title: Effects of sand burial on biomass, chlorophyll fluorescence and extracellular polysaccharides of man-made cyanobacterial crusts under experimental conditions.
abstract: Soil cyanobacterial crusts occur throughout the world, especially in the semiarid and arid regions. It always encounters sand burial, which is an important feature of mobile sand dunes. A greenhouse study was conducted to determine the effects of sand burial on biomass, chlorophyll fluorescence and extracellular polysaccharides of man-made cyanobacterial crusts in six periods of time (0, 5, 10, 15, 20 and 30 d after burying) and at five depths (0, 0.2, 0.5, 1 and 2 cm). The results indicated that with the increase of the burial time and burial depth extracellular polysaccharides content and Fv/Fm decreased correspondingly and there were no significant differences between 20 and 30 burial days under different burial depths. The degradation of chlorophyll a content appeared only at 20 and 30 burial days and there was also no significant difference between them under different burial depths. It was also observed a simultaneous decrease of the values of the Fv/Fm and the content of extracellular polysaccharides happened in the crusted cyanobacterium Microcoleus vaginatus Gom. It may suggest that there exists a relationship between extracellular polysaccharides and recovery of the activity of photosystem II (PS II) after rehydration.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: WeiBo
authors.initials: W
authors.lastname: Wang
authors.forename: CuiYun
authors.initials: C
authors.lastname: Yang
authors.forename: DongShan
authors.initials: D
authors.lastname: Tang
authors.forename: DunHai
authors.initials: D
authors.lastname: Li
authors.forename: YongDing
authors.initials: Y
authors.lastname: Liu
authors.forename: ChunXiang
authors.initials: C
authors.lastname: Hu
mesh_terms: D018533:Biomass; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D000458:Cyanobacteria / Q000254:growth & development / Q000378:metabolism*; D005453:Fluorescence; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D012822:Silicon Dioxide; D012988:Soil Microbiology
chemical_list: D011135:Polysaccharides, Bacterial; D002734:Chlorophyll; D012822:Silicon Dioxide; D000077194:Chlorophyll A