Ecological assessment of short-term dynamics and spatial variability of carbon pools and fluxes in the conditions of the Seim river floodplain ecosystems (on the example of Kursk region)

The assessment of carbon pools and fluxes in ecosystems of different types and scales increases the reliability of national and global assessments of net carbon inflow and net carbon absorption, and clarifies the possibility of using certain carbon balance management technologies. The aim of the work is to study the short-term dynamics and spatial variability of carbon emissions from the surface of alluvial dark humus soils (Eutric Fluvisols) and carbon sequestration in grassy vegetation in the Seim River floodplain. The paper presents the data on the ecological and functional state of the soil and vegetation cover in various elements of the Seim River floodplain. In the studied areas of the floodplain, the soil carbon pool is characterized by high spatial variability due to local features of the mesorelief, dynamics of fiver bed evolution and the species diversity of herbaceous vegetation, while the carbon pool of phytomass varies slightly in space. The rates of CO2 emission from the surface of alluvial dark humus soils (fluvisols) in the last decade of June - the first decade of July can vary quite widely - from 9.6 to 28.7 g CO2 m-2 day-1. In the summer months (June and July), the ecosystems of the Seim River floodplain with contrasting edaphic, biocenotic, orographic and hydrological conditions are a stable carbon sink, in which the difference between CO2 sequestration and its emission into the atmosphere ranges from 7.5 ± 0.8 to 10.8 ± 0.7 g CO2 m-2 day-1.