The role of permafrost ecosystems of Yakutia in global climate change

Institute for Biological Problems of Cryolithozone, SB RAS, Yakutsk

Head of the Institute:

Boris I.Ivanov, Doctor of Agricultural Sciences, Professor
41 Lenin Ave. Yakutsk, 677891, Russia
Tel.: 8 (411 2) 44 56 90, Fax: 8 (411 2) 44 58 12

Principal researchers:

T.C.Maximov, Ph.D., Head of the Plant Ecology Laboratory

Project objectives

Investigation of carbon cycle and water balance in typical taiga-alas and tundra ecosystems under global climate changes.

Background and significance of objectives

According to prognoses of some ecologists, by the middle of the next century an increase in average planet temperature by 3+1,5°Ñ will have occured (Manabe, Wetherald, 1980; Thomas, 1979). The increase may be 7-8°Ñ at mid- and high latitudes and can reach 12°Ñ on the poles. Data analyses from 400 observatories around the world, made by Japanese scientists, show that the planet air temperature increase for 1980-90 was about 0.3°Ñ. In connection with possible climate warming, two variants are discussed: first, the warming will not be accompanied by an increase in precipitation amount and will result in aridisation of territories; secondly, there will be a compensatory increase in precipitation amount. Forecasting, precipitation amount in Central Yakutia will increase inappreciably – up to 30 mm per year, exceeding 60 mm in northern tundra regions (Zavelskaya et al., 1993). Under these conditions, the movement of larch into tundra will occur at a speed of about 80 m per year (Velichko et al., 1990; Huntley, Birsk, 1983; Keuk, 1989). For some tree species the rate of transgression may reach 200-300 m, and for pioneer species – more than 500 m per year (The greenhouse effect.., 1989). It is possible for some plant species to extinct. Together with that, the movement of C4 plant species with specific morphological, physiological and biochemical features to the North is noticed. Among all the greenhouse gases, the share of carbon dioxide in air temperature rise is about 43% (Veretennikov, 1992).

The Arctic zone of Sakha Republic (Yakutia) with its vast tundra and forest-tundra ecosystems is a huge reservoir of organic material accumulated during centuries. Universally distributed and near-surface laying highly-iced frost is a conservative of the greenhouse gases of the past époques accumulated during millennia. A temperature rise under these conditions can trigger activation of biogeochemical processes of organic material stock transformation, speed up release of air conserved by frost, and will lead to change in boundaries of agricultural zones. On the other hand, relative atmosphere enrichment by CO2 is facilitated by anthropogenic degradation of forests of cryolithozone, which leads to a decrease in the volume of photosynthetic carbon dioxide absorption and to loss of ecological importance of boreal forests.

A considerable contribution of vast ecosystems of Yakutia (tundra, forest) to atmosphere enrichment by CO2 has been shown. This phenomenon is connected with intensive carbon dioxide release from soil in summer-autumn and winter periods when resident woody-shrub plants are in the state of organic and induced dormancy – carbon dioxide is practically not absorbed (Ivanov et al., 1993, 1995, 1996; Maximov et al., 1996; Ivanov, Maximov, 1998). Entering dormancy and slowdown of physiological processes in plants of different formation-typological composition occurs from the end of August till the end of September. The results of these changes can strongly influence energy and water cycle of the whole Pacific region.

The project is directed at solving fundamental problems of ecology in relation to the global climate change and finding out the role of frost ecosystems in these processes.

On this direction of investigations, large scientific material has been obtained by the staff of the IBPC SB RAS on forest ecosystems, more that 50 papers have been published in Russian and foreign press, including 7 thematic workbooks, and 8 international symposia and conferences have been held.

Research plan: approaches and methods

Modern methods will be used on ecology, pedology and plant physiology for studying circle fluxes of energy and water using domestic and foreign devices with the automated system Data Logger.

Within the framework of the international project GEWEX/GAME-Siberia, in summer 1996, a tower (30 m in height, made in Holland) was installed in the typical larch forest around scientific station “Spasskaya Pad” of the IBPC SB RAS (30 km away from Yakutsk). This installation for ecological monitoring is the only in Russia and equipped with unique and high-priced automatic devices and equipment. In this research program on GAME-Siberia our Institute provides biological part of the study, namely, conduction of hydroclimatic, ecological-physiological and soil investigations (see Figure). As it was planned in the project, expanding of monitoring sites is scheduled, with installation of masts and towers with analogous devices in an alas ecosystem and a typical pine forest.

Expected results

Monitoring and ecological researches of energy and water fluxes in natural complexes of tundra and forest-tundra zones of Yakutia will allow us to reveal the role of northern ecosystems in global climate change and estimate their contribution on the planet level. Special attention will be given to substances and energy cycle in the system “plant-soil-atmosphere”. For the first time original data will be presented on water and carbon balance and their effect on productivity of tundra and forest-tundra ecosystems of multi-year-frost zone. The results of the investigations can be used in forecasting climate changes of frost areas under the influence of circle processes in atmosphere, climate influence on the productivity of natural vegetation, and also in forecasting shifts of agricultural zone boundaries to the North.

Research in this direction has not been conducted before. There are occasional measurements by foreign scientists, mainly from the USA, Japan and Italy, which provide difficult interpretation of the data concerning this region.

List of publications of participants related to the project