黄土高原不同侵蚀类型区生物结皮中蓝藻的多样性

Abstract

Cyanobacteria were the major components in biological soil crusts(biocrusts).So far,studies on species composition and distribution of cyanobacteria in the biocrusts in the Loess Plateau region were fresh.Biocrusts from the revegetated grasslands in different erosion regions(wind erosion,water erosion,and the wind-water crisscross regions) of the Loess Plateau region were collected,cultured,observed and identified.Results showed that cyanobacteria were the dominant component of the biocrusts.We found 54 species belonging to 10 genera and 4 families,with filamentous cyanobacteria dominant.The Shannon-Wiener index was used to evaluate diversity of the regions.No significant difference was found between the species diversity of water-wind erosion crisscross region and water erosion regions,while diversity in the wind erosion region was significantly lower than the water erosion region or the wind-water crisscross erosion region.Species composition and dominant species of the three erosion regions were different.Oscillatoriaceae was the dominant family from all the three regions.Cyanobacteria species diversity was greatest(39) in the water-wind erosion crisscross region,followed by the water erosion region(26) and the wind erosion region(20).However,the dominant species were different in the three erosion regions.The dominant cyanobacteria species in water-wind erosion crisscross region,water erosion and wind erosion region were Lyngbya allorgei,Phormidium calciola and Oscillatoria granulate,respectively.Differences in cyanobacteria composition in the three different erosion regions were likely associated with differences in soil texture,soil pH and climatic regimes.