Some types of high grasses form dense tussocks, such grains are common in the southern hemisphere, they are called “tuesok” or “tassok.” In Eurasia, similar life forms observed in ences (Lasiagrostis splendens). With strong herding role of inedible grasses, including nightshade (Solanum), thistle (Carduus), and types of Rapistrum Supaga cardunculus. In the low-lying saline grow Distichlis, tussokovy grass Spartina montevidensis, barley Hordeum stenostachys and salt-tolerant grasses, sedges, reeds, rushes. In the most saline sites can often grow some halophytes (glasswort, Sweda).
I still do not cease debate about the causes of the treeless steppes, prairies, and Pampa. Some researchers even believe that these entities have only a result of human information forests by logging and fires. However, the fires, which indeed have a major impact on the vegetation, there arise naturally (lightning). In addition, there are already data based on pollen analysis, which showed that the existence of the original, even within the forest areas of herbaceous communities. In addition, supportive impact on the appearance of the steppes, prairies, and probably the Pampa previously provided numerous wild ungulates, rodents and locusts.
Tall options steppes, prairies and pampas different well-developed layering of vegetation, which is also evident in the soil horizons – Different species have different structure and length of the root system. All this forms a highly adapted photosynthetic system using a fairly complete energy of solar radiation even for some lack of moisture.
The total phytomass (including underground) here comes to 1500 kg / ha, or 15 kg/m2, although on average these values are close to 5 kg/m2. The annual production of tall herbaceous communities is estimated at 100-200 kg / ha, or 1.2 kg/m2. This compares with a highly productive communities such as deciduous forests of temperate latitudes (see map on p. 62-65).
With increasing aridity phytomass productivity and falling, respectively, up to 100-200 kg / ha (2.1 kg/m2) and 50-100 kg / ha (0.5-1 kg/m2) per year.
First-order heterotrophs that consume dead phytomass (herbivores) and humus (saprophagous) include, as in other biomes, different groups of bacteria, fungi, actinomycetes, invertebrate animals. Among the latter, earthworms are peculiar only to the most humid areas of tall, and is dominated by species able to penetrate deep into the soil. During the summer drought, these animals become less active and go to great depths. A clear rhythmic activity in connection with the change of moisture and other important characteristic of soil littered saprophages know the biological groups of nematodes, soil mites, springtails. Participation in zoomass usually one of the first places belong to the larvae of beetles, in particular the various Khrushchev and dung beetles (family Scarabaeidae), wireworms (larvae of click beetles Elateridae), and pyltseedov larvae of darkling beetles (Tenebrionidae, Alleculidae).
However, these groups of beetles, as well as some other groups of insects, soil-only partly belong to saprophages. This side of the power supply is better expressed in a period of sufficient moisture. In a time of relative drought all the larvae are very happy to move on to the eating of live roots, bulbs and rhizomes.
The abundance of nutrients underground geophytes can exist in the steppes and grasslands similar to numerous rodent-digger who eat mainly cupolas, tubers, rhizomes. Thus in various remote regions of this vital form malorodstvennye are very different kinds of families (mole voles, mole rats, zokor in Eurasia, the prairie gophers, tuco-tuco the pampa). Emissions from land and burrows of rodents burrowing soil scientists usually incorrectly referred to as “wormhole”, although the moles are more common in forest areas.
The rich herbage attracts a diverse consumers of the food. Among invertebrates, surface – is primarily abundant and diverse representatives of the Orthoptera, mainly from the family of grasshoppers (Acrididae). From a close family grasshoppers for our steppes can mention the gigantic size, up to 10 cm, the saga (Saga pedo), although this is quite rare. Most recently, in our European herds roamed the steppes of the ancestors of modern cows – tours, as well as wild horses wild horses, antelopes. Herbivorous rodents in the steppes of Eurasia are of the genus Microtus voles and lemming (Lagurus), but mainly ground squirrels (Citellus) and Baibak or marmots (Marmota).
In the prairies of ungulates were carried out (unfortunately, in the past), bison, pronghorn. Rodents are different kinds of ground squirrels and prairie dogs (Cynomys), like marmots. In the pampas typical rodent – viskacha (Lagostomus maximus). Marmots, ground squirrels, prairie dogs, viskachi form large settlement of a complex system of burrows. Catching sight of the danger, they alert their fellow colony loud shout or whistle, and stand in a column, tail flap and show their concern.
Heterotrophic higher orders in the diet is usually guided by the most massive herbivores. Large birds of prey (steppe eagle, buzzards, harriers) caught mainly rodents and smaller as numerous insects (grasshoppers, beetles). Predatory animals are as common species (wolf, fox – in Eurasia, the coyote – in North America), as well as more typical of the area. The last ones are small (steppe, or light, ferret, for example).