Typic Haploturbels Research Articles

Soil-landscape interplays at Harmony Point, Nelson Island, Maritime Antarctica: Chemistry, mineralogy and classification

Soils and landforms of Nelson Island remain one of the least studied in the South Shetlands Archipelago, despite that it is one of the oldest ice-free areas and is strongly vegetated. In this paper, we examine the main processes and factors of soil formation at Harmony Point and the relation of soils to landforms, vegetation and lithology.To achieve the goals, 26 pedons were collected and studied from a 4 km2 ice-free area at Harmony Point (S62°18′; W059°10′) on the southern area of Nelson Island (Maritime Antarctica). The soils were sampled on all representative local landforms, including three levels of uplifted marine terraces up to cryoplanated plateau, waterlogged depressions, rock felsenmeer, debris slopes and patterned ground, and a paraglacial border of the ice cap (270 m a.s.l). Sampling along the cryoplanated plateau was carried out along a gradient extending inland from the margins of the Ice Cap; and sampling of the marine terraces was performed along a chronosequence under varying bird-nesting influence and age. The main pedogenetic processes observed in this area are marked phosphatization, melanization from the accumulation of organic matter, and cryoturbation. Soil development varies from weakly developed, shallow, stony and cryoturbated to well-developed and organic-rich, phosphate soils with colors ranging from grayish to brown. The mineralogical composition of the clay fraction contains secondary minerals, indicating the active role of chemical weathering. Ornithogenic soils have mature phosphate minerals such as vivianite and taranakite, as well as poorly crystalline leucophosphite. Intensively cryoturbated soils are underlain by permafrost and are classified as Typic Haploturbels; polygonal soils are widespread on the cryoplanated plateau. Areas without permafrost were classified as Typic Gelorthents. Phosphatization is a dominant soil-forming process in this area and is associated with past and present-day guano accumulation by bird nesting and has led to the the development of deeper Ornithogenic Haplorthels. The ornithogenic soils occur at different topographic levels on the cryplanated platform and marine terraces. High P concentrations can be used as a proxy of the past nesting birds' activities, with far-reaching implications, especially with regards to vegetation growth and microbial activity and diversity.

Microbial biomass and biological activity of soils and soil-like bodies in coastal oases of Antarctica

The method of luminescent microscopy has been applied to study the structure of the microbial biomass of soils and soil-like bodies in East (the Thala Hills and Larsemann Hills oases) and West (Cape Burks, Hobbs coast) Antarctica. According to Soil Taxonomy, the studied soils mainly belong to the subgroups of Aquic Haploturbels, Typic Haploturbels, Typic Haplorthels, and Lithic Haplorthels. The major contribution to their microbial biomass belongs to fungi. The highest fungal biomass (up to 790 μg C/g soil) has been found in the soils with surface organic horizons in the form of thin moss/lichen litters, in which the development of fungal mycelium is most active. A larger part of fungal biomass (70–98%) is represented by spores. For the soils without vegetation cover, the accumulation of bacterial and fungal biomass takes place in the horizons under surface desert pavements. In the upper parts of the soils without vegetation cover and in the organic soil horizons, the major part (>60%) of fungal mycelium contains protective melanin pigments. Among bacteria, the high portion (up to 50%) of small filtering forms is observed. A considerable increase (up to 290.2 ± 27 μg C/g soil) in the fungal biomass owing to the development of yeasts has been shown for gley soils (gleyzems) developing from sapropel sediments under subaquatic conditions and for the algal–bacterial mat on the bottom of the lake (920.7 ± 46 μg C/g soil). The production of carbon dioxide by the soils varies from 0.47 to 2.34 μg C–CO2/(g day). The intensity of nitrogen fixation in the studied samples is generally low: from 0.08 to 55.85 ng С2Н4/(g day). The intensity of denitrification varies from 0.09 to 19.28 μg N–N2O/(g day).

Distribution of soil taxa in Antarctica: A preliminary analysis

Only 0.35% (49,500km2) of Antarctica is ice-free. These areas are scattered around the periphery of the continent and in interior mountain ranges, making soil mapping difficult. Here we compile the results of mapping in five of the nine ice-free areas that account for 79% of the ice-free area on a reconnaissance scale and interpret the distribution of soil subgroups in Soil Taxonomy. Soils of Antarctica are contained in four orders, dominantly Gelisols (84%), 13 suborders, 27 great groups, and 76 subgroups. Forty-five percent of the soils of Antarctica are Orthels, Gelisols that show minimal cryoturbation and occur in dry landscape positions; 38% of the soils are Turbels showing cryoturbation and occurring in more moist landscape positions. Only 16% of the soils of Antarctica lack permafrost in the control section and are classified as Entisols (Gel-great groups), Inceptisols (Gelepts suborder or Gelaquepts), or Histosols (Gel-great groups). These soils occur almost exclusively along the western Antarctic Peninsula and at elevations below 30m in the South Shetland Islands (SSI) and South Orkney Islands (SOI). Typic Anhyorthels are the dominant soil subgroup comprising nearly 15,340km2, or 31% of the soils in Antarctica. These soils occur primarily in central and southern Victoria Land, but also occur in the Thiel and Pensacola Mountains and Shackleton Range, the Prince Charles Mountains, and the mountains of Queen Maud Land. Typic Haploturbels and Typic Anhyturbels occupy 14 and 13% of the soils of ice-free regions of Antarctica, respectively. Most abundant in central Victoria Land, they are common in most mountainous regions of Antarctica. The dominant soil processes of maritime Antarctica are cryoturbation, gleization, melanization, podzolization, paludization, and phosphatization. In coastal East Antarctica, the major soil processes are rubification, salinization, calcification, pervection, and gleization. The predominant soil-forming processes in the Transantarctic Mountains include rubification, salinization, desert pavement formation, and permafrost development. Measures of pedodiversity will be valuable in the selection of protected areas in Antarctica.

Soils and Landforms at Hope Bay, Antarctic Peninsula: Formation, Classification, Distribution, and Relationships

Antarctic soils occur in restricted areas, but few integrated studies on soils and landforms have focused in the Antarctic Peninsula. We studied the representative soils of Hope Bay, emphasizing the processes of quaternary sedimentation, landforms, soil classification, and distribution. Results show that landforms and soils are closely associated in Hope Bay. Ornithogenic soils are associated with Late Pleistocene to Holocene stable ground moraines; these are currently being destroyed by thermokarst erosion around Lake Boekella. Lithic Haploturbels occur chiefly on shallow rocky terrains whereas Typic Haploturbels are found on patterned ground. In Hope Bay, a much colder climate prevails compared with the South Shetlands, and the widespread permafrost close to the surface warrants strong cryoclastic weathering with active and general gelifraction across different lithologies. The shallow occurrence of permafrost in Hope Bay has a strong regulating effect on soils, retarding leaching and soil development processes. Local soils are, in general, shallow and cryoturbic, and the current pedoenvironment on lowland stable areas was subjected to varying phosphatization on previously weathered sedimentary material. The evidence of phosphatization of a formerly larger area appears to be the main driver of pedogenesis at Hope Bay, and nesting activity by penguins on stable surfaces is capable of enhancing weathering and soil formation.

Soil formation in the Transantarctic Mountains from the Middle Paleozoic to the Anthropocene

In the Transantarctic Mountains (TAMs), soils from the middle Paleozoic and from the Oligocene to the present have been examined. Soils representing other sections of the geologic column are missing, probably because of the low proportion of ice-free areas (0.35%) in Antarctica. The evolution of soils in Antarctica reflects changes in climate and geologic conditions as the continent became separated and increasingly isolated from Gondwana. A greenhouse climate existed during the middle Paleozoic; and an icehouse climate began in the early Oligocene. The climate of the TAMs has become increasingly hyper-arid since the middle Miocene. Humans have had a dramatic effect on the climate of the TAMs during the Anthropocene. The first forest soils (under Callixylon–Archaeopteris forest) on Earth, identified as Alfisols, were discovered in Antarctica and assigned to the middle Devonian. During the Permian, Dicroidium forests covered Entisols and Inceptisols. In the Oligocene, Nothofagus–Podocarpaceae forests contained Gelisols. Miocene-aged soils enriched in silt are common in the TAMs, but they tend to be poorly developed because they have been eroded. A soil evolutionary sequence exists in the TAMs from the Holocene through the Pliocene that includes Glacic Haploturbels on ice-cored Holocene drift, Typic Haploturbels on late Pleistocene surfaces, Typic Anhyorthels on middle Pleistocene surfaces, Salic Anhyorthels on early Pleistocene surfaces, and Petrosalic Anhyorthels on Pliocene surfaces. These changes reflect gradual sublimation of ice in ice-cored drift and ice-wedge polygons, a recovery of the surface from cryoturbation, accumulation of salts, and eventual development of a salt pan. Soils of the TAMs are undergoing rapid change as the climate warms, including loss of semi-permanent snowbanks, an expansion of the hyporheic zone, flushing of salts from soils along valley walls, and the development of thermokarst.

Microbial biomass and community structure changes along a soil development chronosequence near Lake Wellman, southern Victoria Land

AbstractFour pedons on each of four drift sheets in the Lake Wellman area of the Darwin Mountains were sampled for chemical and microbial analyses. The four drifts, Hatherton, Britannia, Danum, and Isca, ranged from early Holocene (10 ka) to mid-Quaternary (c. 900 ka). The soil properties of weathering stage, salt stage, and depths of staining, visible salts, ghosts, and coherence increase with drift age. The landforms contain primarily high-centred polygons with windblown snow in the troughs. The soils are dominantly complexes of Typic Haplorthels and Typic Haploturbels. The soils were dry and alkaline with low levels of organic carbon, nitrogen and phosphorus. Electrical conductivity was high accompanied by high levels of water soluble anions and cations (especially calcium and sulphate in older soils). Soil microbial biomass, measured as phospholipid fatty acids, and numbers of culturable heterotrophic microbes, were low, with highest levels detected in less developed soils from the Hatherton drift. The microbial community structure of the Hatherton soil also differed from that of the Britannia, Danum and Isca soils. Ordination revealed the soil microbial community structure was influenced by soil development and organic carbon.

Distribution of Glacial Deposits, Soils, and Permafrost in Taylor Valley, Antarctica

ABSTRACTWe provide a map of lower and central Taylor Valley, Antarctica, that shows deposits from Taylor Glacier, local alpine glaciers, and grounded ice in the Ross Embayment. From our electronic database, which includes 153 sites from the coast 50 km upvalley to Pearse Valley, we show the distribution of permafrost type and soil subgroups according to Soil Taxonomy. Soils in eastern Taylor Valley are of late Pleistocene age, cryoturbated due to the presence of ground ice or ice-cemented permafrost within 70 cm of the surface, and classified as Glacic and Typic Haploturbels. In central Taylor Valley, soils are dominantly Typic Anhyorthels of mid-Pleistocene age that have dry-frozen permafrost within the upper 70 cm. Salt-enriched soils (Salic Anhyorthels and Petrosalic Anhyorthels) are of limited extent in Taylor Valley and occur primarily on drifts of early Pleistocene and Pliocene age. Soils are less developed in Taylor Valley than in nearby Wright Valley, because of lesser salt input from atmospheric deposition and salt weathering. Ice-cemented permafrost is ubiquitous on Ross Sea, pre–Ross Sea, and Bonney drifts that occur within 28 km of the McMurdo coast. In contrast, dry-frozen permafrost is prevalent on older (≥115 ky) surfaces to the west.

Genesis, properties and classification of Cryosols from Admiralty Bay, maritime Antarctica

Soils from maritime Antarctica are different than those from other Antarctic climatic zones and are among the least studied soils in Antarctica. We here present analytical and morphological data for the main soils found in Admiralty Bay, King George Island in the South Shetland Group. Fifty-six (56) pedons were described, sampled and analyzed according to standard international methods and classified according to both U.S. Soil Taxonomy and the WRB. The soils are generally weakly developed and have chemical, physical and morphological characteristics strongly influenced by the parent material. We identify four main soil groups: (i) basaltic/andesitic, (ii) acid sulfate, (iii) weakly ornithogenic and (iv) ornithogenic soils. Small adjustments are proposed for both classification systems for allowing a more adequate classification for maritime Antarctica. Greyish colored, eutric Lithic and Typic Haploturbels (Turbi–leptic Cryosols) with neutral to alkaline reaction are the most common soils in Admiralty Bay, and are usually developed from basaltic/andesitic tills. Yellowish, acid, dystric Sulphuric Haploturbels (Turbi–thionic Cryosols) are restricted to areas affected by pyritized andesites. Umbriturbels (Turbi–umbric Cryosols) only occur at sites under bird influence. Ornithogenic soils are the most developed soils in Admiralty Bay and show pronounced chemical, physical and morphological alteration of parent materials, with formation of umbric epipedons and phosphatic B horizons. Fibristels (Organo–turbic Cryosols) are restricted to hydromorphic areas under thick moss carpets.

Soil distribution in the McMurdo Dry Valleys, Antarctica

The McMurdo Dry Valleys (MDVs) are the largest ice-free area (ca. 6692 km 2) in Antarctica. Here we present a reconnaissance (scale = 1:2 million) soil map of the MDVs. The soil map units are subgroups as identified in the U.S. Department of Agriculture Soil Taxonomy. The dominant soil subgroups in the MDVs are Typic Anhyorthels (43%), Typic Haploturbels (36%), and Typic Anhyturbels (14%). Soils of the MDVs represent an evolutionary sequence that include Glacic Haploturbels/Anhyturbels on Holocene surfaces, Typic Haploturbels/Anhyturbels on late Quaternary surfaces, Typic Anhyorthels on late to mid-Quaternary surfaces, Salic Anhyorthels on mid-to early Quaternary surfaces, and Petrosalic/Petrogypsic/Petronitric Anhyorthels on Pliocene and older surfaces. Soils on silt-rich tills of Pliocene and older age generally are Typic or Salic Anhyorthels; they feature less weathering than younger soils because (i) they are derived from quartzose materials largely devoid of weatherable minerals and (ii) they have been subject to considerable wind erosion.

Soil formation in Wright Valley, Antarctica since the late Neogene

We investigated over 180 soil profiles on 15 drift units ranging from Recent to Pliocene or older in age in Wright Valley, Antarctica. The drifts originate from (1) post-valley cutting by an advance of the East Antarctic Ice Sheet, (2) advances of the Wright Lower Glacier from grounding of ice in the Ross Embayment, and (3) advance of alpine glaciers along the south valley wall. Holocene and LGM soils lack staining (from oxidation of iron-bearing minerals) and visible salts, contain ice or ice-cemented permafrost in the upper 0.5 m, and are classified as Glacic or Typic Haploturbels. Other soils of late Quaternary age are stained to < 10 cm, contain ice-cemented permafrost in the upper 0.5 m, have stage 1 salts (encrustations beneath surface clasts) and < 1000 mg salts cm − 2 in the upper 70 cm of profile, and are classified as Typic Haploturbels. Soils of mid-late Quaternary age are stained to 20 cm, have ice-cemented permafrost at depths in excess of 1 m and stage 2 salts (flecks and patches covering < 20% of the profile face), contain 1000–1700 mg salts cm − 2 , and are classified as Typic Anhyorthels. Soils of early Quaternary to late Pliocene age are oxidized to depths > 30 cm, have stage 3 salts (flecks and patches covering > 20% of the profile face), contain 4000–4200 mg salts cm − 2 , and are classified as Salic Anhyorthels. Soils of Pliocene age are deeply oxidized (> 50 cm), have stage 5–6 salts (strongly cemented or indurated salt pans), contain 5000–7000 mg salts cm − 2 , and are classified as Petrosalic Anhyorthels. Soils of early Pliocene or older age do not show the degree of development of younger soils because they are derived from Peleus till which contains highly erosive, fine-sandy, quartz-rich rock. Our data question the notion of high-level Antarctic lakes occupying most of the valley during the LGM and early Holocene.