588 results on '"Structure du peuplement"'
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2. Models of Silviculture for Portuguese Species: Old and New Guidelines.
- Author
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Cristina Gonçalves, Ana
- Subjects
FORESTS & forestry ,RANGE management ,CHESTNUT ,CORK oak ,FOREST management ,CLUSTER pine - Abstract
Copyright of Silva Lusitana is the property of Unidade de Investigacao de Silvicultura e Productos Florestais and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
3. The role of advanced regeneration at time of partial harvest on tolerant hardwood stands development.
- Author
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Danyagri, Gabriel, Baral, Sharad Kumar, Girouard, Monique, Adégbidi, Hector Guy, and Pelletier, Gaëtan
- Subjects
- *
HARDWOODS , *FOREST management , *SILVICULTURAL systems , *TREE mortality , *SUGAR maple , *YELLOW birch - Abstract
In tolerant hardwood forests of eastern North America, multiple-aged silvicultural systems rely on advanced regeneration to restock the forests. Evaluation of the long-term influence of advanced regeneration on the mature stand is critical for improving management practices. We used a retrospective approach to evaluate the influence of advanced regeneration present at the time of harvest on the current (2012) stand structure and the quality of the growing stock. The study was carried out in partially harvested stands in northwestern New Brunswick, Canada. Trees were sampled from stands with varying degrees of harvest intensities, times since harvest, and site characteristics. Pre-existing advanced regeneration contributed the bulk of trees in the 10-19 cm diameter class across the stands. In stands with low-intensity harvest, the overstory was dominated by sugar maple ( Acer saccharum Marsh.) that originated as advanced regeneration. In stands with high-intensity harvest, however, yellow birch ( Betula alleghaniensis Britt.) pre-existing advanced regeneration dominated the overstory. The probability of sugar maple and yellow birch being acceptable growing stock peaked at a diameter at breast height (DBH) of about 30-40 cm, while other species combined peaked at a DBH of around 20-25 cm. Our results suggest that harvest intensities based on the dominant advanced regeneration composition and harvesting systems that minimize the risk of physical damage to advanced regeneration are required to achieve partial harvesting objectives. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
4. Assessing mangrove species diversity, zonation and functional indicators in response to natural, regenerated, and rehabilitated succession
- Author
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Uday Pimple, Kumron Leadprathom, Dario Simonetti, Asamaporn Sitthi, Ronny Peters, Sukan Pungkul, Tamanai Pravinvongvuthi, Hélène Dessard, Uta Berger, Kraiwut Siri-on, Patiya Kemacheevakul, and Valery Gond
- Subjects
Environmental Engineering ,F40 - Écologie végétale ,Management, Monitoring, Policy and Law ,Forests ,Mangrove ,Waste Management and Disposal ,Ecosystem ,General Medicine ,Biodiversity ,Écologie des populations ,Structure du peuplement ,succession écologique ,Wetlands ,Conservation de la diversité biologique ,Succession végétale ,Rhizophoraceae ,P01 - Conservation de la nature et ressources foncières ,Biodiversité ,Succession secondaire ,Écosystème - Abstract
The United Nations Decade on Ecosystem restoration (2021¬-2030) lists mangrove ecosystems as a restoration priority. Interest in their conservation has increased recently due to their widespread degradation. Anthropogenic stressors and rehabilitation practices, specifically, have resulted in a significant decline in their species compositions. We investigated the knowledge gaps in terms of potential spatial diversity, intertidal zonation, and the historic state of mangrove forest species, and tested the role of environmental factors such as topography, as well as rehabilitation practices on diversity. Diversity and complexity indices, surface elevation, and species and structural diversities along three simplified transect lines over a broad geographical area and under various management practices were analyzed in Trat province, Thailand. Quantitative statistical zonation analyses within each transect and at the landscape-scale were performed using randomization tests and hierarchical cluster analysis. A modified "automatic regrowth monitoring algorithm (ARMA)," based on Landsat (1987-2020) and Sentinel-2 MSI (2015-2020) annual median composites was also used. Fifteen species were identified, with Ceriops tagal as the dominant species. Statistical analysis, however, failed to identify any significant zonation patterns at transect or landscape-scales at specific elevations. Rehabilitated and naturally regenerated stands showed gradual increases in their Normalized Difference Infrared Index over time. After 30 years, the rehabilitated stands made up of Rhizophoraceae monocultures were the same height as the adjacent natural stands. Depending on the location and propagule availability, the diversity and structure of regenerated stands exhibited high variation. Effluent from shrimp farms may have contributed to the disturbance of the forest stands and changes in shrimp farming practices could have facilitated their recovery. The results of the present study provide a valuable diversity baseline for the study site and secondary succession in rehabilitated and regenerated mangroves. The ARMA algorithm has also been confirmed as a valuable tool for future investigations of secondary succession and mangrove biodiversity status.
- Published
- 2022
5. Differential growth response to increasing growing stock and structural complexity in even- and uneven-sized mixed Picea abies stands in southern Finland1.
- Author
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Zenner, Eric K.
- Subjects
- *
NORWAY spruce , *PLANT growth , *FOREST thinning , *SILVICULTURAL systems , *TIMBER - Abstract
Widespread application of the selection system will depend on whether creating stands with uneven-sized (UES) structures comes at the expense of net periodic annual basal area increment (PAI) compared with stands with even-sized (ES) structures. I modeled PAI on growing stock and structural complexity over 12 years in midrotation stands with ES and UES structure types. Average PAI of the largest trees did not differ among types and decreased with increasing stocking, whereas PAI of the smallest trees in the UES type declined with stocking. Trees ≥ 10 cm in diameter grew more slowly in the ES type than the UES type, but no difference was seen after incorporating small trees (down to 5 or 2 cm). In the ES type, PAI of most trees increased linearly with increasing stocking, whereas in the UES type, it increased only up to ∼20 m2·ha−1. As structural complexity increased, PAI of the largest trees increased in the ES type, whereas PAI of all but the largest trees decreased in the UES type. Neither silvicultural system was innately more productive, as each can outperform the other under optimal levels of stocking and structural complexity. However, optimizing increment of only large trees would undermine the UES type. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
6. Differential growth response to increasing growing stock and structural complexity in even- and uneven-sized mixed Picea abies stands in southern Finland1.
- Author
-
Zenner, Eric K.
- Subjects
NORWAY spruce ,PLANT growth ,FOREST thinning ,SILVICULTURAL systems ,TIMBER - Abstract
Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2016
- Full Text
- View/download PDF
7. Using Model Analysis to Unveil Hidden Patterns in Tropical Forest Structures
- Author
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N. Ayyappan, Frédéric Mortier, David Harris, Faustin Boyemba Bosela, Thomas W. Crowther, Alfred Ngomanda, Pierre Couteron, Nestor Laurier Engone Obiang, Géraldine Derroire, Sylvie Gourlet-Fleury, John R. Poulsen, Nicolas Picard, Bonaventure Sonké, Connie J. Clark, Eric Forni, Pierre Ploton, Fabrice Bénédet, Jingjing Liang, Jean-François Bastin, Groupement d'Interêt Public Ecosystèmes Forestiers GIP ECOFOR (GIP ECOFOR ), Forêts et Sociétés (UPR Forêts et Sociétés), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Département Environnements et Sociétés (Cirad-ES), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Purdue University [West Lafayette], Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Gembloux Agro-Bio Tech [Gembloux], Université de Liège, Institut Français de Pondichéry (IFP), Ministère de l'Europe et des Affaires étrangères (MEAE)-Centre National de la Recherche Scientifique (CNRS), Université de Kisangani, Duke University [Durham], Department of Environmental Systems Science [ETH Zürich] (D-USYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Centre National de la Recherche Scientifique et Technologique (CNRST), Royal Botanic Garden [Edinburgh], University of Yaoundé [Cameroun], ANR-18-CE02-0025,GAMBAS,Nouvelles avancées dans la modélisation de la biodiversité et des services écosystémiques : améliorations statistiques et pertinences écologiques des modèles de distribution multi-espèces(2018), and Royal Botanic Garden Edinburgh
- Subjects
0106 biological sciences ,[SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy ,01 natural sciences ,Allométrie ,K01 - Foresterie - Considérations générales ,parcelle ,Forêt tropicale humide ,QH540-549.5 ,Ecology ,type forestier (composition botanique) ,U10 - Informatique, mathématiques et statistiques ,Null model ,[SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics ,Correlation ,Forest typology ,Geography ,forest structure ,F40 - Écologie végétale ,Evolution ,010603 evolutionary biology ,[SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems ,QH359-425 ,Ordination ,Ecology, Evolution, Behavior and Systematics ,010604 marine biology & hydrobiology ,Rain forest ,15. Life on land ,Tropical forest ,Structure du peuplement ,forest typology ,null model ,pattern and process ,rain forest ,correlation ,ordination ,Modélisation ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,Modèle végétal ,Pattern and process - Abstract
When ordinating plots of tropical rain forests using stand-level structural attributes such as biomass, basal area and the number of trees in different size classes, two patterns often emerge: a gradient from poorly to highly stocked plots and high positive correlations between biomass, basal area and the number of large trees. These patterns are inherited from the demographics (growth, mortality and recruitment) and size allometry of trees and tend to obscure other patterns, such as site differences among plots, that would be more informative for inferring ecological processes. Using data from 133 rain forest plots at nine sites for which site differences are known, we aimed to filter out these patterns in forest structural attributes to unveil a hidden pattern. Using a null model framework, we generated the anticipated pattern inherited from individual allometric patterns. We then evaluated deviations between the data (observations) and predictions of the null model. Ordination of the deviations revealed site differences that were not evident in the ordination of observations. These sites differences could be related to different histories of large-scale forest disturbance. By filtering out patterns inherited from individuals, our model analysis provides more information on ecological processes., Frontiers in Ecology and Evolution, 9, ISSN:2296-701X
- Published
- 2021
8. Using model analysis to unveil hidden patterns in tropical forest structures
- Abstract
When ordinating plots of tropical rain forests using stand-level structural attributes such as biomass, basal area and the number of trees in different size classes, two patterns often emerge: a gradient frompoorly to highly stocked plots and high positive correlations between biomass, basal area and the number of large trees. These patterns are inherited from the demographics (growth, mortality and recruitment) and size allometry of trees and tend to obscure other patterns, such as site differences among plots, that would be more informative for inferring ecological processes. Using data from 133 rain forest plots at nine sites for which site differences are known, we aimed to filter out these patterns in forest structural attributes to unveil a hidden pattern. Using a null model framework, we generated the anticipated pattern inherited from individual allometric patterns. We then evaluated deviations between the data (observations) and predictions of the null model. Ordination of the deviations revealed site differences that were not evident in the ordination of observations. These sites differences could be related to different histories of large-scale forest disturbance. By filtering out patterns inherited from individuals, our model analysis provides more information on ecological processes.
- Published
- 2021
9. Using model analysis to unveil hidden patterns in tropical forest structures
- Abstract
When ordinating plots of tropical rain forests using stand-level structural attributes such as biomass, basal area and the number of trees in different size classes, two patterns often emerge: a gradient frompoorly to highly stocked plots and high positive correlations between biomass, basal area and the number of large trees. These patterns are inherited from the demographics (growth, mortality and recruitment) and size allometry of trees and tend to obscure other patterns, such as site differences among plots, that would be more informative for inferring ecological processes. Using data from 133 rain forest plots at nine sites for which site differences are known, we aimed to filter out these patterns in forest structural attributes to unveil a hidden pattern. Using a null model framework, we generated the anticipated pattern inherited from individual allometric patterns. We then evaluated deviations between the data (observations) and predictions of the null model. Ordination of the deviations revealed site differences that were not evident in the ordination of observations. These sites differences could be related to different histories of large-scale forest disturbance. By filtering out patterns inherited from individuals, our model analysis provides more information on ecological processes.
- Published
- 2021
10. Structure élémentaire de l’arganeraie Argania spinosa L. Skeels de Tindouf (Sahara occidental algérien) / Elementary structure of the argan forest Argania spinosa L. Skeels of Tindouf (Algerian western Sahara)
- Author
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Réda Kechairi
- Subjects
buttes ,arganier ,structure du peuplement ,régénération naturelle ,dendrométrie ,Ecology ,argan tree ,stand structure ,natural regeneration ,dendrometry ,mounds ,Ecology, Evolution, Behavior and Systematics - Abstract
The argan tree is well adapted to drought conditions in Algerian western Sahara. The argan forest of Tindouf has a structure of coppice on stumps, characterized by an average height of 4.7m. Regeneration by dense resprouts represents 43% for 1,192 inventoried trees. The mother trees of Argania spinosa have a significant potential to resprout in coppice or suckers, thus forming crowns around mounds on beds of wadis. It should be noted that 21% of the trees are damaged by illegal cutting. The average spacing between the trees is around 13m. The argan tree retains a large volume of soil input with an average of 23.6 ± 36.3m3/ stump in the form of mounds. Linear regression analysis revealed an increasing relationship between mound volume and the number of stems per stump. Thanks to its powerful root system, the argan tree accumulates additional soil and contributes to the slow mechanism of sedimentation of micro-horizons, constituting mounds around the feet of trees., L’arganier est bien adapté aux conditions de sécheresse du Sahara occidental algérien. L’arganeraie de Tindouf a une structure dominée par les taillis sur souches, et caractérisée par une hauteur moyenne de 4,7 m. La régénération par rejets denses représente 43 % pour 1 192 pieds inventoriés. Les souches-mères d’Argania spinosa ont une potentialité importante de rejeter par les cépées ou par les drageons, formant ainsi des couronnes aux alentours des buttes sur lits d’oueds. Il est à signaler que 21 % des souches sont détériorées par les coupes illicites. L’écartement moyen entre les arbres est de l’ordre de 13 m. L’arganier retient un volume important de sol d’apport d’une moyenne de 23,6 ± 36,3 m3/ souche sous forme de buttes. L’analyse de régression linéaire a révélé une relation croissante entre le volume des buttes et le nombre de brins par souche. Grâce à son puissant système racinaire, l’arganier accumule des sols d’apport et contribue au mécanisme lent de sédimentation de micro-horizons en constituant des buttes aux pieds des arbres., Kechairi Réda. Structure élémentaire de l’arganeraie Argania spinosa L. Skeels de Tindouf (Sahara occidental algérien) / Elementary structure of the argan forest Argania spinosa L. Skeels of Tindouf (Algerian western Sahara). In: Ecologia mediterranea, tome 47 n°2, 2021. pp. 73-84.
- Published
- 2021
11. Isolation and characterization of microsatellite markers for the threatened African endemic tree species Pterocarpus erinaceus Poir.
- Abstract
To study the genetic diversity and structure of the forest species Pterocarpus erinaceus Poir., seventeen polymorphic nuclear microsatellite markers were isolated and characterized, using next‐generation sequencing. Three hundred and sixty‐five (365) individuals were analyzed within fifteen (15) West African populations. The number of alleles for these loci varied from 4 to 30, and the heterozygosity varied from 0.23 to 0.82. The seventeen (17) primers designed here will allow characterizing the genetic diversity of this threaten species on its natural stands and to better understand the population differentiation mechanisms shaping it.
- Published
- 2020
12. Isolation and characterization of microsatellite markers for the threatened African endemic tree species Pterocarpus erinaceus Poir.
- Abstract
To study the genetic diversity and structure of the forest species Pterocarpus erinaceus Poir., seventeen polymorphic nuclear microsatellite markers were isolated and characterized, using next‐generation sequencing. Three hundred and sixty‐five (365) individuals were analyzed within fifteen (15) West African populations. The number of alleles for these loci varied from 4 to 30, and the heterozygosity varied from 0.23 to 0.82. The seventeen (17) primers designed here will allow characterizing the genetic diversity of this threaten species on its natural stands and to better understand the population differentiation mechanisms shaping it.
- Published
- 2020
13. Spruce and birch growth in pure and mixed stands in Sweden.
- Author
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Lundqvist, Lars, Mörling, Tommy, and Valinger, Erik
- Subjects
TREE growth ,SPRUCE ,EUROPEAN white birch ,DOWNY birch ,NORWAY spruce - Abstract
Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2014
- Full Text
- View/download PDF
14. Isolation and characterization of microsatellite markers for the threatened African endemic tree species Pterocarpus erinaceus Poir
- Author
-
Kouami Kokou, Kossi Novinyo Segla, Adzo Dzifa Kokutse, Christine Ouinsavi, Gilles Chaix, Hélène Vignes, Létizia Camus-Kulandaivelu, Marie Luce Akossiwoa Quashie, Kossi Adjonou, Benziwa Nathalie Johnson, Babou André Bationo, Habou Rabiou, Université de Lomé [Togo], Amélioration génétique et adaptation des plantes méditerranéennes et tropicales (UMR AGAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-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 National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Département Systèmes Biologiques (Cirad-BIOS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Université de Parakou (UP), Institut de l'Environnement et Recherches Agricoles [Ouagadougou] (INERA), Institut de Recherche pour le Développement (IRD), Université de Diffa, Sud Expert Plantes Developpement Durable (SEP2D) program (AAP1-45), Agence Universitaire de la Francophonie (AUF) (DRAO-1448-2019-02), Programme d'Appui a la Lutte contre le Changement Climatique: PALCC -AMCC+ (DCI-ENV/2016/39289, DCI-ENV-2017/387-416), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, and 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)
- Subjects
0106 biological sciences ,[SDV]Life Sciences [q-bio] ,Organisme indigène ,Population ,Zoology ,Biology ,010603 evolutionary biology ,01 natural sciences ,F30 - Génétique et amélioration des plantes ,Loss of heterozygosity ,03 medical and health sciences ,Variation génétique ,nuclear microsatellites ,Marqueur génétique ,Allele ,education ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,Nature and Landscape Conservation ,Pterocarpus erinaceus ,[SDV.EE]Life Sciences [q-bio]/Ecology, environment ,0303 health sciences ,education.field_of_study ,Genetic diversity ,Ecology ,espèce en danger ,Microsatellite ,genetic diversity ,15. Life on land ,biology.organism_classification ,Isolation (microbiology) ,Structure du peuplement ,next‐ ,generation sequencing (NGS) ,Threatened species ,SEQUENCIAMENTO GENÉTICO ,African tree species - Abstract
To study the genetic diversity and structure of the forest species Pterocarpus erinaceus Poir., seventeen polymorphic nuclear microsatellite markers were isolated and characterized, using next-generation sequencing. Three hundred and sixty-five (365) individuals were analyzed within fifteen (15) West African populations. The number of alleles for these loci varied from 4 to 30, and the heterozygosity varied from 0.23 to 0.82. The seventeen (17) primers designed here will allow characterizing the genetic diversity of this threaten species on its natural stands and to better understand the population differentiation mechanisms shaping it.
- Published
- 2020
15. Great genetic diversity but high selfing rates and short-distance gene flow characterize populations of a tree (Foetidia; Lecythidaceae) in the fragmented tropical dry forest of the Mascarene Islands
- Abstract
Following the global trend of deforestation and degradation, tropical dry forests in the Mascarenes archipelago on Reunion has undergone harsh reduction and fragmentation within 3 centuries of human occupation. We investigated the genetic diversity, mating system, and gene flow in fragmented populations of the native tree Foetidia mauritiana (Lecythidaceae) on Reunion, using microsatellite genotyping of adults (in- and ex situ) and seed progenies (in situ only). To test genetic isolation between the Mascarene islands, we also genotyped conspecific adults on Mauritius, and trees of Foetidia rodriguesiana on Rodrigues. We found a high genetic diversity among the trees on Reunion, but no population structure (G_ST: 0.039–0.090), and an increase of the fixation index (FIS) from adults to progenies. A subsequent analysis of mating systems from progeny arrays revealed selfing rates >50% in fragmented populations and close to 100% in lone trees. A paternity analysis revealed pollen flow ranging from 15.6 to 296.1 m within fragments. At broader scale, the populations of F. mauritiana on Reunion and Mauritius are genetically differentiated. The morphologically allied taxa F. rodriguesiana and F. mauritiana are clearly isolated. Therefore, this case study shows that genetic diversity may persist after deforestation, especially in long-lived tree species, but the reproductive features may be deeply altered during this process. This would explain the low seed production and the absence of recruitment in F. mauritiana. Restoration programs should take into account these features, as well as the importance that trees ex situ represent in restoring and conserving diversity.
- Published
- 2019
16. Great genetic diversity but high selfing rates and short-distance gene flow characterize populations of a tree (Foetidia; Lecythidaceae) in the fragmented tropical dry forest of the Mascarene Islands
- Abstract
Following the global trend of deforestation and degradation, tropical dry forests in the Mascarenes archipelago on Reunion has undergone harsh reduction and fragmentation within 3 centuries of human occupation. We investigated the genetic diversity, mating system, and gene flow in fragmented populations of the native tree Foetidia mauritiana (Lecythidaceae) on Reunion, using microsatellite genotyping of adults (in- and ex situ) and seed progenies (in situ only). To test genetic isolation between the Mascarene islands, we also genotyped conspecific adults on Mauritius, and trees of Foetidia rodriguesiana on Rodrigues. We found a high genetic diversity among the trees on Reunion, but no population structure (G_ST: 0.039–0.090), and an increase of the fixation index (FIS) from adults to progenies. A subsequent analysis of mating systems from progeny arrays revealed selfing rates >50% in fragmented populations and close to 100% in lone trees. A paternity analysis revealed pollen flow ranging from 15.6 to 296.1 m within fragments. At broader scale, the populations of F. mauritiana on Reunion and Mauritius are genetically differentiated. The morphologically allied taxa F. rodriguesiana and F. mauritiana are clearly isolated. Therefore, this case study shows that genetic diversity may persist after deforestation, especially in long-lived tree species, but the reproductive features may be deeply altered during this process. This would explain the low seed production and the absence of recruitment in F. mauritiana. Restoration programs should take into account these features, as well as the importance that trees ex situ represent in restoring and conserving diversity.
- Published
- 2019
17. Sampling design and precision of basal area growth and stand structure in uneven-aged northern hardwoods.
- Author
-
Guillemet, François, Lambert, Marie-Claude, and Bédard, Steve
- Subjects
SAMPLING (Process) ,FIELDWORK (Educational method) ,BASAL area (Forestry) ,HARDWOODS ,TREE growth - Abstract
Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2012
18. Linking stand attributes to cartographic information for ecosystem management purposes in the boreal forest of eastern Québec.
- Author
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Côté, Guillaume, Bouchard, Mathieu, Pothier, David, and Gauthier, Sylvie
- Subjects
TAIGAS ,SILVICULTURAL systems ,ECOSYSTEM management ,MAPS - Abstract
Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2010
19. Analyzing building stock using topographic maps and GIS.
- Author
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Meinel, Gotthard, Hecht, Robert, and Herold, Hendrik
- Subjects
STOCKS (Finance) ,BUILDINGS ,SOCIAL settlements ,TOPOGRAPHIC maps ,DIGITAL mapping - Abstract
Building stock is an extremely cost-intensive and long-lived component of the settlement structure. Considering its importance, the information available on building stock and its development is often inadequate. Data such as the age and structure of buildings, the number of dwelling units and floors are not comprehensively available nor sufficiently processed. In order to fill this gap, this paper presents a method for the calculation of settlement structure parameters by means of a spatial disaggregation through a combination of building data obtained from topographic maps 1:25 000, block boundaries taken from authoritative digital maps, and statistical data at municipality level. The inexpensive analogue maps are available nationwide and also for earlier time slices due to defined update intervals. The maps are scanned at high resolution and geo-referenced. The building stock, which is shown interspersed with traffic, vegetation and lettering... [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
20. Long-term black spruce plantation growth and structure after release and juvenile cleaning: A 24-year study.
- Author
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Cyr, Guillaume and Thiffault, Nelson
- Subjects
VEGETATION management ,CONIFERS ,FOREST management ,PLANTATIONS ,SILVICULTURAL systems - Abstract
Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2009
- Full Text
- View/download PDF
21. Impact of a spruce budworm outbreak in balsam fir and subsequent stand development over a 40-year period.
- Author
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MacLean, David A. and Andersen, Allison R.
- Subjects
SPRUCE budworm ,BALSAM fir ,CHORISTONEURA ,PINACEAE ,CASE studies ,TREE diseases & pests ,TREE growth - Abstract
Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2008
- Full Text
- View/download PDF
22. Great Genetic Diversity but High Selfing Rates and Short-Distance Gene Flow Characterize Populations of a Tree (Foetidia; Lecythidaceae) in the Fragmented Tropical Dry Forest of the Mascarene Islands
- Author
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Gérard Lebreton, Olivier Flores, Florent Martos, Nicolas Cuénin, Eric Rivière, Bernard Reynaud, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), UMR Peuplement Végétaux et Bioagresseurs en Milieu Tropical (UMR PVBMT - INRA), Institut National de la Recherche Agronomique (INRA), Université de La Réunion (UR), Peuplements végétaux et bioagresseurs en milieu tropical (UMR PVBMT), Institut de Recherche pour le Développement (IRD)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de La Réunion (UR)-Institut National de la Recherche Agronomique (INRA), Institut de Systématique, Evolution, Biodiversité (ISYEB ), Muséum national d'Histoire naturelle (MNHN)-École pratique des hautes études (EPHE)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Muséum national d'Histoire naturelle (MNHN), Sorbonne Université (SU), Université des Antilles (UA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université de La Réunion (UR), Muséum national d'Histoire naturelle (MNHN)-École pratique des hautes études (EPHE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)
- Subjects
0106 biological sciences ,0301 basic medicine ,[SDV]Life Sciences [q-bio] ,forêt tropicale ,État dispersé ,Forests ,01 natural sciences ,F30 - Génétique et amélioration des plantes ,Fixation index ,Trees ,érosion génétique ,Lecythidaceae ,Croisement ,Genetics (clinical) ,Phylogeny ,Islands ,biology ,Ecology ,Reproduction ,Méthode d'accouplement ,Seeds ,Pollen ,Genetic isolate ,Biotechnology ,Tropical and subtropical dry broadleaf forests ,Gene Flow ,010603 evolutionary biology ,03 medical and health sciences ,Variation génétique ,Genetics ,Genetic erosion ,Molecular Biology ,Mauritiana ,Genetic diversity ,Tropical Climate ,[SDV.GEN]Life Sciences [q-bio]/Genetics ,fragmentation de l'habitat ,Selfing ,Genetic Variation ,15. Life on land ,biology.organism_classification ,Structure du peuplement ,030104 developmental biology ,Genetics, Population - Abstract
International audience; Following the global trend of deforestation and degradation, tropical dry forests in the Mascarenes archipelago on Reunion has undergone harsh reduction and fragmentation within 3 centuries of human occupation. We investigated the genetic diversity, mating system, and gene flow in fragmented populations of the native tree Foetidia mauritiana (Lecythidaceae) on Reunion, using microsatellite genotyping of adults (in- and ex situ) and seed progenies (in situ only). To test genetic isolation between the Mascarene islands, we also genotyped conspecific adults on Mauritius, and trees of Foetidia rodriguesiana on Rodrigues. We found a high genetic diversity among the trees on Reunion, but no population structure (G′ST: 0.039–0.090), and an increase of the fixation index (FIS) from adults to progenies. A subsequent analysis of mating systems from progeny arrays revealed selfing rates >50% in fragmented populations and close to 100% in lone trees. A paternity analysis revealed pollen flow ranging from 15.6 to 296.1 m within fragments. At broader scale, the populations of F. mauritiana on Reunion and Mauritius are genetically differentiated. The morphologically allied taxa F. rodriguesiana and F. mauritiana are clearly isolated. Therefore, this case study shows that genetic diversity may persist after deforestation, especially in long-lived tree species, but the reproductive features may be deeply altered during this process. This would explain the low seed production and the absence of recruitment in F. mauritiana. Restoration programs should take into account these features, as well as the importance that trees ex situ represent in restoring and conserving diversity.
- Published
- 2019
23. Les effets immédiats de la mise en eau : 1994-1996
- Author
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Merona, Bernard de
- Subjects
barrage ,structure du peuplement ,Petit Saut (barrage) ,RNK ,Environmental Studies ,conséquence écologique ,cours d’eau ,poisson d’eau douce ,zonation écologique ,biodiversité ,NAT011000 ,structure trophique ,Guyane française ,Sinnamary (cours d’eau) - Abstract
Le 6 janvier 1994, le barrage de Petit-Saut a fermé ses portes après près de quatre ans de travaux. Le remplissage de la retenue s’est effectué en deux temps. Entre janvier 1994 et début juillet 1994, le niveau s’est élevé de près de 30 m puis, pour des raisons techniques, le remplissage a été arrêté et repris en décembre de la même année. Le remplissage total s’est achevé en juin 1995 lorsque la cote 35 m a été atteinte (fig. 26). Conformément à la législation en vigueur, un débit minimum de...
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- 2018
24. Chapitre II. Différents types de pièce calcifiée
- Author
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Wright, P.J., Panfili, J., Morales-Nin, B., Geffen, A.J., and Meunier, F.J.
- Subjects
otolithe ,structure du peuplement ,RNK ,poisson ,âge physiologique ,maturité sexuelle ,estimation de stock ,Environmental Studies ,migration ,écaille ,croissance ,méthode d’analyse ,NAT011000 - Abstract
Les pièces calcifiées ont des origines ontogéniques et des propriétés différentes. C’est pourquoi, dans le but d’évaluer les utilisations potentielles des otolithes, des écailles et des tissus squelettiques pour les études de sclérochronologie, il est important de bien comprendre la nature et la formation des accroissements dans ces différentes structures. Dans ce chapitre, nous décrirons la fonction, la morphologie et la structure des différentes pièces calcifiées. Puis, nous ferons une revu...
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- 2018
25. Le fleuve, le barrage et les poissons
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Merona, Bernard de, Cayré, Patrice, Grégoire, Alain, and Karam, Antoine
- Subjects
barrage ,structure du peuplement ,Petit Saut (barrage) ,RNK ,Environmental Studies ,conséquence écologique ,cours d’eau ,poisson d’eau douce ,zonation écologique ,biodiversité ,NAT011000 ,structure trophique ,Guyane française ,Sinnamary (cours d’eau) - Abstract
Entre 1990 et 2002. l’IRD a mené des études approfondies sur les peuplements piscicoles du fleuve Sinnamary en Guyane française, afin d’évaluer les effets du barrage hydroélectrique de Petit-Saut, mis en eau en janvier 1994. Quatre années d’observations avant la construction du barrage et neuf années après ont permis une description détaillée des peuplements de poissons dans le fleuve et une analyse de leur évolution sous l’effet de la perturbation majeure subie par ce bassin tropical. Cet ouvrage constitue une synthèse de ces études. Il est exceptionnel, en milieu tropical, de disposer de données exhaustives concernant les conséquences d’un barrage sur les peuplements de poissons. La prise en compte d’études parallèles sur les autres compartiments de l’écosystème (invertébrés, végétation, chimie des eaux, hydrologie) rend possible une interprétation des mécanismes en jeu dans les transformations, seule à même d'anticiper les changements et d’en limiter les impacts négatifs. Accessible à un large public grâce à une présentation didactique des méthodes scientifiques utilisées, l'ouvrage intéressera également les spécialistes à travers les interprétations des résultats présentés. Il constituera une référence utile dans le cadre d’autres projets de barrage ou d’aménagements similaires en région tropicale.
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- 2018
26. Chapitre I. Introduction
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Pontual, H. de, Panfili, J., Wright, P.J., Troadec, H., and Meunier, F.J.
- Subjects
otolithe ,structure du peuplement ,RNK ,poisson ,âge physiologique ,maturité sexuelle ,estimation de stock ,Environmental Studies ,migration ,écaille ,croissance ,méthode d’analyse ,NAT011000 - Abstract
H. de Pontual, J. Panfili, P.J. Wright, H. Troadec Étymologiquement, le terme « sclérochronologie » est dérivé des racines grecques sklêros « dur », khronos « temps » et logos « étude ». Littéralement, cette science vise à reconstruire l’histoire vécue par les organismes vivants à partir de l’étude de leurs pièces calcifiées (PC). Elle couvre ainsi non seulement les problèmes d’estimation de l’âge mais aussi ceux de l’estimation de la période et de la durée d’événements marquants de l’histoir...
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- 2018
27. Chapitre VIII. Techniques de préparation et d’observation
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H.Troadec, Pontual, H. de, Panfili, J., McCurdy, W.J., Meunier, F.J., Geffen, A.J., and Morales-Nin, B.
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otolithe ,structure du peuplement ,RNK ,poisson ,âge physiologique ,maturité sexuelle ,estimation de stock ,Environmental Studies ,migration ,écaille ,croissance ,méthode d’analyse ,NAT011000 - Abstract
Les chapitres précédents ont montré que les écailles, les otolithes et les os du squelette sont utilisés pour estimer l’âge des poissons en année, en saison ou en jour. La préparation des pc nécessite une série d’étapes de traitement qui peuvent être longues et complexes. Préalablement au démarrage d’une étude de sclérochronologie, il est nécessaire d’identifier les contraintes en termes de temps et de coûts et surtout les objectifs finaux et les résultats attendus (chap. III). Le choix d’une...
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- 2018
28. La phase de stabilisation : 1997-2002
- Author
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Merona, Bernard de
- Subjects
barrage ,structure du peuplement ,Petit Saut (barrage) ,RNK ,Environmental Studies ,conséquence écologique ,cours d’eau ,poisson d’eau douce ,zonation écologique ,biodiversité ,NAT011000 ,structure trophique ,Guyane française ,Sinnamary (cours d’eau) - Abstract
Fin 1995, la retenue est remplie, la production d’électricité devient totalement opérationnelle. À l’aval, le seuil de ré-oxygénation fonctionne et la qualité de l’eau est satisfaisante. Dans la retenue, tous les arbres noyés sont morts et, progressivement, les branches tombent en commençant par les plus petites, si bien qu’à la fin de la période, seuls les squelettes des arbres persistent. Les seules touches de vert dans ce paysage hivernal sont les épiphytes (orchidées, broméliacées) qui re...
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- 2018
29. Conclusions générales
- Author
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Merona, Bernard de
- Subjects
barrage ,structure du peuplement ,Petit Saut (barrage) ,RNK ,Environmental Studies ,conséquence écologique ,cours d’eau ,poisson d’eau douce ,zonation écologique ,biodiversité ,NAT011000 ,structure trophique ,Guyane française ,Sinnamary (cours d’eau) - Abstract
La construction d’un barrage sur un cours d’eau, comme d’ailleurs tout aménagement destiné à améliorer le bien-être de la société en général, est précédée de tout un processus de décision. Celui-ci consiste, d’une part, à évaluer la faisabilité de l’opération et, d’autre part, à tenter de prévoir son bilan coût-bénéfice. En termes économiques, ce bilan est relativement facile à réaliser, mais il n’en est pas de même lorsque l’on y inclut le coût environnemental qui est difficilement chiffrabl...
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- 2018
30. Introduction
- Author
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Merona, Bernard de
- Subjects
barrage ,structure du peuplement ,Petit Saut (barrage) ,RNK ,Environmental Studies ,conséquence écologique ,cours d’eau ,poisson d’eau douce ,zonation écologique ,biodiversité ,NAT011000 ,structure trophique ,Guyane française ,Sinnamary (cours d’eau) - Abstract
La construction de barrages n’est pas un phénomène récent. Dès l’Antiquité, des ouvrages ont été élaborés essentiellement à des fins d’irrigation ou de stockage de l’eau (WCD, 2000). Récente, en revanche, est la prolifération de barrages de grande taille observée durant le siècle dernier. À la fin du xxe siècle, on comptait plus de 45 000 grands barrages dans plus de 140 pays (WCD, 2000). Ces ouvrages et les réservoirs qu’ils génèrent, conçus pour favoriser le développement, induisent de prof...
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- 2018
31. Chapitre IV. Méthodes de validation et de vérification
- Author
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Wright, P.J., Panfili, J., Folkvord, A., Mosegaard, H., Meunier, F.J., and Morales-Nin, B.
- Subjects
otolithe ,structure du peuplement ,RNK ,poisson ,âge physiologique ,maturité sexuelle ,estimation de stock ,Environmental Studies ,migration ,écaille ,croissance ,méthode d’analyse ,NAT011000 - Abstract
Il est impossible de connaître l’âge absolu, « âge véritable », d’un poisson prélevé au hasard dans son environnement naturel. De nombreuses analyses de pêcheries dépendent cependant d’estimations exactes et fiables des structures en âge des captures. La constatation de nombreuses erreurs dans les estimations d’âge a relancé l’intérêt des méthodes de validation. « Valider » signifie qu’il faut prouver qu’une technique est exacte. Ceci peut être démontré ou estimé. Une estimation a bien sûr mo...
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- 2018
32. Le fleuve Sinnamary
- Author
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Merona, Bernard de
- Subjects
barrage ,structure du peuplement ,Petit Saut (barrage) ,RNK ,Environmental Studies ,conséquence écologique ,cours d’eau ,poisson d’eau douce ,zonation écologique ,biodiversité ,NAT011000 ,structure trophique ,Guyane française ,Sinnamary (cours d’eau) - Abstract
Géographie physique Le bassin du Sinnamary occupe une position centrale dans le système hydrographique guyanais (fig. 3, cf. cahier couleur). Le fleuve prend sa source dans les reliefs peu élevés des massifs centraux de la Guyane à quelque 130 m d’altitude et s’écoule du sud au nord jusqu’à la plaine côtière (fig. 4, cf. cahier couleur). Il s’agit d’un fleuve de moyenne importance avec un bassin de 6 565 km2 et une extension d’environ 250 km. Il n’a que deux affluents de taille significative,...
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- 2018
33. Chapitre III. Bases de la sclérochronologie
- Author
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Morales-Nin, B., Panfili, J., Geffen, A.J., Pontual, H. de, Wright, P.J., and Mosegaard, H.
- Subjects
otolithe ,structure du peuplement ,RNK ,poisson ,âge physiologique ,maturité sexuelle ,estimation de stock ,Environmental Studies ,migration ,écaille ,croissance ,méthode d’analyse ,NAT011000 - Abstract
Contrairement aux idées reçues, la sclérochronologie, en particulier l’estimation de l’âge chez les poissons, n’est pas une science aisée. Elle implique une série de processus et de traitements de données qui sont souvent complexes et consommateurs de temps. Avant même de commencer de telles études, il est nécessaire de connaître à l’avance les contraintes sur le temps disponible et sur les coûts et, particulièrement, les objectifs de l’étude ainsi que les résultats attendus. Ce chapitre va a...
- Published
- 2018
34. Chapitre VI. Estimation de l’âge assistée par ordinateur
- Author
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H.Troadec and Benzinou, A.
- Subjects
otolithe ,structure du peuplement ,RNK ,poisson ,âge physiologique ,maturité sexuelle ,estimation de stock ,Environmental Studies ,migration ,écaille ,croissance ,méthode d’analyse ,NAT011000 - Abstract
L’estimation de l’âge à partir de pièces calcifiées est, avant tout, basée sur un processus répétitif d’interprétation de zones de croissance associant des mécanismes de perception visuelle et des connaissances biologiques. Devant la multiplicité des sources de biais et la subjectivité de certains critères d’interprétation, les sclérochronologues ont cherché à introduire une certaine objectivité à la fois dans l’acquisition des informations de base, essentiellement visuelles, et dans les sché...
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- 2018
35. Chapitre VII. Microchimie de l’otolithe
- Author
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Pontual, H. de and Geffen, A.J.
- Subjects
otolithe ,structure du peuplement ,RNK ,poisson ,âge physiologique ,maturité sexuelle ,estimation de stock ,Environmental Studies ,migration ,écaille ,croissance ,méthode d’analyse ,NAT011000 - Abstract
A. Introduction Depuis le début des années soixante-dix, un effort de recherche croissant a été consenti pour utiliser la composition chimique des pièces calcifiées (pc) comme source d’information permettant d’aborder un large éventail de questions en halieutique. Cette approche suppose que la composition chimique des tissus durs des poissons reflète les caractéristiques physico-chimiques de l’environnement au sein duquel ces poissons évoluent. Les otolithes en particulier ont été qualifiés d...
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- 2018
36. La diversité des poissons
- Author
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Merona, Bernard de
- Subjects
barrage ,structure du peuplement ,Petit Saut (barrage) ,RNK ,Environmental Studies ,conséquence écologique ,cours d’eau ,poisson d’eau douce ,zonation écologique ,biodiversité ,NAT011000 ,structure trophique ,Guyane française ,Sinnamary (cours d’eau) - Abstract
Les fleuves et rivières tropicaux, du fait de leur grande richesse faunistique, constituent des laboratoires du plus grand intérêt pour l’étude de l’écologie des communautés animales. Il s’agit, d’une part, d’évaluer la biodiversité, dont l’un des indices les plus simples est le nombre d’espèces ou richesse spécifique. Il s’agit, d’autre part, de tenter de comprendre comment de nombreuses espèces coexistent dans un même lieu. Une population (ensemble des individus d’une même espèce habitant d...
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- 2018
37. Pan-tropical prediction of forest structure from the largest trees
- Author
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Narayanaswamy Parthasarathy, Stephen P. Hubbell, Cintia Rodrigues de Souza, Takeshi Toma, Ben Swanepoel, Raphaël Pélissier, Donatien Zebaze, Luzmila Arroyo, Juliana Stropp, James R. Kellner, Alejandro Araujo-Murakami, Thomas E. Lovejoy, Benoît Cassart, Ben Hur Marimon Junior, James Grogan, Sebastian K. Herzog, Yadvinder Malhi, Krisna Gajapersad, José Luís Camargo, Christelle Gonmadje, Renato Valencia, Connie J. Clark, Denise Sasaki, Fabien Wagner, Francesco Rovero, Katrin Boehning-Gaese, David Kenfack, Olaf Bánki, John Terborgh, Ferry Slik, Arafat S. Mtui, Javier Silva Espejo, Hans Beeckman, Germaine Alexander Parada Gutierrez, Tinde van Andel, Luis Valenzuela, Thalès de Haulleville, Hans ter Steege, Elizabeth Kearsley, Martin J. P. Sullivan, Wilson Roberto Spironello, Rodolfo Vasque, Emmanuel H. Martin, Thomas Duncan, William F. Laurance, Jason Vleminckx, Paulus Matius, Charles De Cannière, Yves Laumonier, Ted R. Feldpausch, Andrew R. Marshall, John R. Poulsen, J. Daniel Soto, Priya Davidar, Jean François Gillet, Iêda Leão do Amaral, Papi Puspa Warsudi, Eurídice N. Honorio Coronado, Vincent A. Vos, Laurent Descroix, Nicolas Texier, Philippe Saner, Roderick Zagt, Marc P. E. Parren, Luiz Marcelo Brum Rossi, Robert Bitariho, Fernando Cornejo Valverde, Jon Lloyd, Nina Farwig, James Singh, Jean-Louis Doucet, Francis Q. Brearley, Leandro Valle Ferreira, Celso Paulo de Azevedo, Ervan Rutishauser, Johanna Hurtado, Bruno Hérault, Albert Angbonga-Basia, Jérôme Chave, David A. Neill, Jean Claude Razafimahaimodison, Pierre Ploton, Hilandia Brandão, Susan G. Laurance, Richard Condit, Roel J. W. Brienen, Jean-François Bastin, Ana Andrade, Marcos Silveira, Oliver L. Phillips, Gauthier Ligot, David B. Clark, Casimero Mendoza Bautista, Narayanan Ayyappan, Robin L. Chazdon, Hans Verbeeck, Santiago Espinosa, Jürgen Homeier, Mireille Breuer-Ndoundou Hockemba, Simon L. Lewis, Patricia Alvarez-Loyayza, Vincent Droissart, Sassan Saatchi, Nigel C. A. Pitman, Victoria Meyer, Nicolas Barbier, Wannes Hubau, Jorcely Barroso, Nicolas Labrière, Plinio Sist, Georges Chuyong, Pascal Boeckx, Hugo Romero Saltos, Antonio Ferraz, David Harris, Verginia Wortel, Pandi Vivek, Mark Schulze, Bonaventure Sonké, Jan Bogaert, Abel Monteagudo-Mendoza, Guido Pardo, Quentin Ponette, Ahimsa Campos-Arceiz, Michael Kessler, Beatriz Schwantes Marimon, Samir Gonçalves Rolim, Maxime Réjou-Méchain, Koen Hufkens, Narcisse Guy Kamdem, Adeline Fayolle, Aurélie Dourdain, Christine Fletcher, Moses Libalah, B.R. Ramesh, Research Unit of Landscape Ecology and Plant Production Systems, Université libre de Bruxelles (ULB), Carbon For Expert, California Institute of Technology (CALTECH), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Département Environnements et Sociétés (Cirad-ES), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Université de Liège, University of Mary Washington, Instituto Nacional de Pesquisas da Amazônia (INPA), Universidad Autonoma Gabriel René Moreno (UAGRM), Institut Français de Pondichéry (IFP), Ministère de l'Europe et des Affaires étrangères (MEAE)-Centre National de la Recherche Scientifique (CNRS), Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam [Amsterdam] (UvA), Universidade Federal do Acre (UFAC), School of Engineering and Science, Jacobs University [Bremen], Laboratory of Applied Physical Chemistry, Universiteit Gent = Ghent University (UGENT), School of Geography [Leeds], University of Leeds, Universidad Nacional de San Antonio Abad del Cusco (UNSAAC), Evolution et Diversité Biologique (EDB), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), University of Buea, Department of Computer Science, King‘s College London, Patrimoines Locaux et Gouvernance (PALOC), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD), Gembloux Agro-Bio Tech [Gembloux], Department of Ecology-Conservation Ecology, Faculty of Biology, Philipps Universität Marburg = Philipps University of Marburg, AgroBioTech, Forest Research Institute Malaysia (FRIM), Mount Holyoke College, Royal Botanic Gardens, Georg-August-University = Georg-August-Universität Göttingen, Royal Museum for Central Africa [Tervuren] (RMCA), Smithsonian Conservation Biology Institute, Center for Conservation Education and Sustainability, MRC 705, Box 37012, Washington, DC, VA 20013-7012, USA, Universität Zürich [Zürich] = University of Zurich (UZH), AgroParisTech, Center for International Forestry Research (CIFOR), Consultative Group on International Agricultural Research [CGIAR] (CGIAR), Université de Yaoundé I, Imperial College London, Environmental Science and Policy Department and the Department of Public and International Affairs, George Mason University [Fairfax], Environmental Change Inst., School of Geography and the Environment, University of Oxford, Universidade do Estado de Mato Grosso (UNEMAT), Centre Maurice Halbwachs (CMH), École des hautes études en sciences sociales (EHESS)-Centre National de la Recherche Scientifique (CNRS)-Département de Sciences sociales ENS-PSL, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Missouri Botanical Garden, Universidad Estatal Amazonica, Universidad Autonoma del Beni, Analytical and Biophysical Environmental Chemistry (CABE), University of Geneva, Sciences II, Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University [Durham], Université Catholique de Louvain = Catholic University of Louvain (UCL), Département Systèmes Biologiques (Cirad-BIOS), MUSE – Science Museum of Trento, Forêts et Sociétés (UPR Forêts et Sociétés), Amazonia Central, Brazilian Agricultural Research Corporation (Embrapa), JRC Institute for Environment and Sustainability (IES), European Commission - Joint Research Centre [Ispra] (JRC), Department of Forest Vegetation, Forestry and Forest Products Research Institute (FFPRI), Laboratorio de Ecología de Plantas y Herbario QCA, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Chercheur indépendant, Computational & Applied Vegetation Ecology (CAVElab), Instituto Nacional de Pesquisas Espaciais (INPE), Ministério da Ciência, Tecnologia e Inovação, Biodiversity Department, Center for Agricultural Research in Suriname (CELOS), Laboratoire de Botanique systématique et d'Ecologie [ENS Yaoudé], Université de Yaoundé I-École normale supérieure [ENS] - Yaoundé 1, Université Libre de Bruxelles [Bruxelles] (ULB), Université des Antilles (UA)-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS)-Ministère de l'Europe et des Affaires étrangères (MEAE), Ghent University [Belgium] (UGENT), Universidad Nacional San Antonio Abad del Cusco, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Phillips Universität (Marburg), Georg-August-Universität Göttingen, University of Zurich, Université de Yaoundé, École normale supérieure - Paris (ENS Paris)-École des hautes études en sciences sociales (EHESS)-Centre National de la Recherche Scientifique (CNRS), Missouri Botanical Garden (USA), Université Catholique de Louvain (UCL), Pontificia Universidad Catolica del Ecuador, Université de Yaoundé I [Yaoundé]-École normale supérieure [ENS] - Yaoundé 1, Systems Ecology, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud]), Universiteit Gent = Ghent University [Belgium] (UGENT), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Georg-August-University [Göttingen], University of Oxford [Oxford], École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École des hautes études en sciences sociales (EHESS)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
P33 - Chimie et physique du sol ,0106 biological sciences ,pan-tropical ,010504 meteorology & atmospheric sciences ,P40 - Météorologie et climatologie ,REDD ,Rainforest ,F50 - Anatomie et morphologie des plantes ,010603 evolutionary biology ,01 natural sciences ,Basal area ,[SDV.SA.SF]Life Sciences [q-bio]/Agricultural sciences/Silviculture, forestry ,K01 - Foresterie - Considérations générales ,Quadratic mean diameter ,Ecology, Evolution, Behavior and Systematics ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Changement climatique ,Global and Planetary Change ,Biomass (ecology) ,Tree canopy ,Ecology ,carbon ,Diameter at breast height ,large trees ,Tropics ,15. Life on land ,Structure du peuplement ,séquestration du carbone ,climate change ,13. Climate action ,Forêt ,Environmental science ,Physical geography ,tropical forest ecology ,REDD+ ,Woody plant ,forest structure - Abstract
© 2018 John Wiley & Sons Ltd Aim: Large tropical trees form the interface between ground and airborne observations, offering a unique opportunity to capture forest properties remotely and to investigate their variations on broad scales. However, despite rapid development of metrics to characterize the forest canopy from remotely sensed data, a gap remains between aerial and field inventories. To close this gap, we propose a new pan-tropical model to predict plot-level forest structure properties and biomass from only the largest trees. Location: Pan-tropical. Time period: Early 21st century. Major taxa studied: Woody plants. Methods: Using a dataset of 867 plots distributed among 118 sites across the tropics, we tested the prediction of the quadratic mean diameter, basal area, Lorey's height, community wood density and aboveground biomass (AGB) from the ith largest trees. Results: Measuring the largest trees in tropical forests enables unbiased predictions of plot- and site-level forest structure. The 20 largest trees per hectare predicted quadratic mean diameter, basal area, Lorey's height, community wood density and AGB with 12, 16, 4, 4 and 17.7% of relative error, respectively. Most of the remaining error in biomass prediction is driven by differences in the proportion of total biomass held in medium-sized trees (50–70 cm diameter at breast height), which shows some continental dependency, with American tropical forests presenting the highest proportion of total biomass in these intermediate-diameter classes relative to other continents. Main conclusions: Our approach provides new information on tropical forest structure and can be used to generate accurate field estimates of tropical forest carbon stocks to support the calibration and validation of current and forthcoming space missions. It will reduce the cost of field inventories and contribute to scientific understanding of tropical forest ecosystems and response to climate change.
- Published
- 2018
38. Structure démographique et répartition spatiale des populations de Sclerocarya birrea (A. Rich.) Hochst. du secteur sahélien du Niger
- Abstract
Cette étude a pour objectif principal d'ana- lyser la structure démographique et la distribution spatiale des populations de Sclerocarya birrea dans les forêts classées de Dan Kada Dodo et de Dan Gado, et dans leurs zones périphériques. La connais- sance de ces paramètres constitue une étape indispensable à leur gestion durable. Un échantillonnage stratifié aléatoire sur la base des trois unités d'occupation du sol identifiées (steppe arborée, parc agrofores- tier, zones agricoles riveraines) a permis la mise en place de placettes d'inventaire de 50 x 20 m. Le diamètre à 1,30 m du sol, la hauteur totale et les deux diamètres per- pendiculaires du houppier des individus de S. birrea ont été mesurés. Pour préciser la répartition spatiale des individus de S. bir- rea, les données ont été collectées par car- tographie des individus sur deux parcelles de 1,96 ha chacune (140 x 140 m) dans les unités " steppe arborée " et " parc agro- forestier ". Les résultats montrent que les individus de S. birrea présentent une répar- tition spatiale aléatoire à agrégée, avec des agrégats de taille variable (environ 7 m et 25 m), en cohérence avec le mode de dis- persion zoochore et barochore des fruits, et la capacité de multiplication végétative de l'espèce. Les plus fortes valeurs de densité (25,2 individus/ha), de surface terrière (1,6 m2/ha) et de hauteur moyenne (6,9 m) ont été obtenues dans les unités des forêts classées. La forme en cloche de la distribution des classes de hauteur et des diamètres des populations traduit une meilleure représentation des classes intermédiaires, par rapport aux classes extrêmes. Par contre, la structure erratique observée dans les " zones agricoles rive- raines " traduit une répartition très irré- gulière dans les classes de diamètre. Les populations de S. birrea requièrent donc une conservation plus efficace qui passera par le développement de stratégies appro- priées en vue de leur restauration.
- Published
- 2017
39. An assessment of a community-based, forest restoration programme in Durban (eThekwini), South Africa
- Abstract
The restoration of degraded forests to enhance biodiversity, ecosystem services, as well as climate change mitigation and adaptation is now a major priority in cities around the world. This study evaluated the success of the Buffelsdraai Landfill Site Community Reforestation Project in Durban, South Africa, by assessing ecological attributes. Measures of plant richness, diversity, vegetation structure, invasive alien plants (IAPs) and ecological processes were contrasted across a chronosequence of habitats under restoration (0-year-old, 3-year-old and 5-year-old) and compared with a reference forest habitat (remnant natural forest). Native tree species recruitment and vegetation structure increased with restoration age. Ecological processes, represented by the composition of pollination and seed dispersal traits in all of the habitats under restoration, were similar to the reference habitat. However, low tree density and an increase in IAP cover with an increase in restoration age were identified as threats to reforestation success. We recommend enrichment planting and an effective IAP management strategy to promote more rapid habitat restoration while reducing site maintenance costs. Enrichment planting should not only focus on increasing tree species density and richness, but also on the inclusion of species with missing pollination and seed dispersal categories.
- Published
- 2017
40. Present-day central African forest is a legacy of the 19th century human history
- Abstract
The populations of light-demanding trees that dominate the canopy of central African forests are now aging. Here, we show that the lack of regeneration of these populations began ca. 165 ya (around 1850) after major anthropogenic disturbances ceased. Since 1885, less itinerancy and disturbance in the forest has occurred because the colonial administrations concentrated people and villages along the primary communication axes. Local populations formerly gardened the forest by creating scattered openings, which were sufficiently large for the establishment of light-demanding trees. Currently, common logging operations do not create suitable openings for the regeneration of these species, whereas deforestation degrades landscapes. Using an interdisciplinary approach, which included paleoecological, archaeological, historical, and dendrological data, we highlight the long-term history of human activities across central African forests and assess the contribution of these activities to present-day forest structure and composition. The conclusions of this sobering analysis present challenges to current silvicultural practices and to those of the future.
- Published
- 2017
41. Nutrient-cycling mechanisms other than the direct absorption from soil may control forest structure and dynamics in poor Amazonian soils
- Abstract
Tropical forests store large amounts of biomass despite they generally grow in nutrient-poor soils, suggesting that the role of soil characteristics in the structure and dynamics of tropical forests is complex. We used data for >34 000 trees from several permanent plots in French Guiana to investigate if soil characteristics could predict the structure (tree diameter, density and aboveground biomass), and dynamics (growth, mortality, aboveground wood productivity) of nutrient-poor tropical forests. Most variables did not covary with site-level changes in soil nutrient content, indicating that nutrient-cycling mechanisms other than the direct absorption from soil (e.g. the nutrient uptake from litter, the resorption, or the storage of nutrients in the biomass), may strongly control forest structure and dynamics. Ecosystem-level adaptations to low soil nutrient availability and long-term low levels of disturbance may help to account for the lower productivity and higher accumulation of biomass in nutrient-poor forests compared to nutrient-richer forests.
- Published
- 2017
42. Structure démographique et répartition spatiale des populations de Sclerocarya birrea (A. Rich.) Hochst. du secteur sahélien du Niger
- Abstract
Cette étude a pour objectif principal d'ana- lyser la structure démographique et la distribution spatiale des populations de Sclerocarya birrea dans les forêts classées de Dan Kada Dodo et de Dan Gado, et dans leurs zones périphériques. La connais- sance de ces paramètres constitue une étape indispensable à leur gestion durable. Un échantillonnage stratifié aléatoire sur la base des trois unités d'occupation du sol identifiées (steppe arborée, parc agrofores- tier, zones agricoles riveraines) a permis la mise en place de placettes d'inventaire de 50 x 20 m. Le diamètre à 1,30 m du sol, la hauteur totale et les deux diamètres per- pendiculaires du houppier des individus de S. birrea ont été mesurés. Pour préciser la répartition spatiale des individus de S. bir- rea, les données ont été collectées par car- tographie des individus sur deux parcelles de 1,96 ha chacune (140 x 140 m) dans les unités " steppe arborée " et " parc agro- forestier ". Les résultats montrent que les individus de S. birrea présentent une répar- tition spatiale aléatoire à agrégée, avec des agrégats de taille variable (environ 7 m et 25 m), en cohérence avec le mode de dis- persion zoochore et barochore des fruits, et la capacité de multiplication végétative de l'espèce. Les plus fortes valeurs de densité (25,2 individus/ha), de surface terrière (1,6 m2/ha) et de hauteur moyenne (6,9 m) ont été obtenues dans les unités des forêts classées. La forme en cloche de la distribution des classes de hauteur et des diamètres des populations traduit une meilleure représentation des classes intermédiaires, par rapport aux classes extrêmes. Par contre, la structure erratique observée dans les " zones agricoles rive- raines " traduit une répartition très irré- gulière dans les classes de diamètre. Les populations de S. birrea requièrent donc une conservation plus efficace qui passera par le développement de stratégies appro- priées en vue de leur restauration.
- Published
- 2017
43. An assessment of a community-based, forest restoration programme in Durban (eThekwini), South Africa
- Abstract
The restoration of degraded forests to enhance biodiversity, ecosystem services, as well as climate change mitigation and adaptation is now a major priority in cities around the world. This study evaluated the success of the Buffelsdraai Landfill Site Community Reforestation Project in Durban, South Africa, by assessing ecological attributes. Measures of plant richness, diversity, vegetation structure, invasive alien plants (IAPs) and ecological processes were contrasted across a chronosequence of habitats under restoration (0-year-old, 3-year-old and 5-year-old) and compared with a reference forest habitat (remnant natural forest). Native tree species recruitment and vegetation structure increased with restoration age. Ecological processes, represented by the composition of pollination and seed dispersal traits in all of the habitats under restoration, were similar to the reference habitat. However, low tree density and an increase in IAP cover with an increase in restoration age were identified as threats to reforestation success. We recommend enrichment planting and an effective IAP management strategy to promote more rapid habitat restoration while reducing site maintenance costs. Enrichment planting should not only focus on increasing tree species density and richness, but also on the inclusion of species with missing pollination and seed dispersal categories.
- Published
- 2017
44. Present-day central African forest is a legacy of the 19th century human history
- Abstract
The populations of light-demanding trees that dominate the canopy of central African forests are now aging. Here, we show that the lack of regeneration of these populations began ca. 165 ya (around 1850) after major anthropogenic disturbances ceased. Since 1885, less itinerancy and disturbance in the forest has occurred because the colonial administrations concentrated people and villages along the primary communication axes. Local populations formerly gardened the forest by creating scattered openings, which were sufficiently large for the establishment of light-demanding trees. Currently, common logging operations do not create suitable openings for the regeneration of these species, whereas deforestation degrades landscapes. Using an interdisciplinary approach, which included paleoecological, archaeological, historical, and dendrological data, we highlight the long-term history of human activities across central African forests and assess the contribution of these activities to present-day forest structure and composition. The conclusions of this sobering analysis present challenges to current silvicultural practices and to those of the future.
- Published
- 2017
45. Nutrient-cycling mechanisms other than the direct absorption from soil may control forest structure and dynamics in poor Amazonian soils
- Abstract
Tropical forests store large amounts of biomass despite they generally grow in nutrient-poor soils, suggesting that the role of soil characteristics in the structure and dynamics of tropical forests is complex. We used data for >34 000 trees from several permanent plots in French Guiana to investigate if soil characteristics could predict the structure (tree diameter, density and aboveground biomass), and dynamics (growth, mortality, aboveground wood productivity) of nutrient-poor tropical forests. Most variables did not covary with site-level changes in soil nutrient content, indicating that nutrient-cycling mechanisms other than the direct absorption from soil (e.g. the nutrient uptake from litter, the resorption, or the storage of nutrients in the biomass), may strongly control forest structure and dynamics. Ecosystem-level adaptations to low soil nutrient availability and long-term low levels of disturbance may help to account for the lower productivity and higher accumulation of biomass in nutrient-poor forests compared to nutrient-richer forests.
- Published
- 2017
46. Present-day central African forest is a legacy of the 19th century human history
- Author
-
Julie Morin-Rivat, Charly Favier, Nicolas Bayol, Adeline Fayolle, Sylvie Gourlet-Fleury, Philippe Lejeune, Hans Beeckman, Laurent Bremond, Jean-Louis Doucet, Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226, Forêts et Sociétés (UPR Forêts et Sociétés), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS)
- Subjects
0106 biological sciences ,Plant Biology ,forêt tropicale ,Forests ,01 natural sciences ,Paléobotanique ,K01 - Foresterie - Considérations générales ,Dynamique des populations ,Human Activities ,Biology (General) ,European colonization ,Silviculture ,tropical forests ,geography.geographical_feature_category ,Ecology ,General Neuroscience ,Logging ,History, 19th Century ,General Medicine ,Old-growth forest ,recent history ,Forêt ,Écosystème forestier ,Medicine ,P01 - Conservation de la nature et ressources foncières ,Research Article ,Human ,010506 paleontology ,Conservation of Natural Resources ,Écologie ,F40 - Écologie végétale ,anthropogenic disturbance ,QH301-705.5 ,Production forestière ,Science ,Aménagement forestier ,Biology ,central Africa ,010603 evolutionary biology ,Abattage d'arbres ,History, 21st Century ,General Biochemistry, Genetics and Molecular Biology ,Deforestation ,Humans ,E50 - Sociologie rurale ,Africa, Central ,Regeneration (ecology) ,Ecosystem ,0105 earth and related environmental sciences ,geography ,Histoire naturelle ,General Immunology and Microbiology ,Land use ,Composition botanique ,Sociologie rurale ,Impact sur l'environnement ,15. Life on land ,Régénération naturelle ,History, 20th Century ,Structure du peuplement ,Déboisement ,K10 - Production forestière ,Disturbance (ecology) ,Secondary forest ,Dendrométrie ,tree regeneration ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology - Abstract
The populations of light-demanding trees that dominate the canopy of central African forests are now aging. Here, we show that the lack of regeneration of these populations began ca. 165 ya (around 1850) after major anthropogenic disturbances ceased. Since 1885, less itinerancy and disturbance in the forest has occurred because the colonial administrations concentrated people and villages along the primary communication axes. Local populations formerly gardened the forest by creating scattered openings, which were sufficiently large for the establishment of light-demanding trees. Currently, common logging operations do not create suitable openings for the regeneration of these species, whereas deforestation degrades landscapes. Using an interdisciplinary approach, which included paleoecological, archaeological, historical, and dendrological data, we highlight the long-term history of human activities across central African forests and assess the contribution of these activities to present-day forest structure and composition. The conclusions of this sobering analysis present challenges to current silvicultural practices and to those of the future. DOI: http://dx.doi.org/10.7554/eLife.20343.001, eLife digest The world’s forests contain trillions of trees. Some of those trees require more light than others to mature, and certain species can only grow to reach the forest canopy if they have access to sunlight throughout their whole life. Central Africa is home to the second largest tropical rainforest in the world. Previous studies showed that few young trees of light-demanding species were growing to replace the old trees in this forest. As a result this population is aging and at risk of disappearing, which is a major concern. Many light-demanding tree species in the Central African forest are cut down for their valuable timber. However, if young trees do not grow to replace the mature ones that are logged, even logging operations that follow national and international environmental rules cannot guarantee the sustainability of these trees. As such, Morin-Rivat et al. set out to understand what changed in the Central African forest in the past to stop the regeneration of the light-demanding trees. The analyses focused on four species classified as light-demanding trees in part of Central Africa called the northern Congo Basin. Most of the trees in these species were about 165 years old. This was the case even though the different species grow at different rates, and it means that they all grew from young trees that settled in the middle of the 19th century. So what was it that changed after this period to stop this population of light-demanding trees in the Central African forest from regenerating? By combining information from a number of datasets and historical records, Morin-Rivat et al. arrived at the following conclusion. Before the mid-19th century, many people lived in the forest and their activities created clearings that turned the forest into a relatively patchy landscape. However from about 1850 onwards, when Europeans started to colonize the region, people and villages were moved out of the forests and closer to rivers and roads for administrative and commercial purposes. Moreover, many people were killed in conflicts or died because of newly introduced diseases, which also led to fewer people in the forest. As a result, the forest became less disturbed. With fewer clearings, fewer light-demanding trees would have had enough access to sunlight to grow to maturity. The findings of Morin-Rivat et al. show that disturbance is needed to maintain certain forest habitats and tree species, including light-demanding species of tree. As common logging operations do not create openings large enough to guarantee that such species will be able to establish themselves naturally, complementary treatments are needed. These might include selectively logging mature trees around young members of light-demanding species, or planting threatened species. DOI: http://dx.doi.org/10.7554/eLife.20343.002
- Published
- 2017
47. Nutrient-cycling mechanisms other than the direct absorption from soil may control forest structure and dynamics in poor Amazonian soils
- Author
-
Mathilde Desprez, Stéphane Guitet, Lilian Blanc, Josep Peñuelas, Christopher Baraloto, Bruno Hérault, Jérôme Chave, Jordi Sardans, Ivan A. Janssens, Aurélie Dourdain, Bruno Ferry, Oriol Grau, Vincent Freycon, Laurent Descroix, Centre de Recerca Ecològica i Aplicacions Forestals (CREAF), Ecole Nationale du Génie Rural, des Eaux et des Forêts (ENGREF), Forêts et Sociétés (Cirad-Es-UPR 105 Forêts et Sociétés), Département Environnements et Sociétés (Cirad-ES), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Evolution et Diversité Biologique (EDB), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), ONF Guyane, Réserve de Montabo, Office National des Forêts (ONF), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), University of Antwerp (UA), Spanish Government projects CGL2013-48074, ANR-10-LABX-25-01, TULIP, ref. ANR-10-LABX-0041)., Forêts et Sociétés (UPR Forêts et Sociétés), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud]), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
0106 biological sciences ,Litière forestière ,010504 meteorology & atmospheric sciences ,[SDV]Life Sciences [q-bio] ,F62 - Physiologie végétale - Croissance et développement ,forêt tropicale ,Forests ,01 natural sciences ,Soil ,Nutrient ,K01 - Foresterie - Considérations générales ,Biomasse ,Dynamique des populations ,Biomass ,Transport des substances nutritives ,Biomass (ecology) ,Multidisciplinary ,Ecology ,Soil chemistry ,F70 - Taxonomie végétale et phytogéographie ,forest ecosystem ,Nutrition des plantes ,Facteur édaphique ,French Guiana ,Productivity (ecology) ,Diamètre ,Seasons ,Engineering sciences. Technology ,Nutrient cycle ,forêt tropicale humide ,Production forestière ,Biology ,010603 evolutionary biology ,complex mixtures ,Article ,tropical rain forests ,Fertilité du sol ,Forest ecology ,Ecosystem ,Croissance ,Plant Physiological Phenomena ,0105 earth and related environmental sciences ,écosystème forestier ,Tropical Climate ,P35 - Fertilité du sol ,15. Life on land ,fertilité chimique ,Structure du peuplement ,F61 - Physiologie végétale - Nutrition ,Soil water ,guyane française ,Plant sciences ,écophysiologie forestière ,Espacement - Abstract
Tropical forests store large amounts of biomass despite they generally grow in nutrient-poor soils, suggesting that the role of soil characteristics in the structure and dynamics of tropical forests is complex. We used data for >34 000 trees from several permanent plots in French Guiana to investigate if soil characteristics could predict the structure (tree diameter, density and aboveground biomass), and dynamics (growth, mortality, aboveground wood productivity) of nutrient-poor tropical forests. Most variables did not covary with site-level changes in soil nutrient content, indicating that nutrient-cycling mechanisms other than the direct absorption from soil (e.g. the nutrient uptake from litter, the resorption, or the storage of nutrients in the biomass), may strongly control forest structure and dynamics. Ecosystem-level adaptations to low soil nutrient availability and long-term low levels of disturbance may help to account for the lower productivity and higher accumulation of biomass in nutrient-poor forests compared to nutrient-richer forests.
- Published
- 2017
48. The inland water fishes of Africa : diversity, ecology and human use
- Author
-
Fabrice Duponchelle, Christian Levêque, Jos Snoeks, Yves Fermon, Paugy, Didier (ed.), Lévêque, Christian (ed.), and Otero, O. (ed.)
- Subjects
MILIEU LACUSTRE ,STRUCTURE DU PEUPLEMENT ,OXYGENE ,ESPECE DEMERSALE ,SUBSTRAT ,Oceanography ,East African Rift ,THERMOCLINE ,%22">Fish ,PROFONDEUR ,ESPECE PELAGIQUE ,CONTRAINTE ,Geology ,FAUNE ICHTYOLOGIQUE - Published
- 2017
49. The inland water fishes of Africa : diversity, ecology and human use
- Author
-
Christian Levêque, Didier Paugy, Paugy, Didier (ed.), Lévêque, Christian (ed.), and Otero, O. (ed.)
- Subjects
Biotope ,EAU CONTINENTALE ,VARIATION SAISONNIERE ,BIOMASSE ,STRUCTURE DU PEUPLEMENT ,Biology ,PLAINE INONDABLE ,DEBIT ,Fishery ,BIOTOPE ,COURS D'EAU ,ESTIMATION ,%22">Fish ,ZONATION ECOLOGIQUE ,FAUNE ICHTYOLOGIQUE - Published
- 2017
50. Fish communities in shallow lakes
- Author
-
Christian Levêque, Paugy, Didier (ed.), Lévêque, Christian (ed.), and Otero, O. (ed.)
- Subjects
Fishery ,MILIEU LACUSTRE ,FLUCTUATION ,NIVEAU DE L'EAU ,STRUCTURE DU PEUPLEMENT ,ZONE COTIERE ,%22">Fish ,Biology ,FAUNE ICHTYOLOGIQUE - Published
- 2017
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