The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Gregorio Montero - One of the best experts on this subject based on the ideXlab platform.
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Adapting a model for Even-Aged Pinus pinea L. Stands to complex multi-aged structures
Forest Ecology and Management, 2008Co-Authors: Rafael Calama, Ignacio Barbeito, Marta Pardos, Miren Del Río, Gregorio MonteroAbstract:Abstract Stone pine (Pinus pinea L.) Stands have been usually managed as Even-Aged Stands. Main objectives in management combine two main commercial productions, timber and pine nuts with other social aspects: soil protection, recreational use and biodiversity conservation. Multifunctional management, together with the occurrence of successive events affecting regeneration have oriented managers to propose a management schedule based on the establishment and preservation of a low-stocking multi-aged complex structure on favourable locations. Despite the recent effort on modelling growth and yield on Even-Aged Stands of stone pine, no studies focusing on modelling dynamics for unEven-Aged Stands have yet been developed up to present. In this study, a proposal is presented for adapting and calibrating an existing tree-level model, originally developed for Even-Aged Stands of stone pine (model PINEA2), to multi-aged complex Stands. Data from four multi-aged trials and 61 plots from the National Forest Inventory were used to adapt the whole set of functions included in the original model. In our study, four different methods have been proposed to adapt the original equations: (1) direct validation and re-parameterization; (2) size class modelling; (3) refit of functions after removing typical Even-Aged covariates; and (4) multilevel calibration. Adaptation is based on assuming that a multi-aged stand of stone pine can be seen as the sum of independent, smaller, Even-Aged groups. The low densities of the Stands, the early liberation of the most vigorous trees in all size classes and the major importance of root-level competition for water in Mediterranean forests are the main factors explaining these particular dynamics. Results show the suitability of the proposed method, attaining unbiased estimates with a degree of accuracy similar to that achieved in applying the original model to Even-Aged Stands. The adapted model (PINEA_IRR) constitutes a flexible tool for the management and maintenance of stone pine Stands, covering a wide range of within stand structural complexity, including forests in transition.
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Inter-regional variability in site index models for Even-Aged Stands of stone pine (Pinus pinea L.) in Spain
Annals of Forest Science, 2003Co-Authors: Rafael Calama, Nieves Cañadas, Gregorio MonteroAbstract:Data from 96 stem analysis and 37 permanent plots in Even-Aged Stands of stone pine (Pinus pinea L.) in four regions of Spain (Central Range, Northern Plateau, West Andalusia and Catalonia) are used to develop a dominant height growth model for each region. These models are compared to detect similarities or differences in height growth patterns between regions, which will justify the need to build more regional site index curves for the species in Spain. Comparing these models involves homogeneity tests of parameters and a statistical analysis of the bias.
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Inter-regional variability in site index models for Even-Aged Stands of stone pine (Pinus pinea L.) in Spain
Annals of Forest Science, 2003Co-Authors: Rafael Calama, Nieves Cañadas, Gregorio MonteroAbstract:Variabilite inter-regionale des modeles de site index pour les peuplements reguliers de pin pignon (Pinus pinea L.) en Espagne. Les donnees de 96 analyses de tige et de 37 placettes permanentes de pin pignon (Pinus pinea L.) reparties dans quatre regions d'Espagne (Massif central. Plateau de Nord-Castille, Andalousie et Catalogue) ont ete utilisees pour le developpement d'un modele de croissance (hauteur dominante) pour chaque region. Les modeles sont compares entre eux afin de detecter des similarites ou des differences sur la croissance en hauteur entre les peuplements des quatre regions, ce qui pourrait justifier la necessite de construire des modeles regionaux pour Pinus pinea en Espagne. Pour comparer les modeles entre eux, des tests sur l'homogeneite de parametres et des analyses statistiques de biais ont ete utilises.
Rafael Calama - One of the best experts on this subject based on the ideXlab platform.
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Adapting a model for Even-Aged Pinus pinea L. Stands to complex multi-aged structures
Forest Ecology and Management, 2008Co-Authors: Rafael Calama, Ignacio Barbeito, Marta Pardos, Miren Del Río, Gregorio MonteroAbstract:Abstract Stone pine (Pinus pinea L.) Stands have been usually managed as Even-Aged Stands. Main objectives in management combine two main commercial productions, timber and pine nuts with other social aspects: soil protection, recreational use and biodiversity conservation. Multifunctional management, together with the occurrence of successive events affecting regeneration have oriented managers to propose a management schedule based on the establishment and preservation of a low-stocking multi-aged complex structure on favourable locations. Despite the recent effort on modelling growth and yield on Even-Aged Stands of stone pine, no studies focusing on modelling dynamics for unEven-Aged Stands have yet been developed up to present. In this study, a proposal is presented for adapting and calibrating an existing tree-level model, originally developed for Even-Aged Stands of stone pine (model PINEA2), to multi-aged complex Stands. Data from four multi-aged trials and 61 plots from the National Forest Inventory were used to adapt the whole set of functions included in the original model. In our study, four different methods have been proposed to adapt the original equations: (1) direct validation and re-parameterization; (2) size class modelling; (3) refit of functions after removing typical Even-Aged covariates; and (4) multilevel calibration. Adaptation is based on assuming that a multi-aged stand of stone pine can be seen as the sum of independent, smaller, Even-Aged groups. The low densities of the Stands, the early liberation of the most vigorous trees in all size classes and the major importance of root-level competition for water in Mediterranean forests are the main factors explaining these particular dynamics. Results show the suitability of the proposed method, attaining unbiased estimates with a degree of accuracy similar to that achieved in applying the original model to Even-Aged Stands. The adapted model (PINEA_IRR) constitutes a flexible tool for the management and maintenance of stone pine Stands, covering a wide range of within stand structural complexity, including forests in transition.
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Inter-regional variability in site index models for Even-Aged Stands of stone pine (Pinus pinea L.) in Spain
Annals of Forest Science, 2003Co-Authors: Rafael Calama, Nieves Cañadas, Gregorio MonteroAbstract:Data from 96 stem analysis and 37 permanent plots in Even-Aged Stands of stone pine (Pinus pinea L.) in four regions of Spain (Central Range, Northern Plateau, West Andalusia and Catalonia) are used to develop a dominant height growth model for each region. These models are compared to detect similarities or differences in height growth patterns between regions, which will justify the need to build more regional site index curves for the species in Spain. Comparing these models involves homogeneity tests of parameters and a statistical analysis of the bias.
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Inter-regional variability in site index models for Even-Aged Stands of stone pine (Pinus pinea L.) in Spain
Annals of Forest Science, 2003Co-Authors: Rafael Calama, Nieves Cañadas, Gregorio MonteroAbstract:Variabilite inter-regionale des modeles de site index pour les peuplements reguliers de pin pignon (Pinus pinea L.) en Espagne. Les donnees de 96 analyses de tige et de 37 placettes permanentes de pin pignon (Pinus pinea L.) reparties dans quatre regions d'Espagne (Massif central. Plateau de Nord-Castille, Andalousie et Catalogue) ont ete utilisees pour le developpement d'un modele de croissance (hauteur dominante) pour chaque region. Les modeles sont compares entre eux afin de detecter des similarites ou des differences sur la croissance en hauteur entre les peuplements des quatre regions, ce qui pourrait justifier la necessite de construire des modeles regionaux pour Pinus pinea en Espagne. Pour comparer les modeles entre eux, des tests sur l'homogeneite de parametres et des analyses statistiques de biais ont ete utilises.
Francois Ningre - One of the best experts on this subject based on the ideXlab platform.
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evaluation and comparison of size density relationships for pure even aged Stands of ash fraxinus excelsior l beech fagus silvatica l oak quercus petraea liebl and sycamore maple acer pseudoplatanus l
Annals of Forest Science, 2011Co-Authors: Noel Le Goff, Jeanmarc Ottorini, Francois NingreAbstract:• Introduction Size-density relationships define the maximum number of stems that Even-Aged Stands of a given species can hold in relation to the mean size of trees. They are used to derive stand density measures and are useful tools used to control tree mortality.
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Evaluation and comparison of size–density relationships for pure Even-Aged Stands of ash (Fraxinus excelsior L.), beech (Fagus silvatica L.), oak (Quercus petraea Liebl.), and sycamore maple (Acer pseudoplatanus L.)
Annals of Forest Science, 2011Co-Authors: Noël Le Goff, Jeanmarc Ottorini, Francois NingreAbstract:• Introduction Size-density relationships define the maximum number of stems that Even-Aged Stands of a given species can hold in relation to the mean size of trees. They are used to derive stand density measures and are useful tools used to control tree mortality.
Nieves Cañadas - One of the best experts on this subject based on the ideXlab platform.
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Inter-regional variability in site index models for Even-Aged Stands of stone pine (Pinus pinea L.) in Spain
Annals of Forest Science, 2003Co-Authors: Rafael Calama, Nieves Cañadas, Gregorio MonteroAbstract:Data from 96 stem analysis and 37 permanent plots in Even-Aged Stands of stone pine (Pinus pinea L.) in four regions of Spain (Central Range, Northern Plateau, West Andalusia and Catalonia) are used to develop a dominant height growth model for each region. These models are compared to detect similarities or differences in height growth patterns between regions, which will justify the need to build more regional site index curves for the species in Spain. Comparing these models involves homogeneity tests of parameters and a statistical analysis of the bias.
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Inter-regional variability in site index models for Even-Aged Stands of stone pine (Pinus pinea L.) in Spain
Annals of Forest Science, 2003Co-Authors: Rafael Calama, Nieves Cañadas, Gregorio MonteroAbstract:Variabilite inter-regionale des modeles de site index pour les peuplements reguliers de pin pignon (Pinus pinea L.) en Espagne. Les donnees de 96 analyses de tige et de 37 placettes permanentes de pin pignon (Pinus pinea L.) reparties dans quatre regions d'Espagne (Massif central. Plateau de Nord-Castille, Andalousie et Catalogue) ont ete utilisees pour le developpement d'un modele de croissance (hauteur dominante) pour chaque region. Les modeles sont compares entre eux afin de detecter des similarites ou des differences sur la croissance en hauteur entre les peuplements des quatre regions, ce qui pourrait justifier la necessite de construire des modeles regionaux pour Pinus pinea en Espagne. Pour comparer les modeles entre eux, des tests sur l'homogeneite de parametres et des analyses statistiques de biais ont ete utilises.
Jeanmarc Ottorini - One of the best experts on this subject based on the ideXlab platform.
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evaluation and comparison of size density relationships for pure even aged Stands of ash fraxinus excelsior l beech fagus silvatica l oak quercus petraea liebl and sycamore maple acer pseudoplatanus l
Annals of Forest Science, 2011Co-Authors: Noel Le Goff, Jeanmarc Ottorini, Francois NingreAbstract:• Introduction Size-density relationships define the maximum number of stems that Even-Aged Stands of a given species can hold in relation to the mean size of trees. They are used to derive stand density measures and are useful tools used to control tree mortality.
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Evaluation and comparison of size–density relationships for pure Even-Aged Stands of ash (Fraxinus excelsior L.), beech (Fagus silvatica L.), oak (Quercus petraea Liebl.), and sycamore maple (Acer pseudoplatanus L.)
Annals of Forest Science, 2011Co-Authors: Noël Le Goff, Jeanmarc Ottorini, Francois NingreAbstract:• Introduction Size-density relationships define the maximum number of stems that Even-Aged Stands of a given species can hold in relation to the mean size of trees. They are used to derive stand density measures and are useful tools used to control tree mortality.