|Scientific Name:||Luronium natans|
|Species Authority:||(L.) Raf.|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer/s:||Gigot, G., Ericsson, S., Burden, A. & Bilz, M.|
European regional assessment: Least Concern (LC)
EU 27 regional assessment: Least Concern (LC)
This European endemic plant is widespread but suffers from local declines and faces a range of local threats such as the modification of its aquatic habitats or water pollution. However, the populations are not declining at a rate that makes them likely to go extinct in the near future and the species is therefore classed as Least Concern.
Luronium natans is endemic to west and central Europe. The quality and coverage of data on its distribution and abundance varies throughout its range. The literature and a number of databases were reviewed, employing an approach described as ‘high dispute tolerance’ (IUCN 2001), which involves relying strictly on records that can be confirmed. Cook (1983) disregards records in Tutin et al. (1980) from Bulgaria, Italy and the former Yugoslavia. In addition, this review shows that in spite of claims to the contrary, there are and have been no confirmed records of L.natans for Bosnia-Herzegovina, Croatia, Hungary, Lithuania, Macedonia, Montenegro, Romania, Russia, Serbia, Slovakia (I. Jarolimek pers. comm. 2010), Slovenia, Austria (I. Bagi pers. comm. 2010) the Transcarpathian region of the Ukraine and Transylvania. These areas are therefore considered to be outside the natural range of the species. As a result of this review, the global range of L. natans has been revised. Based on confirmed records, its range can be described as extending from southern Norway and Sweden in the north, through the Republic of Ireland and France to northern Spain, east to Poland and the Czech Republic.
Native:Belgium; Czech Republic; Denmark; France (France (mainland)); Germany; Ireland; Netherlands; Norway; Poland; Spain (Spain (mainland)); Sweden; United Kingdom (Great Britain)
|Range Map:||Click here to open the map viewer and explore range.|
There are very few localities only in Scandinavia: two to three localities for Norway (one of which is a cluster of four lakes), three small localities in Sweden (20 km² occupied area) and three localities in Denmark.
In Ireland it is known from two localities that are 500 m apart. It can be found at higher altitude (450 m) in the western UK (Wales) (Preston et al. 2002).
In Czech Republic, it is found in two pools of less than 1 km² (Natura 2000). In Poland, the species occurred in more than 100 localities in the past, now it inhabits no more than several tens of lakes in the Pomeranian Lake District. Two isolated localities were recorded in 2004 on Lower Silesia, in Żwirownia w Starej Olesznej (a gravel pit in Stara Oleszna) and in Starorzecze Potok in Nysa Łużycka River Valley, and in Zgorzelec-Osiecznica Forest. In Germany, there are around 115 localities and the species is common in the northwest.
In France, it occurs everywhere except for the Mediterranean or the Alps, there are 416 localities in total. In the Netherlands, it is known from more than 100 sites. In the Iberian Peninsula, its population is confined to five areas that are very spread apart summing up to 13 known populations that are often fluctuating. In Galicia, where this species was considered extinct, recent localities have been found in A Terra Cha (Lugo) (Bañares et al. 2004).
The populations are decreasing in Belgium, Germany, France, Netherlands, and Poland and stable in Sweden, Czech Republic and Spain (Commission of the European Communities 2009).
|Habitat and Ecology:||
The species can be found in and along a wide range of water bodies. In Sweden, for example, it inhabits shallow poor clear waters, small water bodies, sand, non-eutrophic water. In Spain, this small hydrophyte develops at the edges of pools and lakes as well as in dead-waters of streams and rivers. Sometimes it can create mono-specific communities, especially when it acts without competitors. Depending on the environment in which it develops (lotic or lentic) and the volume of water, it can appear with species such as Nymphaea alba, Sparganium erectum, Isoetes velata, Pilularia globulifera or Baldellia alpestris. The populations are often fluctuating. When the plant acts as a pioneer species without competing with others, it can be very dense. When the number of species is balanced, the abundance of the species is less. The vegetative reproduction gains importance once the species has been well established (Bañares et al. 2004).
Luronium natans can be found in the following Habitats Directive habitats:
|Major Threat(s):||The main threats to the species are due to habitat destruction or degradation. Water and soil pollution due to the use of pesticides and fertilizers as well as eutrophication are leading to population reductions. One of the main threats is the change of hydrological regimes, be it canalization and the modification of water courses, management of water levels, drainage, management of bank vegetation. The filling of water bodies or removal of sediment affect the populations. Changes in agricultural practices, abandonment of pastoral systems as well as unfavourable forest management are threatening the species survival. Negative impacts come from aquaculture and from recreational activities such as fishing, nautical sports, walking, horseriding and non-motorised vehicles (Commission of the European Communities 2009).|
This species is listed on Annex II of the EU Habitats Directive and under Appendix I of the Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention). It is also protected by national policies/laws (e.g. France, Sweden). It is classed as Critically Endangered in the Czech Republic and Endangered in Spain (Moreno 2008), Germany (level 2) (Ludwig and Schnittler 1996), and Sweden.
The species occurs in protected areas (e.g. Czech Republic, Spain, UK). Some important populations are not protected and require conservation measures such as the Polish populations in Jeziora Wdzydzkie (Wdzydze Lakes), in Lobelia lakes near Bobęcino, in Jezioro Krasne (Lake Krasne), and in Puszcza Drawska (Drawska Forest) are not covered. Silesian localities are also completely omitted.
|Citation:||Lansdown, R.V. 2011. Luronium natans. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 22 May 2013.|
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