Long-lived banks of oospores in lake sediments from the Trans-Urals (Russia) indicated by germination in over 300 years old radiocarbon dated sediments

Article · October 2014with137 Reads
DOI: 10.1016/j.aquabot.2014.07.004
Plant macro remains of more than 40 samples from 13 lakes of the Trans-Urals have been radiocarbon dated. Sediment samples from one lake (Lake FS, Russia, oblast Tscheljabinsk; 50°–54° N, 59°–62° E) contained oospores of Characeae which were transferred to water containers to test their viability. Oospores of Nitella mucronata (A. Braun) Miquel (Characeae) germinated and completed their lifecycle coming from a sediment depth of more than 50 cm. Radiocarbon datings derived from seeds of the same depth of the lake sediments imply an age over 300 years (339 ± 33 uncal. BP (1469–1641 cal. AD) and 386 ± 36 uncal. BP (1440–1633 cal. AD. Results indicate the potentials of oospores to survive under favorable conditions for much longer time as previously suggested.
    • Many aquatic organisms have evolved strategies for surviving habitat desiccation as dormant propagules. These propagules comprise aquatic macrophyte seeds (de Winton et al., 2000), oospores (Beltman and Allegrini, 1997;Stobbe et al., 2014) and cladoceran 'resting eggs' (Hairston, 1996) that can remain viable for centuries and allow rapid species' re-establishment following habitat restoration (Beltman and Allegrini, 1997;Kaplan et al., 2014). While long-term viability of propagules has been established for extant aquatic habitats (Bakker et al., 1996;Beltman and Allegrini, 1997;de Winton et al., 2000;Hairston, 1996), their fate in 'ghost ponds', ponds that have been in-filled for agricultural land consolidation, has remained unexplored.
    [Show abstract] [Hide abstract] ABSTRACT: The widespread loss of wetlands due to agricultural intensification has been highlighted as a major threat to aquatic biodiversity. However, all is not lost as we reveal that the propagules of some aquatic species could survive burial under agricultural fields in the sediments of ‘ghost ponds’ - ponds in-filled during agricultural land consolidation. Our experiments showed at least eight aquatic macrophyte species to germinate from seeds and oospores, following 50–150 years of dormancy in the sediments of ghost ponds. This represents a significant proportion of the expected macrophyte diversity for local farmland ponds, which typically support between 6 and 14 macrophyte species. The rapid (< 6 months) re-colonisation of resurrected ghost ponds by a diverse aquatic vegetation similarly suggests a strong seed-bank influence. Ghost ponds represent abundant, dormant time capsules for aquatic species in agricultural landscapes around the globe, affording opportunities for enhancing landscape-scale aquatic biodiversity and connectivity. While reports of biodiversity loss through agricultural intensification dominate conservation narratives, our study offers a rare positive message, demonstrating that aquatic organisms survive prolonged burial under intensively managed agricultural fields. We urge conservationists and policy makers to consider utilizing and restoring these valuable resources in biodiversity conservation schemes and in agri-environmental approaches and policies.
    Full-text · Article · Aug 2017
  • [Show abstract] [Hide abstract] ABSTRACT: Results of the project for the development of nature and landscape " Sprotteaue und FFH-Eremit-Lebensräume, Altenburger Land " The ENL project-Sprotteaue und FFH-Eremit-Lebensräume, Altenburger Land " operated between October 2012 and May 2015 in wide parts of the thuringian district Altenburger Land. Nature protection as well as optimization of living conditions in natural flood plain habitats have occured in accordance with the regulations of Council Directive 92/43/EEC on the Conservation of natural habitats and of wild fauna and flora. Care and development measures in favor of target species like european otter (Lutra lutra), white stork (Ciconia ciconia), european green toad (Bufo viridis), common spadefoot (Pelopates fuscus), natterjack toad (Bufo calamita), agile frog (Rana dalmatina), moor frog (Rana arvalis), european tree frog (Hyla arborea), hermit beetle (Osmoderma eremita) and dusky large blue butterfly (Maculinea nausithous) were implemented.
    Full-text · Article · Jul 2015 · Biological Reviews
  • [Show abstract] [Hide abstract] ABSTRACT: Long-term and interannual changes in composition of submerged vegetation, diaspore reservoir and germination were investigated in the lagoon system Westrügensche Boddenkette, Baltic Sea, north-east Germany. Comparison with a survey from 1932, showed vegetation cover is similar to the past, maintaining high cover to depths of 2.8 m despite a period of eutrophication between about 1960 and 1990. Species dominance shifted, however, from small charophytes to larger species like Potamogeton pectinatus. We explain interannual vegetation changes by weather conditions. Such changes were observed in several species, most notably in Chara canescens. This annual species seems to be favoured by extensive winter ice cover. The diaspore reservoir and the germination success of submerged macrophytes do not mirror their frequency in the vegetation, but rather reflect life form strategies. Small oospores, mainly of annual charophytes, represented >97% of all diaspores but very few Chara oospores germinated. The numerous Tolypella oospores probably originated from a discrete period with high abundance during the 1950s and have completely failed to germinate. Angiosperm seeds are larger and less frequent but have higher germination success, especially Ruppia seeds. In conclusion, charophytes are outcompeted by larger angiosperms due to the combined effect of moderate eutrophication and climate change.
    Article · Feb 2016
  • [Show abstract] [Hide abstract] ABSTRACT: In the past decade, research on long-term persistence of phytoplankton resting stages has intensified. Simultaneously, insight into life-cycle variability in the diverse groups of phytoplankton has also increased. Aquatic 'seed banks' have tremendous significance and show many interesting parallels to terrestrial seed beds of vascular plants, but are much less studied. It is therefore timely to review the phenomenon of long-term persistence of aquatic resting stages in sediment seed banks. Herein we compare function, morphology and physiology of phytoplankton resting stages to factors central for persistence of terrestrial seeds. We review the types of resting stages found in different groups of phytoplankton and focus on the groups for which long-term (multi-decadal) persistence has been shown: dinoflagellates, diatoms, green algae and cyanobacteria. We discuss the metabolism of long-term dormancy in phytoplankton resting stages and the ecological, evolutionary and management implications of this important trait. Phytoplankton resting stages exhibiting long-term viability are characterized by thick, often multi-layered walls and accumulation vesicles containing starch, lipids or other materials such as pigments, cyanophycin or unidentified granular materials. They are reported to play central roles in evolutionary resilience and survival of catastrophic events. Promising areas for future research include the role of hormones in mediating dormancy, elucidating the mechanisms behind metabolic shutdown and testing bet-hedging hypotheses.
    Full-text · Article · May 2017
The database "Chromosome numbers of the Flora of Germany" has been developed as an online-accessible repository and database system of chromosome counts and flow cytometric ploidy estimations of fe…" [more]
Discover more