Swamps

SWAMPS, a characteristic landscape of the middle (taiga) and northern (tundra) zones of the USSR, extending far south along river valleys into the steppe zone. The basic feature of any swamp is the presence of peat deposits, i.e., the accumulation of plant residues in various stages of aerobic and anaerobic decomposition. This decomposition process only partially brings the organic matter of plants to complete mineralization, i.e., to the breakdown into CO2, water, and ash; in most cases, only humification, or peat formation, of plant residues occurs, resulting in a mixture of undecomposed parts of plants with humic acids and their salts. The humification process is accompanied by the enrichment of peat with carbon at the expense of hydrogen and oxygen. The excess water causing peat deposition and, consequently, the formation of swamps, is created either due to topographic conditions raising the water to the surface of the soil, or solely from atmospheric precipitation retained by the already formed layers of peat (mossy watershed swamps). The physical and chemical properties of peat in swamps depend, first of all, on the plants that form this peat. The vegetation of swamps, in turn, is closely linked to the amount of mineral nutrients in the soil layer. Two sharply different groups of swamps have long been noted by practitioners and scientific researchers. The first group includes lowland, or meadow, swamps, which do not rise above the level of lake or groundwater, rich in mineral substances. This group includes swamps in the valleys of slowly flowing rivers, at the foot of their terraces, along the banks of hard-water lakes, and on mountain slopes. The vegetation cover on lowland swamps is very diverse but is always formed by plants requiring mineral nutrition: sedges (Carex species), green mosses (from the genera Hypnum, Meesea, Paludella, etc.), grasses (reeds, couch grass), a whole series of other herbaceous plants, and from woody species—alder, birch, spruce, and willows. Peat from lowland swamps contains 5 to 15% ash, and in some cases even more. The second group includes highland, or moss, swamps; they are located almost exclusively on watersheds, in areas with poor sandy or podzolic soils. Occupying a watershed position, highland swamps have no inflow of water from the side and are nourished only by atmospheric precipitation. The southern boundary of the distribution of highland swamps passes through the BSSR, the Kaluga, Ryazan, Nizhny Novgorod, and former Kazan provinces. The development of highland swamps is conditioned by the peculiarities of the dominant plant on them—peat moss, or sphagnum (Sphagnum). The latter consists of hollow cells equipped with pores, which allows it to absorb water up to 20 times its weight. A highland swamp composed of layers of sphagnum peat can be compared to a sponge saturated with water. The extreme unpretentiousness of sphagnum to mineral salts allows it to develop with scanty mineral nutrition from atmospheric moisture. The average ash content of sphagnum peat fluctuates from 2 to 4%. On a continuous whitish-yellow cover of sphagnum grow only a few higher plants—cranberry, bog rosemary, Cassandra, andromeda, cotton-grass, blueberry, and from woody vegetation—a wretched, suppressed, early-decaying pine. The area occupied by swamps in the European part of the USSR is distributed between highland and lowland swamps in the Central Industrial region approximately equally; to the north, the percentage of highland swamps increases, and in the Leningrad region (Western Leningrad and Novgorod provinces), Vologda and Arkhangelsk provinces, highland swamps dominate. The total area of swamps (both highland and lowland) is characterized by the following figures as a percentage of the area of the provinces: Arkhangelsk—54%, Western Leningrad—31%, Western Novgorod—28%, Tver—12%, Moscow—6%. South of this, the area of swamps rarely exceeds 3%, except in the Polissya region, where swamps occupy up to 28% of the entire area. Swamps play a large role in the life of the country. Countries such as Holland and the northwestern districts of Germany have made swamps, to a certain extent, a source of their prosperity by simultaneously using peat from swamps for fuel and for animal bedding, and the surfaces of swamps and areas remaining after peat extraction—for fuel for agricultural crops. Draining swamps, with rare exceptions, is a technically easily accomplished task, but requires thorough surveys (leveling and probing) and a well-thought-out plan, since improperly conducted drainage works can lead to further swampy conditions (and consequently to an increase in new places for the breeding of mosquitoes). Draining large swampy masses is not harmful to the country's water management; on the contrary, it has been proven to introduce uniformity into the water regime of river systems. Some types of lowland peat, especially those containing hydrogen sulfide, are used for medicinal purposes along with the sludge of salt lakes and lagoons. Only for the Lipetsk muds is it known that reed-sedge peat is applied there; in most cases, the botanical composition of medicinal "muds" has not been elucidated.

D. Gerasimov. Swamps in Sanitary Aspect. If swamps play a large role in the economic life of the country, they have no less significance for the health of those living in swampy areas. The presence of high humidity in the atmospheric air of swampy regions is reflected, first of all, in its influence on air temperature. The presence of a significant amount of water vapor in the air, on the one hand, promotes greater absorption of solar rays by the atmosphere, and on the other, significantly hinders the emission of heat from the earth's surface at night. The high degree of humidity of the atmospheric air in swampy areas also influences the state of the surface layers of soil (excessive moistening) and the state of vegetation, the longer preservation and reproduction of microorganisms, the disturbance of the thermal economy of the human organism, and the change in the hygroscopic state of surrounding objects (clothing). Damp soil, with high-standing soil water, in swampy areas has an unfavorable effect on dwellings (dampening of foundations and walls, appearance of dampness inside rooms, air pollution, mold, etc.). Due to the processes of rotting and decomposition of organic substances in swamps, there is also constant air pollution. Swamp water, due to its pollution, can in no case be used for drinking. The water of peat quarries, due to the large amount of calcium and magnesium salts, is hard; moreover, the presence of iron salts and humic acids makes it unacceptable from the point of view of general sanitary assessment. Among epidemic diseases characteristic of swampy areas, malaria must be mentioned first of all. Not only the population living in swampy areas but also doctors-geniens of former times linked the appearance of various epidemics to swamps. Malaria is a vivid example of such epidemic diseases. For a long time, the view prevailed in science that malaria is contracted by inhaling swamp vapors ("miasms"), which is why the expression "miasmatic diseases" originated. It is now known that the culprit of malaria is not miasms but plasmodium, and that it is transmitted by the mosquito Anopheles. Although not all swamps are equally suitable for the breeding of Anopheles, the presence of extensive water spaces, mostly small and easily warmed by the sun in the summer period, makes these places constantly vulnerable in a malaria regard. Furthermore, swamps can be a source of outbreaks of intestinal infections, depending on the pollution of swamp water with corresponding microbes. Finally, swamp water can also serve as a source of infection with some helminthic diseases.