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6 results on '"Neringa Mannerheim"'

1. Patterns of total root and shoot carbon dioxide fluxes and their impact on daily tree carbon budget in large tropical tree saplings

Author

Israel Oren, Neringa Mannerheim, Andreas Fangmeier, Nina Buchmann, and José M Grünzweig

Subjects
Physiology, Plant Science, Carbon Dioxide, Photosynthesis, Plant Roots, Carbon Cycle, Trees
Abstract

A significant amount of the carbon (C) assimilated in photosynthesis by trees is re-emitted to the atmosphere via the respiratory CO2 flux of roots. Because of technical constraints, we have little understanding of the extent and dynamics of the respiratory CO2 flux of roots at the total root system scale (RCF). This study aimed to fill this gap and to quantify the daily C budget of entire trees. We used aeroponics as a novel approach to measure directly and simultaneously RCF and the net CO2 flux of the entire shoot (SCF), to estimate their night- and day-time contributions to daily tree CO2 budget and to estimate the relative contribution of different root categories to RCF in large saplings of the tropical tree species Ceiba pentandra (L.) Gaertn. By maintaining root temperature within a narrow range (24-27.5 degrees C), we controlled for its effect on RCF, thus allowing the potential relationship between RCF and SCF to be tested. The carbon gain of the fast-growing saplings was 0.79 +/- 0.10 g C sapling(-1) day(-1), with day-time shoot CO2 uptake outweighing night-time shoot and day- and night-time root CO2 losses by a factor of two. Other than a slight rise in the morning hours, RCF was relatively stable and not coupled to the daily dynamics of SCF. Albeit having lower specific respiration rates compared with fine-roots, the relative contributions of coarse-roots (diameter >2 mm) to RCF were substantial because of their large biomass and were estimated to range from 43 to 63% of RCF at midday of different days during the growing season. The results of this study suggest that (i) the entire root system needs to be monitored for its impact on the tree CO2 budget, (ii) RCF cannot be derived from SCF and (iii) the importance of coarse-root respiration to RCF may be greater than appreciated., Tree Physiology, 42 (5), ISSN:0829-318X, ISSN:1758-4469

Published
2022

2. Carbon allocation to the root system of tropical tree Ceiba pentandra using 13C pulse labelling in an aeroponic facility

Author

Israel Oren, José M. Grünzweig, Carola H. Blessing, Christoph Bachofen, Neringa Mannerheim, and Nina Buchmann

Subjects
0106 biological sciences, 0301 basic medicine, Canopy, Aeroponics, Physiology, Starch, Plant Science, Root system, Biology, Plant Roots, 01 natural sciences, Trees, 03 medical and health sciences, chemistry.chemical_compound, Respiration, Ecosystem, Carbon Isotopes, Ceiba, Carbon Dioxide, 15. Life on land, biology.organism_classification, Horticulture, 030104 developmental biology, chemistry, Phloem, 010606 plant biology & botany
Abstract

Despite the important role of tropical forest ecosystems in the uptake and storage of atmospheric carbon dioxide (CO2), the carbon (C) dynamics of tropical tree species remains poorly understood, especially regarding belowground roots. This study assessed the allocation of newly assimilated C in the fast-growing pioneer tropical tree species Ceiba pentandra (L.), with a special focus on different root categories. During a 5-day pulse-labelling experiment, 9-month-old (~3.5-m-tall) saplings were labelled with 13CO2 in a large-scale aeroponic facility, which allowed tracing the label in bulk biomass and in non-structural carbohydrates (sugars and starch) as well as respiratory CO2 from the canopy to the root system, including both woody and non-woody roots. A combined logistic and exponential model was used to evaluate 13C mean transfer time and mean residence time (MRT) to the root systems. We found 13C in the root phloem as early as 2 h after the labelling, indicating a mean C transfer velocity of 2.4 ± 0.1 m h−1. Five days after pulse labelling, 27% of the tracers taken up by the trees were found in the leaves and 13% were recovered in the woody tissue of the trunk, 6% in the bark and 2% in the root systems, while 52% were lost, most likely by respiration and exudation. Larger amounts of 13C were found in root sugars than in starch, the former also demonstrating shorter MRT than starch. Of all investigated root categories, non-woody white roots (NRW) showed the largest 13C enrichment and peaked in the deepest NRW (2–3.5 m) as early as 24 ± 2 h after labelling. In contrast to coarse woody brown roots, the sink strength of NRW increased with root depth. The findings of this study improve the understanding of C allocation in young tropical trees and provide unique insights into the changing contributions of woody and non-woody roots to C sink strengths with depth.

Published
2020
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3. Patterns and dynamics of canopy-root coupling in tropical tree saplings vary with light intensity but not with root depth

Author

José M. Grünzweig, Nina Buchmann, Rita Dumbur, Israel Oren, Andreas Fangmeier, and Neringa Mannerheim

Subjects
0106 biological sciences, Canopy, Aeroponics, Light, Physiology, Khaya anthotheca, Plant Science, Root system, Phloem, 01 natural sciences, Plant Roots, Trees, Khaya, 03 medical and health sciences, Xylem, Meliaceae, Photosynthesis, 030304 developmental biology, 0303 health sciences, Photons, Tropical Climate, biology, Ceiba, Temperature, Plant Transpiration, Starch, 15. Life on land, Carbon Dioxide, biology.organism_classification, Plant Leaves, Horticulture, Light intensity, Solubility, Plant Bark, Rheology, Sugars, 010606 plant biology & botany
Abstract

Carbon (C) dynamics in canopy and roots influence whole-tree carbon fluxes, but little is known about canopy regulation of tree-root activity. Here, the patterns and dynamics of canopy-root C coupling are assessed in tropical trees. Large aeroponics facility was used to study the root systems of Ceiba pentandra and Khaya anthotheca saplings directly at different light intensities. In Ceiba, root respiration (Rr ) co-varied with photosynthesis (An ) in large saplings (3-to-7-m canopy-root axis) at high-light, but showed no consistent pattern at low-light. At medium-light and in small saplings (c. 1-m axis), Rr tended to decrease transiently towards midday. Proximal roots had higher Rr and nonstructural carbohydrate concentrations than distal roots, but canopy-root coupling was unaffected by root location. In medium-sized Khaya, no Rr pattern was observed, and in both species, Rr was unrelated to temperature. The early-afternoon increase in Rr suggests that canopy-root coupling is based on mass flow of newly fixed C in the phloem, whereas the early-morning rise in Rr with An indicates an additional coupling signal that travels faster than the phloem sap. In large saplings and potentially also in higher trees, light and possibly additional environmental factors control the diurnal patterns of canopy-root coupling, irrespective of root location.

Published
2019

4. Measurement precision and accuracy of high artificial enrichment 15N and 13C tracer samples

Author

Neringa Mannerheim, Roland A. Werner, and Nina Buchmann

Subjects
Accuracy and precision, Isotope, Chemistry, 010401 analytical chemistry, Organic Chemistry, Analyser, Analytical chemistry, Natural abundance, Mass spectrometry, 01 natural sciences, 0104 chemical sciences, Analytical Chemistry, Dilution, TRACER, Sample preparation, Spectroscopy
Abstract

Rapid Communications in Mass Spectrometry, 33 (13), ISSN:1097-0231, ISSN:0951-4198

Published
2019
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5. Measurement precision and accuracy of high artificial enrichment

Author

Neringa, Mannerheim, Roland A, Werner, and Nina, Buchmann

Abstract

Oversaturation of the Faraday cup amplifiers of isotope ratio mass spectrometers when using tracers that are highly enriched in heavier isotopes (up to 99.9%) remains a major bottleneck to obtaining high-precision measurements. The memory effect plays a key role in reducing tracer sample measurement precision and accuracy. Several sample preparation approaches are known to reduce memory effects and to improve tracer sample measurement precision. However, the potential benefits when using very high enrichment tracer samples (+1000 mUr) have not been tested.In this study, we test how specific sample positioning for measurements and frequent use of natural isotope abundance reference materials within the sequence affects the precision and accuracy of isotopic ratio analyses when using a Flash elemental analyser coupled to a DeltaFrequent use of natural isotope abundance materials and specific positioning increasedWe conclude that highly enriched tracer samples do not require dilution before analysis. Tracer sample precision can be improved by using a specific measurement order of expected isotope abundance and by the frequent use of natural abundance reference materials.

Published
2018

6. Genotypic variability enhances the reproducibility of an ecological study

Author

Markus Lange, Anne Pando, Manuel Blouin, Michael Bonkowski, Jean-Christophe Lata, Agnès Gigon, Carlo Grignani, Sebastien Barot, Nina Buchmann, Simone Cesarz, Ruben Puga-Freitas, Aaron M. Ellison, Alexandru Milcu, Laura Zavattaro, Neringa Mannerheim, Stefan Scheu, Nico Eisenhauer, Rahme Seyhun, Jacques Roy, Anna Greiner, Laura Rose, Marina E.H. Muller, Olaf Butenschoen, Alexandra Weigelt, Sébastien Devidal, Michael Scherer-Lorenzen, Martin Lukac, Jean-François Le Galliard, Arthur Gessler, Davide Assandri, Zachary Kayler, Amandine Hansart, Katherine R. Urban-Mead, Gerd Gleixner, Thomas Girin, Grégoire T. Freschet, Paula Rotter, Écotron Européen de Montpellier, Centre National de la Recherche Scientifique (CNRS), Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Université Paul-Valéry - Montpellier 3 (UPVM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut de Recherche pour le Développement (IRD [France-Sud]), Institut d'écologie et des sciences de l'environnement de Paris (iEES), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Recherche Agronomique (INRA), Harvard University [Cambridge], Agroécologie [Dijon], Université de Bourgogne (UB)-Institut National de la Recherche Agronomique (INRA)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, University of Göttingen - Georg-August-Universität Göttingen, Department of Forest Resources, University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Institut Jean-Pierre Bourgin (IJPB), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Department of Terrestrial Ecology, Institut of Zoology, University of Cologne, Institute of Plant, Animal and Agroecosystem Sciences, J. F. Blumenbach Institute of Zoology and Anthropology, Georg-August-University [Göttingen], Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, Swiss Federal Research Institute, Department of Agricultural, Forestry, and Food Sciences, University of Turin, CEREEP-Ecotron Ile de France (UMS 3194), Centre National de la Recherche Scientifique (CNRS)-Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), School of Agriculture, Policy and Development, University of Reading, Faculty of Biology, University of Freiburg [Freiburg], Special Botany and Functional Biodiversity, Universität Leipzig [Leipzig], State allocation ‘Investissement d’Avenir’ [ANR-11-INBS-0001], European Project: 262060,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2010-1,EXPEER(2010), Université Paul-Valéry - Montpellier 3 (UM3)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École pratique des hautes études (EPHE)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), UPS 3248, Écotron Européen de Montpellier - Baillarguet, Institut d'écologie et des sciences de l'environnement de Paris (IEES), Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Université Bourgogne Franche-Comté [COMUE] (UBFC), Johann-Friedrich Blumenbach Institut für Zoologie und Anthropologie, Institut de Recherche pour le Développement (IRD [France-Ouest]), Université de Leipzig, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Institut d'écologie et des sciences de l'environnement de Paris (IEES (UMR_7618 / UMR_D_242 / UMR_A_1392 / UM_113) ), Institut National de la Recherche Agronomique (INRA)-Sorbonne Université (SU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS), Biogéochimie et écologie des milieux continentaux (Bioemco), Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Recherche Agronomique (INRA)-École normale supérieure - Paris (ENS Paris), NERC, Imperial College London, Faculty of Biology, Chair of Geobotany, University of Freiburg, Department Systematic Botanic and Functional Biodiversity, Institute Biology, Université Paul-Valéry - Montpellier 3 (UPVM)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Georg-August-University = Georg-August-Universität Göttingen, Università degli studi di Torino = University of Turin (UNITO), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Écotron Européen de Montpellier - UPS 3248, George August University Goettingen, University of Minnesota [Twin Cities], Université Paul-Valéry - Montpellier 3 (UPVM)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École Pratique des Hautes Études (EPHE), Harvard University, and Universität Leipzig

Subjects
0106 biological sciences, 0301 basic medicine, Grassland ecology, Microcosms, Genotype, Evolution, [SDE.MCG]Environmental Sciences/Global Changes, Ecosystem ecology, [SDV]Life Sciences [q-bio], Biology, Environment, Transparency, 010603 evolutionary biology, 01 natural sciences, 03 medical and health sciences, reproducibility crisis, Behavior and Systematics, Medicago truncatula, [SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology, Genetic variability, Repeatability, Ecology, Evolution, Behavior and Systematics, Scientific disciplines, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, Reproducibility, Diversity, Ecology, business.industry, Ecological study, Reproducibility of Results, food and beverages, Biodiversity, biology.organism_classification, Biotechnology, Europe, Animal-experiments, 030104 developmental biology, Agronomy, Research Design, Brachypodium distachyon, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, business, Microcosm, Brachypodium
Abstract

International audience; Many scientific disciplines are currently experiencing a 'reproducibility crisis' because numerous scientific findings cannot be repeated consistently. A novel but controversial hypothesis postulates that stringent levels of environmental and biotic standardization in experimental studies reduce reproducibility by amplifying the impacts of laboratory-specific environmental factors not accounted for in study designs. A corollary to this hypothesis is that a deliberate introduction of controlled systematic variability (CSV) in experimental designs may lead to increased reproducibility. To test this hypothesis, we had 14 European laboratories run a simple microcosm experiment using grass (Brachypodium distachyon L.) monocultures and grass and legume (Medicago truncatula Gaertn.) mixtures. Each laboratory introduced environmental and genotypic CSV within and among replicated microcosms established in either growth chambers (with stringent control of environmental conditions) or glasshouses (with more variable environmental conditions). The introduction of genotypic CSV led to 18% lower among-laboratory variability in growth chambers, indicating increased reproducibility, but had no significant effect in glasshouses where reproducibility was generally lower. Environmental CSV had little effect on reproducibility. Although there are multiple causes for the 'reproducibility crisis', deliberately including genetic variability may be a simple solution for increasing the reproducibility of ecological studies performed under stringently controlled environmental conditions.

Published
2018
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