Grasses are among the most prevalent types of plants found all around the world and can be found in a large variety of environments and biomes. However, only one biome type, a grassland, is defined by the presence of grass. So, what makes a grassland a grassland, and what are the different types of grasslands?
The two most fundamental characteristics of grasslands are the presence of grass species as the dominant type of plant in the area and the general lack of taller vegetation, specifically trees and large shrubs. While other taller plant species may exist in small numbers alongside the local grass species, these large, flat areas are dominated by grasses that can be tall, short and everything in between. Beyond these basic qualifications, grassland biomes can vary widely across the globe, and each type supports an ecosystem unique to its geographic location.
Types of Grassland
Grasslands can be found on every continent except for Antarctica, and while they all share some common characteristics, they’re often given different names because their climate and geography vary broadly. Although some terms for grasslands are used interchangeably around the world, based on geography and climate they can be sorted into four basic categories: pampas, prairie, savanna and steppe.
Pampas
“Pampas” is the term for the large grassland that stretches across the southeastern coast of South America, across portions of Argentina, Brazil and Uruguay. The climate of this region varies slightly between the generally warmer and wetter northern climate and the drier and cooler southern climate, but overall is considered temperate. This means that the pampas receive a moderate amount of rainfall each year and follow mostly predictable seasonal patterns, with warm summers and cold, but relatively mild, winters.
This temperate climate has also made the pampas an attractive location for human agriculture, as the rich soil and grasses can support a large variety of crop plants as well as domesticated animals like sheep and pigs (Sus domesticus).
Some examples of animal species native to this region are the pampas deer (Ozotoceros bezoarticus); the greater rhea (Rhea americana), which is a large flightless bird; the maned wolf (Chrysocyon brachyurus), which is South America’s largest canine species and only species in its genus; and a few different species of armadillo, including the southern long-nosed armadillo (Dasypus hybridus).
Prairie
“Prairie” is the term used to describe the vast plains found in North America, which span much of the middle of the United States and portions of central and western Canada. There are three types of prairie: shortgrass, tallgrass and mixed grass. As the names suggest, the primary differences between these types are how tall native grasses are able to grow. Grass heights are largely determined by the amount of rainfall the prairie receives each year. Tallgrass prairies, which require a larger amount of water to feed the grasses to heights of up to two meters (six feet), are found most commonly in the wetter eastern portions of the plains, whereas shortgrass prairies tend to appear in the drier western regions where grasses do not receive as much water each year. Like pampas, prairies experience a broad range of seasonal temperatures across the summers and winters, but depending on the local region, these seasonal changes may be more extreme. Some regions become exceptionally hot in the summer, and others drop well below freezing temperatures during the winter.
Much like the pampas, North American prairies have rich, fertile soil that is appealing for farming and raising livestock. So appealing, in fact, that virtually no part of the prairie has remained untouched by human farmers and ranchers. While small pockets of natural prairie still exist, most of the area is now taken up by farms, ranches and other human activities.
Species native to the prairie include American bison (Bison bison), prairie dogs (Genus Cynomys), coyotes (Canis latrans), rattlesnakes (Genus Crotalus), burrowing owls (Athene cunicularia), pronghorn (Antilocapra americana) and many more.
To learn more about prairies, take a look at the resource Prairie.
Savanna
While “pampas” and “prairie” are often used in reference to grasslands on a specific continent, “savanna” is used more broadly to mean grasslands found in subtropical regions. Although savannas can be found in other parts of the world, two of the most notable savannas can be found in Africa and Australia. The African savanna is well known for its biodiversity and unique wildlife species, particularly its large mammal species. In Australia, savannas are one of several biomes that coexist in the region known as "the outback."
African savannas can be found primarily to the north and south of equatorial Africa, the western half of which is a rainforest biome. These savanna grasslands to the north and south often include scattered tree cover, despite the fact that they are grasslands. They experience warm to hot weather all year round, and seasonal change is defined by the wet and dry seasons experienced by the region, where most annual rainfall occurs in one half of the year.
African savannas are incredibly biodiverse, and are home to some of Earth’s most iconic species, including the largest land animal, the African elephant (Genus Loxodonta). Other native species include lions (Panthera leo), giraffes (Giraffa camelopardalis), plains zebras (Equus quagga), aardvarks (Orycteropus afer), ostriches (Struthio camelus) and many, many more. Although human agriculture has not yet taken up as much of the savanna as in North American prairies, humans pose a threat to native species as a result of expanding land use, human-wildlife conflict and poaching. Many of the savannas’ native species are endangered. Some, like the black rhino (Diceros bicornis), are critically endangered, with only a few thousand individuals left in the wild. For this reason, the savanna is also home to many ongoing conservation efforts, including protecting parks and nature reserves that aim to protect both the native species and their habitats.
See some of the work being in Africa's savannas with this video featuring Explorer Dominique Correia Gonçalves.
Australian savannas are just one biome that can be found in the outback, which is found in the interior of the continent. Here, savannas blend with deserts as well as woodlands to create a unique environment that supports some of Australia’s many native species, like kangaroos (Genera Macropus and Osphranter), emus (Dromaius novaehollandiae), frill-necked lizards (Chalamydosaurus kingii), short-beaked echidnas (Tachyglossus aculeatus) and more.
Like the African savannas, Australian savannas are reliably warm to hot all year round, and experience distinct wet and dry seasons, where virtually all annual rainfall occurs in one half of the year. Today, there are fewer humans living in the Australian savannas than in the much more densely populated coastal regions. However, the savannas have supported human populations for at least 65,000 years, and contain the oldest known evidence of human occupation on the continent.
Steppe
“Steppe” is the term used to describe the wide stretches of grassland found in Asia as well as portions of Eastern Europe. The steppe is one of the largest grasslands in the world, and stretches east to west from Manchuria in eastern China, almost all of Mongolia, Kazakhstan, portions of Russia, a large part of Ukraine and parts of Eastern Europe all the way to Hungary. Covering such a large area, this grassland experiences several different regional climates and is home to a wide variety of animal and plant species, some that are found across the whole grassland and others that are native to a very specific region. Because it is so large, the steppe is often discussed in terms of smaller segments, like the eastern steppe, the western steppe or the central steppe. These divisions are not necessarily based on geographic boundaries and tend to reflect differences in climate and ecology rather than the physical landscape.
Like the pampas and prairies, the entire steppe experiences seasonal temperature changes, hot in the summers and cold in the winters. However, the eastern reaches of the steppe experiences far colder, more extreme, temperature changes in comparison to the western portions closer to Europe. The eastern and western portions are also differentiated by the amount of rainfall they receive. The eastern portion of the steppe tends to be a dry, arid environment, whereas the western steppe is a more humid, temperate climate that receives a larger amount of rainfall each year.
While humans have lived across the steppe for thousands of years, the colder eastern portions tend to be less populated due to its extreme climate. In the western regions, the wetter, warmer portions of the steppe tend to be better suited for human agriculture, and are more heavily populated today.
Because the steppe spans over such a large geographic area, there is a huge variety of species native to this grassland, some more widespread than others. A few examples of notable species include the saiga (Saiga tatarica), Przewalski’s horse (Equus ferus przewalksii), steppe wolf (Canis lupus campestris), corsac fox (Vulpes corsac), steppe eagle (Aquila nipalensis) and the great bustard (Otis tarda).
At first glance, grasslands can appear to be empty or even barren places with their vast, flat plains. However, a closer look reveals the rich ecosystems that exist in each of these similar but unique habitats. Although grass is the defining factor of all four types of grassland, this biome can take many different forms. From cold to hot, wet to dry, temperate to extreme and everywhere in between, grasslands support incredible ecosystems all around the planet. From tiny grasshoppers to giant elephants, a huge variety of species depend on these environments, and our own species, Homo sapiens, is no exception.
