scholarly journals Long term subfossil Cladocera record from the partly varved sediment of Lake Tiefer See (NE Germany)

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Krystyna Szeroczyńska
Keyword(s):  
Open Water ◽  
Sediment Record ◽  
Lake Productivity ◽  
Trophic Conditions ◽  
Subfossil Cladocera ◽  
Lake Evolution ◽  
Ne Germany ◽  
Lake Circulation ◽  
Varved Sediment

<p>The partly varved and well-dated sediment record of Lake Tiefer See (NE Germany) allowed the high resolution paleolimnological reconstruction of the lake evolution during the whole Holocene. This paper presents results of subfossil Cladocera analysis. During the Holocene, the fauna of subfossil cladoceran was represented by 36 species belonging to 6 families. Cladocera were dominated by typical open-water species, belonging especially of the Bosminidae family. The sediment record of Lake Tiefer See exhibited distinct decadal- to centennial-scale alternations of well- and non-varved intervals, which were related to changes in the thermal circulation of the lake water column. In general, well varved sediments were deposited during periods of reduced lake circulation, and were characterised by maximum abundance of Cladocera, whereas non-varved sedimentation phases occurred during periods of increased lake circulation and showed a lower number of Cladocera specimens. The most suitable conditions for the development of cladoceran fauna occurred during the early Holocene and from ~ 2055 – 725 yr cal BP. On the basis of the increasing number of species associated with high lake productivity, eight stages of increasing trophy were inferred. The first two were attributed to climate warming, while the next six to human impact. Higher human driven trophic conditions of Lake Tiefer See occurred in the periods 5750-5500 and 4500-4100 yr cal BP, and four times from 1000 to50 yr cal BP. During the last 750 years and in the period from 6000 to 2500 yr cal BP, the species of <em>Eubosmina</em> produced extreme morphs. The cyclomorphosis of <em>Eubosmina </em>was likely connected to more pronounced changes in the lake environmental conditions.</p>

Varve microfacies and varve preservation record of climate change and human impact for the last 6000 years at Lake Tiefer See (NE Germany)

The Holocene ◽  
2016 ◽  
Vol 27 (3) ◽  
pp. 450-464 ◽  
Author(s):  
Nadine Dräger ◽  
Martin Theuerkauf ◽  
Krystyna Szeroczyńska ◽  
Sabine Wulf ◽  
Rik Tjallingii ◽  
...  
Keyword(s):  
Lake Productivity ◽  
Proxy Record ◽  
Holocene Sediment ◽  
Ne Germany ◽  
Lake Circulation ◽  
Varved Sediment ◽  
The Baltic ◽  
Induced Changes ◽  
Sediment Variability ◽  
Varve Counting

The Holocene sediment record of Lake Tiefer See exhibits striking alternations between well-varved and non-varved intervals. Here, we present a high-resolution multi-proxy record for the past ~6000 years and discuss possible causes for the observed sediment variability. This approach comprises microfacies, geochemical and microfossil analyses and a multiple dating concept including varve counting, tephrochronology and radiocarbon dating. Four periods of predominantly well-varved sediment were identified at 6000–3950, 3100–2850 and 2100–750 cal. a BP and AD 1924–present. Except of sub-recent varve formation, these periods are considered to reflect reduced lake circulation and consequently, stronger anoxic bottom water conditions. In contrast, intercalated intervals of poor varve preservation or even extensively mixed non-varved sediments indicate strengthened lake circulation. Sub-recent varve formation since AD 1924 is, in addition to natural forcing, influenced by enhanced lake productivity due to modern anthropogenic eutrophication. The general increase in periods of intensified lake circulation in Lake Tiefer See since ~4000 cal. a BP presumably is caused by gradual changes in the northern hemisphere orbital forcing, leading to cooler and windier conditions in Central Europe. Superimposed decadal- to centennial-scale variability of the lake circulation regime is likely the result of additional human-induced changes of the catchment vegetation. The coincidence of major non-varved periods at Lake Tiefer See and intervals of bioturbated sediments in the Baltic Sea implies a broader regional significance of our findings.

scholarly journals Long-term changes of phytoplankton in the lake, not affected by anthropogenic impact (Lake Krivoe, North Karelia)

2016 ◽  
Vol 320 (3) ◽  
pp. 336-347 ◽  
Author(s):  
V.N. Nikulina
Keyword(s):  
Open Water ◽  
Small Cell ◽  
Lake Ecosystem ◽  
Total Biomass ◽  
Trophic Conditions ◽  
Phytoplankton Species Composition ◽  
Spring Maximum ◽  
Natural Dynamic ◽  
Biological Program

First studies of the lake ecosystem were performed in 1968–1969 in framework of the International Biological Program, as on a model lake for the observations on the natural dynamic processes. Further work had continued in 1972 and annually from 2002 to 2014. During all study period Cyanobacteria and Chrysophyta have been permanent representatives in phytoplankton. Cyanobacteria were mostly represented by small-cell species from Chroococcales, so their share in the total biomass was low, despite the high abundance. Algae from genera Dinobryon and Uroglena, had dominated in Spring and remained in the plankton during entire season. A distinctive feature of the lake plankton was a low development of diatoms (less than 10% in abundance and biomass) and the absence of the spring outbreak of diatoms in both: under ice and in open water. Cryptomonads (Cryptopyta), which also had been represented throughout of season, became practically new, fairly widespread group in lake phytoplankton. Detailed studies carried out in 2002–2014, have shown that the spring maximum of phytoplankton rarely exceeded the summer one and reached in average 0.46 mg/L. The percentage of each size class of algae in the total biomass of the plankton was determined. Algae with size to 40 microns, which are the most consumed ones by filter feeding zooplankton, constituted a significant share in the Spring time. However the most favorable trophic conditions for zooplankton were during the summer. The development of single-celled Cryptomonad, which reached about 30% of the total biomass, has increased the trophic importance of phytoplankton. Species composition and abundance of phytoplankton in the lake may indicate a conservation of the lake as a clean oligotrophic reservoir.

Eemian environmental changes recorded in the north located lakes (N Poland and Germany) - subfossil Cladocera data

2020 ◽  
Author(s):  
Monika Niska ◽  
Anna Hrynowiecka ◽  
Joanna Mirosław-Grabowska ◽  
Andreas Borner ◽  
Robert Sokołowski
Keyword(s):  
Species Composition ◽  
Environmental Changes ◽  
Open Water ◽  
Dominant Group ◽  
Local Conditions ◽  
Subfossil Cladocera ◽  
The North ◽  
Ne Germany ◽  
Eemian Interglacial ◽  
Nw Poland

&lt;p&gt;In the current study the result of subfossil Cladocera analysis of the lake sediments from tree sites: Hinterste M&amp;#252;hle (H-M) (NE Germany), Rzecino (NW Poland) and &amp;#321;&amp;#281;czyce (N Poland) of the Eemian Interglacial and the inferred environmental alterations are presented. The aim of the study was to reconstruct and compare the development of Eemian lakes located within the north of Poland and Germany as determined on the basis of the changes in subfossil Cladocera composition in the context of local conditions, climate change and natural evolutionary processes.&lt;/p&gt;&lt;p&gt;The studied reservoirs, fully developed during the Eemian Interglacial, were formed at the end of Late Saalian (MIS 6) and Early Eemian. The Hinterste M&amp;#252;hle profile is located in Mecklenburg-Western Pomerania. The site lies in the southeastern edge of the gravel pit, at about 48 m a.s.l. The Rzecino paleolake is located in the West Pomerania Lakeland (NW Poland), at an elevation of 104.5 m a.s.l. The &amp;#321;&amp;#281;czyce palaeolake is located in northern Poland, on the northern slope of the &amp;#321;eba river valley.&lt;/p&gt;&lt;p&gt;The subfossil Cladocera fauna from the H-M palaeolake is represented by 14 species belonging to three families. Three of them belong to a benthic group inhabiting mainly the bottom sediments, one to the open water zone, while the remaining species the dominant group occur among aquatic plants. Such a species composition marks a shallow water body or the littoral, macrophyte zone of a deeper lake. The Cladoceran fauna of deposits from the Rzecino paleolake are represented by 22 species that belong to four families. The majority of the remains consist of Chydoridae and Bosminidae. In the deposits, the ephippial eggs of the &lt;em&gt;Daphnia longispina&lt;/em&gt; group, &lt;em&gt;Ceriodaphnia&lt;/em&gt; spp., &lt;em&gt;Chydorus spp&lt;/em&gt;., and &lt;em&gt;Bosmina&lt;/em&gt; spp. are also identified. The subfossil cladoceran fauna of sediments in the &amp;#321;&amp;#281;czyce profile is represented by 18 species that belong to four families. Most of the remains belong to the family of Chydoridae (13). Such species composition points to a deeper reservoir with a developed littoral zone with macrophytes.&lt;/p&gt;&lt;p&gt;Summing up, a similar pattern was observed in the research paleolakes related to the beginning of the existing of the lakes, their full development and ending time, different from the paleolakes found in the south, related to the location and more intense contact with cool air masses from Northern Europe.&lt;/p&gt;

Determining the date of ice-melt for low Arctic lakes along Søndre Strømfjord, southern West Greenland

2001 ◽  
pp. 54-59 ◽  
Author(s):  
N. John Anderson ◽  
Klaus P. Brodersen
Keyword(s):  
Ice Cover ◽  
Arctic Lakes ◽  
Sediment Record ◽  
Lake Productivity ◽  
Lake Ecosystems ◽  
West Greenland ◽  
Weather Patterns ◽  
Ice Melt ◽  
Low Arctic

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Anderson, N. J., & Brodersen, K. P. (2001). Determining the date of ice-melt for low Arctic lakes along Søndre Strømfjord, southern West Greenland. Geology of Greenland Survey Bulletin, 189, 54-59. https://doi.org/10.34194/ggub.v189.5156 _______________ The length of ice cover has considerable influence on the functioning of lake ecosystems, particularly so in continental and high-latitude regions where lakes freeze annually. Long-term trends in the length of ice cover and the date of ice break-up can be related to regional weather patterns, such as the North Atlantic Oscillation. It is this relationship to weather patterns that has generated considerable interest in the use of long-term icerecords as climate proxies. Although it is reasonable to assume a relationship between the length of the icefree period and lake productivity, it is unclear if this relationship influences the sedimentary record. Whether these ice-climate interactions can be identified in the sediment record is important for distinguishing long-term palaeoclimatic trends from variations in the sediment record (Anderson et al. 2000).

Using a lake sediment record to infer the long-term history of cyanobacteria and the recent rise of an anatoxin producing Dolichospermum sp.

Harmful Algae ◽  
2021 ◽  
Vol 101 ◽  
pp. 101971
Author(s):  
William O. Hobbs ◽  
Theo W. Dreher ◽  
Edward W. Davis ◽  
Rolf D. Vinebrooke ◽  
Siana Wong ◽  
...  
Keyword(s):  
Lake Sediment ◽  
Sediment Record ◽  
History Of

Sedimentary Cladocera as indicators of past water-level changes in shallow northern lakes

2011 ◽  
Vol 75 (3) ◽  
pp. 430-437 ◽  
Author(s):  
Liisa Nevalainen ◽  
Kaarina Sarmaja-Korjonen ◽  
Tomi P. Luoto
Keyword(s):  
Water Level ◽  
Lake Level ◽  
Water Levels ◽  
Sediment Record ◽  
Inference Model ◽  
Water Level Changes ◽  
Long Term Changes ◽  
Lower Water Level ◽  
The Relationship

AbstractThe usability of subfossil Cladocera assemblages in reconstructing long-term changes in lake level was examined by testing the relationship between Cladocera-based planktonic/littoral (P/L) ratio and water-level inference model in a surface-sediment dataset and in a 2000-yr sediment record in Finland. The relationships between measured and inferred water levels and P/L ratios were significant in the dataset, implying that littoral taxa are primarily deposited in shallow littoral areas, while planktonic cladocerans accumulate abundantly mainly in deepwater locations. The 2000-yr water-level reconstructions based on the water-level inference model and P/L ratio corresponded closely with each other and with a previously available midge-inferred water-level reconstruction from the same core, showing a period of lower water level around AD 300–1000 and suggesting that the methods are valid for paleolimnological and -climatological use.

scholarly journals Climate variability in SE Europe since 1450 AD based on a varved sediment record from Etoliko Lagoon (Western Greece)

2017 ◽  
Vol 159 ◽  
pp. 63-76 ◽  
Author(s):  
Andreas Koutsodendris ◽  
Achim Brauer ◽  
Jane M. Reed ◽  
Birgit Plessen ◽  
Oliver Friedrich ◽  
...  
Keyword(s):  
Climate Variability ◽  
Sediment Record ◽  
Varved Sediment ◽  
Western Greece
Sign in / Sign up

Export Citation Format

Share Document