SOIL SCIENCE FACULTY Seasonal dynamics of soil CO2 efflux and soil profile CO2 concentrations in arboretum of Moscow botanical garden Goncharova Olga (goncholgaj@gmail.com), Matyshak G. and Udovenko M. Department of Soil Science, Lomonosov Moscow State University, Russia

Global Distribution of Botanic Gardens The main goal: Evaluate the contribution of soil properties, vegetation, moisture and temperature conditions to the spatial and temporal variability of the carbon dioxide production in urban ecosystems.

Moscow region Rainfall (cm) Min/Max (°C) Rainfall (cm) The mean annual temperature is 5°C, total annual precipitation averages 689.2 mm.

Botanical Garden of the Lomonosov Moscow State University 2004 Red Square Botanic Garden 1958 1962

Sites descriptions Arboretum Cárpinus bétulus Pínus sylvéstris Pícea obováta

Soil morphology Site Depth, cm Color Texture Structure Artifacts, rock fragments Carbonate test Spruce 0-0.5 litter   0.5-8 7,5YR2,5/2 sandy loam very fine – fine subangular blocky ­­– 8-20 7,5YR4/4 fine subangular blocky single fine gravel 20-38 7,5YR5/3, 6/3 silty loam fine angular blocky small pieces of brick and coal 38-60 7,5YR 4/4 loam coarse angular blocky //-//, fine gravel Pine 0.5-15 7,5YR3/2 small pieces of brick and coal, fine gravel 15-45 7,5YR3/2 (8/1) Brick, coal, rubber, metal, glass, carbonate (>10%) Slightly 45-65 Brick, coal, rubber, metal, glass, carbonate (<10%) 65-80 7,5YR4/3 medium-coarse angular blocky – Hornbeam 0.5-18 7,5YR2,5/2 (8/1) medium subangular blocky Carbonate, brick  Slightly 18-34 7,5YR3/2, 3/4 single сarbonate, brick 34-60 7,5YR4/6 very coarse platy

Soil chemistry Site Water-soluble organic carbon, mg kg-1   Water-soluble organic carbon, mg kg-1 Basal respiration, С_CO2µg g-1 h-1 Microbial C, mg kg-1 in upper 10 cm layer hornbeam 49 1,3 1195 spruce 56 0,2 831 pine _ 1,1

Methods Gas analyzer RMT DX6210 Monitoring of the carbon dioxide efflux from the soil surface (close non-steady-state non-through-flow chamber method) (Smagin, 2005; Reth et al., 2005; Bekele et al., 2007) Regime monitoring of the temperature of air and soil (Thermochron iButton), soil volumetric moisture (ТDR-100 Spectrum) Soil CO2 profiles were measured on the same days as soil respiration measurements with subsurface soil air equilibration tubes (Bekele, Kellman et al., 2007; Pacific, McGlynn et al., 2008).

Soil temperature regime Air temperature The annual temperature profile of the soil in spruce plantation (November 2013-October 2014) cm

Seasonal variation of soil carbon fluxes Spruce Pine Hornbeam

Environmental regulations on carbon fluxes Moisture (%, v/v)

CO2 concentration in soil air cm

Conclusions General trends in the annual CO2 production by artificial soils of urban forests are similar to those of natural soils and managed by the same factors. Because the value of CO2 efflux is associated with temperature conditions, the city “heat island” effect can contribute to increased CO2 fluxes. In climatic conditions typical for investigations region, soil moisture in summer period plays a key role in the processes of organic matter mineralization. The value of CO2 efflux by urban soils greatly depends on their construction, organic substrate composition and moisture. A value and fluctuations of the winter-spring CO2 production is associated mostly with physical processes, such as soil freezing-thawing.  

Thanks for attention This work was funded by the Russian Foundation for Basic Research grant № 13-04-01577