Why are laterals less affected than main axes by homogeneous unfavourable physical conditions? A model-based hypothesis
When plants develop in strong soils, growth of the root system is generally depressed. However, branching and elongation of branches are often less affected than growth of the main axes, whenever the whole root system encounters even-impeded conditions. On the basis of a model simulating root growth and architecture as related to assimilate availability, we propose a simple hypothesis to explain such behaviour. In the model, growth of each root depends on its own elongation potential, which is estimated by its apical diameter. The potential elongation rate-apical diameter relationship is the same for all the roots of the system and is described by a monomolecular function. Our hypothesis is that the effect of soil strength can be simulated by introducing an impedance factor in the definition of root maximum potential elongation rate, common to the whole root system. When such impedance factor is applied, it affects more the potential of larger roots (main axes) than that of thinner roots (secondary and tertiary branches). Simulations provided in high impedance conditions led to root systems characterised by short taproots, whereas growth of secondary roots was unaffected and growth of tertiary roots was enhanced. Actual branching density was also higher, although branching rules have been unchanged. Such simulated systems where similar to that observed in strong soils. Friction laws or pore size can be involved in the larger reduction of the potential growth of main axes. Moreover, when growth of main axes is restricted, assimilate availability becomes higher for branches and that could explain that their growth could be increased in a homogeneous strong soil.
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Subjects: | F62 - Physiologie végétale - Croissance et développement, U10 - Informatique, mathématiques et statistiques, P33 - Chimie et physique du sol, système racinaire, racine, croissance, morphogénèse, résistance mécanique du sol, relation plante sol, modèle de simulation, http://aims.fao.org/aos/agrovoc/c_16034, http://aims.fao.org/aos/agrovoc/c_6651, http://aims.fao.org/aos/agrovoc/c_3394, http://aims.fao.org/aos/agrovoc/c_4943, http://aims.fao.org/aos/agrovoc/c_25399, http://aims.fao.org/aos/agrovoc/c_16146, http://aims.fao.org/aos/agrovoc/c_24242, |
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dig-cirad-fr-4767072024-01-28T08:37:54Z http://agritrop.cirad.fr/476707/ http://agritrop.cirad.fr/476707/ Why are laterals less affected than main axes by homogeneous unfavourable physical conditions? A model-based hypothesis. Thaler Philippe, Pagès Loïc. 2000. In : The supporting roots of trees and woody plants: form, function, and physiology. Stokes A. (ed.). Dordrecht : Kluwer Academic Publishers, 209-215. (Developments in Plant and Soil Sciences, 87) ISBN 0-7923-5964-X Colloque sur les Racines principales, structures et fonctionnement. 1, Bordeaux, France, 20 Juillet 1998/24 Juillet 1998. Why are laterals less affected than main axes by homogeneous unfavourable physical conditions? A model-based hypothesis Thaler, Philippe Pagès, Loïc eng 2000 Kluwer Academic Publishers The supporting roots of trees and woody plants: form, function, and physiology F62 - Physiologie végétale - Croissance et développement U10 - Informatique, mathématiques et statistiques P33 - Chimie et physique du sol système racinaire racine croissance morphogénèse résistance mécanique du sol relation plante sol modèle de simulation http://aims.fao.org/aos/agrovoc/c_16034 http://aims.fao.org/aos/agrovoc/c_6651 http://aims.fao.org/aos/agrovoc/c_3394 http://aims.fao.org/aos/agrovoc/c_4943 http://aims.fao.org/aos/agrovoc/c_25399 http://aims.fao.org/aos/agrovoc/c_16146 http://aims.fao.org/aos/agrovoc/c_24242 When plants develop in strong soils, growth of the root system is generally depressed. However, branching and elongation of branches are often less affected than growth of the main axes, whenever the whole root system encounters even-impeded conditions. On the basis of a model simulating root growth and architecture as related to assimilate availability, we propose a simple hypothesis to explain such behaviour. In the model, growth of each root depends on its own elongation potential, which is estimated by its apical diameter. The potential elongation rate-apical diameter relationship is the same for all the roots of the system and is described by a monomolecular function. Our hypothesis is that the effect of soil strength can be simulated by introducing an impedance factor in the definition of root maximum potential elongation rate, common to the whole root system. When such impedance factor is applied, it affects more the potential of larger roots (main axes) than that of thinner roots (secondary and tertiary branches). Simulations provided in high impedance conditions led to root systems characterised by short taproots, whereas growth of secondary roots was unaffected and growth of tertiary roots was enhanced. Actual branching density was also higher, although branching rules have been unchanged. Such simulated systems where similar to that observed in strong soils. Friction laws or pore size can be involved in the larger reduction of the potential growth of main axes. Moreover, when growth of main axes is restricted, assimilate availability becomes higher for branches and that could explain that their growth could be increased in a homogeneous strong soil. conference_item info:eu-repo/semantics/conferenceObject Conference info:eu-repo/semantics/closedAccess http://catalogue-bibliotheques.cirad.fr/cgi-bin/koha/opac-detail.pl?biblionumber=181 http://agritrop.cirad.fr/6653/ |
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F62 - Physiologie végétale - Croissance et développement U10 - Informatique, mathématiques et statistiques P33 - Chimie et physique du sol système racinaire racine croissance morphogénèse résistance mécanique du sol relation plante sol modèle de simulation http://aims.fao.org/aos/agrovoc/c_16034 http://aims.fao.org/aos/agrovoc/c_6651 http://aims.fao.org/aos/agrovoc/c_3394 http://aims.fao.org/aos/agrovoc/c_4943 http://aims.fao.org/aos/agrovoc/c_25399 http://aims.fao.org/aos/agrovoc/c_16146 http://aims.fao.org/aos/agrovoc/c_24242 F62 - Physiologie végétale - Croissance et développement U10 - Informatique, mathématiques et statistiques P33 - Chimie et physique du sol système racinaire racine croissance morphogénèse résistance mécanique du sol relation plante sol modèle de simulation http://aims.fao.org/aos/agrovoc/c_16034 http://aims.fao.org/aos/agrovoc/c_6651 http://aims.fao.org/aos/agrovoc/c_3394 http://aims.fao.org/aos/agrovoc/c_4943 http://aims.fao.org/aos/agrovoc/c_25399 http://aims.fao.org/aos/agrovoc/c_16146 http://aims.fao.org/aos/agrovoc/c_24242 |
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F62 - Physiologie végétale - Croissance et développement U10 - Informatique, mathématiques et statistiques P33 - Chimie et physique du sol système racinaire racine croissance morphogénèse résistance mécanique du sol relation plante sol modèle de simulation http://aims.fao.org/aos/agrovoc/c_16034 http://aims.fao.org/aos/agrovoc/c_6651 http://aims.fao.org/aos/agrovoc/c_3394 http://aims.fao.org/aos/agrovoc/c_4943 http://aims.fao.org/aos/agrovoc/c_25399 http://aims.fao.org/aos/agrovoc/c_16146 http://aims.fao.org/aos/agrovoc/c_24242 F62 - Physiologie végétale - Croissance et développement U10 - Informatique, mathématiques et statistiques P33 - Chimie et physique du sol système racinaire racine croissance morphogénèse résistance mécanique du sol relation plante sol modèle de simulation http://aims.fao.org/aos/agrovoc/c_16034 http://aims.fao.org/aos/agrovoc/c_6651 http://aims.fao.org/aos/agrovoc/c_3394 http://aims.fao.org/aos/agrovoc/c_4943 http://aims.fao.org/aos/agrovoc/c_25399 http://aims.fao.org/aos/agrovoc/c_16146 http://aims.fao.org/aos/agrovoc/c_24242 Thaler, Philippe Pagès, Loïc Why are laterals less affected than main axes by homogeneous unfavourable physical conditions? A model-based hypothesis |
description |
When plants develop in strong soils, growth of the root system is generally depressed. However, branching and elongation of branches are often less affected than growth of the main axes, whenever the whole root system encounters even-impeded conditions. On the basis of a model simulating root growth and architecture as related to assimilate availability, we propose a simple hypothesis to explain such behaviour. In the model, growth of each root depends on its own elongation potential, which is estimated by its apical diameter. The potential elongation rate-apical diameter relationship is the same for all the roots of the system and is described by a monomolecular function. Our hypothesis is that the effect of soil strength can be simulated by introducing an impedance factor in the definition of root maximum potential elongation rate, common to the whole root system. When such impedance factor is applied, it affects more the potential of larger roots (main axes) than that of thinner roots (secondary and tertiary branches). Simulations provided in high impedance conditions led to root systems characterised by short taproots, whereas growth of secondary roots was unaffected and growth of tertiary roots was enhanced. Actual branching density was also higher, although branching rules have been unchanged. Such simulated systems where similar to that observed in strong soils. Friction laws or pore size can be involved in the larger reduction of the potential growth of main axes. Moreover, when growth of main axes is restricted, assimilate availability becomes higher for branches and that could explain that their growth could be increased in a homogeneous strong soil. |
format |
conference_item |
topic_facet |
F62 - Physiologie végétale - Croissance et développement U10 - Informatique, mathématiques et statistiques P33 - Chimie et physique du sol système racinaire racine croissance morphogénèse résistance mécanique du sol relation plante sol modèle de simulation http://aims.fao.org/aos/agrovoc/c_16034 http://aims.fao.org/aos/agrovoc/c_6651 http://aims.fao.org/aos/agrovoc/c_3394 http://aims.fao.org/aos/agrovoc/c_4943 http://aims.fao.org/aos/agrovoc/c_25399 http://aims.fao.org/aos/agrovoc/c_16146 http://aims.fao.org/aos/agrovoc/c_24242 |
author |
Thaler, Philippe Pagès, Loïc |
author_facet |
Thaler, Philippe Pagès, Loïc |
author_sort |
Thaler, Philippe |
title |
Why are laterals less affected than main axes by homogeneous unfavourable physical conditions? A model-based hypothesis |
title_short |
Why are laterals less affected than main axes by homogeneous unfavourable physical conditions? A model-based hypothesis |
title_full |
Why are laterals less affected than main axes by homogeneous unfavourable physical conditions? A model-based hypothesis |
title_fullStr |
Why are laterals less affected than main axes by homogeneous unfavourable physical conditions? A model-based hypothesis |
title_full_unstemmed |
Why are laterals less affected than main axes by homogeneous unfavourable physical conditions? A model-based hypothesis |
title_sort |
why are laterals less affected than main axes by homogeneous unfavourable physical conditions? a model-based hypothesis |
publisher |
Kluwer Academic Publishers |
url |
http://agritrop.cirad.fr/476707/ |
work_keys_str_mv |
AT thalerphilippe whyarelateralslessaffectedthanmainaxesbyhomogeneousunfavourablephysicalconditionsamodelbasedhypothesis AT pagesloic whyarelateralslessaffectedthanmainaxesbyhomogeneousunfavourablephysicalconditionsamodelbasedhypothesis |
_version_ |
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