D. G. Zamolodchikov

Carbon Stock and Deposition in Phytomass of the Russian Forests

Russian forests occupy an area of 771 Mha with a wood volume of 81.6 × 109 m3. In this paper we estimate the carbon (C) storage and annual C deposition in living vegetation for stands of different age groups according to information in the Russian National Forest Inventory (NFI). Conversion of root C storage into phytomass was based on phytomass/storage ratios calculated from data from 1900 test areas in the different forest regions of Russia. We developed these conversion ratios for different phytomass fractions, namely: stems, branches, roots and foliage, for different forest forming species. Of the total forest area (771 Mha), C storage in the living phytomass is 35.07 Pg C. Total annual C deposition in forest vegetation is estimated at 213.2 Tg C. We considered the role of the main forest forming species in the C cycle of the forest vegetation taking into account the actual structure of the Russian forests.

CO2 flux measurements in Russian Far East tundra using eddy covariance and closed chamber techniques

The objective of this study was to estimate the CO2 exchange of a tundra ecosystem in the Russian Far East using the eddy covariance technique using closed-chamber measurements as a reference. An eddy covariance tower was placed near the Lavrentiya settlement (Chukotskiy Peninsula, Russia, 65° 36′N, 171°04′W) within a typical tundra landscape. During the 85 d of continuous measurements [Julian days (JD) 205–289, 2000] the CO2 exchange of the studied ecosystem was found to be close to equilibrium (a carbon sink at 10.2 gC m−2). In the late summer period (JD 205–240) the ecosystem sequestered 32.1 gC m−2, whereas in autumn (JD 241–289), it was functioning as a carbon source of 21.9 gC m−2. Model-based estimates of ecosystem respiration and gross primary production were obtained over the period of observations. These are the first eddy covariance-based measurements performed in the Russian tundra.

Sensitivity of tundra carbon balance to ambient temperature.

Summer field observations in thenorth-east European region of Russia (1995–1996) proved thatnatural local and temporal warming could cause similarreversible changes of carbon (C) balance pattern ofsouth tundra ecosystems. Thirty-six diurnal chambermeasurements of carbon dioxide fluxes at two differentsites (67°57′N, 64°40′E; 67°20′N,63°44′E) in 4 main types of ecosystems werestudied. Wide magnitude of ambient mean diurnal airtemperature (from +4.1 to +20.2 °C) allowed toobtain significant linear relationship between thisparameter and variation in ecosystems C net flux (from–2.6 (sink) to +2.0 (source) gC m-2 d-1, R2 = 0.769). In the midst ofthe vegetative season, an increase of mean diurnal airtemperature in the plant canopy over the criticalvalue of +14 °C lead to a change in the C netflux from sink to source. This can revert with atemperature decreases below the critical value. Theabove-mentioned effect is mostly due to thetemperature influenced increase of gross ecosystemrespiration. The summer temperature induced changesmay result in positive (C source) annual C balance insome studied ecosystems. The annual C loss ofshrub-dwarf shrub community in 1996 was estimated at45 gC m-2 yr-1. We consider ourresults to be another evidence of possible positivefeed-back between climate warming and C emission tothe atmosphere on short-term and regional scales.

Dynamics of carbon pools and fluxes in Russia's forest lands

The state and results of studies on the carbon cycle of forests on lands of the Russian forest fund (total area 1172 × 106 ha) are analyzed at the federal level. Consideration is given to changes in the areas of different categories of forest lands, the age structure of stands, the pool and deposition of carbon in the phytomass, and the organic carbon pool of soils over the period from 1966 to 1998; the dynamics of activity in the forest industry by years and the extent of pyrogenic transformation of the forest cover between 1990 and 2001; and carbon fluxes associated with forest exploitation, including carbon emission resulting from fires.

Active-Layer Monitoring in Northeast Russia: Spatial, Seasonal, and Interannual Variability

This paper focuses on regional analysis of results from a program of active-layer monitoring at three active CALM (Circumpolar Active Layer Monitoring program) sites in northeast Russia. The length of the observation period varied between 3 and 9 years at different sites. Thaw depth was measured mechanically on 100 × 100 m grids with 1-4 replications at each grid node, 1-4 times per thawing season. Additional parameters, depending on site, were volumetric soil moisture, thickness of the organic layer, thickness of the moss cover, absolute elevation of nodes, surface disturbance and quality of microhabitats, and density of vegetation cover. There were no evident trends in end-of-season thaw depth at our sites in northeast Russia during the 1994-2002 period. Water tracks, surface disturbances, soil moisture, and organic soil horizon thickness are major controls over spatial variations of end-of-season thaw depth. The influence of different factors on the thawing process is seasonally specific. Temporal variation of thaw depths is strongly temperature dependent.

Mitigation Potential for Carbon Sequestration Through Forestry Activities in Russia

Publisher Summary This chapter assesses the carbon budget of Russian forests and estimates possible carbon sequestration through forestry and land use activities. Forests occupy enormous areas in Russia and play an important role in the global carbon cycle. The existing data on a Russian forest land inventory produces an initial approximation of the carbon cycle of forest ecosystems. The carbon pool in living vegetation of the Russian Forest Fund has varied during the past 35 years between 33 and 35 Gt C, depending on the year. The soil carbon pool is significantly larger than the vegetation pool and varies from 178 to 184 Gt C. Since 1966, the annual accumulation of carbon in growing forests has increased from 185 to 252 Mt C per year. The amount of carbon in wood removed and logging residue decreased from 160 Mt C per year in 1966, to 70 Mt C per year in 1998. The area suitable for reforestation constitutes 45 million ha, while an additional 11.0 million ha are designated for afforestation for soil protection purposes. The maximum total annual amount of sequestration due to reforestation and afforestation is 81 Mt C per year. The accumulated carbon pool in the woody biomass of newly established forest stands potentially amounts to 4.1 Gt C.

The Carbon Cycle in the Ecosystems of Thermal Springs in the Chukchi Peninsula as a Natural Model of Warming

Comparative studies on the ecosystems in the vicinity of thermal springs and in the typical tundra were performed in the southeastern Chukchi Peninsula in July and August 1997. Biogenic carbon fluxes during the greater part of the growing season were determined, the aboveground phytomass structure was studied, and the carbon reserve in the soil was estimated. It was demonstrated that the gross primary production and soil carbon in thermal ecosystems are greater than in similar permafrost ecosystems. The structural and ecophysiological changes leading to an increase in the gross production of plant communities were analyzed.