The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Johan Uddling - One of the best experts on this subject based on the ideXlab platform.
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Contrasting Dependencies of Photosynthetic Capacity on Leaf Nitrogen in Early- and Late-Successional Tropical Montane Tree Species
Frontiers in Plant Science, 2020Co-Authors: Camille Ziegler, Mirindi Eric Dusenge, Göran Wallin, Brigitte Nyirambangutse, Etienne Zibera, Johan UddlingAbstract:Differences in Photosynthetic Capacity among tree species and tree functional types are currently assumed to be largely driven by variation in leaf nutrient content, particularly nitrogen (N). However, recent studies indicate that leaf N content is often a poor predictor of variation in Photosynthetic Capacity in tropical trees. In this study, we explored the relative importance of area-based total leaf N content (N tot) and within-leaf N allocation to Photosynthetic Capacity versus light-harvesting in controlling the variation in Photosynthetic Capacity (i.e. V cmax , J max) among mature trees of 12 species belonging to either early (ES) or late successional (LS) groups growing in a tropical montane rainforest in Rwanda, Central Africa. Photosynthetic Capacity at a common leaf temperature of 25˚C (i.e. maximum rates of Rubisco carboxylation, V cmax25 and of electron transport, J max25) was higher in ES than in LS species (+ 58% and 68% for V cmax25 and J max25 , respectively). While N tot did not significantly differ between successional groups, the Photosynthetic dependency on N tot was markedly different. In ES species, V cmax25 was strongly and positively related to N tot but this was not the case in LS species. However, there was no significant trade-off between relative leaf N investments in compounds maximizing Photosynthetic Capacity versus compounds maximizing light harvesting. Both leaf dark respiration at 25˚C (+ 33%) and, more surprisingly, apparent Photosynthetic quantum yield (+ 35%) was higher in ES than in LS species. Moreover, R d25 was positively related to N tot for both ES and LS species. Our results imply that efforts to quantify carbon fluxes of tropical montane rainforests would be improved if they considered contrasting within-leaf N allocation and Photosynthetic N tot dependencies between species with different successional strategies.
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Photosynthetic Capacity of tropical montane tree species in relation to leaf nutrients, successional strategy and growth temperature.
Oecologia, 2015Co-Authors: Mirindi Eric Dusenge, Göran Wallin, Johanna Gårdesten, Felix Niyonzima, Lisa Adolfsson, Donat Nsabimana, Johan UddlingAbstract:Photosynthetic Capacity of tree leaves is typically positively related to nutrient content and little affected by changes in growth temperature. These relationships are, however, often poorly supported for tropical trees, for which interspecific differences may be more strongly controlled by within-leaf nutrient allocation than by absolute leaf nutrient content, and little is known regarding Photosynthetic acclimation to temperature. To explore the influence of leaf nutrient status, successional strategy and growth temperature on the Photosynthetic Capacity of tropical trees, we collected data on Photosynthetic, chemical and morphological leaf traits of ten tree species in Rwanda. Seven species were studied in a forest plantation at mid-altitude (~1,700 m), whereas six species were studied in a cooler montane rainforest at higher altitude (~2,500 m). Three species were common to both sites, and, in the montane rainforest, three pioneer species and three climax species were investigated. Across species, interspecific variation in Photosynthetic Capacity was not related to leaf nutrient content. Instead, this variation was related to differences in within-leaf nitrogen allocation, with a tradeoff between investments into compounds related to Photosynthetic Capacity (higher in pioneer species) versus light-harvesting compounds (higher in climax species). Photosynthetic Capacity was significantly lower at the warmer site at 1,700 m altitude. We conclude that (1) within-leaf nutrient allocation is more important than leaf nutrient content per se in controlling interspecific variation in Photosynthetic Capacity among tree species in tropical Rwanda, and that (2) tropical montane rainforest species exhibit decreased Photosynthetic Capacity when grown in a warmer environment.
Mirindi Eric Dusenge - One of the best experts on this subject based on the ideXlab platform.
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Contrasting Dependencies of Photosynthetic Capacity on Leaf Nitrogen in Early- and Late-Successional Tropical Montane Tree Species
Frontiers in Plant Science, 2020Co-Authors: Camille Ziegler, Mirindi Eric Dusenge, Göran Wallin, Brigitte Nyirambangutse, Etienne Zibera, Johan UddlingAbstract:Differences in Photosynthetic Capacity among tree species and tree functional types are currently assumed to be largely driven by variation in leaf nutrient content, particularly nitrogen (N). However, recent studies indicate that leaf N content is often a poor predictor of variation in Photosynthetic Capacity in tropical trees. In this study, we explored the relative importance of area-based total leaf N content (N tot) and within-leaf N allocation to Photosynthetic Capacity versus light-harvesting in controlling the variation in Photosynthetic Capacity (i.e. V cmax , J max) among mature trees of 12 species belonging to either early (ES) or late successional (LS) groups growing in a tropical montane rainforest in Rwanda, Central Africa. Photosynthetic Capacity at a common leaf temperature of 25˚C (i.e. maximum rates of Rubisco carboxylation, V cmax25 and of electron transport, J max25) was higher in ES than in LS species (+ 58% and 68% for V cmax25 and J max25 , respectively). While N tot did not significantly differ between successional groups, the Photosynthetic dependency on N tot was markedly different. In ES species, V cmax25 was strongly and positively related to N tot but this was not the case in LS species. However, there was no significant trade-off between relative leaf N investments in compounds maximizing Photosynthetic Capacity versus compounds maximizing light harvesting. Both leaf dark respiration at 25˚C (+ 33%) and, more surprisingly, apparent Photosynthetic quantum yield (+ 35%) was higher in ES than in LS species. Moreover, R d25 was positively related to N tot for both ES and LS species. Our results imply that efforts to quantify carbon fluxes of tropical montane rainforests would be improved if they considered contrasting within-leaf N allocation and Photosynthetic N tot dependencies between species with different successional strategies.
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Photosynthetic Capacity of tropical montane tree species in relation to leaf nutrients, successional strategy and growth temperature.
Oecologia, 2015Co-Authors: Mirindi Eric Dusenge, Göran Wallin, Johanna Gårdesten, Felix Niyonzima, Lisa Adolfsson, Donat Nsabimana, Johan UddlingAbstract:Photosynthetic Capacity of tree leaves is typically positively related to nutrient content and little affected by changes in growth temperature. These relationships are, however, often poorly supported for tropical trees, for which interspecific differences may be more strongly controlled by within-leaf nutrient allocation than by absolute leaf nutrient content, and little is known regarding Photosynthetic acclimation to temperature. To explore the influence of leaf nutrient status, successional strategy and growth temperature on the Photosynthetic Capacity of tropical trees, we collected data on Photosynthetic, chemical and morphological leaf traits of ten tree species in Rwanda. Seven species were studied in a forest plantation at mid-altitude (~1,700 m), whereas six species were studied in a cooler montane rainforest at higher altitude (~2,500 m). Three species were common to both sites, and, in the montane rainforest, three pioneer species and three climax species were investigated. Across species, interspecific variation in Photosynthetic Capacity was not related to leaf nutrient content. Instead, this variation was related to differences in within-leaf nitrogen allocation, with a tradeoff between investments into compounds related to Photosynthetic Capacity (higher in pioneer species) versus light-harvesting compounds (higher in climax species). Photosynthetic Capacity was significantly lower at the warmer site at 1,700 m altitude. We conclude that (1) within-leaf nutrient allocation is more important than leaf nutrient content per se in controlling interspecific variation in Photosynthetic Capacity among tree species in tropical Rwanda, and that (2) tropical montane rainforest species exhibit decreased Photosynthetic Capacity when grown in a warmer environment.
Göran Wallin - One of the best experts on this subject based on the ideXlab platform.
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Contrasting Dependencies of Photosynthetic Capacity on Leaf Nitrogen in Early- and Late-Successional Tropical Montane Tree Species
Frontiers in Plant Science, 2020Co-Authors: Camille Ziegler, Mirindi Eric Dusenge, Göran Wallin, Brigitte Nyirambangutse, Etienne Zibera, Johan UddlingAbstract:Differences in Photosynthetic Capacity among tree species and tree functional types are currently assumed to be largely driven by variation in leaf nutrient content, particularly nitrogen (N). However, recent studies indicate that leaf N content is often a poor predictor of variation in Photosynthetic Capacity in tropical trees. In this study, we explored the relative importance of area-based total leaf N content (N tot) and within-leaf N allocation to Photosynthetic Capacity versus light-harvesting in controlling the variation in Photosynthetic Capacity (i.e. V cmax , J max) among mature trees of 12 species belonging to either early (ES) or late successional (LS) groups growing in a tropical montane rainforest in Rwanda, Central Africa. Photosynthetic Capacity at a common leaf temperature of 25˚C (i.e. maximum rates of Rubisco carboxylation, V cmax25 and of electron transport, J max25) was higher in ES than in LS species (+ 58% and 68% for V cmax25 and J max25 , respectively). While N tot did not significantly differ between successional groups, the Photosynthetic dependency on N tot was markedly different. In ES species, V cmax25 was strongly and positively related to N tot but this was not the case in LS species. However, there was no significant trade-off between relative leaf N investments in compounds maximizing Photosynthetic Capacity versus compounds maximizing light harvesting. Both leaf dark respiration at 25˚C (+ 33%) and, more surprisingly, apparent Photosynthetic quantum yield (+ 35%) was higher in ES than in LS species. Moreover, R d25 was positively related to N tot for both ES and LS species. Our results imply that efforts to quantify carbon fluxes of tropical montane rainforests would be improved if they considered contrasting within-leaf N allocation and Photosynthetic N tot dependencies between species with different successional strategies.
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Photosynthetic Capacity of tropical montane tree species in relation to leaf nutrients, successional strategy and growth temperature.
Oecologia, 2015Co-Authors: Mirindi Eric Dusenge, Göran Wallin, Johanna Gårdesten, Felix Niyonzima, Lisa Adolfsson, Donat Nsabimana, Johan UddlingAbstract:Photosynthetic Capacity of tree leaves is typically positively related to nutrient content and little affected by changes in growth temperature. These relationships are, however, often poorly supported for tropical trees, for which interspecific differences may be more strongly controlled by within-leaf nutrient allocation than by absolute leaf nutrient content, and little is known regarding Photosynthetic acclimation to temperature. To explore the influence of leaf nutrient status, successional strategy and growth temperature on the Photosynthetic Capacity of tropical trees, we collected data on Photosynthetic, chemical and morphological leaf traits of ten tree species in Rwanda. Seven species were studied in a forest plantation at mid-altitude (~1,700 m), whereas six species were studied in a cooler montane rainforest at higher altitude (~2,500 m). Three species were common to both sites, and, in the montane rainforest, three pioneer species and three climax species were investigated. Across species, interspecific variation in Photosynthetic Capacity was not related to leaf nutrient content. Instead, this variation was related to differences in within-leaf nitrogen allocation, with a tradeoff between investments into compounds related to Photosynthetic Capacity (higher in pioneer species) versus light-harvesting compounds (higher in climax species). Photosynthetic Capacity was significantly lower at the warmer site at 1,700 m altitude. We conclude that (1) within-leaf nutrient allocation is more important than leaf nutrient content per se in controlling interspecific variation in Photosynthetic Capacity among tree species in tropical Rwanda, and that (2) tropical montane rainforest species exhibit decreased Photosynthetic Capacity when grown in a warmer environment.
Rossella Guerrieri - One of the best experts on this subject based on the ideXlab platform.
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Global Photosynthetic Capacity is optimized to the environment
Ecology letters, 2019Co-Authors: Nicholas G. Smith, Trevor F. Keenan, I. Colin Prentice, Han Wang, Ian J. Wright, Ülo Niinemets, Kristine Y. Crous, Tomas F. Domingues, Rossella Guerrieri, F. Yoko IshidaAbstract:Earth system models (ESMs) use Photosynthetic Capacity, indexed by the maximum Rubisco carboxylation rate (Vcmax ), to simulate carbon assimilation and typically rely on empirical estimates, including an assumed dependence on leaf nitrogen determined from soil fertility. In contrast, new theory, based on biochemical coordination and co-optimization of carboxylation and water costs for photosynthesis, suggests that optimal Vcmax can be predicted from climate alone, irrespective of soil fertility. Here, we develop this theory and find it captures 64% of observed variability in a global, field-measured Vcmax dataset for C3 plants. Soil fertility indices explained substantially less variation (32%). These results indicate that environmentally regulated biophysical constraints and light availability are the first-order drivers of global Photosynthetic Capacity. Through acclimation and adaptation, plants efficiently utilize resources at the leaf level, thus maximizing potential resource use for growth and reproduction. Our theory offers a robust strategy for dynamically predicting Photosynthetic Capacity in ESMs.
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leaf level Photosynthetic Capacity in lowland amazonian and high elevation andean tropical moist forests of peru
New Phytologist, 2017Co-Authors: Nur H A Bahar, Rossella Guerrieri, Yoko F Ishida, Lasantha K Weerasinghe, Odhran S Osullivan, Keith J Bloomfield, Gregory P Asner, Roberta E MartinAbstract:We examined whether variations in Photosynthetic Capacity are linked to variations in the environment and/or associated leaf traits for tropical moist forests (TMFs) in the Andes/western Amazon regions of Peru. We compared Photosynthetic Capacity (maximal rate of carboxylation of Rubisco (V-cmax), and the maximum rate of electron transport (J(max))), leaf mass, nitrogen (N) and phosphorus (P) per unit leaf area (M-a, N-a and P-a, respectively), and chlorophyll from 210 species at 18 field sites along a 3300-m elevation gradient. Western blots were used to quantify the abundance of the CO2-fixing enzyme Rubisco. Area- and N-based rates of Photosynthetic Capacity at 25 degrees C were higher in upland than lowland TMFs, underpinned by greater investment of N in photosynthesis in high-elevation trees. Soil [P] and leaf Pa were key explanatory factors for models of area-based Vcmax and Jmax but did not account for variations in Photosynthetic N-use efficiency. At any given N-a and P-a, the fraction of N allocated to photosynthesis was higher in upland than lowland species. For a small subset of lowland TMF trees examined, a substantial fraction of Rubisco was inactive. These results highlight the importance of soil- and leaf-P in defining the Photosynthetic Capacity of TMFs, with variations in N allocation and Rubisco activation state further influencing Photosynthetic rates and N-use efficiency of these critically important forests.
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Leaf‐level Photosynthetic Capacity in lowland Amazonian and high‐elevation Andean tropical moist forests of Peru
The New phytologist, 2016Co-Authors: Nur H A Bahar, Rossella Guerrieri, F. Yoko Ishida, Lasantha K Weerasinghe, Keith J Bloomfield, Gregory P Asner, Roberta E Martin, Odhran S. O'sullivan, Jon Lloyd, Yadvinder MalhiAbstract:We examined whether variations in Photosynthetic Capacity are linked to variations in the environment and/or associated leaf traits for tropical moist forests (TMFs) in the Andes/western Amazon regions of Peru. We compared Photosynthetic Capacity (maximal rate of carboxylation of Rubisco (V-cmax), and the maximum rate of electron transport (J(max))), leaf mass, nitrogen (N) and phosphorus (P) per unit leaf area (M-a, N-a and P-a, respectively), and chlorophyll from 210 species at 18 field sites along a 3300-m elevation gradient. Western blots were used to quantify the abundance of the CO2-fixing enzyme Rubisco. Area- and N-based rates of Photosynthetic Capacity at 25 degrees C were higher in upland than lowland TMFs, underpinned by greater investment of N in photosynthesis in high-elevation trees. Soil [P] and leaf Pa were key explanatory factors for models of area-based Vcmax and Jmax but did not account for variations in Photosynthetic N-use efficiency. At any given N-a and P-a, the fraction of N allocated to photosynthesis was higher in upland than lowland species. For a small subset of lowland TMF trees examined, a substantial fraction of Rubisco was inactive. These results highlight the importance of soil- and leaf-P in defining the Photosynthetic Capacity of TMFs, with variations in N allocation and Rubisco activation state further influencing Photosynthetic rates and N-use efficiency of these critically important forests.
William W. Adams - One of the best experts on this subject based on the ideXlab platform.
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Evaluating the link between Photosynthetic Capacity and leaf vascular organization with principal component analysis
Photosynthetica, 2018Co-Authors: Stephanie K. Polutchko, Jared J. Stewart, Barbara Demmig-adams, William W. AdamsAbstract:Significant linear relationships between Photosynthetic Capacity and principal components loaded by phloem cell numbers and tracheary elements per minor vein as well as the latter two normalized for vein density (proxy for apoplastic phloem loading Capacity involving membrane transporters) were revealed for all apoplastic loaders (summer annuals and winter annual Arabidopsis thaliana). In addition, significant linear relationships between Photosynthetic Capacity and a principal component loaded by tracheary element cross-sectional areas and volumes per unit of leaf area (water flux Capacity proxy) was present for symplastic and apoplastic loaders. Lastly, a significant linear relationship between Photosynthetic Capacity and a principal component loaded by phloem cell cross-sectional areas and volumes per unit of leaf area (proxy for symplastic loading Capacity involving cytosolic enzymes for companion cells) was revealed for summer annual symplastic loaders as well as for A. thaliana (in the case of sieve elements, a proxy for sugar export Capacity from the leaves).
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Environmental regulation of intrinsic Photosynthetic Capacity: an integrated view
Current opinion in plant biology, 2017Co-Authors: Barbara Demmig-adams, Jared J. Stewart, William W. AdamsAbstract:Environmental modulation of Photosynthetic Capacity is reviewed in the context of its assessment and its regulation, genetic differences among species and ecotypes, and links to plant stress tolerance and productivity. Modulation of intrinsic Photosynthetic Capacity matches investment in Photosynthetic components to opportunity for CO2 uptake and productivity in specific environments, with exceptionally high rates during particularly narrow windows of opportunity. Response varies among species and ecotypes and should be evaluated on multiple reference bases as well as chloroplast, leaf, and whole plant scales. Photosynthetic Capacity, total foliar vascular transport Capacity, and plant sink strength are modulated in concert. Switching among alternative target sinks and alternative foliar vascular architectures may provide avenues for co-optimization of productivity and stress tolerance.
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Photosynthetic Capacity and light harvesting efficiency during the winter-to-spring transition in subalpine conifers.
The New phytologist, 2006Co-Authors: C. Ryan Zarter, Barbara Demmig-adams, Volker Ebbert, Iwona Adamska, William W. AdamsAbstract:Summary • Some coniferous forest ecosystems undergo complete Photosynthetic down-regulation in winter. The present study examined the influence of several environmental parameters on intrinsic, needle-level photosynthesis and photoprotection during the spring reactivation of photosynthesis in subalpine conifers. • Maximal photosystem II (PSII) efficiency, Photosynthetic Capacity, and amounts of zeaxanthin and early light-inducible protein (Elip) family members were assessed in three subalpine conifer species over 3 years, and intensively during the 2003 winter-to-spring transition. • During summers, maximal PSII efficiency remained high while intrinsic Photosynthetic Capacity varied depending on precipitation. During winters and the winter-to-spring transition, Photosynthetic Capacity and PSII efficiency were highly correlated and (during the spring transition) strongly influenced by air and soil temperature and liquid water availability. Decreases in the amount of Elip family members from winter through spring paralleled disengagement of sustained zeaxanthin-dependent photoprotection, although one of four anti-Elip antibody-reactive bands increased during spring. • Intrinsic Photosynthetic Capacity and maximal PSII efficiency were highly responsive to day-to-day environmental changes during spring, indicating that multiple environmental signals are integrated to orchestrate the reactivation of photosynthesis from the inactive winter state to the active summer state.