Intracanopy variation in leaf morphology and physiology in dominant shrubs of Florida’s xeric uplands

Botany ◽  
2009 ◽  
Vol 87 (1) ◽  
pp. 112-125 ◽  
Author(s):  
Elizabeth L. Stephens ◽  
Sonali Saha ◽  
Eric S. Menges
Keyword(s):  
Structure Function ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Morphological Traits ◽  
Light Attenuation ◽  
Photon Flux ◽  
Shade Leaves ◽  
Sun Leaves ◽  
Rosemary Scrub ◽  
Photosynthetic Traits

The variation in morphological traits and photosynthetic potentials associated with light conditions in the canopy can determine whole-plant function. However, leaf structure–function relationships are poorly studied in ecosystems experiencing nominal light attenuation. We examined morphological leaf traits (area, specific leaf area, thickness, revoluteness, length–width) and photosynthetic traits estimated from rapid light curves (PARsat, ETRmax, light harvesting efficiency α) in seven shrub species in two xeric upland ecosystems of Florida: rosemary scrub and sandhill. Across species and ecosystem types, shade leaves had greater specific leaf area, were thinner, and less revolute than sun leaves. Surprisingly, shade leaves had smaller areas than sun leaves. Three out of six species showed a tight relationship between morphological and photosynthetic traits. Species common to both sandhill and rosemary scrub ecosystems showed similar photosynthetic traits but greater sclerophylly in the scrub ecosystem. Overall, greater leaf thickness and greater leaf area of upper canopy leaves yielded higher photosynthetic capacities and saturation at higher photon flux densities compared with lower canopy leaves. Our results suggest that variation in leaf morphological traits governed by patterns in light availability have functional significance; however, ecosystem properties such as nutrient availability might also impact light-driven structure-function relationships.

scholarly journals Photosynthetic Light Response and Epidermal Characteristics of Sun and Shade Pecan Leaves

2009 ◽  
Vol 134 (3) ◽  
pp. 372-378 ◽  
Author(s):  
Leonardo Lombardini ◽  
Hermann Restrepo-Diaz ◽  
Astrid Volder
Keyword(s):  
Leaf Area ◽  
Management Practices ◽  
Light Response ◽  
Tree Canopy ◽  
Photon Flux ◽  
Leaf Type ◽  
Chl A ◽  
Sun And Shade ◽  
Shade Leaves ◽  
Sun Leaves

An experiment was conducted to investigate the morphologic characteristics and photosynthetic response of sun and shade leaves of mature pecan [Carya illinoinensis (Wangenh.) K. Koch] trees. Treatments were established according to leaf type (sun or shade leaves) and cultivar (Pawnee and Stuart). Sun leaves were chosen from those growing on exterior portions of the tree canopy and exposed to full sunlight for most of the day [≥1500 μmol·m−2·s−1 photosynthetic photon flux (PPF)]. Shade leaves were those growing in interior parts of the tree canopy (≤100 μmol·m−2·s−1 PPF). Epidermis characteristics, leaf area, and chlorophyll (Chl) content were also measured. Results indicated that stomatal density (stomata/mm2), leaf area, and leaflet area were greater in sun leaves than in shade leaves in both cultivars investigated. Specific leaf area was greater in shade leaves than sun leaves. Chlorophyll fluorescence, total Chl content, Chl a, Chl b, and Chl a/b were unaffected by leaf type or cultivar. In both cultivars, photosynthetic light response curves showed that area-based maximum assimilation rate (Amax) in shade leaves was about half of that measured in sun leaves in June through August. However, in October, Amax of sun leaves dropped to values similar to those measured in shade leaves. Light compensation point of photosynthesis and dark respiration rate were always lower in shade leaves than in sun leaves. Overall, there were only minor differences between the cultivars. Pecan trees require careful canopy management to avoid self shading and to maintain productivity. These results could help determine optimal levels of canopy light interception and could be used to develop canopy and crop management practices.

scholarly journals Carbon gain optimization in five broadleaf deciduous trees in response to light variation within the crown: correlations among morphological, anatomical and physiological leaf traits

2015 ◽  
Vol 74 (1) ◽  
pp. 71-94 ◽  
Author(s):  
Rosangela Catoni ◽  
Loretta Gratani ◽  
Francesco Sartori ◽  
Laura Varone ◽  
Mirko U. Granata
Keyword(s):  
Phenotypic Plasticity ◽  
Deciduous Forest ◽  
Light Variation ◽  
Stress Factors ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Carbon Gain ◽  
Deciduous Species ◽  
Shade Leaves ◽  
Sun Leaves

AbstractLeaf trait variations in five deciduous species (Quercus robur, Corylus avellana, Populus alba, Acer campestre, Robinia pseudoacacia) growing in an old broadleaf deciduous forest in response to light variation within the tree crown was analyzed. Net photosynthetic rate (PN), leaf respiration rate (R) and the photosynthetic nitrogen use efficiency were, on average, more than 100% higher in sun than in shade leaves. A. campestre and C. avellana sun leaves had the highest specific leaf area (SLA, 156.0 ± 17.9 cm2 g-1) and the lowest total leaf thickness (L, 101.9 ± 8.8 μm) underlining their shade-tolerance. Among the shade-intolerant species (Q. robur, P. alba and R. pseudoacacia), Q. robur had the lowest SLA and the highest L in sun leaves (130.6 ± 10.0 cm2 g-1 and 160.8 ± 9.6 μm, respectively) since shade-intolerant species typically have thicker leaves. The higher PN decrease in respect to R decrease from sun to shade leaves attested the higher sensitivity of PN than R to light variations within the crown. This determined a 69% lower R/PN in sun than in shade leaves. This result is further attested by the significant correlation between PN and the relative photosynthetic photon flux density. The shade-tolerant species have a 76% higher R/PN ratio than the shade-intolerant ones. The measured leaf phenotypic plasticity (PI = 0.35) was in the range of broadleaf deciduous species. Plasticity is a key trait useful to quantify plant response to environmental stimuli. It is defined as the ability of a genotype to produce different phenotypes depending on the environment. Among the considered species, Q. robur showed the highest PI (0.39) and P. alba the lowest (0.29). Knowledge on phenotypic plasticity is important in making hypotheses about the dynamics of the studied forest in consideration of environmental stress factors, including invasive species competition and global climate change.

scholarly journals The relationship of leaf photosynthetic traits -VcmaxandJmax- to leaf nitrogen, leaf phosphorus, and specific leaf area: a meta-analysis and modeling study

2014 ◽  
Vol 4 (16) ◽  
pp. 3218-3235 ◽  
Author(s):  
Anthony P. Walker ◽  
Andrew P. Beckerman ◽  
Lianhong Gu ◽  
Jens Kattge ◽  
Lucas A. Cernusak ◽  
...  
Keyword(s):  
Leaf Area ◽  
Specific Leaf Area ◽  
Meta Analysis ◽  
Leaf Nitrogen ◽  
Relationship Of ◽  
The Relationship ◽  
Photosynthetic Traits ◽  
Modeling Study

scholarly journals Photosynthetic Photon Flux, Photoperiod, and CO2 Concentration Affect Growth and Morphology of Lettuce Plug Transplants

HortScience ◽  
1998 ◽  
Vol 33 (6) ◽  
pp. 988-991 ◽  
Author(s):  
Yoshiaki Kitaya ◽  
Genhua Niu ◽  
Toyoki Kozai ◽  
Maki Ohashi
Keyword(s):  
Leaf Area ◽  
Specific Leaf Area ◽  
Dry Mass ◽  
Leaf Length ◽  
Leaf Number ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Hypocotyl Length ◽  
R Ratio ◽  
Four Levels

Lettuce (Lactuca sativa L. cv. Summer-green) plug transplants were grown for 3 weeks under 16 combinations of four levels (100, 150, 200, and 300 μmol·m-2·s-1) of photosynthetic photon flux (PPF), two photoperiods (16 and 24 h), and two levels of CO2 (400 and 800 μmol·mol-1) in growth chambers maintained at an air temperature of 20 ±2 °C. As PPF increased, dry mass (DM), percent DM, and leaf number increased, while ratio of shoot to root dry mass (S/R), ratio of leaf length to leaf width (LL/LW), specific leaf area, and hypocotyl length decreased. At the same PPF, DM was increased by 25% to 100% and 10% to 100% with extended photoperiod and elevated CO2 concentration, respectively. Dry mass, percent DM, and leaf number increased linearly with daily light integral (DLI, the product of PPF and photoperiod), while S/R, specific leaf area, LL/LW and hypocotyl length decreased as DLI increased under each CO2 concentration. Hypocotyl length was influenced by PPF and photoperiod, but not by CO2 concentration. Leaf morphology, which can be reflected by LL/LW, was substantially influenced by PPF at 100 to 200 μmol·m-2·s-1, but not at 200 to 300 μmol·m-2·s-1. At the same DLI, the longer photoperiod promoted growth under the low CO2 concentration, but not under the high CO2 concentration. Longer photoperiod and/or higher CO2 concentration compensated for a low PPF.

Sun and shade leaves: clues to how salal (Gaultheriashallon) responds to overstory stand density

1991 ◽  
Vol 21 (3) ◽  
pp. 300-305 ◽  
Author(s):  
N. J. Smith
Keyword(s):  
Leaf Area Index ◽  
Relative Density ◽  
Leaf Area ◽  
Stand Density ◽  
Leaf Biomass ◽  
Area Index ◽  
Sun And Shade Leaves ◽  
Sun And Shade ◽  
Shade Leaves ◽  
Sun Leaves

Salal (Gaultheriashallon Pursh) leaf biomass, leaf area index, specific leaf area, and leaf morphology were examined in 13 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands from 37 destructively measured 1-m2 quadrats. In response to light and stand overstory density, salal shoots produced either mainly sun leaves or mainly shade leaves. Sun leaves were associated with sunflecks in open-grown or variably stocked stands. Shade leaves were associated with diffuse light under denser stands. Sun-leaf quadrats had mean specific leaf areas less than 90 cm2/g; shade-leaf quadrats had mean specific leaf areas greater than 90 cm2/g. Sun leaves were narrower, with average leaf widths less than 5 cm. Quadrat salal leaf biomass and leaf area index peaked at Curtis' metric relative density 5.9, which corresponded to an availability of 15% of global photosynthetically active radiation. Sun-leaf quadrats occurred below relative density 5; shade-leaf quadrats occurred above relative density 4. A mixture of sun- and shade-leaf quadrats occurred between about relative density 4 and 5, depending on the uniformity of stocking.

scholarly journals Differing Trade-Off Patterns of Tree Vegetative Organs in a Tropical Cloud Forest

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuanyuan Yang ◽  
Chuchu Xiao ◽  
Xianming Wu ◽  
Wenxing Long ◽  
Guang Feng ◽  
...  
Keyword(s):  
Leaf Area ◽  
Specific Leaf Area ◽  
Morphological Traits ◽  
Cloud Forest ◽  
Principal Component ◽  
Leaf Thickness ◽  
Vegetative Organs ◽  
Trade Off ◽  
Tropical Cloud Forest ◽  
Nitrogen Contents

Functional trait ecology demonstrates the significance of the leaf economics spectrum in understanding plants’ trade-off between acquisitive and conservative resource utilization. However, whether trait variations of different vegetative organs are coordinated and whether the plant economics spectrum is characterized by more than one vegetative organ remain controversial. To gain insights into these questions, within a tropical cloud forest in Hainan Island, a total of 13 functional traits of 84 tree species were analyzed here, including leaf, stem and root traits. By using standardized major axis (SMA) regression and principal components analysis, we examined the trait variations and correlations for deciphering plants’ trade-off pattern. We found decreases of leaf phosphorus content, leaf nitrogen content and specific leaf area and increases of leaf mass per unit area (LMA), wood density and leaf thickness along the first principal component, while there were decreases of specific root length and specific root area and increases of root tissue density along the second principal component. Root phosphorus and nitrogen contents were significantly positively associated with the phosphorus and nitrogen contents of both stem and leaf. Wood density was significantly positively associated with LMA and leaf thickness, but negatively associated with leaf thickness and specific leaf area. Our results indicate that, in the tropical cloud forest, there is a “fast–slow” economic spectrum characterized by leaf and stem. Changes of nutrient trait are coordinated, whereas the relationships of morphological traits varied independently between plant above- and below-ground parts, while root nutrient traits are decoupled from root morphological traits. Our findings can provide an insight into the species coexistence and community assembly in high-altitude tropical forests.

scholarly journals The effects of sooty mold on photosynthesis and mesophyll structure of mahogany (Swietenia macrophylla King., Meliaceae)

Bragantia ◽  
2006 ◽  
Vol 65 (1) ◽  
pp. 11-17 ◽  
Author(s):  
José Pires de Lemos Filho ◽  
Élder Antônio Sousa Paiva
Keyword(s):  
Incident Light ◽  
Light Availability ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Effective Quantum Yield ◽  
Swietenia Macrophylla ◽  
Sooty Mold ◽  
Fluorescence Measurements ◽  
Shade Leaves ◽  
Sun Leaves

The aim of present study was to evaluate the effects of the sooty mold on anatomy and photochemical activity of mahogany (Swietenia macrophylla) leaves. The photochemical features of shade-developed leaves with or without sooty mold were compared to those of sun leaves using chlorophyll a fluorescence measurements. Leaf anatomy was also evaluated using conventional techniques. The degree of blockage of the photosynthetic active photon flux density (PPFD) by sooty mold and its effect on photochemistry were evaluated. Sun leaves showed thick mesophyll with palisade parenchyma disposed in a uniseriate layer, whereas shade leaves showed narrow mesophyll, independently of sooty mold presence. The effective quantum yield (deltaF/Fm') and the apparent electron transport rate (ETR) of sun leaves were higher than those of shade leaves. The values of ETR suggested that photochemistry saturation occurred at lower PPFD in shade-grown plants. Lower values of the deltaF/Fm' and, consequently, lower values of ETR were observed in leaves with sooty mold. A reduction of 40% of the incident light was seen due to physical blockage by sooty mold which is presumably responsible for an additional decrease of ETR values. Our data indicated that sooty mold did not directly damage the leaf, but reduce leaf photochemistry capacity, by decreasing light availability.

scholarly journals Growth, biomass allocation and photosynthesis of Rolandra fruticosa (asteraceae) in response to shade

2000 ◽  
Vol 18 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Moacyr B. Dias-Filho ◽  
Aloisio F. Chagas Júnior
Keyword(s):  
Leaf Area ◽  
Biomass Allocation ◽  
Weed Management ◽  
Dark Respiration ◽  
Experimental Period ◽  
Perennial Weed ◽  
Full Sunlight ◽  
Shade Leaves ◽  
Sun Leaves ◽  
Shade Plants

The effects of shade on growth, biomass allocation patterns and photosynthetic response was examined for Rolandra fruticosa (L.) Kuntze, a common perennial weed shrub in cultivated pastures and agricultural areas of Brazilian Amazonia, for plants grown in full sunlight and those shaded to 30 % of full sunlight over a 34-d period. Specific leaf area and leaf area ratio were higher for shade plants during all the experimental period. Shade plants allocated significantly less biomass to root tissue than sun plants and relative growth rate was higher in sun plants. Sun leaves had significantly higher dark respiration and light saturated rates of photosynthesis than shade leaves. The apparent quantum efficiency was higher for shade leaves, while light compensation point was higher for sun leaves. These results are discussed in relation to their ecological and weed management implications.

scholarly journals Nutritional status and specific leaf area of mahogany and tonka bean under two light environments

2005 ◽  
Vol 35 (1) ◽  
pp. 23-27 ◽  
Author(s):  
José Francisco de C. Gonçalves ◽  
Gil Vieira ◽  
Ricardo A. Marenco ◽  
João Baptista S. Ferraz ◽  
Ulysses Moreira dos Santos Junior ◽  
...  
Keyword(s):  
Nutritional Status ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Leaf Growth ◽  
Leaf Traits ◽  
Swietenia Macrophylla ◽  
Nutrient Contents ◽  
Full Sunlight ◽  
Successional Species ◽  
Sun Leaves

Studies on nutritional status and leaf traits were carried out in two tropical tree species Swietenia macrophylla King (mahogany) and Dipetryx odorata Aubl. Willd. (tonka bean) planted under contrasting light environments in Presidente Figueiredo-AM, Brazil. Leaves of S. macrophylla and D. odorata were collected in three year-old trees grown under full sunlight (about 2000 µmol m-2 s-1) and natural shade under a closed canopy of Balsa-wood plantation (Ochroma pyramidale Cav. Ex. Lam.Urb) about 260 µmol m-2 s-1. The parameters analysed were leaf area (LA), leaf dry mass (LDM), specific leaf area (SLA) and leaf nutrient contents. It was observed that, S. macrophylla leaves grown under full sunlight showed LA 35% lower than those grown under shade. In D. odorata leaves these differences in LA were not observed. In addition, it was observed that S. macrophylla shade leaves, for LDM, were 50% smaller than sun leaves, while in D. odorata, there differences were not observed. SLA in S. macrophylla presented that sun leaves were three times smaller than those grown under shade. In D. odorata, no differences were observed. Nutrient contents in S. macrophylla, regardless of their light environments, showed higher contents for P and Ca than those found in D. odorata. The N, K, Fe and Mn contents in S. macrophylla leaves decreased under shade. Finally, we suggest that the decreasing in leaf nutrient contents may have a negative influence on leaf growth. The results demonstrated that the tested hypothesis is true for leaf traits, which D. odorata, late-successional species, showed lower plasticity for leaf traits than Swietenia macrophylla, mid-successional species.

scholarly journals Does selective logging affect the leaf structure of a late successional species?

Rodriguésia ◽  
2012 ◽  
Vol 63 (2) ◽  
pp. 419-427 ◽  
Author(s):  
Guilherme Rodrigues Rabelo ◽  
Denise Espellet Klein ◽  
Maura Da Cunha
Keyword(s):  
Leaf Area ◽  
Structural Characteristics ◽  
Selective Logging ◽  
Leaf Structure ◽  
The Sun ◽  
Seasonally Dry ◽  
Sun And Shade Leaves ◽  
Sun And Shade ◽  
Shade Leaves ◽  
Sun Leaves

The anatomical characteristics of both sun and shade leaves of Alseis pickelii were investigated in order to evaluate the consequences of selective logging (in seasonally dry Atlantic Forest) on the leaf structure of this species. Fully expanded sun and shade leaves were collected in two distinct stands of tabuleiro forest; a stand of recently logged forest and an unlogged stand. Only leaves from the unlogged stand revealed significantly different magnitudes of response to light regimes, producing leaves with structural characteristics associated with different levels of irradiance. The sun leaves from this stand had a thicker adaxial surface, mesophyll, palisade and spongy parenchyma, a secondary cell wall of fibers and a lower leaf area compared with the shade leaves. However, in the logged stand, the leaf cuticles of sun and shade leaves showed no significant differences, although the leaf area of the sun leaves was higher than the shade leaves. According to these data, we concluded that the unlogged stand produced typical "sun" and "shade" leaves. In contrast, leaves from the logged stand showed a lower variation of types, where neither typical "sun" nor typical "shade" leaves were produced, suggesting lower leaf plasticity of this late successional tree in this area.

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