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Bill Shipley - One of the best experts on this subject based on the ideXlab platform.
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InterSpecific consistency and intraSpecific variability of Specific Leaf Area with respect to irradiance and nutrient availability
Ecoscience, 2016Co-Authors: Bill Shipley, Jarcilene S. Almeida-cortezAbstract:Specific Leaf Area (SLA) is a common variable in comparative plant ecology that is often measured on field-grown plants, yet SLA is known to be a plastic trait. The motivation for this study was th...
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is Leaf dry matter content a better predictor of soil fertility than Specific Leaf Area
Annals of Botany, 2011Co-Authors: J Hodgson, Bill Shipley, Peter J. Wilson, Johannes H. C. Cornelissen, Gabriel Montserratmarti, Michael Charles, Glynis Jones, M Sharafi, Bruno Enrico Leone Cerabolini, S R BandAbstract:†Background and Aims Specific Leaf Area (SLA), a key element of the ‘worldwide Leaf economics spectrum’, is the preferred ‘soft’ plant trait for assessing soil fertility. SLA is a function of Leaf dry matter content (LDMC) and Leaf thickness (LT). The first, LDMC, defines Leaf construction costs and can be used instead of SLA. However, LT identifies shade at its lowest extreme and succulence at its highest, and is not related to soil fertility. Why then is SLA more frequently used as a predictor of soil fertility than LDMC? †Methods SLA, LDMC and LT were measured and Leaf density (LD) estimated for almost 2000 species, and the capacity of LD to predict LDMC was examined, as was the relative contribution of LDMC and LT to the expression of SLA. Subsequently, the relationships between SLA, LDMC and LT with respect to soil fertility and shade were described. †Key Results Although LD is strongly related to LDMC, and LDMC and LT each contribute equally to the expression of SLA, the exact relationships differ between ecological groupings. LDMC predicts Leaf nitrogen content and soil fertility but, because LT primarily varies with light intensity, SLA increases in response to both increased shade and increased fertility. †Conclusions Gradients of soil fertility are frequently also gradients of biomass accumulation with reduced irradiance lower in the canopy. Therefore, SLA, which includes both fertility and shade components, may often discriminate better between communities or treatments than LDMC. However, LDMC should always be the preferred trait for assessing gradients of soil fertility uncoupled from shade. Nevertheless, because leaves multitask, individual Leaf traits do not necessarily exhibit exact functional equivalence between species. In consequence, rather than using a single stand-alone predictor, multivariate analyses using several Leaf traits is recommended.
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Specific Leaf Area and dry Matter Content Estimate thickness in Laminar Leaves
Annals of Botany, 2005Co-Authors: Denis Vile, Bill Shipley, John G. Hodgson, Eric Garnier, G. Laurent, Marie-laure Navas, Catherine Roumet, Sandra Lavorel, Sandra Díaz, Francisco LloretAbstract:• Background and Aims Leaf thickness plays an important role in Leaf and plant functioning, and relates to a species' strategy of resource acquisition and use. As such, it has been widely used for screening purposes in crop science and community ecology. However, since its measurement is not straightforward, a number of estimates have been proposed. Here, the validity of the (SLA x LDMC)–1 product is tested to estimate Leaf thickness, where SLA is the Specific Leaf Area (Leaf Area/dry mass) and LDMC is the Leaf dry matter content (Leaf dry mass/fresh mass). SLA and LDMC are two Leaf traits that are both more easily measurable and often reported in the literature. • Methods The relationship between Leaf thickness (LT) and (SLA x LDMC)–1 was tested in two analyses of covariance using 11 datasets (three original and eight published) for a total number of 1039 data points, corresponding to a wide range of growth forms growing in contrasted environments in four continents. • Key Results and Conclusions The overall slope and intercept of the relationship were not significantly different from one and zero, respectively, and the residual standard error was 0·11. Only two of the eight datasets displayed a significant difference in the intercepts, and the only significant difference among the most represented growth forms was for trees. LT can therefore be estimated by (SLA x LDMC)–1, allowing Leaf thickness to be derived from easily and widely measured Leaf traits.
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A standardized protocol for the determination of Specific Leaf Area and Leaf dry matter content
Functional Ecology, 2001Co-Authors: Eric Garnier, Bill Shipley, Catherine Roumet, G. LaurentAbstract:Summary 1 The impact of sample preparation, rehydration procedure and time of collection on the determination of Specific Leaf Area (SLA, the ratio of Leaf Area to Leaf dry mass) and Leaf dry matter content (LDMC, the ratio of Leaf dry mass to fresh mass) of mature leaves was studied in three wild species growing in the field, chosen for their contrasting SLA and LDMC. 2 Complete rehydration was achieved 6 h after samples were placed into water, but neither of the procedures tested – preparation of samples before rehydration or temperature applied during rehydration – had a significant effect on the final values of SLA or LDMC. 3 As expected, water-saturated leaves had a lower LDMC than non-rehydrated leaves; more surprisingly, their SLA was also higher. The impact of rehydration on SLA was especially important when the SLA of the species was high. 4 There was no significant effect of time of sampling on either trait in any species over the time period covered (09·00–16·30 h). 5 These results suggest that SLA and LDMC obtained on water-saturated leaves (SLASAT and LDMCSAT) can be used for species comparisons. We propose a standardized protocol for the measurement of these traits. This would allow for better consistency in data collection, a prerequisite for the constitution of large databases of functional traits.
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direct and indirect relationships between Specific Leaf Area Leaf nitrogen and Leaf gas exchange effects of irradiance and nutrient supply
Annals of Botany, 2001Co-Authors: Driss Meziane, Bill ShipleyAbstract:We present a series of competing path models relating interSpecific patterns between Specific Leaf Area, Leaf nitrogen content, net photosynthesis and stomatal conductance and test these against data from 22 species of herbaceous plants grown under controlled conditions with contrasting irradiance and nutrient supply rates. We then compare these results with two previous data sets, one based on field measures and one based on glasshouse measures, to determine the robustness of the results. Only one model was able to account for the patterns of direct and indirect effects between the four variables to all data sets. In this model Specific Leaf Area is the forcing variable that directly affects both Leaf nitrogen levels and net photosynthetic rates. Leaf nitrogen then directly affects net photosynthetic rates which in turn then affect stomatal conductance to water.
A. S. Nelson - One of the best experts on this subject based on the ideXlab platform.
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Spatial variation in Specific Leaf Area and horizontal distribution of Leaf Area in juvenile western larch (Larix occidentalis Nutt.)
Trees, 2018Co-Authors: G. M. Williams, A. S. NelsonAbstract:Key message Models were developed to predict spatial distribution of Specific Leaf Area (SLA) and horizontal distribution of Leaf Area for western larch. Cardinal branch direction significantly influenced both SLA and horizontal Leaf Area distributions. Abstract Leaf Area, Specific Leaf Area (SLA), and their spatial distribution in the crown are important indicators of biological response to changes in growing conditions including light and water availability. Western larch ( Larix occidentalis Nutt.) is a deciduous coniferous pioneer species in the U.S. Inland Northwest known for its rapid growth, high-quality wood, and ecological importance. Analysis with nonlinear models revealed that SLA and horizontal Leaf Area distributions differ between cardinal quadrants of juvenile western larch crowns. SLA was significantly higher in the more illuminated, southern side of the crown, and Leaf Area peaked closer to the stem in the southwest quadrant. Similar to other conifers, horizontal distributions of foliage in western larch also shifted further outward towards the branch tips with increasing depth in the crown. Models developed for horizontal distribution of Leaf Area and spatial distribution of Specific Leaf Area for western larch may be extended by future researchers to predict its response to environmental variables or management practices.
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Spatial variation in Specific Leaf Area and horizontal distribution of Leaf Area in juvenile western larch (Larix occidentalis Nutt.)
Trees-structure and Function, 2018Co-Authors: G. M. Williams, A. S. NelsonAbstract:Models were developed to predict spatial distribution of Specific Leaf Area (SLA) and horizontal distribution of Leaf Area for western larch. Cardinal branch direction significantly influenced both SLA and horizontal Leaf Area distributions. Leaf Area, Specific Leaf Area (SLA), and their spatial distribution in the crown are important indicators of biological response to changes in growing conditions including light and water availability. Western larch (Larix occidentalis Nutt.) is a deciduous coniferous pioneer species in the U.S. Inland Northwest known for its rapid growth, high-quality wood, and ecological importance. Analysis with nonlinear models revealed that SLA and horizontal Leaf Area distributions differ between cardinal quadrants of juvenile western larch crowns. SLA was significantly higher in the more illuminated, southern side of the crown, and Leaf Area peaked closer to the stem in the southwest quadrant. Similar to other conifers, horizontal distributions of foliage in western larch also shifted further outward towards the branch tips with increasing depth in the crown. Models developed for horizontal distribution of Leaf Area and spatial distribution of Specific Leaf Area for western larch may be extended by future researchers to predict its response to environmental variables or management practices.
Anthony P. Walker - One of the best experts on this subject based on the ideXlab platform.
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the relationship of Leaf photosynthetic traits vcmax and jmax to Leaf nitrogen Leaf phosphorus and Specific Leaf Area a meta analysis and modeling study
Ecology and Evolution, 2014Co-Authors: Jens Kattge, Anthony P. Walker, Andrew P. Beckerman, Lucas A. Cernusak, Tomas F. Domingues, Joanna C. Scales, Georg Wohlfahrt, Stan D. Wullschleger, Ian F WoodwardAbstract:Great uncertainty exists in the global exchange of carbon between the atmosphere and the terrestrial biosphere. An important source of this uncertainty lies in the dependency of photosynthesis on the maximum rate of carboxylation (Vcmax) and the maximum rate of electron transport (Jmax). Understanding and making accurate prediction of C fluxes thus requires accurate characterization of these rates and their relationship with plant nutrient status over large geographic scales. Plant nutrient status is indicated by the traits: Leaf nitrogen (N), Leaf phosphorus (P), and Specific Leaf Area (SLA). Correlations between Vcmax and Jmax and Leaf nitrogen (N) are typically derived from local to global scales, while correlations with Leaf phosphorus (P) and Specific Leaf Area (SLA) have typically been derived at a local scale. Thus, there is no global-scale relationship between Vcmax and Jmax and P or SLA limiting the ability of global-scale carbon flux models do not account for P or SLA. We gathered published data from 24 studies to reveal global relationships of Vcmax and Jmax with Leaf N, P, and SLA. Vcmax was strongly related to Leaf N, and increasing Leaf P substantially increased the sensitivity of Vcmax to Leaf N. Jmax was strongly related to Vcmax, and neither Leaf N, P, or SLA had a substantial impact on the relationship. Although more data are needed to expand the applicability of the relationship, we show Leaf P is a globally important determinant of photosynthetic rates. In a model of photosynthesis, we showed that at high Leaf N (3 gm−2), increasing Leaf P from 0.05 to 0.22 gm−2 nearly doubled assimilation rates. Finally, we show that plants may employ a conservative strategy of Jmax to Vcmax coordination that restricts photoinhibition when carboxylation is limiting at the expense of maximizing photosynthetic rates when light is limiting.
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The relationship of Leaf photosynthetic traits – Vcmax and Jmax – to Leaf nitrogen, Leaf phosphorus, and Specific Leaf Area: a meta-analysis and modeling study
Ecology and Evolution, 2014Co-Authors: Anthony P. Walker, Jens Kattge, Andrew P. Beckerman, Lucas A. Cernusak, Tomas F. Domingues, Joanna C. Scales, Georg Wohlfahrt, Stan D. Wullschleger, F. Ian WoodwardAbstract:Great uncertainty exists in the global exchange of carbon between the atmosphere and the terrestrial biosphere. An important source of this uncertainty lies in the dependency of photosynthesis on the maximum rate of carboxylation (Vcmax) and the maximum rate of electron transport (Jmax). Understanding and making accurate prediction of C fluxes thus requires accurate characterization of these rates and their relationship with plant nutrient status over large geographic scales. Plant nutrient status is indicated by the traits: Leaf nitrogen (N), Leaf phosphorus (P), and Specific Leaf Area (SLA). Correlations between Vcmax and Jmax and Leaf nitrogen (N) are typically derived from local to global scales, while correlations with Leaf phosphorus (P) and Specific Leaf Area (SLA) have typically been derived at a local scale. Thus, there is no global-scale relationship between Vcmax and Jmax and P or SLA limiting the ability of global-scale carbon flux models do not account for P or SLA. We gathered published data from 24 studies to reveal global relationships of Vcmax and Jmax with Leaf N, P, and SLA. Vcmax was strongly related to Leaf N, and increasing Leaf P substantially increased the sensitivity of Vcmax to Leaf N. Jmax was strongly related to Vcmax, and neither Leaf N, P, or SLA had a substantial impact on the relationship. Although more data are needed to expand the applicability of the relationship, we show Leaf P is a globally important determinant of photosynthetic rates. In a model of photosynthesis, we showed that at high Leaf N (3 gm−2), increasing Leaf P from 0.05 to 0.22 gm−2 nearly doubled assimilation rates. Finally, we show that plants may employ a conservative strategy of Jmax to Vcmax coordination that restricts photoinhibition when carboxylation is limiting at the expense of maximizing photosynthetic rates when light is limiting.
H. C. S. Nascimento - One of the best experts on this subject based on the ideXlab platform.
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Relationship between Specific Leaf Area, Leaf thickness, Leaf water content and SPAD-502 readings in six Amazonian tree species
Photosynthetica, 2009Co-Authors: Ricardo Antonio Marenco, S. A. Antezana-vera, H. C. S. NascimentoAbstract:The aim of this work was to assess the effect of Leaf thickness, Leaf succulence (LS), Specific Leaf Area (SLA), Specific Leaf mass (Ws) and Leaf water content (LWC) on chlorophyll (Chl) meter values in six Amazonian tree species (Carapa guianensis, Ceiba pentandra, Cynometra spruceana, Pithecolobium inaequale, Scleronema micranthum and Swietenia macrophylla). We also tested the accuracy of a general calibration equation to convert Minolta Chl meter (SPAD-502) readings into absolute Chl content. On average, SPAD values (x) increased with fresh Leaf thickness (FLT [μm] = 153.9 + 0.98 x, r 2 = 0.06**), dry Leaf thickness (DLT [μm] = 49.50 + 1.28 x, r 2 = 0.16**), Specific Leaf mass (Ws [g (DM) m−2] = 6.73 + 1.31 x, r 2 = 0.43**), and Leaf succulence (LS [g(FM)] m−2 = 94.2 + 1.58 x, r 2 = 0.19**). However, a negative relationship was found between SPAD values and either Specific Leaf Area [SLA (m2 kg−1) = 35.1 − 0.37 x, r 2 = 0.38**] or the Leaf water content (LWC [%]= 80.0 − 0.42 x, r 2 = 0.58**). Leaf Chl contents predicted by the general calibration equation significantly differed (p
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relationship between Specific Leaf Area Leaf thickness Leaf water content and spad 502 readings in six amazonian tree species
Photosynthetica, 2009Co-Authors: Ricardo Antonio Marenco, S A Antezanavera, H. C. S. NascimentoAbstract:The aim of this work was to assess the effect of Leaf thickness, Leaf succulence (LS), Specific Leaf Area (SLA), Specific Leaf mass (Ws) and Leaf water content (LWC) on chlorophyll (Chl) meter values in six Amazonian tree species (Carapa guianensis, Ceiba pentandra, Cynometra spruceana, Pithecolobium inaequale, Scleronema micranthum and Swietenia macrophylla). We also tested the accuracy of a general calibration equation to convert Minolta Chl meter (SPAD-502) readings into absolute Chl content. On average, SPAD values (x) increased with fresh Leaf thickness (FLT [μm] = 153.9 + 0.98 x, r 2 = 0.06**), dry Leaf thickness (DLT [μm] = 49.50 + 1.28 x, r 2 = 0.16**), Specific Leaf mass (Ws [g (DM) m−2] = 6.73 + 1.31 x, r 2 = 0.43**), and Leaf succulence (LS [g(FM)] m−2 = 94.2 + 1.58 x, r 2 = 0.19**). However, a negative relationship was found between SPAD values and either Specific Leaf Area [SLA (m2 kg−1) = 35.1 − 0.37 x, r 2 = 0.38**] or the Leaf water content (LWC [%]= 80.0 − 0.42 x, r 2 = 0.58**). Leaf Chl contents predicted by the general calibration equation significantly differed (p<0.01) from those estimated by species-Specific calibration equations. We conclude that to improve the accuracy of the SPAD-502 Leaf thickness and LWC should be taken into account when calibration equations are to be obtained to convert SPAD values into absolute Chl content.
Ricardo Antonio Marenco - One of the best experts on this subject based on the ideXlab platform.
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Relationship between Specific Leaf Area, Leaf thickness, Leaf water content and SPAD-502 readings in six Amazonian tree species
Photosynthetica, 2009Co-Authors: Ricardo Antonio Marenco, S. A. Antezana-vera, H. C. S. NascimentoAbstract:The aim of this work was to assess the effect of Leaf thickness, Leaf succulence (LS), Specific Leaf Area (SLA), Specific Leaf mass (Ws) and Leaf water content (LWC) on chlorophyll (Chl) meter values in six Amazonian tree species (Carapa guianensis, Ceiba pentandra, Cynometra spruceana, Pithecolobium inaequale, Scleronema micranthum and Swietenia macrophylla). We also tested the accuracy of a general calibration equation to convert Minolta Chl meter (SPAD-502) readings into absolute Chl content. On average, SPAD values (x) increased with fresh Leaf thickness (FLT [μm] = 153.9 + 0.98 x, r 2 = 0.06**), dry Leaf thickness (DLT [μm] = 49.50 + 1.28 x, r 2 = 0.16**), Specific Leaf mass (Ws [g (DM) m−2] = 6.73 + 1.31 x, r 2 = 0.43**), and Leaf succulence (LS [g(FM)] m−2 = 94.2 + 1.58 x, r 2 = 0.19**). However, a negative relationship was found between SPAD values and either Specific Leaf Area [SLA (m2 kg−1) = 35.1 − 0.37 x, r 2 = 0.38**] or the Leaf water content (LWC [%]= 80.0 − 0.42 x, r 2 = 0.58**). Leaf Chl contents predicted by the general calibration equation significantly differed (p
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relationship between Specific Leaf Area Leaf thickness Leaf water content and spad 502 readings in six amazonian tree species
Photosynthetica, 2009Co-Authors: Ricardo Antonio Marenco, S A Antezanavera, H. C. S. NascimentoAbstract:The aim of this work was to assess the effect of Leaf thickness, Leaf succulence (LS), Specific Leaf Area (SLA), Specific Leaf mass (Ws) and Leaf water content (LWC) on chlorophyll (Chl) meter values in six Amazonian tree species (Carapa guianensis, Ceiba pentandra, Cynometra spruceana, Pithecolobium inaequale, Scleronema micranthum and Swietenia macrophylla). We also tested the accuracy of a general calibration equation to convert Minolta Chl meter (SPAD-502) readings into absolute Chl content. On average, SPAD values (x) increased with fresh Leaf thickness (FLT [μm] = 153.9 + 0.98 x, r 2 = 0.06**), dry Leaf thickness (DLT [μm] = 49.50 + 1.28 x, r 2 = 0.16**), Specific Leaf mass (Ws [g (DM) m−2] = 6.73 + 1.31 x, r 2 = 0.43**), and Leaf succulence (LS [g(FM)] m−2 = 94.2 + 1.58 x, r 2 = 0.19**). However, a negative relationship was found between SPAD values and either Specific Leaf Area [SLA (m2 kg−1) = 35.1 − 0.37 x, r 2 = 0.38**] or the Leaf water content (LWC [%]= 80.0 − 0.42 x, r 2 = 0.58**). Leaf Chl contents predicted by the general calibration equation significantly differed (p<0.01) from those estimated by species-Specific calibration equations. We conclude that to improve the accuracy of the SPAD-502 Leaf thickness and LWC should be taken into account when calibration equations are to be obtained to convert SPAD values into absolute Chl content.
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Specific Leaf Area AND PHOTOSYNTHETIC PARAMETERS OF TREE SPECIES IN THE FOREST UNDERSTOREY AS A FUNCTION OF THE MICROSITE LIGHT ENVIRONMENT IN CENTRAL AMAZONIA
2005Co-Authors: Ricardo Antonio Marenco, Gil VieiraAbstract:MARENCO, R. A. & VIEIRA, G. 2005. Specific Leaf Area and photosynthetic parameters of tree species in the forest understorey as a function of the microsite light environment in central Amazonia. The effect of the microsite light environment (MLE) on Specific Leaf Area (SLA), light-saturated photosynthesis (Amax), maximum transpiration (Emax) and stomatal conductance (gs-max) was examined in three tree forest species (late successional Minquartia guianensis and Scleronema micranthum, and Goupia glabra, a pioneer species) growing in the forest understorey. Logging of large trees 15 years ago had no significant effect on either SLA or photosynthetic parameters. On a per Area basis, species did not differ in gas exchange parameters. However, when photosynthesis was expressed on a per mass basis (ug C g~' DM s-'), higher photosynthetic rates were observed in Goupia (1.07) than in Scleronema (0.71) or Minquartia (0.57). SLA (m2 kg-1) was greater in Goupia (24.4) than in Scleronema (18) or Minquartia (15.9). Amax, Emax and gs-max increased as the MLE in the understorey became brighter, particularly in Goupia. Leaf respiration in the light (0.2 umol m-2 s-1) and the apparent quantum yield (33 mmol COa mol-1 photon) were similar in all examined species. Regardless of logging disturbance, examined species acclimated to the MLE according to their successional status. Goupia, but not Minquartia or Scleronema, responded to its light environment mainly by changing SLA, indicating that physiological processes are involved in the acclimation of late successional species to the forest understorey.
