Soil Respiration in Forest Ecosystems in the South of the Far East.

The Far East remains the least studied part of Russia with respect to terms of carbon fluxes. A review of the results of field measurements of CO2 emission from the surface of forest soils obtained at 26 sites in the southern part of the Far East on the territory of four constituent entities of the Russian Federation is presented. The measurements were performed in different forest formations (larch, Siberian pine, oak, and ash–elm forests), including forests in the permafrost zone. Information on seasonal and daily dynamics of the emission is presented. For 14 sites, equations for estimating emissions on the basis of air temperature data from the nearest weather station have been obtained. Annual carbon fluxes vary within 5.5–10.1 t C/ha with a maximum in the old-growth Siberian pine–fir forest of the southern Primorye region. The contribution of the summer season to the annual flux is 46–65%. In the Republic of Buryatia, CO2 emissions from the soil surface strongly depend on temperature and soil moisture. In waterlogged soils, the emission is significantly affected by the groundwater level (R2= 0.42). [ABSTRACT FROM AUTHOR]