The Meadow It is a herbaceous plant formation with a dry temperate climate, dominated by grasses in a flat to undulating terrain. In this sense, the term prairie is equivalent to the grassland template of English.
This vegetal formation is part of the biome of graminiform formations of flat lands of the world, next to the tropical savannas (America and tropical Africa). However, temperate prairies or grasslands differ greatly from tropical savannas in temperature regime and species composition..
The meadows have a very simple structure with a single layer of grasses of variable height and in some cases small shrubs. They present a fertile soil, with abundant organic matter in the surface horizon..
The evolution of these ecosystems has been linked to herbivory and periodic burning. On the other hand, human activity has caused a relevant negative impact, particularly hunting, agriculture and farming..
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The meadow is a plant formation with a very simple structure since it is mainly made up of a single herbaceous layer. This stratum varies from west to east in the North American prairies, with sparse grasslands to the west, middle to the center, and highlands to the east..
Typical prairie soil is deep (1 m or more) rich in humus, potassium, phosphorous, and trace elements (Chernozem). Aboveground biomass of grasses dies during dry summer.
Then this biomass is incorporated into the substrate by the action of worms and other animals, forming the layer of humus.
In this context, the limitation for the development of trees and shrubs is the climate and not the edaphic conditions. However, grasslands may develop locally in areas with shallow or heavy metal saline soils..
Fires are a characteristic feature of prairies, be they natural or anthropogenic fires. Periodic burning contributes to the renewal of the pastures and the dark coloration of the soil A horizon.
The large supply of herbaceous biomass generated by grasslands has facilitated the development of large populations of herbivores. These can be large like buffalo or gazelles and antelopes, even small like the prairie dog..
Human beings have altered natural grasslands with their activities for thousands of years. Mainly intensive agriculture and livestock, but also the introduction of exotic plant species such as numerous pastures.
In many cases, especially in Western Europe, human intervention has altered the limits and natural characteristics of grasslands. This is due to the introduction of species or the selection of the most productive natural ones..
The introduction of these species has generated the development of large areas with very little specific variation. For example, ryegrass grass meadows (Lolium spp.) and the forage legume called white clover (Trifolium repens).
In the United States, 55 species of prairie grasses are threatened or endangered. Additionally, 728 more species are candidates to enter the threat category..
Fauna populations have been particularly affected by hunting or due to contamination by agrochemicals. The hunt led to near extinction species such as the buffalo or American bison.
For their part, prairie dogs have been affected by poisoning problems.
Poor management of the prairie by North American farmers produced the disaster known as dust bowl or "dust bowl." This was the product of a massive desertification process due to the intensive use of land for cultivation..
The soils lost their structure combined with a particularly dry period and strong blizzards from 1932 to 39. All this even caused sand storms and the soils were unproductive..
Some authors restrict the term prairie only to these North American grass formations. The prairie is the largest floristic province in this region of the planet
In these meadows, tussock grasses predominate, that is, they form continuous covers on the ground thanks to their stolons and rhizomes. They, in turn, are subdivided into three basic types according to the height of the plants determined by a humidity gradient:
They develop east of the North American central plain, where the influence of rainfall is less. This generates a drier climate that restricts the development of the vegetation called the great North American plain..
They are found in the central region of the North American plain where there is greater precipitation and favors the development of vegetation.
These grasslands receive the highest humidity from oceanic influence and have more fertile soils, therefore the pastures are taller. This vegetal formation limits the east with the temperate forests.
The grasslands in this region of the southern hemisphere present a differentiation based on the amount of precipitation. Thus, the humid pampas have an average rainfall of 1,000 mm per year and the dry pampas only 400 mm on average per year..
The higher humidity in the humid pampas (located to the east), is due to the influence of the Atlantic winds.
These are the plains located in Argentine Patagonia, a plain that extends from north to south in cold weather. In this sense it differs from the pampas due to the climatic conditions, being colder and less humid..
Unlike the other meadows, the veld combine grasses and small shrubs, among them legumes of the genus Acacia. They develop on a high plateau (1,500-2,100 meters above sea level) so they have a cool climate.
These are the great plains that form a central continental strip with a cold semi-arid climate. Plants are xerophilic, that is, adapted to water scarcity and there is a higher proportion of non-grass plants (dicotyledonous).
The predominant biotype of grasses is the tillers (individuals that generate numerous shoots at one point forming a tuft of culms or stems). In this way, a humid and warm microclimate is generated inside the cluster..
They are located in southeastern Australia between the forest zone and the arid interior, from the north to the south of New South Wales. Today, most of it is dedicated to raising sheep and growing wheat.
Unlike other grasslands, in this area there is an open eucalyptus forest with a cover of grasses. Tree species include eucalyptus (Eucalyptus spp.) and casuarinas (Casuarina equisetifolia) and the dominant grass is Mitchell grass (Astrebla lappacea).
In the southern New Zealand Alps, on the South Island, there are temperate grassland communities of secondary origin due to degradation of mixed temperate forests. This was caused by deforestation and burning generated first by the Maori then by the settlers.
In the mountain systems of different latitudes there are graminiform formations called mountain meadows. They are of variable extension and develop in terraces, plateaus and high intramontane valleys.
There are small mountain meadows in the Andean mountain range, in the Rockies, the Alps, the Pyrenees and many other mountain ranges. On the other hand, there are extensive grasslands such as the steppes of the Tibetan plateau (Tibet) or of Dauria (Siberia, Russia).
These plant formations are characterized by low temperatures and freeze in winter. Beyond the climatic similarities imposed by altitude, these grasslands vary greatly in species composition.
The flora and fauna composition is determined by the geographical location, soil conditions and water availability..
In the northern hemisphere grasslands occur in large continuous belts in North America and Eurasia. For the southern hemisphere they are distributed discontinuously, mainly in South America, South Africa and Australasia.
The North American Prairie encompasses the entire Central Plain stretching from southern Canada to northern Mexico. In a west-east direction it goes from the Rockies to the temperate forests of the Atlantic coast.
The Pampean Plain or Pampas extends through the center-east of Argentina, Uruguay and the state of Rio Grande do Sul (Brazil).
The grasslands called steppes extend across the plains of Eastern Europe (Hungary, Ukraine). They also spread through central Asia and the south of the temperate forests of Russia, China and Mongolia..
The veld are grasslands typical of the southern African cone, extending to the north and northeast of South Africa.
These Australian grasslands or savannas are located in the southeastern quadrant of Australia.
The dominant family in the prairie is Poaceae (Gramineae) with various species, especially perennial grasses.
Grasses of the Arundinoideae and Pooideae subfamilies predominate, unlike tropical savannas where Chloridoideae and Panicoideae are abundant..
In the central plains of North America alone there are more than 1,000 species of plants. As for the number of individuals, grasses dominate, but there are many other species of different families.
Of the North American prairie grasses, genera such as Andropogon, Panicum, Poa Y Stipa. There are also composites of the genres Aster, Helianthus, Tridax and few subshrubs and shrubs such as Tephrosia virginiana (Leguminosae) and Smooth sumac (Rhus glabra).
A notable species is the prairie rose (Arkansana rose) and the western prairie orchid (Platanthera oraeclara).
Species of common genera are found in the American prairies, as in the case of Stipa grandis. Likewise, species such as Leymus chinensis and bushes like Artemisia frigida (Compositae) common to North America and Eurasia.
On the other hand, there are legume herbs like Caragana microphylla (Fabaceae), native to Eurasia.
Grasses have adapted to three grassland environmental factors such as drought, herbivory, and fire. In this sense, they have developed various underground propagation structures such as basal buds, rhizomes and stolons..
The basal buds are at the base of the stems or culms below the ground, protected from the action of fire and herbivores. The aerial part is burned or consumed and the plant sprouts again with the fall of the rains.
The same happens with the adaptations of underground stems (rhizomes and stolons) that allow the vegetative reproduction of the species.
The meadows develop temperate climates, dry in most of the year and a temperature that varies from 0º C in winter to 25 ºC in summer. In the northern hemisphere it is the plant formation typical of the intermediate zone between arid zones to the south and temperate forest to the north.
However, in the case of the cold Asian steppe there is a dry continental climate, far from the oceanic influence..
The determining factor for the formation of the prairie is the climate, especially the precipitation and the rain. This differentiates it from tropical savannas where the limiting factor is fundamentally the soil..
In some grasslands most of the precipitation falls in winter, while in others it is in summer. In any case, the total annual precipitation ranges between 300-400 mm and 1,000 mm..
A prominent feature of the grasslands is the presence of large herds of herbivores associated with predatory carnivores..
The emblematic animal of the prairies of North America is the buffalo or American bison. The grasslands supported a population of 60-100 million individuals before the arrival of the European colonizers.
The buffalo was hunted by the North American indigenous communities, but it was not threatened. However, with the European colonization millions of animals were hunted to take advantage of their skin, meat, fat and bones.
Another gregarious grassland herbivore is the prairie dog, of which there are 5 species. This animal forms colonies that in the past numbered about 400 million inhabitants.
Today colonies of up to a million individuals are known, occupying hundreds and even thousands of square kilometers in extension..
They are canids that hunt alone or in pairs, they inhabit a wide area from North America to Colombia. It is an omnivorous animal that has adapted to eat the organic remains in the garbage.
In nature, it feeds by hunting small animals and also consumes fruits and herbs.
It is a nocturnal carnivorous mammal related to weasels and badgers that is in the process of being reintroduced. It inhabited the prairies and its main food was prairie dogs, as well as rodents and rabbits.
It became extinct in the wild in 1980, with some specimens in captivity and today it is being reintroduced in the prairies of Wyoming (USA). The current wild population is estimated at 1,500 individuals.
It is a carnivore related to ferrets and weasels that feeds on small prairie animals..
It is a poisonous snake of 1 to 1.5 m in length, whose name comes from the sound it generates when it wags its tail. The cause is a structure that forms at the end of the tail as a result of the accumulation of skin with the shedding..
It feeds on rodents, prairie dogs and other small animals, which it inoculates with a neurotoxic poison..
Human activities have almost disappeared from the region the larger animals characteristic of the pampas.
It is one of the big cats in the world, it is also called the American lion. It was a common predator in the pampas, but hunting has practically made it disappear from the region.
It is a large running bird endemic to the pampas and there are two subspecies or species according to the author (American rhea Y Rhea pennata). The first of the species inhabits the pampas, while the second is restricted to Patagonia.
It is a medium-sized deer endemic to the pampas, whose populations are extremely small. Today it is protected, but in the past it was subjected to strong hunting pressure and its habitats are greatly altered. During the 19th century, more than 2 million skins of this deer were exported.
It is an omnivorous canid, that is, they eat plants and small animals, endemic to the pampas.
This antelope inhabits the steppes from Russia to China and Mongolia, but the largest populations are in Central Asia (Kazakhstan and Uzbekistan). They are critically endangered by poaching because their horns are in demand in traditional Chinese medicine..
It is the only species of wild horse that exists in the world with scattered, scarce and few populations. This species inhabits the steppes from China and Mongolia to Ukraine.
Most of the large animals have disappeared due to hunting and alteration of their habitats.
It is one of the few large mammals that maintains significant populations in the veld. It is an extremely fast gazelle and is the symbol of the South African rugby team.
It is a subspecies of antelope of very restricted populations that inhabits the South African plateau.
It is a subspecies of the plains zebra that inhabited the South African grassland and had stripes only on the head and forequarters. Unfortunately it became extinct in 1870 in the wild and in 1883 in captivity.
The main economic activity in the grasslands is cereal agriculture and cattle raising. In fact, the great prairies of the United States are considered the granary of the country, as well as the Argentine pampas..
The main crops are cereals, especially wheat and corn and more recently soybeans..
The other major economic activity is the raising of cattle, especially for the production of meat. Likewise, the breeding of sheep and horses are very considerable activities in this type of place..
Many of the grasslands are conserved under figures such as national parks or nature reserves. Which, together with the beauty of its landscapes, is conducive to the development of tourist activities.
It is an area of 44 km2, representative of the high grass prairie of the North American central plain. The tall grass prairie of the Flint Mountains in Kansas is one of the few remaining natural extensions of this ecosystem. Its soil is characterized by being thin and spread over a layer of limestone.
It is the smallest grassland ecoregion in the US, but includes more than 600 species of flowering plants. Among the grasses are bluegrass (Andropogon gerardii) and grass (Panicum virgatum).
It is interesting to note that fire plays an important role in establishing and maintaining this type of meadow. In fact, trials to establish tall grass meadows in botanical gardens have been successful when controlled burning is introduced..
In the past it was the habitat of large herds of buffalo that are currently being reintroduced and deer (Cervus elaphus).
Today there is a great diversity of birds and also large populations of insects. Among the birds, the large grouse or large prairie rooster (Tympanuchus cupido).
This steppe extends for 105,000 km2 in the northeast of Inner Mongolia, being one of the largest grasslands in the world. They are high and undulating plains with average temperatures between 0 and 3 ºC, most of the year there are frosts with low rainfall (250-350 mm).
In it, more than 1,300 plant species and 400 animal species have been identified. The biotype of grasses is the characteristic tuft or tuft of very cold areas.
Among the species of grasses are Leymus chinensis, Stipa baicalensis, Stipa grandis Y Ovine fescue. Similarly, there are non-grass grasses such as Soongaric reaumuria Y Ajania fruticosa and thorny bushes of gymnosperms like Ephedra equisetina.
The economic activities are agriculture, sheep farming, tourism, winter sports and sport hunting..
1. Cao G, Tang Y, Mo W, Wang Y, Li Y and Zhao X (2004). Grazing intensity alters soil respiration in an alpine meadow on the Tibetan plateau. Soil Biology and Biochemistry, 36 (2), 237-243.
2. Christensen L, Coughenour MB, Ellis JE and Chen ZZ (2004). Vulnerability of the Asian Typical Steppe to Grazing and Climate Change. Climatic Change, 63 (3), 351-368.
3. Kindscher K and Wells PV (1995). Prairie plant guilds: a multivariate analysis of prairie species based on ecological and morphological traits. Vegetatio, 117 (1), 29-50.
4. Kull K and Zobel M (1991). High species richness in an Estonian wooded meadow. Journal of Vegetation Science, 2 (5), 715-718.
5. Roesch LF, Vieira F, Pereira V, Schünemann AL, Teixeira I, Senna AJ and Stefenon VM (2009). The Brazilian Pampa: A Fragile Biome. Diversity, 1 (2), 182-198.
6. Sampson, Fred and Knopf, Fritz, "Prairie conservation in North America" (1994). Other Publications in Wildlife Management. 41. digitalcommons.unl.edu
7. World Wild Life (Viewed on August 29, 2019). https://www.worldwildlife.org/biomes/temperate-grasslands-savannas-and-shrublands
8. Zhang G, Xu X, Zhou C, Zhang H and Ouyang H (2011). Responses of grassland vegetation to climatic variations on different temporal scales in Hulun Buir Grassland in the past 30 years. Journal of Geographical Sciences, 21 (4), 634-650.
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