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Dear Steven,<br><br>
Indeed the control of Crassula Helmsii is very hard and almost impossible
for big populations. Total control will always disturb the whole aquatic
ecosystem with no guarantee that the species will never re-establish.
Eradication (with limited collateral damages on the ecosystem) seems only
possible for small populations through repeated manual removing during
several years. This underlines the importance of early
detection.<br><br>
In Belgium a management guide is available on
<a href="http://www.gembloux.ulg.ac.be/biodiversite-et-paysage/telechargements/" eudora="autourl">
http://www.gembloux.ulg.ac.be/biodiversite-et-paysage/telechargements/<br>
</a>Sorry it is in French. You will find general guidelines about the
management of C. Helmsii, with study cases at the end of the
document.<br><br>
Kind regards<br>
Mathieu Halford, AlterIAS project coordinator<br>
Website:
<a href="http://www.alterias.be/" eudora="autourl">www.alterias.be</a>
<br><br>
At 07:44 17/10/2012, Richard Lansdown wrote:<br>
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Dear Steven,<br>
<br>
It is my belief that in the UK no method has been found to control this
species successfully; even in the most successful cases, control of C.
helmsii has required the eradication of all plants in a wetland.<br>
<br>
I would be very interested to hear of successful control.<br>
Best wishes<br>
Richard<br>
<br>
-------------------------------------------------------<br>
Richard Lansdown<br>
Chair IUCN/SSC Freshwater Plant Specialist Group<br>
Ardeola Environmental Services<br>
45 The Bridle<br>
Stroud<br>
Glos. GL5 4SQ<br>
Tel: 01453 763348<br>
Mob: 07802196494<br>
<br>
<b>From:</b> invasive-species-bounces@biodiversity.be
[<a href="mailto:invasive-species-bounces@biodiversity.be" eudora="autourl">
mailto:invasive-species-bounces@biodiversity.be</a>] <b>On Behalf Of
</b>Steven Keteleer<br>
<b>Sent:</b> 16 October 2012 22:33<br>
<b>To:</b> invasieve soorten mailinglijst;
invasive-species-owner@biodiversity.be<br>
<b>Subject:</b> [Invasive-species] a question about Crassula helmsii, an
invasive waterplant species in Western Europe<br>
<br>
Dear members of this mailing list,<br>
<br>
I've been asked to get information about the most effective combats
against Crassula helmsii. This species is now widely scaterred in
Flanders and before that elsewhere in Western Europe.<br>
<br>
Is there anyone between you who knows a way to fight this invasive
waterplant effectively?<br>
<br>
I should like to know about cases in other countries than Belgium and
Flanders where methods of combats against this species are proven to be
effective and efficiënt.<br>
Particullarly important to us is the effectiveness over the longer term.
Thus, which methods are proven to make this species disappear for a
longer period?<br>
Of course methods without the use of poison are of most interest. <br>
<br>
Answers may be send to my private email but may also be shared over this
list.<br>
<br>
Kind regards,<br>
<br>
Steven Keteleer<br>
<br>
<br>
_______________________________________________<br>
Invasive-species mailing list<br>
Invasive-species@biodiversity.be<br>
<a href="http://mailman.biodiversity.be/mailman/listinfo/invasive-species" eudora="autourl">
http://mailman.biodiversity.be/mailman/listinfo/invasive-species</a>
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<br>
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<font size=2>
-------------------------------------------------------------------------------------------------------------------<br>
<b>Ing. M. Halford<br>
</b>Unité Biodiversité & Paysage / Biodiversity & Landscape
Unit<br>
Département Forêts, Nature et Paysage / Forest, Nature and Landscape
Department<br><br>
Université de Liège<br>
Gembloux Agro-Bio Tech (GxABT)<br>
Passage des Déportés, 2<br>
5030 Gembloux<br>
Belgique<br>
Tél. : 081/62.23.89<br>
Fax : 081/61.48.17<br>
Mail : mhalford@ulg.ac.be</font> </body>
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