PROBLEMS OF THE PRESENT-DAY FOREST
Актуальные публикации по вопросам экологии и природопользования.
The jubilee conference of the International Association of Researchers of Boreal Forests (northern forests exposed to stormy winds) was held in August 2011 in Krasnoyarsk. It was established in 1991 in Transcarpathia (Ukraine). Since then such meetings are held on a regular basis but never in Siberia. The importance of relevant biosphere processes is difficult to overestimate. Alexander Onuchin, Dr. Sc. (Biol.), Director of the RAS SB Institute of Forest named after V. Sukachev, told about the results of the last forum to a correspondent of the Science in Siberia newspaper.
According to Onuchin, lately he and his colleagues are mostly preoccupied with one of the key aspects of northern forests, namely, their hydrogeological functions.
Assessment of boreal (as well as temperate) forests is of current interest for North America, Canada, and northern regions of Europe. For example, boreal forests growing in the temperate climate reduce the river flow. By the way, in these regions trees act as moisture evaporators as they have a considerable biomass and high performance.
Northern forests are less productive in this sense--unlike southern forests, they are more sparse and form a thicker snow cover; southern forests normally "catch" precipitation with crowns, especially snow in terms of increased winter temperatures. As for the northern regions, the situation is totally different: solid atmospheric precipitation penetrates the forest cover. In tundra regions, snow is not deep and most of its mass evaporates.
Onuchin pointed out: they carried out a series of laboratory and field experiments showing that during blizzards in terms of severe winters snow evaporates more
Science in Russia, No. 1, 2012
actively than in case of moderate climate. This fact helped local researchers to explain discrepancies in the hydrological assessment of forests: American scientists assured that forests are efficient evaporators and reduce river flows, whereas our specialists who carried out research works in different geographical and climatic conditions obtained opposite results, i.e. according to them, forests are sources of water for water bodies. Thus, as cited by the scientist, the "hydrological significance of forests is, to a greater extent, apparent in boreal forests, where the snow cover is stable for a long period of time and its transformation is evident in winter. In summer, characterized by liquid precipitation, atmospheric water immediately gets into the active moisture circulation, and the moisture balance here first of all depends on the productivity of biogeocenters, not on their type."
Moreover, Onuchin emphasized one of the most urgent environmental problems to be in the focus of mankind in general and scientists particularly: global warming of our planet. Forests are naturally among restraining factors of this process. Further on, the scientist showed that there exist different standpoints on this problem. The greenhouse theory explains warming and increased concentration of carbonic acid gas by progressing use of fossilized fuel by man. There is another point of view that cannot definitely determine causes and consequences of this process. According to it, the increasing air temperature is a result of greenhouse gases evolved from thawing out of frozen soil, methane--from bog systems, etc., in other words, it is not a result of human activity, it is due to global warming.
Moreover, geologists have data proving the fact that warm periods existed on the Earth even before and were accompanied by an increased concentration of carbonic acid gas; inter alia, one of the proofs is an analysis taken from glacial deposits in the Antarctic Continent and Greenland.
S. Churilov, "Forests in the Changing World," -- Science in Siberia, No. 34-35, 2011
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