Pilot carbon polygon in Russia: analysis of carbon stocks in soils and vegetation

Abstract

The aim of the study: Analysis of carbon stocks in soils and vegetation on the territory of the Pilot Carbon Polygon “Ugra”. Location and time of the study. Kaluga region, Ugra National Park, March–October, 2020. Methodology. The study was carried out on soils of four land use types: i) arable lands, ii) abandoned arable lands under grassland vegetation, iii) young forest vegetation (25–30 years old), and iv) mature mixed forest (75–80 years old). Two-four plots were located in each land use type. Soil samples were taken up to 50 cm by 10 cm layers. The content of organic carbon (Corg), total nitrogen (N), and the C/N ratio were determined. Considering soil density, the Corg and N stocks were calculated in the top 20 and top 50 cm. In the top 20 cm, the particle size distribution, pH(KCl), water holding capacity (WHC), and microbial properties (basal respiration, BR and content of microbial biomass, Cmic) were determined. Based on the forest inventory, the carbon stocks in phytomass and mortmass (dead trees) were estimated. Main results. The Retisols of the Carbon Polygon “Ugra” are characterized by a sandy loamy texture and slightly acidic (arable and abandoned lands) or acidic (forest areas) reaction. Microbial activity in the top 20 cm of soil decreases in the following order: abandoned lands under grassland > young forest stands (25–30 years old) > arable lands > mature mixed forest. The BR variability was determined by 86–90 % by the Cmic content. The highest Corg stock in the 0–50 cm layer was in the arable soils (65.4±4.4 t C/ha), and the lowest Corg stock (41.4±0.4 t C/ha) was observed in the soils under young forest. The C/N ratio in the top 10 cm varied from 8.9 to 17.6 and depended on the composition of plant litter at the soil surface. The main C pool in the forest ecosystems, regardless of their age, was the phytomass of woody plants. This C pool exceeded the total Corg stocks in the 50-cm soil layer by 1.6 and 4 times in young forest and mature mixed forest, respectively. The total C stocks in the mature mixed forest were 3 times larger than in young forest stands. Conclusions. The C stocks and the state of the soils of the Carbon Polygon “Ugra” depend on the current land use type, which in turn determines the composition of plant residues input on and in the soil. This is the reason for the most distinct differences between the studied soils in terms of Corg and N content, C/N ratio, and microbial characteristics. The age of forest stands is a key factor determining the total C stocks in soils and forest biomass.

Dynamics of Soil Fertility Indicators in Protective Forest Plantations

“…The speed and direction of soil transformation under the influence of various types of vegetation in various natural and climatic conditions is not only of particular scientific interest, but also of agroeconomic interest due to the significant potential of the agricultural sector in the country's economy [5,6]. Afforestation is a powerful tool in solving the problem of global climate change due to carbon sequestration by the phytomass of woody and herbaceous vegetation, as well as the soils of protective plantings [3]. However, the question of the role of forest belts in the production of soil organic matter requires further study, which is the goal of this work.…”

The Characterization of Biodiversity and Soil Emission Activity of the “Ladoga” Carbon-Monitoring Site

“…The global soil carbon stock is 3.2 times the size of the atmospheric pool and 4 times the size of the biotic carbon pool [9]. There are different estimates that about 20% of the world pedosphere carbon stocks are accumulated on the territory of Russia; for the 0-100 cm layer, it is from 285 to 364 Pg SOC under the global carbon stocks of 1417-1824 Pg SOC in the one-meter layer [10][11][12]. For the 30 cm soil layer on the territory of Russia, the major part of carbon stocks is accumulated in mineral soil horizons-62%; the rest falls on organogenic soil horizons as follows: 20%-peat of wetland soils; 9%-peat of semihydromorphic soils; 9%-carbon of litter [12].…”

“…For the 30 cm soil layer on the territory of Russia, the major part of carbon stocks is accumulated in mineral soil horizons-62%; the rest falls on organogenic soil horizons as follows: 20%-peat of wetland soils; 9%-peat of semihydromorphic soils; 9%-carbon of litter [12]. In addition, significant stocks of organic carbon in Russia are concentrated in terrestrial phytomass, which is 38.8 Pg C or 7.2% of the global carbon stocks of terrestrial phytomass estimated at 550 Pg [10,11]. Losses of soil organic carbon result from various factors; at the global level, the main factor in the reduction of world stocks of SOC is global climate warming [13].…”

“…The loss of carbon from forest degradation and deforestation is up to 15% of anthropogenic carbon emissions [16]. Therefore, in the framework of the implementation of the Russian Carbon Supersites project, a qualitative and quantitative assessment of soil carbon stocks and emission potential of soils at each of the monitoring sites is mandatory [11].…”

Pilot Carbon Landfill: Analysis of Carbon Reserves in Farmland Soils

“…На Россию приходится пятая часть мировых запасов почвенного органического углерода. Пул почвенного органического углерода, включая торфяные залежи, в метровом слое почвы на территории нашей страны составляет от 298 до 342 Гт С, или от 18 до 23% мировых запасов углерода в педосфере [7]. Размеры биомассы почвы почти в 700 раз больше, чем в океане, хотя на долю суши приходится менее 1/3 земной поверхности.…”