scholarly journals Phytocenosis biodiversity at various water levels in mesotrophic Lake Arakhley, Lake Baikal basin, Russia

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11628
Author(s):  
Gazhit Ts. Tsybekmitova ◽  
Larisa D. Radnaeva ◽  
Natalya A. Tashlykova ◽  
Valentina G. Shiretorova ◽  
Balgit B. Bazarova ◽  
...  

Small lakes have lower water levels during dry years as was the case in 2000–2020. We sought to show the biodiversity of plant communities at various water levels in Lake Arakhley. Changes in moisture content are reflected in the cyclical variations of the water level in the lake, which decreased approximately 2 m in 2017–2018. These variations affect the biological diversity of the aquatic ecosystems. We present the latest data on the state of the plant communities in this mesotrophic lake located in the drainage basin of Lake Baikal. Lake Arakhley is a freshwater lake with low mineral content and a sodium hydrocarbonate chemical composition. Changes in the nutrient concentration were related to precipitation; inflow volume and organic matter were autochtonous at low water levels. The most diverse groups of phytoplankton found in the lake were Bacillariophyta, Chlorophyta, and Chrysophyta. High biodiversity values indicate the complexity and richness of the lake’s phytoplankton community. A prevalence of Lindavia comta was observed when water levels were low and Asterionella formosa dominated in high-water years. The maximum growth depth of lacustrine vegetation decreased from 11.0 m to 4.0 m from 1967 to 2018. Decreasing water levels were accompanied by a reduction in the littoral zone, altering the communities of aquatic plants. The hydrophyte communities were monodominant in the dry years and were represented by Ceratophyllum demersum. The vegetation cover of the lake was more diverse in high-water years and variations in the lake’s water content altered the composition of biogenic substances. These changes were reflected in the lake’s phytocenosis.

2011 ◽  
Vol 2 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Dale M. Robertson ◽  
William J. Rose

To determine how climate-induced changes in hydrology and water level may affect the trophic state (productivity) of stratified lakes, two relatively pristine dimictic temperate lakes in Wisconsin, USA, were examined. Both are closed-basin lakes that experience changes in water level and degradation in water quality during periods of high water. One, a seepage lake with no inlets or outlets, has a small drainage basin and hydrology dominated by precipitation and groundwater exchange causing small changes in water and phosphorus (P) loading, which resulted in small changes in water level, P concentrations, and productivity. The other, a terminal lake with inlets but no outlets, has a large drainage basin and hydrology dominated by runoff causing large changes in water and P loading, which resulted in large changes in water level, P concentrations, and productivity. Eutrophication models accurately predicted the effects of changes in hydrology, P loading, and water level on their trophic state. If climate changes, larger changes in hydrology and water levels than previously observed could occur. If this causes increased water and P loading, stratified (dimictic and monomictic) lakes are expected to experience higher water levels and become more eutrophic, especially those with large developed drainage basins.


2020 ◽  
Vol 6 ◽  
pp. 11-32
Author(s):  
Anna Yu. Bessudova ◽  
Larisa M. Sorokovikova ◽  
Valery N. Sinyukovich ◽  
Alena D. Firsova ◽  
Irina V. Tomberg ◽  
...  

Large tributaries of Lake Baikal considered as a “hotspot” for silica-scaled chrysophytes diversity. Here we presented the updated species composition of silica-scaled chrysophytes and ecological parameters of their habitat in the Barguzin and Selenga River tributaries and delta in a high water level period. The number of registered taxa was significantly lower compared to the low water conditions (23 versus 66 species) and included the following genera with a given number of species: Chrysosphaerella – 1; Paraphysomonas – 2; Clathromonas – 1; Spiniferomonas – 3; Mallomonas – 9; Synura – 7. Mallomonas guttata and Synura borealis were identified in Russian waters for the first time. Thus, the corrected total list of silica-scaled chrysophytes in the Baikal Region includes 79 taxa. Though, the high water level reduced the total number of silica-scaled chrysophyte taxa, it made the water ecosystem more dynamic by enriching it with the entirely new species for this region.


Author(s):  
André Mauchamp ◽  
Olivier Gore ◽  
Jean-Marc Paillisson ◽  
Benjamin Bergerot ◽  
Anne Bonis

AbstractMarshlands and floodplains are generally characterized by a long history of human occupation and management, with strong impacts on biodiversity. In these landscapes, ditch networks often represent the last or most significant aquatic habitat, and significantly contribute to regional biodiversity. To determine the drivers of biodiversity in ditch networks, especially the importance of the water regime, we monitored vegetation in ditches in 11 sites (independent blocks of ditch networks) of an Atlantic marshland (the Marais poitevin, France) over a 4-year period, and a panel of local environmental conditions and landscape characteristics. Large differences in the species richness and composition of ditch plant communities were observed among sites. The water regime had a predominant effect on all descriptors of ditch plant communities. High water levels combined with strong temporal variability, including drying-out periods, were found associated to the communities with the highest species richness. By contrast, water quality parameters did not influence plant communities across sites. Among landscape variables, woodland cover combined with high hedge cover along the ditches significantly influenced plant composition and species richness. These results are discussed in terms of management actions that may promote the diversity and composition of ditch plant communities and address conservation challenges.


Author(s):  
Sergey Krylenko ◽  
Sergey Krylenko

Preservation of biological diversity is necessary for sustainable development and rational use of coastal resources. In this paper structure of the cliff plant communities of the massif Tuapkhat (the Black Sea coast, Russia) are characterized. Flora of this coastal zone combines features of Mediterranean and middle European Russia types. Herbaceous and shrub life-forms and xeromorphous and petrophilous plant associations dominate at the studied area. The main factor determining the species composition of the examined communities is substrate character.


2007 ◽  
Vol 158 (1-2) ◽  
pp. 14-21
Author(s):  
Vasyl Sabadosh ◽  
Oleg Suprunenko

The upper Theresian Valley lies along the southwest-facing ridge of the Ukrainian Carpathians. Despite expansive forestation high water levels are frequent. The forest belongs to the state and is centrally administrated. Felling is sometimes outsourced to private companies and private companies have also been founded to process the timber. Job opportunities have become fewer and illegal work is increasing. A new democratic awareness has emerged since the «Orange Revolution» in 2004. With foreign investors, however, new risks emerge. The authors recommend giving monies from forest management to the communities, the founding of new wood processing enterprises and more transparent information.


Author(s):  
Sergey Krylenko ◽  
Sergey Krylenko

Preservation of biological diversity is necessary for sustainable development and rational use of coastal resources. In this paper structure of the cliff plant communities of the massif Tuapkhat (the Black Sea coast, Russia) are characterized. Flora of this coastal zone combines features of Mediterranean and middle European Russia types. Herbaceous and shrub life-forms and xeromorphous and petrophilous plant associations dominate at the studied area. The main factor determining the species composition of the examined communities is substrate character.


2021 ◽  
Vol 9 (4) ◽  
pp. 760
Author(s):  
Tatyana V. Butina ◽  
Yurij S. Bukin ◽  
Ivan S. Petrushin ◽  
Alexey E. Tupikin ◽  
Marsel R. Kabilov ◽  
...  

Lake Baikal is a unique oligotrophic freshwater lake with unusually cold conditions and amazing biological diversity. Studies of the lake’s viral communities have begun recently, and their full diversity is not elucidated yet. Here, we performed DNA viral metagenomic analysis on integral samples from four different deep-water and shallow stations of the southern and central basins of the lake. There was a strict distinction of viral communities in areas with different environmental conditions. Comparative analysis with other freshwater lakes revealed the highest similarity of Baikal viromes with those of the Asian lakes Soyang and Biwa. Analysis of new data, together with previously published data allowed us to get a deeper insight into the diversity and functional potential of Baikal viruses; however, the true diversity of Baikal viruses in the lake ecosystem remains still unknown. The new metaviromic data will be useful for future studies of viral composition, distribution, and the dynamics associated with global climatic and anthropogenic impacts on this ecosystem.


The Holocene ◽  
2020 ◽  
pp. 095968362098168
Author(s):  
Christian Stolz ◽  
Magdalena Suchora ◽  
Irena A Pidek ◽  
Alexander Fülling

The specific aim of the study was to investigate how four adjacent geomorphological systems – a lake, a dune field, a small alluvial fan and a slope system – responded to the same impacts. Lake Tresssee is a shallow lake in the North of Germany (Schleswig-Holstein). During the Holocene, the lake’s water surface declined drastically, predominately as a consequence of human impact. The adjacent inland dune field shows several traces of former sand drift events. Using 30 new radiocarbon ages and the results of 16 OSL samples, this study aims to create a new timeline tracing the interaction between lake and dunes, as well, as how both the lake and the dunes reacted to environmental changes. The water level of the lake is presumed to have peaked during the period before the Younger Dryas (YD; start at 10.73 ka BC). After the Boreal period (OSL age 8050 ± 690 BC) the level must have undergone fluctuations triggered by climatic events and the first human influences. The last demonstrable high water level was during the Late Bronze Age (1003–844 cal. BC). The first to the 9th century AD saw slightly shrinking water levels, and more significant ones thereafter. In the 19th century, the lake area was artificially reduced to a minimum by the human population. In the dunes, a total of seven different phases of sand drift were demonstrated for the last 13,000 years. It is one of the most precisely dated inland-dune chronologies of Central Europe. The small alluvial fan took shape mainly between the 13th and 17th centuries AD. After 1700 cal. BC (Middle Bronze Age), and again during the sixth and seventh centuries AD, we find enhanced slope activity with the formation of Holocene colluvia.


1975 ◽  
Vol 2 (4) ◽  
pp. 381-391 ◽  
Author(s):  
J. W. Kamphuis

A number of lightweight coastal protection structures, built on the Lake Erie shore are discussed in this paper. There were two constraints on the design; limited funds and a very precarious downdrift beach. Thus the structures were inexpensive and the protection was low-key to prevent damage downdrift. In 1972–1974 these structures were subjected to a combination of large waves and high water levels and thus they were tested well beyond their design limits.The paper discusses the structures, their performance under normal conditions, and their performance during and after the abnormally high water levels. It is found that inexpensive, low-key structures are sufficiently strong to survive normal conditions, but fail by overtopping and flanking under conditions beyond their low design limits.


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