II Международная студенческая научная конференция Студенческий научный форум - 2010

Cyanobacteria are the most important source of nitrogen in arctic ecosystems. The aim of this study was to determine the quantity and diversity of cyanobacteria in association with mosses and lichens in high and low nutrient areas across Spitsbergen, Svalbard. These associations are known to be important for nitrogen fixation in the arctic. It was also important to see how the water content of the site affected the presence of cyanobacteria. For analyzing the cyanobacteria in the cephalodia of the lichens, a PCR based STRR fingerprint method specially developed for genetic diversity analyses of cyanobacteria strains was applied. Nine different fingerprints were obtained from this method. The highest diversity of cyanobacteria was seen at the bird cliffs and the lowest diversity was seen at the glacier foreland.  The mosses were analyzed to determine their species name, and then select species were analyzed with a fluorescence microscope. The mosses showed the highest quantity of cyanobacteria by the bird cliff and the lowest quantity of cyanobacteria by the glacier foreland. Cyanobacteria were found in relatively the same amount at a given location, regardless of moss taxa. Moist or wet soil conditions did not affect the quantity of cyanobacteria. The results contradict other scientific studies which indicate that there should be a greater quantity of cyanobacteria in the glacier foreland than at the birdcliffs. However, these studies focused more on free-living colonies than on mosses and lichens.  

The results of this study indicate that there is no correlation between nitrogen fixation and the quantity of cyanobacteria in Arctic habitats. They also indicate that in moss and lichens in Arctic ecosystems, cyanobacteria quantity and diversity is less prevalent in low nutrient areas than in high nutrient areas. However, the sample size of this study was low and these results need to be further investigated before a definite conclusion can be drawn.

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