plants. The trichome density and fruit shape were similar between M2 and control plants; however, a reduction in leaf length and seed number was detected in M2 plants. Interestingly, changes in the expression of four ROS-related genes (ZAT10, Mn-SOD, POD3, and RBOH1) found in M1 were detected in M2 plants. Thus, the changes in phenotype and gene expression induced by chronic gamma irradiation were transmitted to the next generation. Additionally, we found novel mutants from M2 plants, suggesting that chronic gamma irradiation may be considered in tomato mutation breeding.


2017 ◽  
Vol 52 (1) ◽  
pp. 1-6 ◽  
Author(s):  
AA Abdul Rahaman ◽  
OM Olaniran ◽  
FA Oladele

The effect of industrial effluents was studied with respect to growth and leaf anatomy of three Sesamum indicum varieties (NGB 00931, NGB 00937 and NGB 00939). Industrial effluents (25%, 50%, 75% and 100%) from two industries are used to irrigate the plants. Although, the control plants possessed larger leaves and longer stems than the effluent-treated plants, at lower concentration, the plant growth is relatively higher. Gradual decrease in the germination of seeds and seedling growth with increase in effluent concentration was observed. The best germination and seedling growth was observed at the 25% concentration. Leaf epidermal features (stomatal density, stomatal index, stomatal size, trichome density, tricome index, trichome size and number of epidermal cells) are more influenced in the effluent-treated plants than in the control plants from the Peace Standard Pharmaceutical Industry than in the effluent from the Global Soap & Detergent Industry. Thus the industrial effluents can be safely used for irrigation purposes with proper treatment and dilution at 25%.Bangladesh J. Sci. Ind. Res. 52(1), 1-6, 2017


Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 318
Author(s):  
Guangman Song ◽  
Quan Wang ◽  
Jia Jin

A clear understanding of the dynamics of photosynthetic capacity is crucial for accurate modeling of ecosystem carbon uptake. However, such dynamical information is hardly available and has dramatically impeded our understanding of carbon cycles. Although tremendous efforts have been made in coupling the dynamic information of photosynthetic capacity into models, using “proxies” rooted from the close relationships between photosynthetic capacity and other available leaf parameters remains the popular selection. Unfortunately, no consensus has yet been reached on such “proxies”, leading them only applicable to limited cases. In this study, we aim to identify if there are close relationships between the photosynthetic capacity (represented by the maximum carboxylation rate, Vcmax) and leaf traits for mature broadleaves within a cold temperature deciduous forest. This is based on a long-term in situ dataset including leaf chlorophyll content (Chl), leaf nitrogen concentration (Narea, Nmass), leaf carbon concentration (Carea, Cmass), equivalent water thickness (EWT), leaf mass per area (LMA), and leaf gas exchange measurements from which Vcmax was derived, for both sunlit and shaded leaves during leaf mature periods from 2014 to 2019. The results show that the Vcmax values of sunlit and shaded leaves were relatively stable during these periods, and no statistically significant interannual variations occurred (p > 0.05). However, this is not applicable to specific species. Path analysis revealed that Narea was the major contributor to Vcmax for sunlit leaves (0.502), while LMA had the greatest direct relationship with Vcmax for shaded leaves (0.625). The LMA has further been confirmed as a primary proxy if no leaf type information is available. These findings provide a promising way to better understand photosynthesis and to predict carbon and water cycles in temperate deciduous forests.


2013 ◽  
Vol 29 (3) ◽  
pp. 217-228 ◽  
Author(s):  
K. Riaño ◽  
O. Briones

Abstract:Abundance and physiology of three understorey tree fern species were compared in a Mexican cloud forest. We hypothesized that the distribution of species would be associated with canopy openness and leaf physiological characteristics. In gullies (1–2% full sun), Alsophila firma was abundant, Cyathea divergens was distributed in moderately open places (4–9%), and Lophosoria quadripinnata preferred more open canopy (9–30%). Although 11 leaf traits of five plants of each species growing under closed and open canopies over 1 y did not differ within species, there were significant interspecific differences. Alsophila firma had comparatively low maximum electron transport rate ETRmax (26.8 ± 1.81 μmol m−2 s−1) and ETR light saturation point (ETRLSP: 261 ± 36.1 μmol m−2 s−1), high specific leaf area (SLA), thin leaves and decreased quantum yield during a leaf desiccation experiment. Cyathea divergens had relatively high maximum quantum yield (0.84 ± 0.004), ETRmax (37.3 ± 1.8 μmol m−2 s−1) and ETRLSP (409 ± 40.0 μmol m−2 s−1). Lophosoria quadripinnata had comparatively thick leaves, low SLA, high predawn water potential, high density (606 ± 25.5 mm−2) and small length (0.026 ± 0.002 mm) stomata. The results support the hypothesis that light sensitivity shapes tree fern distribution in the cloud forest.


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