Microalgal communities from ornithogenic soils at Cierva Point, Antarctic Peninsula.

MATALONI, G.; TELL, G.

POLAR BIOLOGY

Springer

Lugar: Stuttgart; Año: 2002 p. 488 - 491

0722-4060

Abstract             Microalgal communities inhabiting three soil sites with different degrees of influence from penguin colonies within and near the Cierva Point Site of Special Scientific Interest (64º 10´S, 61º 01´W) were analysed and their species composition and diversity compared with those in nearby mineral soils. Concentrations of NH4-N and PO4-P increased drastically as a function of the degree of use by the penguins. This chemical variation was accompanied  by changes in algal community structure: chlorophytes and diatoms dominated the less enriched site, while cyanobacteria were the exclusive dominants at the most enriched site.  A significant fraction (28%) of the recorded species were also present in the mineral soils, but their abundances decreased with nutrient concentration. Biodiversity as measured by Shannon diversity index was lower than in the mineral soils, and dropped from 1.796 to 0.444 with increasing influence of the bird colonies. These observations indicate that soil algal  biodiversity decreases with increasing trophic status, as recorded for freshwater phytoplanktonic communities.