[article]
Titre : |
Crassula helmsii (T. Kirk) cockayne : Is it an aggressive alien aquatic plant in Britain |
Type de document : |
texte imprimé |
Auteurs : |
F. H Dawson, Auteur ; E. A. Warman, Auteur |
Année de publication : |
1987 |
Article en page(s) : |
pp. 247-272 |
Langues : |
Anglais (eng) |
Catégories : |
[habitats/milieux] 2 - Milieux aquatiques non marins [habitats/milieux] ZH - Zones humides [Espèces (in biblio)] Crassula helmsii
|
Mots-clés : |
plante macrophyte plante aquatique plante invasive |
Résumé : |
"The occurrence of this alien aquatic macrophyte has rapidly increased during the last decade reaching c. 100 sites mainly in England; these range from shallow acidic seasonal pools to small, more alkaline, nutrient-rich lakes. It is frequently dominant and can grow in an emergent form from 0·7m above the water to a submerged form 1·3m in length, to depths of c. 3m. Plant bimass is generally high with little seasonal cessation of growth. The habit is frequently a dense sward growth which smothers out other flora; it is present in c. ten reserves and is causing concern. It is widely available from aquatic suppliers, it has an enormous potential to propagate from small fragments and has a high growth rate. It is associated with soft sediments and possibly iron-rich areas; this is confirmed by growth trials in static water tanks. In flowing water trials, growth was even faster in water velocities up to 0·32 m s−1, indicating its potential—although no river sites in Britain are yet known. Control by physical removal, often recommended, results in numerous propagules and should be combined with a secondary technique. This initial study suggests that this plant will remain a problem and caution is required to prevent its further spread. Studies of techniques for its control are needed." (source : auteurs) |
Type de publication : |
périodique |
Référence biblio : |
Dawson F.-H., Warman E.-A., 1987 - Crassula helmsii (T. Kirk) cockayne : Is it an aggressive alien aquatic plant in Britain. Biological conservation, 42 (4) : 247-272. |
ID PMB : |
68735 |
Permalink : |
http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=68735 |
in Biological conservation > vol. 42, n°4 (Année 1987) . - pp. 247-272
[article]
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