ШИРОТНЫЕ ИЗМЕНЕНИЯ РАЗНООБРАЗИЯ ГРИБОВ НА МОДЕЛЬНОЙ ТРАНСЕКТЕ ЕВРАЗИИ, "Известия Российской академии наук. Серия географическая"

Abstract

Changes in taxonomic, morphological and substrate specificity of distribution of clavarioid fungi were studied at the Oman-Ural longitudinal transect covered over 6300 km from 20° to 80° northern latitude, along 58° eastern longitude. The works were carried out in two scales. First of scale is cells by 100000 km2 inside 12 latitudinal zones, each by 5° latitude, from the tropical deserts of Arabic Peninsula to the Arctic deserts of Novaya Zemlya Islands. Second scale is 50 localities, by 100 km2 area, situated inside 12 latitudinal cells (as in previous scale). For both scales peaks of species richness of fungi in the close ranges of latitudes, from 50 to 60° N latitude for cells in taiga and south-taiga forests, and 50–65° N latitude, are established. The number of species is reduced to almost zero with decreasing latitude. Such results indicate that the distribution of clavarioid fungi from North to South does not correspond to the “classical” latitudinal gradient of diversity. The number of species in the cells of the Arctic and tropical deserts is similar, and the mean number of species in the localities situated in the tropical deserts is lower than in the Arctic counterparts. The richest localities correspond to cells with average annual temperatures from +1.1 to +4.5 °C. The share of species with small and unbranched fruitbodies positively correlated with latitude, as well as the share of species of saprotrofic grassinhabited taxons. The negative correlation is established for leaves-inhabited taxons, and the share of ground species is relatively constant throughout the entire transect. The share of widespread species, for both scales, is maximal at the desert “ends” of transect, whereas is minimal in the middle latitudes, characterized by the highest number of species. This distribution of the microbiota reflects the bioclimatic specificity of transect: a wide spreading of cryo- and arid deserts, and steppes, in which there are no specific species. The distribution of fungi in a greater degree demonstrates no pattern of changes in diversity with latitude, but the rule of limiting under extreme conditions, which is characterized by a decrease in species richness with increasing pessimal conditions.