Thousands of tourists come to Kamchatka every year to admire the Valley of Geysers. The impressive natural complex of hot fountains has been well studied for a long time. At the same time, the soils of the unique landscape are undeservedly forgotten, according to the geographers of Lomonosov Moscow State University. In the meantime, unusual properties allow them to be distinguished into a special group. Due to the bright multi-colored hue, the name proposed for them will remind of the ancient Greek myth.
The richly colored soil horizon, altered by the high temperature, impresses with an abundance of flowers. Here, red, purple and yellow shades are found on white or blue underlying clays. The geographers at Moscow State University proposed to call the soils of the Valley of Geysers "Narcisols" from the Latin “Narcissus”.
We know daffodils as cute flowers, but not everyone remembers that they got their name from the hero of ancient Greek myths – a young man who became a symbol of vanity and pride. Struck by his beauty, he ended his life tragically, looking at his own reflection on the water surface.
The employees of the Faculty of Geography and Geology of Moscow State University, V.V. Dokuchaev Soil Science Institute, Kharkevich Institute for Information Transmission Problems and Kronotsky Reserve studied in detail the heated (thermal) soils in the Valley of Geysers. So far, they are not included in the vast majority of existing classification systems. At the same time, the analysis of the structure, mineralogical composition, physical and chemical properties showed the presence of specific features in the zones of water and steam outlet with a high content of sulfuric acid. This makes it possible to single out the soils of the Valley of Geysers into a special group, even at the global level.
“Due to the presence of an unusually brightly colored horizon, we suggested calling these soils ‘Narcisols’,” said Ivan Semenkov, a research participant, senior researcher at the Faculty of Geography of Moscow State University.
The soils and vegetation in the Valley of Geysers change depending on the distance from the center of the thermal spot. In the center, the surface temperature reaches 100°С, while at the periphery it remains normal – in the summer it is about 10-15°С. In unheated areas, sandy volcanic soils are widespread – a layered cake of volcanic ash of different ages. Kamchatka tall grasses grow on them – plants up to two meters high. Here, on one square meter, you can find up to 25 of their species.
Soils heated up to 40°C on the surface become more uniform in color. This is due to the more active weathering of minerals. At the same time, the vegetation changes little.
At a higher surface temperature (40–80°C), the species composition of vegetation is sharply depleted. On such sites, on one square meter, no more than six species of flowering plants can be found. The reason is not only a rise in temperature, but also a profound change in soils. Due to the oxidation of hydrogen sulfide, sulfuric acid is formed, which contributes to the transformation of minerals. Soils become saline, toxic substances appear. It is here that a brightly colored horizon, altered by high temperatures, is formed. It can be red, purple, yellow and occurs on white or bluish thermal clays.
Even thermophilic mosses cannot exist at surface temperatures above 80°C. The surface of such areas is covered only with films of algae and bacteria. Under them lie soils, the thickness of which may be less than ten centimeters.
Among the vegetation on thermal soils, representatives of the families of Rosaceae, Poaceae and Cyperaceae predominate. Ferns prefer to live on the periphery of thermal landscapes, where the air humidity is high.
The results of the research carried out in the Valley of Geysers were published on May 27 in an article in “Scientific reports”.