|Scientific Name:||Aldrovanda vesiculosa L.|
Aldrovanda generalis E.H.L. Krause
Aldrovanda verticillata Roxb.
Drosera aldrovanda F. Muell. [Illegitimate]
There are no significant taxonomic issues associated with this name.
|Red List Category & Criteria:||Endangered B2ab(iii,v) ver 3.1|
|Reviewer(s):||Lansdown, R.V. & Bilz, M.|
From 379 natural historical populations distributed throughout 124 regions in 43 countries, this species has declined over the last century to only 50 confirmed extant locations. Two thirds of these are however found in one region within Poland and the Ukraine, with the remaining 18 sites thinly spread across four continents. The species has been confirmed extinct in Austria, Slovakia, Czech Republic, France, Germany, Italy, Bangladesh, India, Japan, Uzbekistan and East Timor, and remains unverified in another 21 countries. The likelihood of persistence in many of these areas is slim due to extensive wetland degradation, and it is undeniable that this species faces a potentially severe outlook if attempts to mediate the species decline are not swiftly made.
Historically, Aldrovanda vesiculosa occurred throughout western, central, southern, northern and eastern Europe, from coastal areas in western and southern France, throughout northern and central Italy, Austria and Germany to Poland, Belarus, Bulgaria, Croatia, the Czech Republic, Greece, Hungary, Lichtenstein, Lithuania, Montenegro, the Ukraine, Romania, the Caucasus, Volga, Ussuri, Amur, Lipetsk and St Petersburg areas of Russia, Serbia, Slovakia and Turkey; with several sites known throughout Asia in Bangladesh, India, the Manchuria region of China, Kazakhstan, Uzbekistan, North and South Korea, and Japan; extending down to East Timor and several coastal areas in southwest, northwest, north, east and southeast Australia. Populations have also been recorded from Botswana, Burundi, Cameroon, Chad, Ghana, Malawi, Mozambique, Rwanda, South Africa, South Sudan, Tanzania, Togo, Uganda and Zambia throughout Equatorial Africa.
Presently, this species remains distributed scarcely throughout Europe in Bulgaria, Greece, Hungary, Lithuania, Poland, Romania, the St Petersburg and Lipetsk areas of Russia, Serbia and the Ukraine; persists in northern and southeastern Australia; and remains in Botswana and South Africa.
Botswana: Five extant locations and two unverified locations in three regions.
Burundi: One unverified location in one region.
Cameroon: Two unverified locations in two regions.
Chad: Four unverified locations in one region.
Ghana: Three unverified locations in two regions.
Malawi: One unverified location in one region.
Mozambique: One unverified location in one region.
Rwanda: One unverified location in one region.
South Africa: Two extant locations in two expansive regions.
South Sudan: Two unverified locations in two regions.
Tanzania: Four unverified locations in two regions.
Togo: One unverified location in one region.
Uganda: One unverified location in one region.
Zambia: Three unverified locations in three regions.
Austria: Four extinct locations in two regions.
Belarus: Twenty-two unverified locations in three regions.
Bulgaria: Two extant locations in two regions.
Croatia: One unverified location in one region.
Czech Republic: One extinct location in one region.
France: Eighteen extinct locations in four large regions.
Germany: Twenty-one extinct sites in six regions.
Greece: One extant location in one region.
Hungary: One extant, two unverified and four extinct populations in six regions.
Italy: Seventeen extinct locations in seven regions.
Lithuania: One extant and two extinct locations in three regions.
Montenegro: One unverified location in one region.
Poland: Twelve extant and seventy-five extinct locations in seven regions.
Romania: One extant and sixteen unverified locations in five regions.
Russia: Two extant and thirty-seven unverified locations in nine regions.
Serbia: One extant and eight extinct locations in five regions.
Slovakia: One extinct location in one region.
Turkey: One unverified location in one region.
Ukraine: Eighteen extant, eight unverified and thirteen extinct locations in five regions.
Bangladesh: Two extinct locations in two regions.
China: At least two unverified locations in one expansive region.
India: Two extinct locations in two regions.
Japan: Twelve extinct locations in nine regions.
Kazakhstan: Three unverified locations and two extinct locations in four regions.
Uzbekistan: One extinct location in one region.
South Korea: One unverified location in one region.
East Timor: One extinct location in one region.
Western Australia: Three unverified locations in three regions.
Northern Territory: Two extant and thirteen unverified locations in eight regions.
Queensland: Two unverified locations in two regions.
New South Wales: Three extant and four unverified locations in three regions.
Native:Australia (New South Wales, Northern Territory, Queensland, Western Australia); Botswana; Bulgaria; Greece (Greece (mainland)); Hungary; Lithuania; Poland; Romania; Serbia (Serbia); South Africa (Limpopo Province, Mpumalanga); Ukraine (Ukraine (main part))
Regionally extinct:Austria; Bangladesh; Belarus; Burundi; Cameroon; Chad; China (Heilongjiang, Nei Mongol); Croatia; Czech Republic; France (France (mainland)); Germany; Ghana; India (Manipur, West Bengal); Italy (Italy (mainland)); Japan (Honshu); Kazakhstan; Korea, Democratic People's Republic of; Korea, Republic of; Malawi; Montenegro; Mozambique; Rwanda; Slovakia; Sudan; Tanzania, United Republic of; Timor-Leste; Togo; Turkey (Turkey-in-Europe); Uganda; Uzbekistan; Zambia
|Range Map:||Click here to open the map viewer and explore range.|
Aldrovanda vesiculosa possesses one of the greatest disjunctions known for any angiosperm species, with populations frequently isolated by around 800-1,500 km and sometimes over 2,000 km. As such the species’ distribution is highly fragmented, with suitable habitat now rare and still declining in availability and quality. It possesses a low dispersive ability and experiences large population fluctuations annually throughout its range. In general, populations number in the hundreds of plants or fewer and may experience up to 70-80% losses due to poor overwintering success throughout Europe (Adamec 1999a). Exceptions are large and relatively stable populations persisting in a handful of sites in Poland, Lithuania, Russia and the Ukraine, though each is extremely disjunct and possesses limited dispersive potential. Only 49 populations have been recently confirmed extant, of which 31 were located within a single region and 18 distributed sparsely between four continents. 184 populations have been sought and confirmed extinct, with a further 146 remaining unverified despite numerous survey attempts of many regions and most generally regarded as extinct.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:|
This species is a perennial, free-floating, rootless aquatic herbaceous plant, with a simple or sparsely branched stem possessing successive whorls of bristled, prey-catching leaves. The leaves are arranged in whorls of 4–9, measuring up to 23 mm in diameter, and are basally fused with a swollen, dorsally flattened petiole that broadens upwards before dividing into 3–8 terminal, filiform bristles of 4–8 mm length. Stem length is dependent upon water quality, prey abundance and irradiance, but is commonly between 6–20 cm. The compact, whorled structure of the species provides the plant with an almost cylindrical appearance, and gives rise to the species’ common name of the “Waterwheel Plant”.
The growth season for this species extends from early–mid spring into early autumn, with flowers produced throughout summer under favourable conditions. As day length decreases and water temperature begins to drop in mid–late autumn, apical growth becomes increasingly compact and temperate populations produce dormant overwintering buds called turions. Any remaining stem and vegetative material senesces and breaks away from the mature turion, which slowly sinks to the bottom of the water where temperatures are stable and warmer during winter. Overwintering often leads to considerable population losses, with survival frequently only 20–30 per cent (Adamec and Lev 1999; Adamec 1999a,d), particularly as turions failing to sink are generally washed ashore, grazed on by waterfowl, or killed by the onset of frost. In spring, when water temperatures begin to rise once again, the surviving turions float to the surface and recommence growth. In latitudes experiencing very mild winters, it may grow year-round with no overwintering period. Flowering in A. vesiculosa is rare and poorly successful, highly variable between season and populations, and yields exceedingly low numbers of viable seed even under optimum conditions (Cross 2012). While plants from warmer climates are known to bloom with greater profusion and regularity, particularly throughout tropical and sub-tropical Australia, these flowers open only for brief periods and also often fail to develop fruit. Under even the most optimal of conditions plants produce scant numbers of viable seeds, and these are thought to originate almost entirely from self-pollination. The primary dispersive agent in it is likely to be vegetative propagules such as stem fragments or turions, transported externally by birds between suitable habitat.
This species occurs in a wide variety of habitats, from small fens and billabongs to lakes, lagoons and river deltas. While it has been infrequently observed in mesotrophic lakes and eutrophic habitats such as fishponds and rice paddies (Barthloft and Ashdown 2007, Adamec 1999a, Breckpot 1997), it is native to nutrient impoverished oligo-mesotrophic and dystrophic (humic) systems (Adamec 1995b). The stenotopic nature and reliance upon carnivory of this species yield little competitive ability, and limits the species’ distribution to specific microhabitats dominated by loose and species-poor plant communities (Adamec 2005, 1999a, 1995a; Kaminski 1987a; Degreef 1986). These are generally shallow backwaters or the littoral zone of larger lakes, where competition with other aquatic species forming dense stands is reduced or absent (Kaminski et al. 1996; Kaminski 1987a,b; Studnicka 1984), and are typically areas experiencing little variation in water level throughout the growing season. This species is extremely intolerant of habitat degradation, and even slight changes to water chemistry can result in local extinction (Kaminski 1987a).
A. vesiculosa possesses virtually all the characteristic traits of a genetically uniform aquatic plant. The species is highly clonal, known to propagate strictly by vegetative means throughout most of its range, and is capable of extremely rapid growth under optimal conditions. It inhabits a restricted ecological niche, with very specific habitat requirements and facing further reductions to the abundance of suitable habitat. A. vesiculosa exhibits strongly repressed sexual function dominated by obligate autogamy, and further limits the chance of recombination with the presence of a non-successful floral morph under suboptimal conditions. It is likely to disperse vegetatively over both short and long distances, and persists through unsuitable periods of winter primarily in the form of dormant or non-dormant winter buds rather than seed. The species is contemporary in geological origin, unlikely to have persisted in any given location for long enough to experience significant genetic drift, and has experienced numerous severe bottlenecks in its recent evolutionary history.
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Use and Trade:||There is limited trade in this species, mainly in Europe.|
According to a review of conservation threats to carnivorous plants presented by Jennings and Rohr (2011), this species is threatened primarily by residential and commercial development, agriculture and aquaculture, natural systems modifications and pollution. The Commission of the European Union (2009) also lists acidification, canalization, desilting, drainage, eutrophication, forestry clearance, gravel extraction, mining, pollution, hydrological modification and limited dispersal as threats to the species throughout Europe. Additionally, though its extent and effects on natural populations are unknown, it is believed that some illegal trade also occurs in A. vesiculosa. Habitat degradation is common throughout the species’ entire range, and very few sites, including those within conservation reserves, remain pristine.
As the true extent of the species’ decline has become clearer, legislative protection has been provided to this species in virtually all countries of its distribution. Though a deficiency of data relating to its distribution has hindered an appraisal of conservation status throughout much of Africa, Asia and Australia, A. vesiculosa has been regarded as critically endangered throughout most of Europe since 1982 (Threatened Plants Unit 1982), and is included in Annex 1 of the Bern Convention as a species requiring specific habitat conservation measures.
A number of populations, though many of them remaining unverified, are located within the borders of lands reserved for conservation purposes. The degree of protection afforded by these areas varies from unfenced game and nature reserves to carefully monitored and well-maintained national parklands and biosphere reserves, however all provide a degree of crucial habitat security. Managed and protected lands known to harbour extant A. vesiculosa populations include the Srebarna Managed Nature Reserve and the recently Ramsar listed Dragoman Marsh Complex (Bulgaria), the Zasavica Special Nature Reserve (Serbia), the Astrakhan Reserve (Kazakhstan), and the New England Tablelands Endangered Ecological Community (Australia). The effectiveness of conserving only small areas such as these is however limited by landscape-scale changes to hydrology and the intrinsic biotic linkages characteristic of wetland habitats, exemplified by the recent extinction of populations in the Obedska bara Special Nature Reserve (Serbia). One conservation area, formed by two large adjacent reserves, harbours over fifty per cent of the entire global distribution of A. vesiculosa and clearly supports both the need for transboundary conservation and the management of larger scale ecological processes. Encompassing much of the expansive Pripyat River basin, the 48,977 hectare Shatskyi Biosphere Reserve in northwest Ukraine was designated in 2002 and provides some of the most ecologically intact freshwater habitat remaining in Europe, including the Ramsar listed Shatsk Lakes. Seventeen extant A. vesiculosa populations are known from the reserve, which is carefully monitored for a number of biotic and abiotic factors under the authority of the Scientific-Technical Council of the Shatskyi National Nature Park. Bordering Shatskyi to the west is the West Polesie Biosphere Reserve in East Poland, a similarly protected 139,917 hectare area maintained by the Forum of the International Biosphere Reserve "Polesie Zachodnie". Though patches of the Polish reserve are designated for extensive economic use, the lowland area is characterised by a mosaic of swamps, moors, lakes and rivers and eight populations persist in the region. It must be noted however that despite the protections afforded to even large landscapes such as these, widespread habitat degradation is not entirely avoided: historically the two regions harboured between them at least 74 populations which have been gradually lost to agricultural development and continued wetland eutrophication.
Adamec, L. 1995. Ecological requirements and recent European distribution of the aquatic carnivorous plant Aldrovanda vesiculosa L.- a review. Folia Geobotanica et phytotaxonomica 30: 53-61.
Adamec, L. 1995. Ecological requirements of Aldrovanda vesiculosa: Testing of its new potential sites in the Czech Republic. Acta Botanica Gallica 142: 673-680.
Adamec, L. 1995. Ecophysiological study of the aquatic carnivorous plant Aldrovanda vesiculosa L. Acta Botanica Gallica 142: 681-684.
Adamec, L. 1996. Will the rare plant Aldrovanda vesiculosa return to the Czech Republic? Zhiva 44: 158-159.
Adamec, L. 1997. Will the rare aquatic carnivorous plant Aldrovanda vesiculosa survive in Europe? Aquaphyte Newletter 17: 4-5.
Adamec, L. 1999. Seasonal growth dynamics and overwintering of the aquatic carnivorous plant Aldrovanda vesiculosa at experimental field sites. Folia Geobotanica 34: 287-297.
Adamec, L. 2003. Ecophysiological characterisation of dormancy states in turions of the aquatic carnivorous plant Aldrovanda vesiculosa. Biologia Plantarum 47: 395-402.
Adamec, L. 2005. Ten years after the introduction of Aldrovanda vesiculosa to the Czech Republic. Acta Botanica Gallica 152: 239-245.
Adamec, L. 2005. What is new in Aldrovanda research? Dionée 58: 22-28.
Amezaga, J., Santamaria, L. & Green, A. 2002. Biotic wetland connectivity - supporting a new approach for wetland policy. Acta Oecologia 23: 213-222.
Cross, A. 2012. Aldrovanda. The waterwheel plant. Redfern Natural History Productions, Poole, Dorset.
Exell, A.W., Wild, H., Fernandes, A., Brenan, J.P.M. and Launert, E. (eds) Flora Zambesiaca. Volumes published up until 1996. Crown Agents, London.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.2). Available at: http://www.iucnredlist.org. (Accessed: 17 October 2012).
Jennings, D.E. and Rohr, J.R. 2011. A review of the conservation threats to carnivorous plants. Biological Conservation 144: 1356-1363.
Kaminski, R. 2006. Restytucja aldrowandy pêcherzykowatej i rozpoznanie czynników decyduj1cych o jej przetrwaniu w klimacie umiarkowanym. Wroclaw University Publishing, Wroclaw, Poland.
Kaminski, R. 2010. Aldrovanda vesiculosa. In: Perzanowska, J. (ed.), Monitoring of Plant Species. Methodological Guide. Part 1, CIEP, Warsaw, Poland.
Komiya, S. and Shibata, C. 1982. Environmental changes of the natural habitat and growth of Aldrovanda vesiculosa L. at Hozoji Pond, Hanyu City. Bulletin of the Nippon Dental University 11: 1-16.
Kondo, K., Kokubugata, G., Varghese, S., I toyama, M., Breckpot, C., Kromer, K. and Kaminski, R. 1997. Conservation of endangered Aldrovanda vesiculosa by tissue culture. Carnivorous Plant Newsletter 26: 89-92.
Kundu, S.R., Basu, S. and Chakraverty, R.K. 1996. Aldrovanda vesiculosa Linn.: Its maiden appearance and disappearance from India: A review. Journal of Economic and Taxonomic Botany 20: 719-724.
|Citation:||Cross, A. 2012. Aldrovanda vesiculosa. The IUCN Red List of Threatened Species 2012: e.T162346A901031.Downloaded on 18 July 2018.|
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