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Sébastien Larrue - One of the best experts on this subject based on the ideXlab platform.

  • Distribution, abundance and photosynthetic characteristics of the invasive tree Spathodea campanulata on the island of Tahiti (South Pacific Ocean)
    2015
    Co-Authors: Sébastien Larrue, Robin Pouteau, Jeanyves Meyer, Curtis C. Daehler, Olivier Voldoire
    Abstract:

    Successful invasion is often a combination of species characteristics (or invasiveness) and habitat suitability (or invasibility). Our objective was to identify preferred habitats and suitable environmental conditions for the African tulip tree Spathodea campanulata (Bignoniaceae), one of the most invasive alien tree in the tropical island of Tahiti (South Pacific Ocean), in relation with its photosynthesis capacity. Spathodea abundance and leaf Chlorophyll fluorescence was examined in relation to topography and micro-climate along an elevational transect between 140 m and 1,300 m. Results show that Spathodea is (1) present up to 1,240 m where the mean daily temperature is 14.7°C, (2) is able to colonize slopes of more than 45°, (3) is over-represented in the elevational range 140-540 m as well as in the less disturbed forests found between 940 m and 1,040 m, suggesting a high threat for indigenous and endemic plants. Between 541-840 m Spathodea is under-represented supporting that this range is a non-preferred environment probably due to micro-climate conditions with punctual extreme events in temperature and air dryness. Major infestations on the island of Tahiti was recently reported on the leeward (drier) west coast, but Spathodea has also been recently found on the slopes of the windward (wetter) east coast. Chlorophyll fluorescence measurements indicate a high photosynthetic capacity among Spathodea in wet environments from sea level up to high elevations, suggesting that Spathodea will become an abundant invader on most of the island of Tahiti. Lien poster : http://geolab.univ-bpclermont.fr/IMG/png/poster_emapi_5.png

  • using range filling rather than prevalence of invasive plant species for management prioritisation the case of Spathodea campanulata in the society islands south pacific
    Ecological Indicators, 2015
    Co-Authors: Robin Pouteau, Jeanyves Meyer, Sébastien Larrue
    Abstract:

    Biological invasion science lacks standardised measures of invasion success that would provide effective prioritisation of invasive species and invaded areas management. Prevalence (area of occupancy) of invasive species is often used as proxy of their success but this metric ignores the extent to which a species fills its potential distribution. This study aims to estimate the performance of invasive tree species by computing the ratio between the compressed canopy area (CCA), assessed through remote sensing, and their potential distribution, estimated using invasive species distribution modelling. This index of ‘range filling’ (RF) has applicability to a broad set of invasive plant species in any biome. A case study is provided using the invasive African tulip tree Spathodea campanulata (Bignoniaceae) on three small tropical oceanic islands (South Pacific) exhibiting different invasion levels to test for differences between CCA and RF. The results show that the RF of Spathodea campanulata varied within islands depending on elevation but not proportionally to the CCA of the species. Another key result was that the RF of the species and its CCA provided different between-island perspectives on the invasions and lead to distinct ranking among islands to prioritise for management. Therefore, managers should disregard species’ prevalence as a measure of success and rather weight it with potential distribution to quantify how an invader is performing in a given environment.

  • Using range filling rather than prevalence of invasive plant species for management prioritisation: the case of Spathodea campanulata in the Society Islands (South Pacific)
    Ecological Indicators, 2015
    Co-Authors: Robin Pouteau, Jeanyves Meyer, Sébastien Larrue
    Abstract:

    Biological invasion science lacks standardised measures of invasion success that would provide effective prioritisation of invasive species and invaded areas management. Area of occupancy of invasive species is often used as proxy of their success but this metric ignores the extent to which a species fills its potential distribution. This study aims to estimate the performance of invasive tree species by computing the ratio between the compressed canopy area (CCA), assessed through remote sensing, and their potential distribution, estimated using invasive species distribution modelling. This index of ‘range filling’ (RF) has applicability to a broad set of invasive plant species in any biome. A case study is provided using the invasive African tulip tree Spathodea campanulata (Bignoniaceae) on three small tropical oceanic islands of French Polynesia (South Pacific Ocean) exhibiting different invasion levels to test for differences between CCA and RF. The results show that the RF of Spathodea campanulata varied within islands depending on elevation but not proportionally to the CCA of the species. Another key result was that the RF of the species and its CCA provided different between-island perspectives on the invasions and leaded to distinct ranking among islands to prioritise for management. Therefore, managers should disregard species’ area of occupancy as a measure of success and rather weight it with potential distribution to quantify how an invader is performing in a given environment.

  • Forest Invasion by the African tulip tree (Spathodea campanulata) in the Hawaiian Islands: Are Seedlings Shade-Tolerant?
    Pacific Science, 2014
    Co-Authors: Sébastien Larrue, Curtis C. Daehler, Franck Vautier, Jennifer L. Bufford
    Abstract:

    Native to West Africa, Spathodea campanulata (African tulip tree) is frequently viewed as a shade-intolerant invader. It commonly colonizes roadsides, human-disturbed forests and abandoned agricultural land in tropical islands, where it can then become dominant in secondary forests. Some authors have suggested that the seedlings may be shade-tolerant and able to establish in closed forest, but the shade tolerance of seedlings has never been evaluated. We identified tolerated light environments of S. campanulata seedlings in wet forests in Hawaii by measuring photosynthetically active radiation (PAR) around naturally occurring seedlings (< 30 cm height) in the field. We also measured photosynthetic responses of seedlings to light under field and lab conditions, and determined seedling growth rates in sun and shade. Seedlings were found in shaded conditions in the field, and they consistently had positive net carbon gain at 50 µmol photons m-2·s-1 PAR, with an estimated mean compensation point below 10 µmol photons m-2·s-1, indicating high shade tolerance. The most frequent midday light environments of S. campanulata seedlings in the field were in the range around 50 to 200 µmol photons m-2·s-1 PAR, i.e., 2.5% to 10% of full sunlight. Among seedlings found growing in shade, minimum saturating light (Ek), determined from chlorophyll fluorescence, averaged 260 µmol photons m-2·s-1, suggesting that seedling maximum photosynthesis can occur at less than 13% of full sun. Growth rates of young seedlings in shade and sun were comparable. Widespread wind dispersal of seeds, seedling tolerance of low light, and our observations of some S. campanulata saplings establishing in rainforest without recent disturbance suggest that S. campanulata will be a persistent component of Hawaiian lowland rainforests.

Jean-marc Boffa - One of the best experts on this subject based on the ideXlab platform.

  • le drageonnage pour la regeneration d especes medicinales en afrique tropicale cas du Spathodea campanulata en ouganda
    VertigO - la revue électronique en sciences de l'environnement, 2006
    Co-Authors: Meunier Quentin, Ronald Bellefontaine, Jean-marc Boffa
    Abstract:

    En Afrique, depuis plus d’un demi siecle, les formations arborees, denses ou claires, sont fortement sollicitees pour leur valeur commerciale ou medicinale et par la recherche perpetuelle de nouveaux espaces pour l’agriculture et l’elevage. De nombreuses especes ligneuses en Afrique equatoriale et tropicale disparaissent des systemes agro-pastoraux et forestiers, consequence d’une forte exploitation et d’une regeneration naturelle peu efficace. En Ouganda, et particulierement dans les zones habitees du sud-ouest du pays, la situation s’aggrave tres rapidement et il devient necessaire de regenerer ces ecosystemes si l’on veut que les conditions socio-economiques n’empirent pas. La maitrise de la multiplication vegetative a faible cout par induction du drageonnage semblerait apporter une reelle alternative a la regeneration des essences recherchees par les populations locales. Les observations sont faites en Ouganda, sur plusieurs Spathodea campanulata, dont le systeme racinaire a ete endommage. Apres avoir observe les reactions physiologiques induites par ce stress au niveau des racines, on constate que le sectionnement complet d’une racine engendre toujours la neoformation d’un ou plusieurs drageons exclusivement sur la partie de la racine deconnectee de l’arbre mere. La partie connectee se stabilise ou produit de nouvelles racines et les blessures superficielles ou profondes sur des racines a l’air libre ou sous terre n’engendrent pas d’organogenese (ni radicelle, ni drageon). On observe dans ce cas la formation d’un cal cicatriciel. Le developpement durable passe necessairement par la regeneration a faible cout des ressources ligneuses dont les populations souvent demunies de l’essentiel ont besoin pour lutter contre les maladies et augmenter leurs revenus par la commercialisation de produits forestiers non ligneux. Ces observations confirment qu’il est possible d’initier l’apparition de drageons lors d’inductions artificielles. Il est souhaitable a l’avenir d’entreprendre des etudes de cas d’especes differentes.

  • Le drageonnage pour la regénération d’espèces médicinales en Afrique tropicale : cas du Spathodea campanulata en Ouganda
    Éditions en environnement VertigO, 2006
    Co-Authors: Meunier Quentin, Ronald Bellefontaine, Jean-marc Boffa
    Abstract:

    In Africa since more than one half century, deciduous forests and open woodlands are seriously harvested for their commercial value and/or for medicinal purposes, and also for the continual research of new lands for agriculture or livestock. Many woody species are disappearing in agricultural and forest systems of Equatorial and Tropical Africa, due to harvesting practices and low natural regeneration. In Uganda, and particularly in the south-western habited zones of the country, the situation is getting worse very rapidly and it is urgent to regenerate these ecosystems before the socio-economical condition deteriorates too much. Vegetative propagation techniques at low cost, such as the root sucker induction method, can provide alternatives for a sustainable regeneration of species required by local populations. Observations were made in Uganda on Spathodea campanulata, for which root systems have been damaged by human activities. We observed physiological reactions on stressed roots. The total severance of a root always induced neo-formation of one or several root suckers on the distal part of the root section (root disconnected from the mother tree). Proximal parts of the roots stabilized or created new roots. Superficial or deep injuries on earthed or unearthed roots did not produce any roots or root suckers. In such cases, we observed the formation of callosity covering the injury. Sustainable development depends necessary on the regeneration at low cost of the woody resources. These poor populations, who don’t even have the essential, need these resources in order to combat disease and increase the incomes by the commercialisation of non woody forest products. This study confirms that artificial induction may lead to root sucker development and thus control the propagation of the species. Through similar case studies and species-based observations, such vegetative propagation methods can be replicated and transferred to threatened woody species in Tropical Africa

Robin Pouteau - One of the best experts on this subject based on the ideXlab platform.

  • Distribution, abundance and photosynthetic characteristics of the invasive tree Spathodea campanulata on the island of Tahiti (South Pacific Ocean)
    2015
    Co-Authors: Sébastien Larrue, Robin Pouteau, Jeanyves Meyer, Curtis C. Daehler, Olivier Voldoire
    Abstract:

    Successful invasion is often a combination of species characteristics (or invasiveness) and habitat suitability (or invasibility). Our objective was to identify preferred habitats and suitable environmental conditions for the African tulip tree Spathodea campanulata (Bignoniaceae), one of the most invasive alien tree in the tropical island of Tahiti (South Pacific Ocean), in relation with its photosynthesis capacity. Spathodea abundance and leaf Chlorophyll fluorescence was examined in relation to topography and micro-climate along an elevational transect between 140 m and 1,300 m. Results show that Spathodea is (1) present up to 1,240 m where the mean daily temperature is 14.7°C, (2) is able to colonize slopes of more than 45°, (3) is over-represented in the elevational range 140-540 m as well as in the less disturbed forests found between 940 m and 1,040 m, suggesting a high threat for indigenous and endemic plants. Between 541-840 m Spathodea is under-represented supporting that this range is a non-preferred environment probably due to micro-climate conditions with punctual extreme events in temperature and air dryness. Major infestations on the island of Tahiti was recently reported on the leeward (drier) west coast, but Spathodea has also been recently found on the slopes of the windward (wetter) east coast. Chlorophyll fluorescence measurements indicate a high photosynthetic capacity among Spathodea in wet environments from sea level up to high elevations, suggesting that Spathodea will become an abundant invader on most of the island of Tahiti. Lien poster : http://geolab.univ-bpclermont.fr/IMG/png/poster_emapi_5.png

  • using range filling rather than prevalence of invasive plant species for management prioritisation the case of Spathodea campanulata in the society islands south pacific
    Ecological Indicators, 2015
    Co-Authors: Robin Pouteau, Jeanyves Meyer, Sébastien Larrue
    Abstract:

    Biological invasion science lacks standardised measures of invasion success that would provide effective prioritisation of invasive species and invaded areas management. Prevalence (area of occupancy) of invasive species is often used as proxy of their success but this metric ignores the extent to which a species fills its potential distribution. This study aims to estimate the performance of invasive tree species by computing the ratio between the compressed canopy area (CCA), assessed through remote sensing, and their potential distribution, estimated using invasive species distribution modelling. This index of ‘range filling’ (RF) has applicability to a broad set of invasive plant species in any biome. A case study is provided using the invasive African tulip tree Spathodea campanulata (Bignoniaceae) on three small tropical oceanic islands (South Pacific) exhibiting different invasion levels to test for differences between CCA and RF. The results show that the RF of Spathodea campanulata varied within islands depending on elevation but not proportionally to the CCA of the species. Another key result was that the RF of the species and its CCA provided different between-island perspectives on the invasions and lead to distinct ranking among islands to prioritise for management. Therefore, managers should disregard species’ prevalence as a measure of success and rather weight it with potential distribution to quantify how an invader is performing in a given environment.

  • using range filling rather than prevalence of invasive plant species for management prioritisation the case of Spathodea campanulata in the
    2015
    Co-Authors: Robin Pouteau, Jeanyves Meyer
    Abstract:

    a b s t r a c t Biological invasion science lacks standardised measures of invasion success that would provide effective prioritisation of invasive species and invaded areas management. Prevalence (area of occupancy) of inva- sive species is often used as proxy of their success but this metric ignores the extent to which a species fills its potential distribution. This study aims to estimate the performance of invasive tree species by computing the ratio between the compressed canopy area (CCA), assessed through remote sensing, and their potential distribution, estimated using invasive species distribution modelling. This index of 'range filling' (RF) has applicability to a broad set of invasive plant species in any biome. A case study is pro- vided using the invasive African tulip tree Spathodea campanulata (Bignoniaceae) on three small tropical oceanic islands (South Pacific) exhibiting different invasion levels to test for differences between CCA and RF. The results show that the RF of Spathodea campanulata varied within islands depending on ele- vation but not proportionally to the CCA of the species. Another key result was that the RF of the species and its CCA provided different between-island perspectives on the invasions and lead to distinct ranking among islands to prioritise for management. Therefore, managers should disregard species' prevalence as a measure of success and rather weight it with potential distribution to quantify how an invader is performing in a given environment. © 2015 Published by Elsevier Ltd.

  • Using range filling rather than prevalence of invasive plant species for management prioritisation: the case of Spathodea campanulata in the Society Islands (South Pacific)
    Ecological Indicators, 2015
    Co-Authors: Robin Pouteau, Jeanyves Meyer, Sébastien Larrue
    Abstract:

    Biological invasion science lacks standardised measures of invasion success that would provide effective prioritisation of invasive species and invaded areas management. Area of occupancy of invasive species is often used as proxy of their success but this metric ignores the extent to which a species fills its potential distribution. This study aims to estimate the performance of invasive tree species by computing the ratio between the compressed canopy area (CCA), assessed through remote sensing, and their potential distribution, estimated using invasive species distribution modelling. This index of ‘range filling’ (RF) has applicability to a broad set of invasive plant species in any biome. A case study is provided using the invasive African tulip tree Spathodea campanulata (Bignoniaceae) on three small tropical oceanic islands of French Polynesia (South Pacific Ocean) exhibiting different invasion levels to test for differences between CCA and RF. The results show that the RF of Spathodea campanulata varied within islands depending on elevation but not proportionally to the CCA of the species. Another key result was that the RF of the species and its CCA provided different between-island perspectives on the invasions and leaded to distinct ranking among islands to prioritise for management. Therefore, managers should disregard species’ area of occupancy as a measure of success and rather weight it with potential distribution to quantify how an invader is performing in a given environment.

Luz Elena A Avilacalderon - One of the best experts on this subject based on the ideXlab platform.

  • caracteristicas higroscopicas de las maderas Spathodea campanulata fraxinus americana y albizia plurijuga impregnadas con boro
    CIENCIA UNEMI, 2021
    Co-Authors: Javier Ramon Sotomayorcastellanos, Luz Elena A Avilacalderon
    Abstract:

    El objetivo de la investigacion fue evaluar si el impregnado de la madera con sales de boro reduce su higroscopicidad y mejora su estabilidad dimensional. En probetas de pequenas dimensiones de madera de Spathodea campanulata, Fraxinus americana y Albizia plurijuga se aplico un tratamiento caliente-frio de sales de boro con una concentracion de 3%. Se realizaron pruebas de higroscopia y tanto antes como despues del impregnado con sales de boro, se analizo la densidad basica, contenido de humedad, higroexpansiones radial, tangencial, longitudinal y volumetrica, puntos de saturacion de la fibra, coeficientes de higroexpansion, indice de antiexpansion y relacion de anisotropia. Despues del bano, las caracteristicas higroscopicas se modificaron segun las especies y las direcciones observadas. El tratamiento mejora la estabilidad dimensional de S. campanulata en 63%, de F. americana en 21% y para A. plurijuga en 18%. Es recomendable investigar la influencia de las caracteristicas anatomicas sobre las propiedades higroscopicas de estas especies.

  • retencion y penetracion de sales de boro en tres maderas angiospermas Spathodea campanulata fraxinus americana y albizia plurijuga
    Revista Ciencia y Tecnología, 2019
    Co-Authors: Javier Ramon Sotomayorcastellanos, Luz Elena A Avilacalderon
    Abstract:

    espanolLa impregnacion con sales de boro es una alternativa tecnologica para la proteccion de la madera al biodeterioro. El objetivo de la investigacion fue determinar la densidad de la madera, la retencion y la penetracion de sales de boro en la madera de tres especies angiospermas: Spathodea campanulata, Fraxinus americana y Albizia plurijuga. Con el metodo bano caliente-frio, se impregnaron probetas de pequenas dimensiones en concentraciones de 1%, 2% y 3% de trihidroxido de boro y tetraborato de sodio, y se reservo un grupo de control sin tratamiento. Despues de la impregnacion, las densidades de S. campanulata y A. plurijuga no variaron para las diferentes concentraciones. En cambio, la densidad del grupo de control de F. americana fue diferente a las de las concentraciones de 1%, 2% y 3%. Las cantidades de las retenciones y de las penetraciones de las sales fueron diferentes para cada especie. La retencion de sales de boro en las tres maderas disminuye a medida que su densidad y la concentracion de sales se incrementan. EnglishThe impregnation with boron salts is a technological alternative for the protection of wood to biodeterioration. The objective of the research was to determine the density of the wood, the retention and the penetration of boron salts in the wood of three angiosperm species: Spathodea campanulata, Fraxinus americana and Albizia plurijuga. Small specimens were impregnated with the hot-cold bath method and concentrations of 1%, 2% and 3% of boron trioxide and sodium tetraborate, and a control group was reserved without treatment. After impregnation, the densities of S. campanulata and A. plurijuga did not vary for the different concentrations. Different case was the density of the control group of F. americana whose density was different from the concentrations of 1%, 2% and 3%. The amounts of the retentions and the penetrations of the salts were different for each species. The retention of boron salts in the three woods decreases as their density and salt concentration increase

Adam Daigneault - One of the best experts on this subject based on the ideXlab platform.

  • cost benefit analysis of managing the invasive african tulip tree Spathodea campanulata in the pacific
    Environmental Science & Policy, 2014
    Co-Authors: Philip H Brown, Adam Daigneault
    Abstract:

    Abstract Invasive alien species such as Spathodea campanulata (African tulip tree) threaten biodiversity in the Pacific islands as well as the economic, social, and cultural wellbeing of Pacific peoples. Despite the potential magnitude of these threats, our scientific understanding of the ecology and management of the African tulip tree is nascent. In this paper, we use data from novel surveys of households and communities to document the direct and direct impacts of African tulip tree in Fiji, focusing on those impacts which may be monetised. We use the same data to describe current management approaches and then describe a state-of-the-science, “integrated” management approach that employs different strategies for trees of different ages and sizes. These two approaches are then compared in a comprehensive cost–benefit analysis. We find strong arguments for pursuing the integrated management approach, which derives monetised benefits of $3.7 for each $1 spent. However, the less costly current approach is also strictly preferred to the baseline, “do nothing” approach, with monetised benefits of $2.7 for each $1 spent. Results of this analysis clearly show that managing African tulip tree is cost effective, even without explicitly considering biodiversity, culture, and other non-monetised benefits of control.