28 февраля 2022 года в рамках научно-образовательной школы Московского университета «Будущее планеты и глобальные изменения окружающей среды» был проведен семинар «Rate of Pedogenic Carbonate Accumulation in Canadian Prairies» (Скорость накопления педогенных карбонатов в канадских прериях), на котором выступил профессор Ахмет Мермут (Университет Саскачевана, Канада; Университет Харран, Турция). Приглашаем ознакомиться с его докладом в записи:
Changes in the soil environment influence organic and inorganic C contents and d13C values of soil C across a landscape. The objective of this study was to examine relationships among landscape elements, soil properties, and storage of organic and inorganic C using stable isotope geochemistry. A hummocky landscape, typical of 38 % of Saskatchewan’s land, with glacial till parent material under native grassland was studied.
Organic C content of A horizons ranges between 20 to 98 g kg-1. Both extremes occur in level positions of the south-facing and north-facing slopes. The lowest d13C value of organic C (-29.6‰) was measured in a depression and the highest (more positive) was obtained on a shoulder (-21.7‰). The d13C value of carbonate ranges from -0.9‰ (carbonatic parent material) at the 114 cm depth in level complex to –7.9‰ at depth of 100 cm in footslope complex and depression. These signify considerable variation in isotope geochemistry in a local hummocky landscape.
The amount and percentage of pedogenic carbonate are higher in north-facing slopes than in southward slopes. The highest proportion and amount of pedogenic carbonate up to 1 m depth (95.8 %, and 222.1 kg m-2) was found in Rego Black Chernozem soils (Calcicryolls) in footslope complex position in the north-facing slope, and likely represents a gain in carbonate through lateral flows from the adjacent depression. The lowest proportion and amount (34.4 %, and 33.9 kg m-2) was found in the shoulder complex segment of west-facing slope and in footslope complex position in east-west direction. On average, the soils have accumulated about 1.25 g C m-2 yr-1 of inorganic C (pedogenic carbonate) and 1.25 g C m-2 yr-1 as organic C. The former is a still-building sink, whereas the organic C may well have been at or close equilibrium for millennia.
 Mermut Short CV.docx | 14 Кб |
