Absorption of Atmospheric Carbon Dioxide by the Wetland Ecosystems of Russia in Holocene. The Problems of Paludification

Wetland ecosystems are the net carbon (atmospheric carbon dioxide) sink for the atmosphere. The analysis of paludification speed and intensity of carbon accumulation in the peat in Russia during the Holocene is presented. During that period most of the peat bogs were formed in Russia. According to the current estimates, the area of peat bogs is 1.68 million km(2), with wetlands - 3.69 million km(2). All these lands contain more than 100 billion tons of carbon (Gt 100.93). Russia ranks first in the world in terms of accumulated peat. Annually 66 thousand Ha are swamped in the world. The average speed of paludification in Russia in Holocene was 15... 18 thousand Ha per year. It varied under the influence of changing climatic, hydrological, geological, morphological and other factors, and it was significantly different in some natural zones and regions of Russia. For example, the average rate of paludification in Karelia (north-western part of Russia) in Holocene was 400 ha per year, while it ranged from 150 to 755 ha per year. The most intensive logging and peat accumulation was found during the Atlantic period of Holocene, when the types of wetland ecosystems and their balance were changed. The other areas of North-Western and Western Siberia of the Russian Federation have similarities of waterlogging. To date, the numerous data on the rate of carbon and peat accumulation in bog ecosystems of different types an average during the Holocene are gathered in Russia. These results are not complete and, unfortunately, make it impossible to determine the current rate of accumulation of organic matter in the marshes and the nature of the ecosystem functioning (whether a marsh is a net sink or a net source of carbon dioxide for the atmosphere). Marsh drainage may increase the emissions of carbon dioxide into the atmosphere. To determine the current (over the seasons, decades) rate of net carbon accumulation the balance method and the method of mathematical modeling of the marsh ecosystem are used. The calculations of the present rate of net carbon accumulation by the swamps according to the R. Clymo model (as modified by I.E. Turchinovich) showed that it was 37.6 million tons of carbon per year. Currently, the process of paludification in Russia have been intensified as a result of the global climate changes and extensive damage of the drainage systems.