Sulfur content in the soils of Skua and Galindez Islands (Maritime Antarctic)

Sulfur is an important nutrient, as well as a part of some aminoacids, enzymes and vitamins. The lack of sulfur in the plant organism is accompanied by a decrease of photosynthetic pigments content and, by external signs, resembles chlorosis caused by nitrogen deficiency. In Maritime Antarctica the main source of sulfur for terrestrial ecosystems are numerous ornithogenic products – guano, feathers, pellets, etc. However, many soils of this region do not contain visual signs of ornithogenous impact. The purpose of this study was to establish whether the sulfur content in these soils is the limiting factor for plant growth and development. It has been found that the total S content in both ornithogenic and non-ornithogenic soils is high, much higher than in the zonal soils of the temperate climate zone. Most of the sulfur is contained in the organic compounds and is not available for plants – more than 80% in ornithogenic and more than 90% in non-ornithogenic soils. It was found that the availability of sulfur is not a limiting factor for the growth and development of plants on the studied soils of Coastal Antarctica. We suggest that sulfur-containing organic substances play an important role as precursors of soil organic matter under Antarctic conditions.