Soils and soil-like bodies of coastal antarctica: genesis, spatial diversity, temperature regime, age, ecological functionsтезисы доклада

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Работа с тезисами доклада

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1. сборник тезисов SouthCOP_2019_Conference_Handbook.pdf 2,7 МБ 21 декабря 2019 [NikitinDA]

[1] Soils and soil-like bodies of coastal antarctica: genesis, spatial diversity, temperature regime, age, ecological functions / A. V. Lupachev, N. S. Mergelov, S. V. Goryachkin et al. // 1st Southern hemisphere conference on permafrost, SouthCop, New Zeland. — Queenstown, New Zeland, 2019. — P. 4–14. Despite the initial investigation of parent rock weathering processes and possible soil formation in Antarctica that was conducted by Soviet scientists in 1958, regular and extensive studies of the Antarctic soils and permafrost simultaneously began only in the late 2000-s by the teams of geocryologists and pedologists from Puschchino headed by David Gilichinsky and from St.-Petersburg headed by Dmitry Vlasov. The spatial coverage of the Russian Antarctic Expedition’s research stations and logistic operations is the world’s most dense with 5 wintering, 2 seasonal and 4 irregularly visited abandoned stations. This allowed the scientific groups to conduct long-term investigations of soils, parent rocks and soil-like bodies and monitoring of the active layer in coastal and trans-ice-shelf oases around the Antarctic continent as well as on the Subantarctic islands. Following the WRB for soil classification, the most widely distributed soils with well-expressed profile organization are Leptosols and Cryosols. The significant areas are occupied by the soils with ornithogenic (2-5% of the whole territory of given oases) and technogenic (5-15%) impact. At the same time, a number of rocks are inhabited by epi-, hypo- and endolithic communities which demonstrate diverse set of organo-mineral interactions and are capable to produce soil-like profiles at the microscale level. The preliminary study shows that in some cases the carbon flux in “ahumic” soil-like bodies with no vegetation cover is comparable to the relatively well-developed soils under the algobacterial mats or lichens. The mean values of carbon dioxide emission during the austral summers varied from to 117 mg C m-2 hour-1 with the highest values recorded in moss rich soils of the wind shelters. According to the 14C analysis the topsoil organic matter is relatively young (< 500 yr BP) mainly due to the disturbances caused by various types of erosion. However, the 14C age of the subsoil organic matter can reach n*1000 yr indicating the presence of legacy carbon. The oldest organic matter in East Antarctica was found in the soils of wind shelters and endolithic soil-like bodies. In the geographical aspect, all the regions of the studied oases may be referred to two soil geographical divisions - Low-Antarctic humid barrens (Bellingshausen station at King George Island) and Mid-Antarctic snow-patch barrens - barren landscapes with contrast hydrological regime where strong paludification caused by thawing snow patches in one places is in combination of soil dryness of other snowless places. The soil cover of the largest oasis of East Antarctic – Bunger Hills is characterized by transitional combination of soil features between snow-patch barrens and cold deserts, including salinization and calcification. The main feature of Antarctic soil geography is that it has no manifested soil zones but only “islands of pedosphere” in glaciers. These fragments of soil cover don’t depend on the latitude and macroclimate but mostly are controlled by local factors – topography, parent materials, wind direction, seas bird rookeries. The results of the 10-years monitoring of the mean depth of the active layer as a part of CALM-S and GTN-P programs show the relatively stable soil temperature regime with no significant signs of active layer depth increasing. Authors underline that the time period of the monitoring is still too short to identify trends. The investigation of the anthropogenically impacted soils and Antarctic Technosols themselves have shown that a significant part of them can be identified as “moderately polluted” and “significantly polluted” by the concentrations of local (oil and polyaromatic hydrocarbons, heavy metals) and global (pesticides and organochlorines) pollutants. The long-term study was logistically supported by Russian Antarctic Expedition and funded by projects of Russian Foundation for Basic Researches and Russian Scientific Foundation.

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