Shrubland
Encyclopedia
Shrubland, scrubland, scrub or brush is a plant community characterized by vegetation
dominated
by shrub
s, often also including grass
es, herb
s, and geophytes. Shrubland may either occur naturally or be the result of human activity. It may be the mature vegetation type in a particular region and remain stable over time, or a transitional community that occurs temporarily as the result of a disturbance, such as fire. A stable state may be maintained by regular natural disturbance such as fire or browsing
. Shrubland may be unsuitable for human habitation because of the danger of fire. The term "shrubland" was first coined in 1903.
Shrubland species generally show a wide range of adaptations to fire, such as heavy seed production, lignotubers, and fire-induced germination.
and ecology
a shrub is defined as a much-branched woody plant
less than 8 m high and usually with many stems
. Tall shrubs are mostly 2–8 m high; small shrubs 1–2 m high: subshrub
s less than 1 m high.
A descriptive system widely adopted in Australia
to describe different types of vegetation is based on structural characteristics based on plant life-form
, plus the height and foliage cover of the tallest stratum or dominant
species
.
For shrubs 2–8 m high the following structural forms result:
For shrubs <2 m high the following structural forms result:
Similarly, shrubland is a category used to describe a type of biome
plant group. In this context, shrublands are dense thickets of evergreen sclerophyll
shrubs and small trees, called:
In some places shrubland is the mature vegetation type, and in other places the result of degradation of former forest
or woodland
by logging
or overgrazing
, or disturbance by major fires.
A number of World Wildlife Fund biomes are characterized as shrublands, including:
Desert scrublands
Xeric or desert scrublands occur in the world's deserts and xeric shrublands
ecoregions, or in areas of fast-draining sandy soils in more humid regions. These scrublands are characterized by plants with adaptations to the dry climate, which include small leaves to limit water loss, thorns to protect them from grazing animals, succulent leaves or stems, storage organ
s to store water, and long taproots to reach groundwater.
Mediterranean scrublands
Mediterranean scrublands occur naturally in the Mediterranean forests, woodlands, and scrub
biome
s, located in the five Mediterranean climate
regions of the world. Scrublands are most common near the seacoast, and have often adapted to the wind and salt air of the ocean. Low, soft-leaved scrublands around the Mediterranean Basin
are known as garrigue
in France
, phrygana in Greece
, tomillares in Spain
, and batha in Israel
. Northern coastal scrub
and coastal sage scrub
occur along the California
coast, strandveld in the Western Cape
of South Africa
, coastal matorral in central Chile
, and sand-heath and kwongan
in Southwest Australia
.
Interior scrublands
Interior scrublands occur naturally in semi-arid areas where soils are nutrient-poor, such as on the matas
of Portugal
which are underlain by Cambrian
and Silurian
schists. Florida scrub
is another example of interior scrublands.
Dwarf shrubs
Some vegetation types are formed of dwarf-shrubs: low-growing or creeping shrubs. These include the maquis
of Mediterranean climates, and the acid-loving dwarf shrubs of heathland and moorland
.
Vegetation
Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader...
dominated
Dominance (ecology)
Ecological dominance is the degree to which a species is more numerous than its competitors in an ecological community, or makes up more of the biomass...
by shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s, often also including grass
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
es, herb
Herbaceous plant
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
s, and geophytes. Shrubland may either occur naturally or be the result of human activity. It may be the mature vegetation type in a particular region and remain stable over time, or a transitional community that occurs temporarily as the result of a disturbance, such as fire. A stable state may be maintained by regular natural disturbance such as fire or browsing
Browsing (predation)
Browsing is a type of herbivory in which an herbivore feeds on leaves, soft shoots, or fruits of high growing, generally woody, plants such as shrubs. This is contrasted with grazing, usually associated with animals feeding on grass or other low vegetation...
. Shrubland may be unsuitable for human habitation because of the danger of fire. The term "shrubland" was first coined in 1903.
Shrubland species generally show a wide range of adaptations to fire, such as heavy seed production, lignotubers, and fire-induced germination.
Shrubland as a botanical structural form
In botanyBotany
Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...
and ecology
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
a shrub is defined as a much-branched woody plant
Woody plant
A woody plant is a plant that uses wood as its structural tissue. These are typically perennial plants whose stems and larger roots are reinforced with wood produced adjacent to the vascular tissues. The main stem, larger branches, and roots of these plants are usually covered by a layer of...
less than 8 m high and usually with many stems
Plant stem
A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...
. Tall shrubs are mostly 2–8 m high; small shrubs 1–2 m high: subshrub
Subshrub
A subshrub or dwarf shrub is a short woody plant. Prostrate shrub is a similar term.It is distinguished from a shrub by its ground-hugging stems and lower height, with overwintering perennial woody growth typically less than 10–20 cm tall, or by being only weakly woody and/or persisting...
s less than 1 m high.
A descriptive system widely adopted in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
to describe different types of vegetation is based on structural characteristics based on plant life-form
Plant life-form
Plant life-form schemes constitute a way of classifying plants alternatively to the ordinary species-genus-family scientific classification. In colloquial speech, plants may be classified as trees, shrubs, herbs , etc...
, plus the height and foliage cover of the tallest stratum or dominant
Dominance (ecology)
Ecological dominance is the degree to which a species is more numerous than its competitors in an ecological community, or makes up more of the biomass...
species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
.
- dense foliage cover (70–100%) — closed-scrub
- mid-dense foliage cover (30–70%) — open-scrub
- sparse foliage cover (10–30%) — tall shrubland
- very sparse foliage cover (<10%) — tall open shrubland
For shrubs <2 m high the following structural forms result:
- dense foliage cover (70–100%) — closed-heathHeath (habitat)A heath or heathland is a dwarf-shrub habitat found on mainly low quality acidic soils, characterised by open, low growing woody vegetation, often dominated by plants of the Ericaceae. There are some clear differences between heath and moorland...
- mid-dense foliage cover (30–70%) — open-heath
- sparse foliage cover (10–30%) — low shrubland
- very sparse foliage cover (<10%) — low open shrubland
Shrubland as a biome plant group
Biome
Biomes are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. Some parts of the earth have more or less the same kind of abiotic and biotic factors spread over a...
plant group. In this context, shrublands are dense thickets of evergreen sclerophyll
Sclerophyll
Sclerophyll is the term for a type of vegetation that has hard leaves and short internodes . The word comes from the Greek sclero and phyllon ....
shrubs and small trees, called:
- ChaparralChaparralChaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...
in CaliforniaCaliforniaCalifornia is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area... - MatorralMatorralMatorral is a Spanish word, along with tomillares, for shrubland, thicket or bushes. It is used in naming and describing a Mediterranean climate ecosystem in Southern Europe.-Mediterranean region:...
in ChileChileChile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
and SpainSpainSpain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula... - MaquisMaquis shrublandthumb|220px|Low Maquis in Corsica.220px|thumb|High macchia in Sardinia.Maquis or macchia is a shrubland biome in the Mediterranean region, typically consisting of densely growing evergreen shrubs such as holm oak, tree heath, strawberry tree, sage, juniper, buckthorn, spurge olive and myrtle...
in FranceFranceThe French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
and elsewhere around the Mediterranean - Macchia in ItalyItalyItaly , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
- FynbosFynbosFynbos is the natural shrubland or heathland vegetation occurring in a small belt of the Western Cape of South Africa, mainly in winter rainfall coastal and mountainous areas with a Mediterranean climate...
in South AfricaSouth AfricaThe Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans... - KwonganKwonganKwongan is a type of heathland found on the coastal plains of Western Australia. The name is derived from the language of the Noongar people. Kwongan comprises floristically-rich heath with dense thickets of sclerophyllous shrubs and isolated small trees...
in Southwest AustraliaWestern AustraliaWestern Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
In some places shrubland is the mature vegetation type, and in other places the result of degradation of former forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
or woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
by logging
Logging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...
or overgrazing
Overgrazing
Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, or by overpopulations of native or non-native wild animals.Overgrazing reduces the...
, or disturbance by major fires.
A number of World Wildlife Fund biomes are characterized as shrublands, including:
Desert scrublands
Deserts and xeric shrublands
Deserts and xeric shrublands is a biome characterized by, relating to, or requiring only a small amount of moisture.-Definition and occurrence:...
ecoregions, or in areas of fast-draining sandy soils in more humid regions. These scrublands are characterized by plants with adaptations to the dry climate, which include small leaves to limit water loss, thorns to protect them from grazing animals, succulent leaves or stems, storage organ
Storage organ
A storage organ is a part of a plant specifically modified for storage of energy or water. Storage organs often grow underground, where they are better protected from attack by herbivores. Plants that have an underground storage organ are called geophytes in the Raunkiær plant life-form...
s to store water, and long taproots to reach groundwater.
Mediterranean scrublands
Mediterranean scrublands occur naturally in the Mediterranean forests, woodlands, and scrub
Mediterranean forests, woodlands, and scrub
Mediterranean forests, woodlands, and scrub biome, defined by the World Wildlife Fund, characterized by dry summers and rainy winters. Summers are typically hot in low-lying inland locations but can be cool near some seas, as near San Francisco, which have a sea of cool waters...
biome
Biome
Biomes are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. Some parts of the earth have more or less the same kind of abiotic and biotic factors spread over a...
s, located in the five Mediterranean climate
Mediterranean climate
A Mediterranean climate is the climate typical of most of the lands in the Mediterranean Basin, and is a particular variety of subtropical climate...
regions of the world. Scrublands are most common near the seacoast, and have often adapted to the wind and salt air of the ocean. Low, soft-leaved scrublands around the Mediterranean Basin
Mediterranean Basin
In biogeography, the Mediterranean Basin refers to the lands around the Mediterranean Sea that have a Mediterranean climate, with mild, rainy winters and hot, dry summers, which supports characteristic Mediterranean forests, woodlands, and scrub vegetation...
are known as garrigue
Garrigue
Garrigue or phrygana is a type of low, soft-leaved scrubland ecoregion and plant community in the Mediterranean forests, woodlands, and scrub biome. It is found on limestone soils around the Mediterranean Basin, generally near the seacoast, where the climate is ameliorated, but where annual summer...
in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, phrygana in Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, tomillares in Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
, and batha in Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...
. Northern coastal scrub
Northern coastal scrub
Northern coastal scrub is a scrubland plant community of California and Oregon. It occurs along the Pacific Coast from Point Sur on the Central California coast in Monterey County, California, to southern Oregon...
and coastal sage scrub
Coastal sage scrub
Coastal sage scrub is a low scrubland plant community found in the California chaparral and woodlands ecoregion of coastal California and northern Baja California. It is characterized by low-growing aromatic, and drought-deciduous shrubs adapted to the semi-arid Mediterranean climate of the...
occur along the California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
coast, strandveld in the Western Cape
Western Cape
The Western Cape is a province in the south west of South Africa. The capital is Cape Town. Prior to 1994, the region that now forms the Western Cape was part of the much larger Cape Province...
of South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, coastal matorral in central Chile
Chilean Matorral
The Chilean Matorral is a terrestrial ecoregion of central Chile, located on the west coast of South America. It is in the Mediterranean forests, woodlands, and scrub biome, part of the Neotropic ecozone....
, and sand-heath and kwongan
Kwongan
Kwongan is a type of heathland found on the coastal plains of Western Australia. The name is derived from the language of the Noongar people. Kwongan comprises floristically-rich heath with dense thickets of sclerophyllous shrubs and isolated small trees...
in Southwest Australia
Southwest Australia
Southwest Australia is a biodiversity hotspot that includes the Mediterranean forests, woodlands, and scrub ecoregions of Western Australia. The region has a wet-winter, dry-summer Mediterranean climate, one of five such regions in the world...
.
Interior scrublands
Interior scrublands occur naturally in semi-arid areas where soils are nutrient-poor, such as on the matas
Matorral
Matorral is a Spanish word, along with tomillares, for shrubland, thicket or bushes. It is used in naming and describing a Mediterranean climate ecosystem in Southern Europe.-Mediterranean region:...
of Portugal
Portugal
Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...
which are underlain by Cambrian
Cambrian
The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...
and Silurian
Silurian
The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
schists. Florida scrub
Florida scrub
Florida scrub is an endangered temperate coniferous forest ecoregion of the state of Florida in the United States. It is found on coastal and inland sand ridges and is characterized by a xeromorphic plant community dominated by shrubs and dwarf oaks. Scrub soils, a type of entisol, are derived...
is another example of interior scrublands.
Dwarf shrubs
Maquis shrubland
thumb|220px|Low Maquis in Corsica.220px|thumb|High macchia in Sardinia.Maquis or macchia is a shrubland biome in the Mediterranean region, typically consisting of densely growing evergreen shrubs such as holm oak, tree heath, strawberry tree, sage, juniper, buckthorn, spurge olive and myrtle...
of Mediterranean climates, and the acid-loving dwarf shrubs of heathland and moorland
Moorland
Moorland or moor is a type of habitat, in the temperate grasslands, savannas, and shrublands biome, found in upland areas, characterised by low-growing vegetation on acidic soils and heavy fog...
.