Chemical properties were measured on soil samples from five sites, differently influenced by penguin guano, from Cape Bird, Antarctica. Organic C and total N contents were high in the more recently influenced soils, but fell to low levels in soil from the longabandoned colony (radiocarbon age of penguin remains from the subsurface horizon, 4b, is 7070±180 years B.P.); total P was less affected. Uric acid and NH4+−N were the major N forms in soil from the occupied and recently-abandoned sites. Re-worked guano and the long-abandoned site contained very little uric acid, but high levels of NO3-−N compared with the other soils. A large proportion of most of these samples was soluble in H2O. The major H2O-soluble ions were NH4+and HPO42-in the most recent soils, and Na+and, usually, Cl−in the others. Mg2+was generally the major exchangeable cation. Results are discussed in relation to previous analyses of antarctic ornithogenic soils, and guano deposits and more normal soils from other parts of the
展开▼
