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Demography of a savanna palm tree : predictions from comprehensive spatial pattern analyses / Sébastien Barot (1999)

Public Citation est un tiré à part de 80 - 1999 (Ecology) Titre : Demography of a savanna palm tree : predictions from comprehensive spatial pattern analyses Type de document : Tiré à part de revue Auteurs : Sébastien Barot ; J. Gignoux ; J.C. Menaut Année de publication : 1999 Importance : 1987-2005 Langues : Français (fre) Catégories : [CBNPMP-Thématique] Démographie Résumé : Existing statistical methods for spatial pattern analysis now permit precise analyses of patterns and, given the appropriate interpretation keys, the formulation of testable hypotheses about the underlying processes. From a comprehensive analysis of the spatial pattern of a plant population and its environment, we infer scenarios of links between demographic processes, plant spatial patterns, and environmental heterogeneity. The palm tree Borassus aethiopum has easily identifiable demographic stages, a root foraging strategy enabling adults to reach distant nutrient sources, and a marked senescence starting with the onset of reproduction. We analyzed map data for palm individuals (in three different life history stages plus two sexes for adults) and for nutrient-rich patches (clumps of other tree species and termite mounds) in three vegetation types (facies) of a humid savanna of West Africa (Lamto, Ivory Coast). Spatial analyses were based on Diggle’s nearest neighbor functions F and G and on Ripley’s K function. The main results were as follows: (1) juveniles and seedlings are aggregated, while adults have a random pattern or are more loosely aggregated; (2) all stages except female adults are spatially associated with nutrient-rich patches, but association distances increase with stage in the life cycle; and (3) seedlings are associated with female adults, whereas the association of juveniles at longer distances is not clear-cut. We propose from these results a parsimonious scenario linking spatial pattern and mortality pattern during the life cycle. The initial pattern of seedlings (close to maternal trees) results from low dispersal distance. Later stages (older seedlings and juveniles) are mostly restricted to nutrient-rich patches through nutrient shortage away from these patches (environment-induced mortality) and form dense clumps of immature palms. Competition on nutrient-rich patches then favors the few juveniles that manage to survive farther from these patches (density-dependent mortality). Finally, the last surviving juvenile of a clump suddenly experiences almost no competition with conspecifics, due to the long distance between clumps of juveniles, and owing to its root-foraging ability, it can now recruit to the adult stage, subject only to senescence. Pattern variations among savanna facies are consistent with this scenario. Lien pérenne : DOI : 10.1890/0012-9658(1999)080[1987:DOASPT]2.0.CO;2 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=130119 Barot, Sébastien, Gignoux, J., Menaut, J.C. 1999 Demography of a savanna palm tree : predictions from comprehensive spatial pattern analyses. Ecology, 80 : 1987-2005.

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
7838	Barot S.	Tiré à part	Centre de documentation	Tirés à part	Consultable

Interactions entre répartition spatiale, hétérogénéité environnementale, et démographie : cas du palmier Rônier dans une savane humide de Côte d'Ivoire. / Sébastien Barot (1999)

Public Citation Titre : Interactions entre répartition spatiale, hétérogénéité environnementale, et démographie : cas du palmier Rônier dans une savane humide de Côte d'Ivoire. Type de document : Imprimé Auteurs : Sébastien Barot ; Université Paris 6 Année de publication : 1999 Importance : 333 p. Langues : Français (fre) Catégories : [CBNPMP-Thématique] Structures des populations végétales [CBNPMP-Thématique] Démographie [CBNPMP-Thématique] Dynamique démographique, sélection [CBNPMP-Thématique] Forme de vie et structure de la population végétale [CBNPMP-Thématique] Relations et interactions individus-milieux [CBNPMP-Thématique] Relations et interactions individus de la même espèce [CBNPMP-Thématique] Cytogénétique [CBNPMP-Thématique] Régime et stratégie de reproduction (allogamie, autogamie, apomixie, reproduction asexué) [CBNPMP-Thématique] Nutrition minérale [CBNPMP-Géographique] Côte d'Ivoire Mots-clés : Borassus aethiopum Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=76042 Barot, Sébastien, Université Paris 6 , 1999. Interactions entre répartition spatiale, hétérogénéité environnementale, et démographie : cas du palmier Rônier dans une savane humide de Côte d'Ivoire. , . 333 pp.

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
7327	8400	Thèse et mémoire	Centre de documentation	Bibliothèque	Consultable

Plant–soil synchrony in nutrient cycles: Learning from ecosystems to design sustainable agrosystems / Sébastien Fontaine in Global Change Biology, 30 (1) (2024) 

Public Citation [article]  inGlobal Change Biology > 30 (1) (2024) . - e17034 Titre : Plant–soil synchrony in nutrient cycles: Learning from ecosystems to design sustainable agrosystems Type de document : Imprimé Auteurs : Sébastien Fontaine ; Luc Abbadie ; Michaël Aubert ; Sébastien Barot ; Juliette Bloor ; Delphine Derrien ; Olivier Dechenne ; Nicolas Gross ; Ludovic Henneron ; Xavier Le Roux (1967-) ; Nicolas Loeuille ; Jennifer Michel ; Sylvie Recous ; Daniel Wipf ; Gaël Alvarez Année de publication : 2024 Article en page(s) : e17034 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Agroécologie [CBNPMP-Thématique] Restauration des écosystèmes Résumé : Redesigning agrosystems to include more ecological regulations can help feed a growing human population, preserve soils for future productivity, limit dependency on synthetic fertilizers, and reduce agriculture contribution to global changes such as eutrophication and warming. However, guidelines for redesigning cropping systems from natural systems to make them more sustainable remain limited. Synthetizing the knowledge on biogeochemical cycles in natural ecosystems, we outline four ecological systems that synchronize the supply of soluble nutrients by soil biota with the fluctuating nutrient demand of plants. This synchrony limits deficiencies and excesses of soluble nutrients, which usually penalize both production and regulating services of agrosystems such as nutrient retention and soil carbon storage. In the ecological systems outlined, synchrony emerges from plant–soil and plant–plant interactions, eco-physiological processes, soil physicochemical processes, and the dynamics of various nutrient reservoirs, including soil organic matter, soil minerals, atmosphere, and a common market. We discuss the relative importance of these ecological systems in regulating nutrient cycles depending on the pedoclimatic context and on the functional diversity of plants and microbes. We offer ideas about how these systems could be stimulated within agrosystems to improve their sustainability. A review of the latest advances in agronomy shows that some of the practices suggested to promote synchrony (e.g., reduced tillage, rotation with perennial plant cover, crop diversification) have already been tested and shown to be effective in reducing nutrient losses, fertilizer use, and N2O emissions and/or improving biomass production and soil carbon storage. Our framework also highlights new management strategies and defines the conditions for the success of these nature-based practices allowing for site-specific modifications. This new synthetized knowledge should help practitioners to improve the long-term productivity of agrosystems while reducing the negative impact of agriculture on the environment and the climate. Lien pérenne : DOI : 10.1111/gcb.17034 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=152220 Fontaine, Sébastien, Abbadie, Luc, Aubert, Michaël, Barot, Sébastien, Bloor, Juliette, Derrien, Delphine, Dechenne, Olivier, Gross, Nicolas, Henneron, Ludovic, Le Roux, Xavier (1967-), Loeuille, Nicolas, Michel, Jennifer, Recous, Sylvie, Wipf, Daniel, Alvarez, Gaël 2024 Plant–soil synchrony in nutrient cycles: Learning from ecosystems to design sustainable agrosystems. Global Change Biology, 30(1): e17034.

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Consultable Article (2024) URL

Seed shadows, survival and recruitement : how simple mechanisms lead to dynamics of population recruitment curves / Sébastien Barot (1999)

Public Citation est un tiré à part de 84 - 1999 (Oikos) Titre : Seed shadows, survival and recruitement : how simple mechanisms lead to dynamics of population recruitment curves Type de document : Tiré à part de revue Auteurs : Sébastien Barot ; J. Gignoux ; J.C. Menaut Année de publication : 1999 Importance : 320-330 Langues : Français (fre) Catégories : [CBNPMP-Thématique] Démographie, écologie des populations (dynamique des populations, démécologie) [CBNPMP-Thématique] Dynamique démographique, sélection Lien pérenne : DOI : 10.2307/3546449 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=130118 Barot, Sébastien, Gignoux, J., Menaut, J.C. 1999 Seed shadows, survival and recruitement : how simple mechanisms lead to dynamics of population recruitment curves. Oikos, 84 : 320-330.

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
7837	Barot S.	Tiré à part	Centre de documentation	Tirés à part	Consultable