meadow(redirected from Professor Sir Samuel Roy Meadow)
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a biogeocenosis whose plant component consists chiefly of perennial mesophilic grasses, adapted to average moisture conditions and growing throughout the growing season (without the summer interruption characteristic of steppe plants).
Meadows are connected by transitional terrain with other grassy biogeocenoses, such as steppes and grassy bogs. Most meadows originate on the site of forests and scrub or dried bogs and lakes or as a result of the irrigation of steppes. Natural meadows develop only where climatic and soil conditions are more favorable for perennial mesophilic grasses than for other plants—on long inundated floodplains, on mountains, at seashores in subarctic and subantarctic regions, and around limans in steppe and semidesert regions.
Meadows are valuable grasslands and are used both as hayfields and as pastures. They are very diverse in origin, age, phytocenoses, plant habitat conditions, and yields (10-100 quintals dry weight per hectare [ha] and more). The formation of herbage and sod (that is, the top layer of soil mixed with the roots and rhizomes of grasses) is common to all meadows. The bulk of the ground plant parts in a meadow is usually from three to five times greater than that of the aboveground parts.
There are about 4,000 species of herbaceous plants growing on meadows in the USSR. Grasses or sedges prevail in the herbage. Marked variability (seasonal and annual) and rapid changes brought about by the grazing of cattle, the mowing of hay, and land improvement and reclamation are characteristic of meadows. The differences between meadow types are more or less equalized by intensive use (especially by properly managed grazing) and care (addition of fertilizers, for example).
There are three types of meadows: continental, floodplain, and mountain meadows. Continental meadows are found on plains other than floodplains and are classified as dry meadows (located on plains and slopes fed only by atmospheric precipitation) and low-lying meadows (located in depressions in which soil and groundwaters are close to the surface). Dry meadows develop in the forest zone on the sites of forests on podzolic or brown (less commonly, gray forest) soils. The grasses are comparatively low-growing and unproductive. Substantial stretches of these meadows are used in field-crop rotations or are converted by liming, fertilization, or sowing into long-term cultivated pastures. Low-lying meadows are found in the forest, forest-steppe, and steppe zones. Their soils are richer, and their grass stands more productive than those of dry meadows.
Floodplain meadows are confined to river valleys inundated during high water. They are widespread from the tundras to the deserts and most extensive in the forest and forest-steppe zones. Floodplain meadows are more productive and varied than continental meadows. Substantial areas are used for truck gardens and field crops.
Mountain meadows are found in mountainous regions with a humid and fairly warm climate (in the USSR, they are found in the Carpathians, Caucasus, Tien-Shan, Altai, and Urals) above the timberline (subalpine and alpine meadows) and in the forest zone on the site of destroyed forests (after-forest meadows). Subalpine meadows with stands of comparatively tall grasses are used both as hayfields and as pastures. They are more productive than the alpine meadows, which are located at higher altitudes, are characterized by low-growing grasses, and are used as pastures.
The total world area of meadows is about 150-200 million ha, concentrated in the temperate zone of the northern hemisphere (mainly in the USSR and Western Europe) and in New Zealand. Meadows are being used more intensively in the USSR and abroad. The sown area is increasing, and greater quantities of fertilizers are being used. Irrigation of meadows has become more common. Meadows formerly mowed only once are mowed two or more times a season or turned into efficient pastures.
REFERENCESKormovye rasteniia senokosov i pastbishch SSSR, vols. 1-3. Edited by I. V. Larin. Moscow-Leningrad, 1950-56.
Rabotnov, T. A. “Chto schitat’ lugom?” Botanicheskii zhurnal, 1959, no. 1.
Senokosy i pastbishcha. Edited by I. V. Larin. Moscow, 1969.
T. A. RABOTNOV