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Auteur Johan van Valkenburg |
Documents disponibles écrits par cet auteur (5)
trié(s) par (Pertinence décroissant(e), Titre croissant(e)) Affiner la rechercheLandoltia punctata (G. Mey.) D.H. Les & D.J. Crawford (dotted duckweed), a new record for The Netherlands / Johan van Valkenburg in Gorteria, vol. 33 (Années 2007-2008)
Titre : Landoltia punctata (G. Mey.) D.H. Les & D.J. Crawford (dotted duckweed), a new record for The Netherlands Type de document : texte imprimé Auteurs : Johan van Valkenburg, Auteur ; Roelf Pot, Auteur Année de publication : 2008 Article en page(s) : pp. 41-49 Langues : Néerlandais (nla) Catégories : [ZG] Pays-Bas Mots-clés : Landoltia punctata illustration description Résumé : "Landoltia punctata, native to Australia and SE Asia, was first recorded in The Netherlands in 2007. The species can be recognized by the narrowly egg-shaped to slightly kidney-shaped fronds, with one or three curved nerves. The ventral side if often purplish-red, especially at the margin. The fronds have more than one, but always relatively few roots. The species was often encountered as contamination in water tanks at garden centres and pet shops selling aquarium plants. It is very plausible that Landoltia punctata has been introduced as a contamination with aquarium plants from South-East Asia. In Europe the number of recent records is low and some were only temporary. It is not very likely that the species will be a nuisance to water management in The Netherlands. Its ecology hardly differs from other indigenous duckweed species and the risk of replacement of a native species is very low." (source : auteurs) Type de publication : périodique Référence biblio : van Valkenburg J., Pot R., 2008 - Landoltia punctata (G. Mey.) D.H. Les & D.J. Crawford (dotted duckweed), a new record for The Netherlands. Gorteria, 33 : 41-49. ID PMB : 69812 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=69812
in Gorteria > vol. 33 (Années 2007-2008) . - pp. 41-49[article]Exemplaires(0)
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Titre : Monographs on invasive plants in Europe N° 5 : Ambrosia trifida L. Type de document : texte imprimé Auteurs : Bruno Chauvel, Auteur ; Guillaume Fried, Auteur ; Swen Follak, Auteur ; Daniel Chapman, Auteur ; Yuliana Kulakova, Auteur ; Thomas Le Bourgeois, Auteur ; Dragana Marisavljevic, Auteur ; Arnaud Monty, Auteur ; Jean-Pierre Rossi, Auteur ; Uwe Starfinger, Auteur ; Rob Tanner, Auteur ; Xavier Tassus, Auteur ; Johan van Valkenburg, Auteur ; Emilie Regnier, Auteur Année de publication : 2021 Article en page(s) : pp. 167-190 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Ambrosia trifida L.
[ZG] EuropeMots-clés : plante invasive Résumé : "Ambrosia trifida L. (giant ragweed, Asteraceae) is native to the North American continent and was introduced into Europe and Asia at the end of the 19th century. In its native range, this tall annual species is common in riparian and ruderal habitats and is also a major weed in annual cropping systems. For nearly a century, A. trifida has also been of great concern in the U.5. for its highly allergenic pollen, necessitating targeted control measures to reduce its impact on human populations.
Based on the distribution of A. trifida in North America and in its introduced range, riparian systems in the rest of the world may be particularly at risk to invasion, with potential negative consequences for their biodiversity. Currently, A. trifida has invaded Asia more widely than Europe, Iikely due to the more favourable local conditions in Asia. Throughout its introduced range, A. trifida is host to a Iimited number of invertebrates and pathogens and only a few biological agents are available for its control. The main impacts of A. trifida at a globallevel are on crop yield and human health, resulting in significant socio-economic impacts. The success of A. trifida invasion in areas in which it has been introduced is still undear, but dimate change may increase dimate suitability, increasing the potential for A. trifida to spread. While effective management in cultivated fields seems potentially possible, the development and control of A. trifida in natural riparian habitats is of great concern due to the difficulty of management in these areas." (source : auteurs)Type de publication : périodique Référence biblio : Chauvel B., Fried G., Follak S., Chapman D., Kulakova Y., Le Bourgeois T., Marisavljevic D., Monty A., Rossi J.-P., Starfinger U., Tanner R., Tassus X., van Valkenburg J., Regnier E., 2022 - Monographs on invasive plants in Europe N° 5 : Ambrosia trifida L. Botany letters, 169 (2) : 167-190. ID PMB : 70319 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=70319
in Botany letters > vol. 168, n°2 (Année 2021) . - pp. 167-190[article]Titre suivantExemplaires(1)
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Titre : Myriophyllum rubricaule sp. nov., a M. aquaticum look-alike only known in cultivation Type de document : texte imprimé Auteurs : Johan van Valkenburg, Auteur ; Leni Duister, Auteur ; Edu Boer, Auteur ; Tom M. Raaymaker, Auteur Année de publication : 2022 Article en page(s) : 15 p. Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Myriophyllum
[Espèces (in biblio)] Myriophyllum aquaticum
[Thèmes] TaxonomieMots-clés : espèce végétale invasive plante horticole Résumé : "A confusingly labeled water-milfoil of obscure status, known only in cultivation, is here formally described as a new species, Myriophyllum rubricaule Valk. & Duist. sp. nov. This species has fully replaced M. aquaticum in the horticultural trade in Europe since the addition of M. aquaticum to the list of invasive alien species of Union concern (EU regulation no. 1143/2014) in 2016. This manuscript provides a morphological description of M. rubricaule sp. nov., and its distinction from M. aquaticum is further supported by molecular data (chloroplast and nuclear loci)." (source : auteurs) Type de publication : périodique Référence biblio : van Valkenburg J., Duister L., Boer E., Raaymaker T., 2022 - Myriophyllum rubricaule sp. nov., a M. aquaticum look-alike only known in cultivation. European Journal of Taxonomy, 2022 : 15 p. ID PMB : 70999 En ligne : https://sciencepress.mnhn.fr/fr/periodiques/european-journal-taxonomy/828/1 Format de la ressource électronique : document Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=70999
in European Journal of Taxonomy > Année 2022 (Année 2022) . - 15 p.[article]Exemplaires(0)
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Titre : Reproduction of Crassula helmsii by seed in western Europe Type de document : texte imprimé Auteurs : Bram D'hondt, Auteur ; Luc Denys, Auteur ; Wim Jambon, Auteur ; Roeland De Wilde, Auteur ; Tim Adriaens, Auteur ; Jo Packet, Auteur ; Johan van Valkenburg, Auteur Année de publication : 2016 Article en page(s) : pp. 125-130 Langues : Anglais (eng) Catégories : [habitats/milieux] 2 - Milieux aquatiques non marins
[Espèces (in biblio)] Crassula helmsii (Kirk) Cockayne
[Thèmes] ReproductionMots-clés : plante invasive germination Résumé : "The amphibious plant species Crassula helmsii is a widely established and still-spreading alien in various parts of Europe, where it is considered invasive as its dense swards stress the viability of local biota. The species was considered to exclusively reproduce through vegetative means, until ex situ germination was recorded from a single locality in Belgium. We assessed whether this seed viability holds on a wider scale, by testing 16 populations from The Netherlands, Belgium, northern France, eastern England and northern Germany in a greenhouse germination experiment. Seedlings were observed from all populations but two, and from each of the five countries. Although most fruits were lacking seeds and the inferred germination percentages were overall low, germinable seed numbers are considerable given the high density of flowering stems. An in situ test revealed seeds to make it through normal winter conditions without signs of physical damage and with retention of germinability. Our results suggest that reproduction by seed is a relatively cryptic but widespread phenomenon throughout western Europe. The persistency of seed banks requires further investigation. Nonetheless, these findings already challenge the efficacy of techniques currently applied in C. helmsii control." (source : auteurs) Type de publication : périodique Référence biblio : D'hondt B., Denys L., Jambon W., De Wilde R., Adriaens T., Packet J., van Valkenburg J., 2016 - Reproduction of Crassula helmsii by seed in western Europe. Aquatic Invasions, 11 (2) : 125-130. ID PMB : 64717 En ligne : https://data.inbo.be/purews/files/11897469/AI_2016_Dhondt_etal.pdf Format de la ressource électronique : document Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=64717
in Aquatic Invasions > vol. 11, n°2 (Année 2016) . - pp. 125-130[article]Exemplaires(0)
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Titre : The EPPO prioritization process for invasive alien plants Type de document : texte imprimé Auteurs : Jules Brunel, Auteur ; Etienne Branquart, Auteur ; Guillaume Fried, Auteur ; Johan van Valkenburg, Auteur ; Giuseppe Brundu, Auteur ; S. Buholzer, Auteur ; A. Uludag, Auteur ; M. Joseffson, Auteur ; R. Baker, Auteur Année de publication : 2010 Article en page(s) : pp. 407-422 Langues : Anglais (eng) Mots-clés : plante invasive méthodologie hiérarchisation liste d'espèces critère déterminant Résumé : "Although invasive alien plants are gaining increased attention within EPPO countries, there is no existing widely agreed method to identify those alien plants that are considered invasive and represent the highest priority for pest risk analysis. In the framework of the ad hoc Panel on Invasive Alien Species, EPPO proposes a prioritization process for invasive alien plants designed (i) to produce a list of invasive alien plants that are established or could potentially establish in the EPPO region and (ii) to determine which of these have the highest priority for an EPPO pest risk analysis. The process consists of compiling available information on alien plants according to pre-determined criteria, and can be run at the EPPO region level, or at a country or local area level. These criteria examine whether the species is alien in the area under study, and whether it is established or not. The criteria used primarily rely on observations in the EPPO region but, if the species is not established, the invasive behaviour of the species in other countries should be investigated, as well as the suitability of the ecoclimatic conditions in the area under consideration. The spread potential, the potential negative impacts on native species, habitats and ecosystems, as well as on agriculture, horticulture or forestry are considered. If the species qualifies as an invasive alien plant of major concern through this first set of questions, the process then investigates the efficiency of international measures (to be justified through a pest risk analysis) to prevent the entry and spread of the species. The second set of questions are designed to determine whether the species is internationally traded or enters new countries through international pathways for which the risk of introduction is superior to natural spread, and whether the species still has a significant suitable area for further spread. If used by several EPPO countries, this prioritization process represents an opportunity to provide consistent country lists of invasive alien plant species, as well as a tool for dialogue and exchange of information." (source : auteurs) Type de publication : périodique Référence biblio : Brunel J., Branquart E., Fried G., van Valkenburg J., Brundu G., Buholzer S., Uludag A., Joseffson M., Baker R., 2010 - The EPPO prioritization process for invasive alien plants. Bulletin OEPP, 40 (3) : 407-422. ID PMB : 65713 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=65713
in Bulletin OEPP > vol. 40, n°3 (Décembre 2010) . - pp. 407-422[article]Exemplaires(0)
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