Cryosols of Antarctica - Cryopedology - page 95

Antarctica which as an ice-free area of 1,635 km 2 (3.3 %); and the inland mountains
which account for 93.3 % (46,165 km 2 ).

9.3.1 Western Antarctic Peninsula

Soils at elevations below 30 m in the South Shetland and South Orkney Islands and
at elevations as high as 200 m along the western Antarctic Peninsula mainland lack
permafrost, are classifi ed as Gelents, Gelepts, and Gelists (Gelists are not formally
recognized in ST yet), and are not considered further here. However, most of the
soils of the WAP contain permafrost in the upper 1 m, are intensely cryoturbated,
and are classifi ed as Turbels. Orthels occur on well-drained uplands, and Histels
occur in wet depressions (Simas et al. 2014 ).
Soils along the WAP contain greater amounts of silt and clay than soils elsewhere
in Antarctica, refl ecting the greater role of liquid water and greater weathering rates
(Table 9.4 ). Because of their proximity to the coast, soils of the WAP are dominated
by Na in water-extracts and on exchange sites. Because of greater plant cover, the
SOC concentrations are greater than in soils elsewhere in Antarctica. The abun-
dance of clay and SOC enables soils of the WAP to have moderately high cation
exchange capacities. However, leaching from abundant precipitation, including
rainfall, results in strongly acid to very strongly acid pH values and low base satura-
tion. Some parent materials contain sulfi des that upon weathering yield acid sulfate
conditions; these soils are common on the Keller Peninsula of King George Island
and on Seymour Island in the Weddell Sea. The ultra-acid pH values in the last
pedon of Table 9.5 refl ect the sulfurization process (De Souza et al. 2012 ).
Soils on the WAP often contain very high levels of Mehlich-1 extractable P
because of the infl uence of penguins and migratory birds such as petrels and skua
gulls. This process is referred to as phosphatization (Pereira et al. 2013a , b ). Birds
also produce high levels of N from their guano and soluble salts from their nasal
excretions. Some examples of soils occurring to a limited extent along the WAP are
given in Fig. 9.2a, d , e. The ornithogenic soil shown in Fig. 9.2f is similar to those
along the WAP.

9.3.2 Coastal East Antarctica

Soils of coastal East Antarctica from Syowa and Molodezhnaya stations in Marie
Byrd Land to Casey Station in Wilkes Land bear properties intermediate between
those of the WAP and Antarctica's inland mountains. These soils are derived from
glacial and marine sediments and tend to be shallow and coarse textured (Table 9.6 ).
However, soils of East Antarctica are often infl uenced by birds (Beyer 2000 ; Beyer
et al. 2000 ), and thin layers of peat may develop in bedrock depressions. One of the