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Grasslands are areas where the
vegetation Vegetation is an assemblage of species and the they provide. It is a general term, without specific reference to particular , life forms, structure, extent, or any other specific or geographic characteristics. It is broader than the term ' ...

vegetation
is dominated by grasses (
Poaceae Poaceae () or Gramineae () is a large and nearly ubiquitous family In , family (from la, familia) is a of people related either by (by recognized birth) or (by marriage or other relationship). The purpose of families is to maintain ...
). However, sedge (
Cyperaceae The Cyperaceae are a family of graminoid (grass-like), monocotyledon Monocotyledons (), commonly referred to as monocots, (Lilianae Lilianae (also known as Liliiflorae) is a botanical name for a superorder (that is, a rank higher than tha ...
) and rush (
Juncaceae Juncaceae is a family of flowering plant The flowering plants, also known as Angiospermae (), or Magnoliophyta (), are the most diverse group of Embryophyte, land plants, with 64 Order(biology), orders, 416 Family (biology), families, approxim ...
) can also be found along with variable proportions of
legumes A legume () is a in the family (or Leguminosae), or the or of such a plant. When used as a dry , the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for and , and as soil-enhancing . Well-kno ...
, like
clover Clover or trefoil are common names for plants of the ''Trifolium'' (Latin, ''tres'' "three" + ''folium'' "leaf"), consisting of about 300 of s in the or pea family originating in Europe. The genus has a with highest diversity in the temperat ...

clover
, and other
herbs In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables Vegetables are parts of plants that are consumed by humans or other animals as food. The original meaning is still commonly used and is appl ...
. Grasslands occur naturally on all continents except
Antarctica Antarctica ( or ) is 's southernmost . It contains the geographic and is situated in the region of the , almost entirely south of the , and is surrounded by the . At , it is the fifth-largest continent and nearly twice the size of . At 0.00 ...

Antarctica
and are found in most
ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an and geographically defined area that is smaller than a , which in turn is smaller than a . Ecoregions cover relatively large areas of land or water, and contain characteristic ...
s of the
Earth Earth is the third planet from the Sun and the only astronomical object known to harbour and support life. 29.2% of Earth's surface is land consisting of continents and islands. The remaining 70.8% is Water distribution on Earth, covered wi ...

Earth
. Furthermore, grasslands are one of the largest
biome A biome is a collection of flora, plants and fauna, animals that have common characteristics for the natural environment, environment they exist in. They can be found over a range of continents. Biomes are distinct biological community (ecology ...
s on earth and dominate the landscape worldwide. There are different types of grasslands: natural grasslands, semi-natural grasslands, and agricultural grasslands. They cover 31–43% of the Earth's land area.


Definitions

There is a variety of definitions for grasslands: * "...any plant community, including harvested forages, in which grasses and/or legumes make up the dominant vegetation." * "...terrestrial ecosystems dominated by herbaceous and shrub vegetation, and maintained by fire, grazing, drought and/or freezing temperatures." (Pilot Assessment of Global Ecosystems, 2000) * "A region with sufficient average annual precipitation (25-75 cm) to support grass..." (Stiling, 1999) Semi-natural grasslands are a very common subcategory of the grasslands biome. These can be defined as: * Grassland existing as a result of human activity (mowing or livestock grazing), where environmental conditions and the species pool are maintained by natural processes. They can also be described as the following: * "Semi-natural grasslands are one of the world's most biodiverse habitats on a small spatial scales." * "Semi-natural grasslands belong to the most species rich ecosystems in the world." * "...have been formed over the course of centuries through extensive grazing and mowing." * "...without the use of pesticides or fertilisers in modern time." There are many different types of semi-natural grasslands, e.g. hay
meadow A meadow (, ; ) is an open habitat Ibex in an alpine habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a p ...

meadow
s.


Evolutionary history

The
graminoid In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the An ...
s are among the most versatile
life form Life form (also spelled life-form or lifeform) is an wikt:entity, entity that is Life, living, such as plants (flora) and animals (fauna). It is estimated that more than 99% of all species that ever existed on Earth, amounting to over five billio ...

life form
s. They became widespread toward the end of the
Cretaceous The Cretaceous ( ) is a that lasted from about 145 to 66 (Mya). It is the third and final period of the , as well as the longest. At around 79 million years, it is the longest geological period of the entire . The name is derived from the Latin ...

Cretaceous
period, and
coprolite A coprolite (also known as a coprolith) is fossilized A fossil (from Classical Latin Classical Latin is the form of Latin language Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the ...

coprolite
s of fossilized
dinosaur Dinosaurs are a diverse group of reptile Reptiles, as most commonly defined, are the animals in the Class (biology), class Reptilia , a paraphyletic grouping comprising all amniotes except synapsids (mammals and their extinct relatives) a ...

dinosaur
feces have been found containing
phytolith Phytoliths (from Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is approxim ...
s of a variety of grasses that include grasses that are related to modern
rice Rice is the seed of the Poaceae, grass species ''Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima'' (African rice). The name wild rice is usually used for species of the genera ''Zizania (genus), Zizania'' and ''Porteresia'', bo ...

rice
and
bamboo Bamboos are a diverse group of evergreen perennial plant, perennial flowering plants in the subfamily (biology), subfamily Bambusoideae of the grass family ''Poaceae''. The origin of the word "bamboo" is uncertain, but it probably comes from t ...

bamboo
. The appearance of mountains in the
western United States The Western United States (also called the American West, the Far West, and the West) is the region In geography Geography (from Greek: , ''geographia'', literally "earth description") is a field of science devoted to the study of the ...
during the
Miocene The Miocene ( ) is the first Epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; its name comes from the Greek words (', "less") and (', "new") and mean ...
and
Pliocene The Pliocene ( ; also Pleiocene) epoch (geology), Epoch is the epoch in the geologic timescale that extends from 5.333 million to 2.58 Around 5 million years ago during the
Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...
in the New World and the Pliocene in the Old World, the first true grasslands occurred. Existing forest biomes declined, and grasslands became much more widespread. It is known that grasslands have existed in Europe throughout the
Pleistocene The Pleistocene ( , often referred to as the ''Ice Age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the earth’s most recent period of repeated glaciations. Before a change finally ...
(the last 1.8 million years). Following the
Pleistocene The Pleistocene ( , often referred to as the ''Ice Age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the earth’s most recent period of repeated glaciations. Before a change finally ...
ice age An ice age is a long period of reduction in the temperature of Earth Earth is the third planet from the Sun and the only astronomical object known to harbour and support life. 29.2% of Earth's surface is land consisting of continents and ...

ice age
s (with their glacials and
interglacial An interglacial period (or alternatively interglacial, interglaciation) is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial period A glacial period (alternatively glacial or ...
s), grasslands expanded in the hotter, drier climates, and began to become the dominant land feature worldwide. Since the grasslands have existed for over 1.8 million years, there is high variability. For example steppe-tundra dominated in Northern and Central Europe whereas a higher amount of xerothermic grasslands occurred in the Mediterranean area. Within temperate Europe, the range of types is quite wide and also became unique due to the exchange of species and genetic material between different biomes. The semi-natural grasslands probably first appeared with the human starting farming. So for the use of agriculture, forests got cleared in Europe. Ancient meadows and pastures were the parts that were suitable for cultivation. The semi-natural grasslands were formed from these areas. The removal of the plants by the grazing animals and later the mowing farmers led to co-existence of other plant species around. In the following, the biodiversity of the plants evolve. Also, the species that already lived there adapted to the new conditions. Most of the grassland areas have been turned to arable fields and disappeared again. Nowadays, semi-natural grasslands are rather located in areas that are unsuitable for agricultural farming.


Ecology


Biodiversity

Grasslands dominated by unsown wild-plant communities ("unimproved grasslands") can be called either natural or "semi-natural" habitat. Although their plant communities are natural, their maintenance depends upon anthropogenic activities such as grazing and cutting regimes. The semi-natural grasslands contain many species of wild plants, including grasses, sedges, rushes, and herbs; 25 plant-species per 100 square centimeters can be found. A European record that was found on a meadow in Estonia described 76 species of plants in one square meter. Chalk downlands in England can support over 40 species per square meter. In many parts of the world, few examples have escaped agricultural improvement (fertilizing, weed killing, plowing, or re-seeding). For example, original North American prairie grasslands or lowland wildflower meadows in the UK are now rare and their associated wild flora equally threatened. Associated with the wild-plant diversity of the "unimproved" grasslands is usually a rich invertebrate fauna; there are also many species of birds that are grassland "specialists", such as the
snipe A snipe is any of about 26 wading bird FIle:Vadare - Ystad-2021.jpg, 245px, A flock of Dunlins and Red knots Waders are birds of the order Charadriiformes commonly found along shorelines and mudflats that wikt:wade#Etymology 1, wade in order ...

snipe
and the
little bustard The little bustard (''Tetrax tetrax'') is a large bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves , characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard ...
. Owing to semi-natural grasslands being referred to as one of the most-species rich ecosystems in the world and essential habitat for many specialists, also including pollinators, there are many approaches to conservation activities lately. Agriculturally improved grasslands, which dominate modern intensive agricultural landscapes, are usually poor in wild plant species due to the original diversity of plants having been destroyed by cultivation and by the use of fertilizers. Almost 90% of the European semi-natural grasslands do not exist anymore due to political and economic reasons. This loss only took place during the 20th century. The ones in Western and Central Europe have almost disappeared completely. There are a few left in Northern Europe. Unfortunately, a large amount of red-listed species are specialists of semi-natural grasslands and are affected by the landscape change due to agriculture of the last century. The original wild-plant communities having been replaced by sown monocultures of cultivated varieties of grasses and clovers, such as
perennial ryegrass ''Lolium perenne'', common name perennial ryegrass, English ryegrass, winter ryegrass, or ray grass, is a grass from the family Poaceae. It is native to Europe, Asia and northern Africa, but is widely cultivated and naturalised around the world. ...
and
white clover ''Trifolium repens'', the white clover (also known as Dutch clover, Ladino clover, or Ladino), is a herbaceous perennial plant in the bean family Fabaceae (previously referred to as Leguminosae). It is native to Europe, including the British Isle ...
. In many parts of the world, "unimproved" grasslands are one of the most threatened types of habitat, and a target for acquisition by wildlife conservation groups or for special grants to landowners who are encouraged to manage them appropriately.


Vegetation

Grassland
vegetation Vegetation is an assemblage of species and the they provide. It is a general term, without specific reference to particular , life forms, structure, extent, or any other specific or geographic characteristics. It is broader than the term ' ...

vegetation
can vary considerably depending on the grassland type and on how strong it is affected by human impact. Dominant trees for the semi-natural grassland are
Quercus robur ''Quercus robur'', commonly known as common oak, pedunculate oak, European oak or English oak, is a species of flowering plant in the beech and oak family, Fagaceae. It is native plant, native to most of Europe west of the Caucasus. The tree is w ...

Quercus robur
,
Betula pendula ''Betula pendula'', commonly known as silver birch, warty birch, European white birch, or East Asian white birch, is a species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of a ...
,
Corylus avellana ''Corylus avellana'', the common hazel, is a species of native to and western , from the south to , , , and , north to central , and east to the central , the , and northwestern .Rushforth, K. (1999). ''Trees of Britain and Europe''. Collins ...

Corylus avellana
,
Crataegus ''Crataegus'' (), commonly called hawthorn, quickthorn, thornapple, Voss, E. G. 1985. ''Michigan Flora: A guide to the identification and occurrence of the native and naturalized seed-plants of the state. Part II: Dicots (Saururaceae–Cornaceae ...

Crataegus
and many kinds of herbs. In
chalk grasslandCalcareous grassland (or alkaline grassland) is an ecosystem An ecosystem is a community (ecology), community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. These Biotic component ...
, the plants can vary from height to very short. Quite tall grasses can be found in
North America North America is a continent A continent is any of several large landmasses. Generally identified by convention (norm), convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continen ...

North America
n
tallgrass prairie The tallgrass prairie is an ecosystem An ecosystem is a community (ecology), community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. These Biotic component, biotic and abiotic ...
,
South America South America is a continent A continent is any of several large landmasses. Generally identified by convention (norm), convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continent ...

South America
n grasslands, and
Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area and 20% of i ...

Africa
n
savanna A savanna or savannah is a mixed woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ' woods), a low-density forming open s with plenty of sunlight and li ...

savanna
. Woody plants, shrubs or trees may occur on some grasslands – forming savannas, scrubby grassland or semi-wooded grassland, such as the African savannas or the Iberian deheza. As flowering
plant Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to Energy transformation, convert light energy into chemical energy that, through cellular respiration, can later be released to fuel ...

plant
s and trees, grasses grow in great concentrations in
climate Climate is the long-term pattern of weather Weather is the state of the atmosphere An atmosphere (from the greek words ἀτμός ''(atmos)'', meaning 'vapour', and σφαῖρα ''(sphaira)'', meaning 'ball' or 'sphere') is a la ...

climate
s where annual
rain Rain is liquid water in the form of droplet Raindrops in a plant. A drop or droplet is a small column of liquid A liquid is a nearly incompressible fluid In physics, a fluid is a substance that continually Deformation (mechani ...

rain
fall ranges between . The root systems of perennial grasses and
forb A forb or phorb is a herbaceous Herbaceous plants are vascular plant Vascular plants (from Latin ''vasculum'': duct), also known as Tracheophyta (the tracheophytes , from the Greek ''trācheia''), form a large group of plants ( 300,000 accepte ...
s form complex mats that hold the
soil Surface-water- gley developed in glacial till, Northern Ireland.">Northern_Ireland.html" ;"title="glacial till, Northern Ireland">glacial till, Northern Ireland. Soil is a mixture of organic matter, minerals, gases, liquids, and organisms tha ...

soil
in place.


Fauna

Grasslands support the greatest aggregations of large animals on earth, including jaguars, African wild dogs,
pronghorn The pronghorn (, ) (''Antilocapra americana'') is a species of artiodactyl The even-toed ungulates (Artiodactyla , ) are ungulate Ungulates ( ) are members of the diverse clade A clade (; from grc, , ''klados'', "branch"), also known ...

pronghorn
,
black-footed ferret The Black-footed ferret (''Mustela nigripes''), also known as the American polecatHeptner, V. G. (Vladimir Georgievich); Nasimovich, A. A; Bannikov, Andrei Grigorovich; Hoffmann, Robert S. (2001)''Mammals of the Soviet Union''Volume: v. 2, pt. 1 ...

black-footed ferret
,
plains bison The Plains bison (''Bison bison bison'') is one of two subspecies In Taxonomy (biology), biological classification, the term subspecies refers to one of two or more populations of a species living in different subdivisions of the species' ran ...
,
mountain plover The mountain plover (''Charadrius montanus'') is a medium-sized ground bird in the plover family In human society, family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by mar ...
, African elephant, Sunda tiger, black rhino, white rhino, savanna elephant, greater one-horned rhino, Indian elephant and
swift fox The swift fox (''Vulpes velox'') is a small light orange-tan fox around the size of a domestic cat The cat (''Felis catus'') is a domestic species In biology, a species is the basic unit of biological classification, classificati ...

swift fox
. Grazing animals, herd animals, and
predators Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation (which ...

predators
in grasslands, like lions and
cheetah The cheetah (''Acinonyx jubatus'') is a large Felidae, cat native to Africa and central Iran. It is the Fastest animals, fastest land animal, estimated to be capable of running at with the fastest reliably recorded speeds being , and as suc ...

cheetah
s live in the grasslands of the African savanna.
Mite Mites are small arachnid Arachnida () is a Class (biology), class of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata. Arachnida includes orders containing spiders (the largest order), scorpions, ticks, mites, op ...
s, insect
larva A larva (plural larvae ) is a distinct juvenile form many animal Animals (also called Metazoa) are organisms that form the Animalia. With few exceptions, animals , , are , can , and grow from a hollow sphere of , the , during . Ove ...
e
nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a broa ...

nematode
s, and
earthworm An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan A body plan, ''Bauplan'' (German plural ''Baupläne''), or ground plan is a set of morphological features common to man ...

earthworm
s inhabit deep soil, which can reach 6 meters underground in undisturbed grasslands on the richest soils of the world. These invertebrates, along with symbiotic
fungi A fungus (plural The plural (sometimes abbreviated An abbreviation (from Latin ''brevis'', meaning ''short'') is a shortened form of a word or phrase, by any method. It may consist of a group of letters, or words taken from the full ...

fungi
, extend the root systems, break apart hard soil, enrich it with
urea Urea, also known as carbamide, is an organic compound In , organic compounds are generally any s that contain - . Due to carbon's ability to (form chains with other carbon s), millions of organic compounds are known. The study of the prop ...

urea
and other natural fertilizers, trap minerals and water and promote growth. Some types of fungi make the plants more resistant to insect and microbial attacks. Grassland in all its form supports a vast variety of mammals, reptiles, birds, and insects. Typical large mammals include the ,
American bison The American bison or simply bison (''Bison bison''), also commonly known as the American buffalo or simply buffalo, is an American species of bison that once roamed North America in vast herds. Its historical range, by 9000 BC, is described as t ...

American bison
,
giant anteater The giant anteater (''Myrmecophaga tridactyla''), also known as the ant bear, is an insectivorous mammal Mammals (from Latin language, Latin , 'breast') are a group of vertebrate animals constituting the class (biology), class Mammalia ( ...
, and
Przewalski's horse Przewalski's horse (, , , ) (''Equus ferus przewalskii'' or ''Equus przewalskii''), also called the takhi, Mongolian wild horse or Dzungarian horse, is a rare and endangered horse originally native to the steppes of Central Asia. It is named afte ...
. The plants and animals that live in grasslands are connected through an unlimited web of interactions. But the removal of key species—such as buffalo and prairie dogs within the American West—and introduction of
invasive species Kudzu, a Japanese vine species invasive in the southeast United States, growing in Atlanta, Georgia (U.S. state), Georgia An invasive species is an introduced species, introduced organism that becomes overpopulated and negatively alters its n ...
, like cane toads in northern Australia, have disrupted the balance in these ecosystems and damaged a number of other species. Grasslands are home to a number of the foremost magnificent animals on the planet - elephants, bison, lions - and hunters have found them to be enticing prey. But when hunting isn't controlled or is conducted illegally, species can become extinct.


Ecosystem Services

Grasslands provide a range of marketed and nonmarketed ecosystem services.


Carbon Sequestration

Grasslands hold about 20 percent of global soil carbon stocks. Herbaceous (non-wooded) vegetation dominates grasslands and, unlike forests, carbon is stored in the roots and soil underground. Furthermore, this above-ground biomass carbon is relatively short-lived due to grazing, fire, and senescence. In contrast, grassland species have an extensive fibrous root system, with grasses often accounting for 60-80% of the biomass carbon in this ecosystem. This underground biomass can extend several meters below the surface and store abundant carbon into the soil, resulting in deep, fertile soils with high organic matter content. For this reason, soil carbon accounts for about 81% of the total ecosystem carbon in grasslands. The close link between soil carbon and underground biomass leads to similar responses of these carbon pools to fluctuations in annual precipitation and temperature on a broad spatial scale. Because plant productivity is limited by grassland precipitation, carbon stocks are highest in regions where precipitation is heaviest, such as the high grass prairie in the humid temperate region of the United States. Similarly, as annual temperatures rise, grassland carbon stocks decrease due to increased evapotranspiration. Grasslands have suffered large losses of
organic carbon Total organic carbon (TOC) is the amount of carbon Carbon (from la, carbo "coal") is a chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, an ...
due to soil disturbances, vegetation degradation, fires, erosion, nutrient deficiencies, and water shortages. The type, frequency and intensity of the disturbance can play a key role in the soil organic carbon ( SOC) balance of grasslands.
Bedrock Bedrock in geology Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and -λoγία, ''-logia'', ("study of", "discourse")) is an Earth science concerned with the solid Earth, the rock (geology), rocks of which it is composed, and ...

Bedrock
, irrigation practices,
soil acidification#REDIRECT Soil acidificationSoil acidification is the buildup of hydrogen cations, which reduces the soil pH. Chemically, this happens when a proton donor gets added to the soil. The donor can be an acid, such as nitric acid, sulfuric acid, or carbon ...
, liming, and
pasture Pasture (from the Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power of the Rom ...

pasture
management can all have potential impacts on grassland organic carbon stocks. Good grassland management can reverse historical soil carbon losses. The relationship of improved biodiversity with carbon storage is subject of research.


Other ecosystem services

* promotion of genetic diversity * weather amelioration * provision of wildlife habitat


Degradation

Grasslands are among the most threatened ecosystems. According to the International Union for the Conservation of Nature (IUCN), the most significant threat to grasslands is human land use, especially agriculture and mining.


Causes


Land use intensification

Grasslands have an extensive history of
human activity Human behavior is the potential and expressed capacity ( mentally, physically, and socially) of human Humans (''Homo sapiens'') are the most populous and widespread species of primates, characterized by bipedality, opposable thumbs, hairl ...
and disturbance. To feed a growing human population, most of the world's grasslands are converted from natural landscapes to fields of corn, wheat or other crops. Grasslands that have remained largely intact thus far, like East African
savanna A savanna or savannah is a mixed woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ' woods), a low-density forming open s with plenty of sunlight and li ...

savanna
s, are in danger of being lost to agriculture. Grasslands are very sensitive to disturbances, such as people hunting and killing key species, or plowing the land to make more space for farms. Grassland vegetation is often a plagioclimax; it remains dominant in a particular area usually due to
grazing In agriculture Agriculture is the science, art and practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentism, sedentary human civilization, whereby farming of domestication, domesticated spec ...

grazing
, cutting, or natural or man-made fires, all discouraging colonization by and survival of tree and shrub
seedling A seedling is a young sporophyte '' Tortula muralis''. In mosses, the gametophyte is the dominant generation, while the sporophytes consist of sporangium-bearing stalks growing from the tips of the gametophytes A sporophyte () is the dip ...

seedling
s. Some of the world's largest expanses of grassland are found in the African savanna, and these are maintained by wild
herbivore A herbivore is an animal Animals (also called Metazoa) are organisms that form the Animalia. With few exceptions, animals , , are , can , and grow from a hollow sphere of , the , during . Over 1.5 million animal have been —of ...
s as well as by nomadic
pastoralists Pastoralism is a form of animal husbandry Animal husbandry is the branch of agriculture concerned with animals that are raised for meat, animal fiber, fibre, milk, eggs, or other products. It includes day-to-day care, selective breeding and th ...
and their
cattle Cattle, taurine cattle, Eurasian cattle, or European cattle (''Bos taurus'' or ''Bos primigenius taurus'') are large domestication, domesticated Cloven hoof, cloven-hooved herbivores. They are a prominent modern member of the subfamily Bovinae ...

cattle
, sheep or goats. Grasslands have an impact on climate change by slower decomposition rates of litter compared to forest environments. Grasslands may occur naturally or as a result of human activity. Hunting cultures around the world often set regular fires to maintain and extend grasslands and prevent fire-intolerant trees and shrubs from taking hold. The tallgrass
prairie Wheatfield intersection in the Southern Saskatchewan prairies, Canada. Prairies are ecosystem An ecosystem is a community (ecology), community of living organisms in conjunction with the nonliving components of their environment, interact ...
s in the U.S. Midwest may have been extended eastward into
Illinois Illinois ( ) is a in the region of the . Of the fifty U.S. states, it has the , population, and the . is the state's largest city and the fifth with the capital in , located in the center of the state; other major metropolitan areas in ...

Illinois
,
Indiana Indiana () is a U.S. state in the Midwestern United States, Midwestern United States. It is the List of U.S. states and territories by area, 38th-largest by area and the List of U.S. states and territories by population, 17th-most populous o ...

Indiana
, and
Ohio Ohio () is a state State may refer to: Arts, entertainment, and media Literature * ''State Magazine'', a monthly magazine published by the U.S. Department of State * The State (newspaper), ''The State'' (newspaper), a daily newspaper in Co ...

Ohio
by human agency. Much grassland in
northwest Europe Northwestern Europe, or Northwest Europe, is a loosely defined subregion of Europe Europe is a continent A continent is one of several large landmasses. Generally identified by convention (norm), convention rather than any stri ...
developed after the
Neolithic Period The Neolithic period is the final division of the Stone Age The Stone Age was a broad prehistoric Prehistory, also known as pre-literary history, is the period of human history Human history, also known as world history, is the ...
when people gradually cleared the forest to create areas for raising their livestock.


Climate change

Grasslands often occur in areas with annual precipitation is between and and average mean annual temperatures ranges from −5 and 20 °C. However, some grasslands occur in colder (−20 °C) and hotter (30 °C) climatic conditions. Grassland can exist in habitats that are frequently disturbed by grazing or fire, as such disturbance prevents the encroachment of woody species. Species richness is particularly high in grasslands of low
soil fertility Soil fertility refers to the ability of soil File:Stagnogley.JPG, Surface-water-Gley soil, gley developed in glacial till, Northern Ireland. Soil is a mixture of organic matter, minerals, gases, liquids, and organisms that together support li ...
such as serpentine barrens and
calcareous ''Calcareous'' is an adjective meaning "mostly or partly composed of calcium carbonate Calcium carbonate is a chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entity, molecula ...
grasslands, where woody encroachment is prevented as low nutrient levels in the soil may inhibit the growth of forest and shrub species. Another common predicament often experienced by the ill-fated grassland creatures is the constant burning of plants, fueled by oxygen and many expired photosynthesizing organisms, with the lack of rain pushing this problem to further heights. When not limited by other factors, increasing CO2 concentration in the air increases plant growth, similarly as water use efficiency, which is very important in drier regions. However, the advantages of elevated CO2 are limited by factors including water availability and available
nutrient A nutrient is a substance Substance may refer to: * Substance (Jainism), a term in Jain ontology to denote the base or owner of attributes * Chemical substance, a material with a definite chemical composition * Matter, anything that has mass and t ...
s, particularly nitrogen. Thus effects of elevated CO2 on plant growth will vary with local climate patterns, species adaptations to water limitations, and nitrogen availability. Studies indicate that nutrient depletion may happen faster in drier regions, and with factors like plant community composition and grazing. Nitrogen deposition from air pollutants and increased mineralization from higher temperatures can increase plant productivity, but increases are often among a discount in
biodiversity Biodiversity is the biological variety and Genetic variability, variability of life, life on Earth. Biodiversity is a measure of variation at the Genetics, genetic, species, and ecosystem level. Terrestrial biodiversity is usually greater near ...

biodiversity
as faster-growing plants outcompete others. A study of a California grassland found that global change may speed reductions in diversity and forb species are most prone to this process.


Afforestation or introduction of invasive species

Misguided afforestation efforts, for example as part of the global effort to increase carbon sequestration, can harm grasslands and their core ecosystem services. A map created by the
World Resources Institute The World Resources Institute (WRI) is a global research non-profit organization established in 1982 with funding from the MacArthur Foundation The John D. and Catherine T. MacArthur Foundation is a private foundation A private foundation i ...
in collaboration with the
IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization An international organization (also known as an international institut ...
identifies 2 billion hectares for potential
forest restoration Forest restoration is defined as “actions to re-instate ecological processes, which accelerate recovery of forest structure, ecological functioning and biodiversity levels towards those typical of climax forest In ecology, scientific ecology, ...
. It is criticised for including 900 million hectares of grasslands. It is expected that non-native grasses will continue to outperform native species under warmer and drier conditions that occur in many grasslands due to climate change.


Types of degradation


Land cover change

Land cover has always changed during the years. The following relates to the changes between 1960 and 2015. There has been a decrease in semi-natural grasslands and an increase in areas with
arable land Arable land (from the la, arabilis, "able to be plough A plough or plow ( US; both ) is a farm tool for loosening or turning the soil before sowing seed or planting. Ploughs were traditionally drawn by oxen and horses, but in modern farms ...

arable land
, forest and land used for
infrastructure Infrastructure is the set of fundamental facilities and systems that support the sustainable functionality of households and firms. Serving a country, city, or other area, including the services and facilities necessary for its economy An eco ...

infrastructure
and buildings. The line style and relative thickness of the lines indicates the percentage of the total area that changed. Changes less than 1% and land-cover classes with all changes less than 1% (i.e. semi-natural wetlands and water) are not included. In 1960 most of the land, 49.7%, was covered with
forest A forest is an area of land dominated by tree In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk (botany), trunk, supporting branches and leaves in most species. In some usages, the definition of a ...

forest
and there was also more semi-natural grassland (18.8%) than arable land (15.8%). In 2015 this has changed drastically. The forest cover has increased (50.8%) and arable land has also increased (20.4%), but the semi-natural grassland cover has decreased. Although it still covers a large area of the earth (10.6%). A quarter of semi-natural grassland was lost through intensification, i.e. it was converted into arable or pasture land and forests. It is more likely that intensification will occur in flat semi-natural grasslands, especially if the soil is fertile. On the other hand, grasslands, where the land is drought-prone or less productive, are more likely to persist as semi-natural grasslands than grasslands with fertile soil and low gradient of the terrain. Furthermore, the accessibility of the land is also important, as it is then easier to fertilize, for example. For instance, if it is located near a road. With the development of technology, it is becoming increasingly easy to cultivate land with a steeper gradient, to the detriment of grasslands. The management of grasslands is also changing permanently. There is increased use of mineral fertilizers, furthermore borders and field edges are removed to enlarge fields and leveling the terrain to facilitate the use of agricultural machinery. The professional study of dry grasslands falls under the category of
rangeland management Rangeland management (also range management, range science, or arid-land management) is a professional natural science that centers around the study of rangelands and the "conservation and sustainable management f Arid-Landsfor the benefit of c ...
, which focuses on
ecosystem services Ecosystem services are the many and varied benefits to humans provided by the natural environment and from healthy . Such ecosystems include, for example, s, s, s and s. These ecosystems, functioning in healthy relationship, offer such things ...
associated with the grass-dominated arid and semi-arid rangelands of the world. Rangelands account for an estimated 70% of the earth's landmass; thus, many cultures including those of the United States are indebted to the economics that the world's grasslands have to offer, from producing grazing animals, tourism, ecosystems services such as clean water and air, and energy extraction. Vast areas of grassland are affected by woody encroachment, which is the expansion of woody plants at the expense of the herbaceous layer. Woody encroachment is caused by a combination of human impact (e.g. fire exclusion, overstocking and resulting overgrazing) and environmental factors (i.e. increased CO2 levels in the atmosphere). It can have severe negative consequences on key ecosystem services, like land productivity and groundwater recharge.


Conservation and restoration

Despite growing recognition of the importance of grasslands, understanding of restoration options remains limited. Cost of grassland retoration is highly variable and respective data is scarce. Successful grassland restoration has several dimensions, including recognition in policy, standardisation of indicators of degradation, scientific innovation, knowledge transfer and data sharing. Restoration methods and measures include the following: * prescribed fires * appropriate management of livestock and wild herbivores: in light of land use intensification caused by global food demand, grassland land use practices may need to be adjusted to better support key ecosystem services. * tree cutting * shrub removal * invasive species control * reintroduction of native grasses and forbs via seeding or transplant: a main challenge for grassland restoration is how to overcome seed limitation. For the period 2021–2030 the
United Nations General Assembly The United Nations General Assembly (UNGA or GA; french: link=no, Assemblée générale, AG) is one of the six principal organs of the United Nations The United Nations System consists of the United Nations The United Nations (UN) ...
has proclaimed the UN Decade on Restoration, involving a joint resolution by over 70 countries. It is led by the
United Nations Environment Programme The United Nations Environment Programme (UNEP) is responsible for coordinating responses to environmental issues within the United Nations system. It was established by Maurice Strong Maurice Frederick Strong, (April 29, 1929 – November 27, 20 ...
and the
Food and Agriculture Organization The Food and Agriculture Organization of the United Nations (FAO)french: Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is a list of specialized ...
.


Types of grassland


Classifications of grasslands

Grassland types by Schimper (1898, 1903):Schimper, A. F. W. 1898. '. Fisher, Jena. 876 pp
English translation, 1903
*
Meadow A meadow (, ; ) is an open habitat Ibex in an alpine habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a p ...

Meadow
(hygrophilous or tropophilous grassland) *
Steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate grassland ...

Steppe
(xerophilous grassland) *
Savanna A savanna or savannah is a mixed woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ' woods), a low-density forming open s with plenty of sunlight and li ...

Savanna
h (xerophilous grassland containing isolated trees) Grassland types by Ellenberg and Mueller-Dombois (1967): Formation-class V. Terrestrial herbaceous communities # Savannas and related grasslands (tropical or subtropical grasslands and parklands) # Steppes and related grasslands (e.g. North American "prairies" etc.) # Meadows,
pasture Pasture (from the Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power of the Rom ...

pasture
s or related grasslands # Sedge
swamp A swamp is a forested wetland A wetland is a distinct ecosystem that is flooded by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (Anoxic waters, anoxic) processes pre ...

swamp
s and flushes # Herbaceous and half-woody salt swamps # Forb vegetation Grassland types by Laycock (1979): # Tallgrass (true) prairie #
Shortgrass prairie The shortgrass prairie is an ecosystem located in the Great Plains of North America. The two most dominant grasses in the shortgrass prairie are blue grama (''Bouteloua gracilis'') and buffalograss (''Bouteloua dactyloides''), the two less dominan ...
# Mixed-grass prairie # Shrub steppe # Annual grassland #
Desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to the processes of ...

Desert
(arid) grassland # High mountain grassland


General grasslands types


Tropical and subtropical

These grasslands can be classified as the tropical and subtropical grasslands, savannas and shrublands biome. The rainfall level for that grassland type is between 90 and 150 centimeters per year. Grasses and scattered trees are common for that ecoregion, as well as large
mammal Mammals (from Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication Communication (from Latin ''communicare'', meaning "to share" or "to be i ...
s, such as
wildebeest Wildebeest ( , , ), also called gnu ( or ), are antelope The term antelope is used to refer to many species of even-toed ruminant Ruminants (suborder In biological classification, the order ( la, wikt:ordo#Latin, ordo) is # a taxo ...

wildebeest
(Connochaetes taurinus) and
zebra Zebras (, ) (subgenus ''Hippotigris'') are African equines ''Equus'' is a genus Genus (plural genera) is a taxonomic rank Taxonomy (general) is the practice and science of classification of things or concepts, including the principles t ...

zebra
(Equus zebra). Notable tropical and subtropical grasslands include the
Llanos The Llanos ( Spanish ''Los Llanos'', "The Plains"; ) is a vast tropical grassland plain In geography, a plain is a flat expanse of land that generally does not change much in elevation. Plains occur as lowlands along valleys or on the doorst ...
grasslands of
South America South America is a continent A continent is any of several large landmasses. Generally identified by convention (norm), convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continent ...

South America
.


Temperate

Mid-latitude grasslands, including the
prairie Wheatfield intersection in the Southern Saskatchewan prairies, Canada. Prairies are ecosystem An ecosystem is a community (ecology), community of living organisms in conjunction with the nonliving components of their environment, interact ...
and Pacific grasslands of
North America North America is a continent A continent is any of several large landmasses. Generally identified by convention (norm), convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continen ...

North America
, the Pampas of Argentina, Brazil and Uruguay, calcareous downland, and the steppes of Europe. They are classified with temperate savannas and shrublands as the temperate grasslands, savannas, and shrublands, temperate grasslands, savannas, and shrublands biome. Temperate grasslands are the home to many large herbivores, such as bison, gazelles,
zebra Zebras (, ) (subgenus ''Hippotigris'') are African equines ''Equus'' is a genus Genus (plural genera) is a taxonomic rank Taxonomy (general) is the practice and science of classification of things or concepts, including the principles t ...

zebra
s, rhinoceroses, and wild horses. Carnivores like lions, wolf, wolves,
cheetah The cheetah (''Acinonyx jubatus'') is a large Felidae, cat native to Africa and central Iran. It is the Fastest animals, fastest land animal, estimated to be capable of running at with the fastest reliably recorded speeds being , and as suc ...

cheetah
s and leopards are also found in temperate grasslands. Other animals of this region include deer, prairie dogs, mouse, mice, jack rabbits, skunks, coyotes, snakes, foxes, owls, badgers, blackbirds, grasshoppers, meadowlarks, Old World sparrow, sparrows, quails, hawks and hyenas.


Flooded

Grasslands that are flooded seasonally or year-round, like the Everglades of Florida, the Pantanal of Brazil, Bolivia and Paraguay or the Esteros del Ibera in Argentina, are classified with flooded savannas as the flooded grasslands and savannas, flooded grasslands and savannas biome and occur mostly in the tropics and subtropics. The species that live in these grasslands are well adapted to the hydrologic regimes and soil conditions. The Everglades - the world's largest rain-fed flooded grassland - is rich in 11,000 species of seed-bearing plants, 25 species of Orchidaceae, orchids, 300 bird species, and 150 fish species. Watermeadow, Water-meadows are grasslands that are deliberately flooded for short periods.


Montane

High-altitude grasslands located on high mountain ranges around the world, like the Páramo of the Andes Mountains. They are part of the montane grasslands and shrublands, montane grasslands and shrublands biome and can be tropical, subtropical, and temperate. The plants and animals, that can be found in the tropical montane, are able to adapt to cool, wet conditions as well as intense sunlight.


Tundra grasslands

Similar to montane grasslands, polar Arctic tundra can have grasses, but high soil moisture means that few tundras are grass-dominated today. However, during the
Pleistocene The Pleistocene ( , often referred to as the ''Ice Age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the earth’s most recent period of repeated glaciations. Before a change finally ...
glacial periods (commonly referred to as
ice age An ice age is a long period of reduction in the temperature of Earth Earth is the third planet from the Sun and the only astronomical object known to harbour and support life. 29.2% of Earth's surface is land consisting of continents and ...

ice age
s), a grassland known as steppe-tundra or mammoth steppe occupied large areas of the Northern Hemisphere. These areas were very cold and arid and featured sub-surface permafrost (hence tundra) but were nevertheless productive grassland ecosystems supporting a wide variety of fauna. As the temperature increased and the climate became wetter at the beginning of the Holocene much of the mammoth steppe transitioned to forest, while the drier parts in central Eurasia remained as a grassland, becoming the modern Eurasian steppe.


Desert and xeric

Also called desert grasslands, they are composed of sparse grassland ecoregions located in the deserts and xeric shrublands, deserts and xeric shrublands biome. Temperature extremes and low amount of rainfall characterise these kinds of grasslands. Therefore, plants and animals are well adapted to minimize water loss.


Temperate grasslands, savannas, and shrublands ecoregions

The grassland ecoregions of the temperate grasslands, savannas, and shrublands
biome A biome is a collection of flora, plants and fauna, animals that have common characteristics for the natural environment, environment they exist in. They can be found over a range of continents. Biomes are distinct biological community (ecology ...
are:


Tropical and subtropical grasslands, savannas, and shrublands ecoregions


See also

*
Meadow A meadow (, ; ) is an open habitat Ibex in an alpine habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a p ...

Meadow
*Forest


References


Further reading

* Courtwright, Julie. 2011. ''Prairie Fire: A Great Plains History''. University Press of Kansas. 274 pp. * French, N. R. (ed.). 1979. ''Perspectives in Grassland Ecology''. Springer, New York, 204 pp.

* Suttie, J. M.; Reynolds, S. G.; C. Batello. 2005. ''Grasslands of the world''. Rome: FAO

* Wilsey, B.J. 2018. Biology of Grasslands. Oxford University Press {{Authority control Grasslands, Grasses, * Poaceae Ecoregions Agricultural land Plains