Diversity of Diatom Algae in the Lena Delta Nature Reserve and the Adjacent Territory in the Specific Ecological Factors of the Arctic

Abstract

A total of 413 diatom taxa were known for aquatic habitats of the Lena Delta Nature Reserve. We identified 385 taxa in 14 small tundra lakes near the reserve that significantly enriched the diatom diversity of the region (666 taxa including definitions to the genus level). Thus, the species composition of diatoms in the reserve and adjacent territories was increased by 278 species. We showed that the species of the genera Pinnularia (57) and Eunotia (51) have predominance at the family and generic levels. The index of intraspecific variability Ssp./Sp. for the lakes of the reserve was 1.11, and that for the lakes of the Tiksi region 1.14, which is typical for high-latitude and high-mountain communities. The number of rare or endangered species varied in different lakes from 1 to 10, totaling 42 species for the entire study area. Bioindication has shown that potentially threatened species prefer moderate temperatures, and slightly acidic or neutral environments free from organic pollution. A comparative analysis of the species composition of diatoms in the vicinity of the Lena Delta and other northern water bodies of Yakutia and the Arctic Islands showed that the species composition of each lake in the Arctic has a discernably different species distribution. The indicator characteristics show a certain response of the species composition of diatoms to changes in salinity, pH, and organic pollution. Regularities in the spatial distribution of diatoms in the study area were revealed in connection with the environmental variables of their habitat. Statistical mapping of diatom diversity data and bioindicators revealed a pronounced response to point pollution, and also let us assume the influence of summer northeast winds on species composition of the studied lake communities. We suggest that the high diversity inherent in the diatom lakes of the Tiksi coastal zone, which can even be updated in further studies, can be considered as a property of coastal biota inherent in ecotones. Since it is in the coastal Tiksi region that a surge in the number of species is observed, this region can be considered not only an ecotone, but also a hotspot of diatom diversity. The results of the study are important for developing the basis for monitoring biodiversity under the conditions of anthropogenic and climatic changes in the Arctic.

Environmental Factors Structuring Diatom Diversity of the Protected High Mountain Lakes in the Kaçkar Mountains National Park (Rize, Turkey)

“…The noticeable presence of species of the genus Pinnularia in the studied flora of the lakes of the park attracted attention, since these species are inherent in the floras of high-mountain and high-latitude reservoirs with fresh, slightly acidic waters and low electrical conductivity [46,49,50], which is confirmed by our chemical analyses (Table 2), that is, they allow us to classify the studied lakes as high mountain habitats not subject to anthropogenic influence. Thus, the ecological conditions of the waters form a suitable environment for the development of representatives of Pinnularia species.…”

“…At the same time, the number of indicators of slightly alkaline waters decreased slightly with altitude. The low degree of the studied lakes' diatom endemism and rarity [15,23,49] was revealed for this first study, which proved to be an insufficient study in the park, on the one hand, and stimulates future research on the other.…”

“…Thus, the ecological conditions of the waters form a suitable environment for the development of representatives of Pinnularia species. In addition, species of the genus Pinnularia are also known to inhabit extreme habitats, including highlands and arctic [49], indicators of diversity hotspots in the Ecotones, which are a border area of different landscapes [51]. Pinnularia interrupta and P. maior, which were found in 14 of the investigated lakes and pond, were recorded very frequently (VF) (86.66%) and were among the important species in the diatom flora of the park (Appendix A Table A1).…”

The Influence of Arctic Conditions on the Formation of Algae and Cyanobacteria Diversity and on the Water Quality of Freshwater Habitats on Kotelny Island, Lena Delta Wildlife Reserve, Yakutia

“…Data on the taxa composition of the Bacillariophyceae, Mediophyceae, and, partly, Chrysophyceae of the studied water bodies were partly published by us earlier [6,8] and their list was borrowed from our works. Handbooks and articles were used for the diatom taxa identification .…”

“…Attention to studying the diversity and conditions influencing the formation of Arctic aquatic communities has a significant history [7,8]. There are still no works devoted to bioindication, the search for the most important environmental factors that determine the biodiversity of aquatic organisms in the conditions of the High Arctic island.…”