Разнообразие сообществ почвенных диатомовых водорослей Государственного природного заказника «Фролихинский»

Abstract

The species composition of soil diatoms in Frolikhinsky State Nature Reserve was studied. Flora of diatoms algae was represented with 128 taxa of 4 classes, 12 orders, 23 families and 49 genera. The greatest diversity of species was found on the bank of the Bireya River (77 species), and the lowest – on the Barguzinsky ridge pass (3 species). In most species and intraspecific taxa of diatoms (97%) found in the reserve, the occurrence rate varied from 10 to 40%. An occurrence rate above 40% was noted only in four taxa that were identified as leading: Pinnularia borealis (80%), Adlafia bryophila (50%), Gomphonema parvulum (50%) and Planothidium lanceolatum (50%). The complex of dominant species was diverse and included representatives of 15 families. 36 species and intraspecific taxa were classified as dominants, 20 taxa were classified as subdominants. The complex of associated species included 6 taxa, 67 taxa were found singly and occasionally. Pinnularia borealis Ehrenberg had the highest occurrence at all sites. The families Fragilariaceae, Achnanthidiaceae, Naviculaceae, Ahnanthaceae, Gomphonemataceae, Cymbellaceae, Cocconeidaceae, Eunotiaceae, Pinnulariaceae, Bacillariaceae, Sellaphoraceae were characterized by high species diversity. Comparison of diatoms complexes (DC) in different plots of the reserve revealed similarities and differences of floristic diversity and taxonomic structure. The main reasons of taxonomic heterogeneity of DC in different areas are the conditions defined by their location within the natural reserve. The largest number of species was found on the shores of water bodies characterized by a high degree of moisture. The least abundant and diverse diatoms were represented in shaded and insufficiently moist areas of coniferous forests with abundant coniferous litter and acidic soils.