Distribution of soil algae in salinized irrigation land in the arid region of Central Asia

Abstract

Distribution patterns of soil algae were investigated in a 14-year-old farm and its surroundings in the salinized irrigation land of Central Asia. Using a culture dilution method, the densities of five groups of soil algae, green colony group (composed of chlorophytes together with xanthophytes), Chroococcales, Oscillatoriales, Nostocales in the orders of blue-green algae, and diatoms, were estimated. The differences in the distribution patterns among the green colony group, the Oscillatoriales and the N ostocales attributed to soil salinity and soil moisture. As the green colony group was more sensitive to salinity than the blue-green algae, the density decreased at a relatively higher salinization level (EC>ca. 8 dS m-1). The blue-green algae, especially the Nostocales, were not affected by such degree of salinization. However, the nostocalean blue-green algae also could not occur in the further developing safinized part where salt crusts were observed. These results show that few soil algae occurring at the study site were able to adapt to the land with high salinity induced artificially. Around the sand dune where salt accumulation had never occurred, several species belong to the green colony group were dominant and few blue-green algae were observed. This observation suggests that these species had developed some strategies to tolerate water stress because this area was subjected to extremely dry conditions.

Irrigation in the Ili River Basin of Central Asia: From Ditches to Dams and Diversion

“…Salinity later rose to 0.75 to 0.9 g/L and by 2000 was 1.1 to 1.2 g/L [105]. Fertility declined as a consequence, as humus was flushed away and the soil became increasingly saline and alkaline [124] and began to support an altered microflora [125,126]. This has led to diminishing rice yields that remain consistently below the 7 tons/ha predicted by the area's climate [105].…”

High-Throughput Absolute Quantification Sequencing Reveals that a Combination of Leguminous Shrubs Is Effective in Driving Soil Bacterial Diversity During the Process of Desertification Reversal

“…Cyanobacteria are photosynthetic bacteria that play an important role when subjected to environmental stress. Biological soil crusts with Cyanobacteria can be isolated in many desert systems [ 78 , 90 ]. After years of sand fixation with straw checkerboards combined with different shrubs, it was found that the abundance of Cyanobacteria was higher in the combination containing one leguminous and one nonleguminous shrub (CaKCaM) (Fig.…”

HEMIFLAGELLOCHLORIS KAZAKHSTANICA GEN. ET SP. NOV.: A NEW COCCOID GREEN ALGA WITH FLAGELLA OF CONSIDERABLY UNEQUAL LENGTHS FROM A SALINE IRRIGATION LAND IN KAZAKHSTAN (CHLOROPHYCEAE, CHLOROPHYTA)1

“…The algal strain (BAKg15) was isolated by Tsujimura (1998) from the soil samples collected in a Bakbakty farm located in the Ili River basin, Kazakhstan. The moisture content and pH of the soil sample were 20.2% and 9.1, respectively.…”

“…Most of the green isolates showed characteristics similar to the species reported in the previous taxonomic studies; however, the characteristics of certain isolates were not congruent with the descriptions hitherto made. Tsujimura (1998) found a coccoid green alga (BAKg15) that had two flagella of considerably unequal lengths.…”