[Energy and mass transfer and the productivity of the main ecosystems of Siberia (according to the results of measurements by the method of turbulent pulsations). 2. Carbon exchange and productivity].

Using direct measurements of CO2 fluxes by the method of turbulent pulsations, it was shown that the studied middle-taiga pine forest, raised bog, true steppe, and southern tundra along the Yenisei meridian (approximately 90 degrees E) are stocks of carbon of different capacity in the annual output. The tundra starts to function as a stock of carbon from June; the forest and bog, from May; and the steppe, from the end of April. In the transitional seasons and winter, the ecosystems are a weak source of carbon: the tundra already in September; the forest and bog, from October; and the steppe, from November. The photosynthetic productivity of the forest and steppe ecosys- tems (480-530 g C/(m x year) exceeds 2-2.5 times the productivity ofbogs and tundras (200-220 g C/(m x year). The relationships between the thermal balance structure and CO2 exchange are shown. Possible feedbacks between the carbon exchange between the ecosystems and the atmosphere as a result of climate warming in the region are assessed.

[Energy and mass exchange and the productivity of the main ecosystems of Siberia (from eddy covariance measurements). 1. Heat balance structure in the vegetation season].

Direct measurements of heat balance (turbulent heat transfer and evaporation heat consumption) by the method of turbulent pulsations in 1998-2000 and 2002-2004 were used to obtain information on the daily, seasonal, and annual dynamics of energy fluxes and mass transfer between the atmosphere and the typical ecosystems of Siberia (middle-taiga pine forest and raised bog, true four-grass steppe, with the use of data for typical tundra) along the Yenisei meridian (90 degrees E).