17:15 〜 19:15
[MIS05-P11] New data on the structure of macrozoobenthos communities of the Arctic lakes of Kolguev Island
キーワード：Arctic ecosystems, macrozoobenthos, lake communities, environmental factors
Arctic ecosystems are highly specific due to the harshness of the living conditions for living organisms. Arctic water bodies mostly have distinct life cycles, from emergence to silting and overgrowing. One of the most important factors influencing this process is climate. Understanding this cycle and the ability to identify stages by macrozoobenthos will allow us to predict the impact of climate on Arctic lake ecosystems. Kolguev Island, being in close proximity to the well-studied Bolshezemelskaya tundra, allows us to assess the impact of island isolation on the composition of macrozoobenthos communities. The territory of the island is occupied by low-arctic tundra. The shores of the reservoirs are surrounded by bushes of shrub willows, turf of Comarum palustre L. and Carex spp. Shallow waters are characterized by thickets of helophyte - Hippuris vulgaris L. The bottom is predominantly silty, often with a large admixture of peaty detritus, sometimes there are areas of sandy-detrital and rocky bottom.
To analyze the structure of lake communities, materials collected in July and August 2018 in the Peschanka River basin were used. Samples were taken using a hemispherical sampler with an area of 0.02 m2. A total of 145 samples from 50 small lakes were analyzed. All samples were fixed with 70% ethyl alcohol. Interpretation of the relationship of macrozoobenthos communities with environmental conditions was carried out using ordination by the methods of Redundancy Analysis RDA and Canonical Correspondence Analysis CCA.
In the collected material, 127 species of macrozoobenthos were found, which greatly expands the fauna of Kolguev Island. More than half of the species richness falls on representatives of the order Diptera, among which the subfamilies Orthocladiinae and Chironominae account for 44% of the total identified species diversity.
Most macrozoobenthos species in both localities have a wide Palearctic (they account for 24% of species) or Holoarctic (70%) distribution. The share of species with arctic species is no more than 10%.
Three types of macrozoobenthos communities are distinguished: phytal, ripal and pelal communities. The greatest contribution to the biomass of communities of all types in both localities is made by representatives of the class Malacostraca and the type Mollusca.
In the thermokarst lakes of Kolguev Island, external factors have a weak effect on communities, the main contribution comes from internal factors or external factors not covered by this study. The greatest contribution is due to the biotope character factor (7.3%). The second most important factor was hydrochemical parameters, explaining 4.1% of the differences, with acidity accounting for 3.1%. No less important were the morphometric characteristics of the lakes, as well as the date of collection (in combination with temperature), explaining 3.4% and 2.2% of the differences, respectively.
To analyze the structure of lake communities, materials collected in July and August 2018 in the Peschanka River basin were used. Samples were taken using a hemispherical sampler with an area of 0.02 m2. A total of 145 samples from 50 small lakes were analyzed. All samples were fixed with 70% ethyl alcohol. Interpretation of the relationship of macrozoobenthos communities with environmental conditions was carried out using ordination by the methods of Redundancy Analysis RDA and Canonical Correspondence Analysis CCA.
In the collected material, 127 species of macrozoobenthos were found, which greatly expands the fauna of Kolguev Island. More than half of the species richness falls on representatives of the order Diptera, among which the subfamilies Orthocladiinae and Chironominae account for 44% of the total identified species diversity.
Most macrozoobenthos species in both localities have a wide Palearctic (they account for 24% of species) or Holoarctic (70%) distribution. The share of species with arctic species is no more than 10%.
Three types of macrozoobenthos communities are distinguished: phytal, ripal and pelal communities. The greatest contribution to the biomass of communities of all types in both localities is made by representatives of the class Malacostraca and the type Mollusca.
In the thermokarst lakes of Kolguev Island, external factors have a weak effect on communities, the main contribution comes from internal factors or external factors not covered by this study. The greatest contribution is due to the biotope character factor (7.3%). The second most important factor was hydrochemical parameters, explaining 4.1% of the differences, with acidity accounting for 3.1%. No less important were the morphometric characteristics of the lakes, as well as the date of collection (in combination with temperature), explaining 3.4% and 2.2% of the differences, respectively.