Soil Organic Matter Accumulation and Carbon Fractions along a Moisture Gradient of Forest Soils

Abstract

Abstract:The aim of the study was to present effects of soil properties, especially moisture, on the quantity and quality of soil organic matter. The investigation was performed in the Czarna Rózga Reserve in Central Poland. Forty circular test areas were located in a regular grid of points (100 × 300 m). Each plot was represented by one soil profile located at the plot's center. Sample plots were located in the area with Gleysols, Cambisols and Podzols with the water table from 0 to 100 cm. In each soil sample, particle size, total carbon and nitrogen content, acidity, base cations content and fractions of soil organic matter were determined. The organic carbon stock (SOCs) was calculated based on its total content at particular genetic soil horizons. A Carbon Distribution Index (CDI) was calculated from the ratio of the carbon accumulation in organic horizons and the amount of organic carbon accumulation in the mineral horizons, up to 60 cm. In the soils under study, in the temperate zone, moisture is an important factor in the accumulation of organic carbon in the soil. The highest accumulation of carbon was observed in soils of swampy variant, while the lowest was in the soils of moist variant. Large accumulation of C in the soils with water table 80-100 cm results from the thick organic horizons that are characterized by lower organic matter decomposition and higher acidity. The proportion of carbon accumulation in the organic horizons to the total accumulation in the mineral horizons expresses the distribution of carbon accumulated in the soil profile, and is a measure of quality of the organic matter accumulated. Studies have confirmed the importance of moisture content in the formation of the fractional organic matter. With greater soil moisture, the ratio of humic to fulvic acids (HA/FA) decreases, which may suggest an increase in carbon mobility in soils.

The Composition and Stability of Clay-Associated Organic Matter along a Soil Profile

“…However, the high diversity of soils and ecosystems make it difficult to predict the impacts of biogeochemical regulators on organic carbon (OC) storage. The relative importance of all the mechanisms may differ depending on specific environmental conditions, soil features, and vegetation [1,6,7]. Understanding of the chemistry and stability of SOM at different soil depths is needed to understand the controlling factors of SOM persistence in dynamic landscapes.…”

Impact of deadwood decomposition on soil organic carbon sequestration in Estonian and Polish forests

“…Dry and wet site conditions cause slower deadwood decomposition rates (Shorohova and Kapitsa 2014). Błońska and Lasota (2017) observed the highest accumulation of carbon in swampy soils where the anaerobic conditions affected the organic matter decomposition, leading to slower decompositional processes. Temperate and boreal forest soils have been proposed to sequester more carbon dioxide to reduce the pressures of climate change (Wan et al 2011;Wiesmeier et al 2016).…”

“…It is believed that, among abiotic factors, climatic conditions have the greatest impact on the soil organic matter content. Among the climatic factors, temperature and moisture are the characteristics that most influence the decomposition of soil organic matter (Bani et al 2018;Błońska and Lasota 2017). Boreal and temperate forests cover 25% of the terrestrial land surface of the Earth.…”

Comparison of Topsoil Organic Carbon Stocks on Slopes under Soil-Protecting Forests in Relation to the Adjacent Agricultural Slopes

“…In the global carbon cycle, soils constitute the third largest reservoir. It is estimated that carbon contained in soil accumulate 75% of the total organic carbon pool, exceeding twice the resources of carbon in the atmosphere [9][10][11]. Globally, the soil contains a carbon pool estimated at approximately 1500 Gt of organic carbon in the first 1 m of the soil profile [12].…”