Pioneer species
Pioneer species are 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...

 which colonize
Colonisation (biology)
Colonisation is the process in biology by which a species spreads into new areas, regions, and continents. It is sometimes also referred to as immigration, but colonisation often refers to successful immigration with integration to a community, having resisted initial local extinction.One classic...

 previously uncolonized land, usually leading to ecological succession
Ecological succession
Ecological succession, is the phenomenon or process by which a community progressively transforms itself until a stable community is formed. It is a fundamental concept in ecology, and refers to more or less predictable and orderly changes in the composition or structure of an ecological community...

. They are the first organisms to start the chain of events leading to a livable biosphere
The biosphere is the global sum of all ecosystems. It can also be called the zone of life on Earth, a closed and self-regulating system...

 or ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

. Since uncolonized land may have thin, poor quality soils with few nutrients, pioneer species are often hearty plants with adaptations such as long roots, root nodes containing nitrogen-fixing bacteria
Diazotrophs are bacteria and archaea that fix atmospheric nitrogen gas into a more usable form such as ammonia.A diazotroph is an organism that is able to grow without external sources of fixed nitrogen. Examples of organisms that do this are rhizobia and Frankia and Azospirillum. All diazotrophs...

, and leaves that employ transpiration
Transpiration is a process similar to evaporation. It is a part of the water cycle, and it is the loss of water vapor from parts of plants , especially in leaves but also in stems, flowers and roots. Leaf surfaces are dotted with openings which are collectively called stomata, and in most plants...

. Pioneer species will die creating plant litter
Plant litter
Plant litter, leaf litter or tree litter is dead plant material, such as leaves, bark, needles, and twigs, that has fallen to the ground. Litter provides habitat for small animals, fungi, and plants, and the material may be used to construct nests. As litter decomposes, nutrients are released to...

, and break down as 'leaf mold
Leaf mold
Leaf mold is a form of compost produced by the fungal breakdown of shrub and tree leaves, which are generally too dry, acidic, or low in nitrogen for bacterial decomposition.-Description:...

' after some time, making new soil for secondary succession
Secondary succession
Secondary succession is one of the two types of ecological succession of plant life. As opposed to the first, primary succession, secondary succession is a process started by an event that reduces an already established ecosystem Secondary succession is one of the two types of ecological...

 (see below), and nutrients for small fish and aquatic plant
Aquatic plant
Aquatic plants are plants that have adapted to living in aquatic environments. They are also referred to as hydrophytes or aquatic macrophytes. These plants require special adaptations for living submerged in water, or at the water's surface. Aquatic plants can only grow in water or in soil that is...

s in adjacent bodies of water.

Pioneer flora

Pioneer species are often grass
The Poaceae is a large and nearly ubiquitous family of flowering plants. Members of this family are commonly called grasses, although the term "grass" is also applied to plants that are not in the Poaceae lineage, including the rushes and sedges...

es such as marram grass, which grows on sand dunes. In more rocky and damp conditions, they are usually lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...

, and small ephemeral bunchgrasses and wildflower
A wildflower is a flower that grows wild, meaning it was not intentionally seeded or planted. Yet "wildflower" meadows of a few mixed species are sold in seed packets. The term "wildflower" has been made vague by commercial seedsmen who are interested in selling more flowers or seeds more...

s in crevices.

The plants, or anything that has the system of a plant, to be specially to the extremes that may be experienced, and once they have modified the environment may be out-competed by less specific plants, eventually leading to a climax community
Climax community
In ecology, a climax community, or climatic climax community, is a biological community of plants and animals which, through the process of ecological succession — the development of vegetation in an area over time — has reached a steady state. This equilibrium occurs because the climax community...


Examples of the plants and organisms that colonize such areas are:
Barren sand - Lyme grass
Leymus is a genus of the true grass family . The common name for this genus is "wild rye"; however, members of the genus Elymus are also sometimes given the same common name...

 (Leymus arenarius
Leymus arenarius
Leymus arenarius Hochst. is a psammophylic species of grass in the Poaceae family, native to Atlantic, Central and Northern Europe and the coldest shores of North America....

), Sea couch grass
Agropyron is a genus of grasses , native to Europe and Asia. Species in the genus are commonly referred to as crested-wheat grasses...

 (Agropyron pungens
Agropyron pungens
Agropyron pungens is a species of grass of the genus Agropyron in the Poaceae family. It is a common grass species native to Europe and Asia. Agropyron pungens is typically found in sandy, and saline environments and can tolerate harsh weather conditions; because of this it is a common pioneer...

), Marram grass (Ammophila breviligulata
Ammophila breviligulata
Ammophila breviligulata is a species of grass that is native to eastern North America, where it grows on sand dunes along the Atlantic Ocean and Great Lakes coasts...

Salt water - green algae
Green algae
The green algae are the large group of algae from which the embryophytes emerged. As such, they form a paraphyletic group, although the group including both green algae and embryophytes is monophyletic...

, Marine eel grass
Zostera is a small genus of widely distributed seagrass, commonly called marine eelgrass or simply eelgrass . The genus Zostera contains sixteen species.-Ecology:Zostera is found on sandy substrates or in estuaries submerged or partially floating...

 (Zostera spp.
Zostera is a small genus of widely distributed seagrass, commonly called marine eelgrass or simply eelgrass . The genus Zostera contains sixteen species.-Ecology:Zostera is found on sandy substrates or in estuaries submerged or partially floating...

), Pickleweed
Pickleweed is a common name used for two unrelated genera of flowering plants:*Batis, family Bataceae*Salicornia, family Amaranthaceae...

 (Salicornia virginica
Salicornia virginica
Salicornia virginica is a halophytic perennial dicot which grows in various zones of intertidal salt marshes and can be found in alkaline flats...

), and Cordgrass (hybrid Spartina × townsendii) and (Spartina anglica
Spartina anglica
Spartina anglica is a species of cordgrass that originated in southern England in about 1870. It is an allotetraploid species derived from the hybrid Spartina × townsendii, which arose when the European native cordgrass Spartina maritima hybridised with the introduced American Spartina...

Clear water - algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

, mosses, Freshwater eel grass
Vallisneria is a genus of freshwater aquatic plant, commonly called eelgrass, tape grass or vallis. The genus has 6-10 species that are widely distributed, but do not grow in colder regions....

 (Vallisneria americana).

Pioneer fauna

Pioneering fauna
Fauna or faunæ is all of the animal life of any particular region or time. The corresponding term for plants is flora.Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess shale fauna"...

 are not responsible for initial colonisation of an area, but will colonize an area only flora
Flora is the plant life occurring in a particular region or time, generally the naturally occurring or indigenous—native plant life. The corresponding term for animals is fauna.-Etymology:...

 and fungi previously inhabited, leading the way for others. A good example of this is the Roe Deer
Roe Deer
The European Roe Deer , also known as the Western Roe Deer, chevreuil or just Roe Deer, is a Eurasian species of deer. It is relatively small, reddish and grey-brown, and well-adapted to cold environments. Roe Deer are widespread in Western Europe, from the Mediterranean to Scandinavia, and from...


Secondary succession and pioneer species

Pioneer species can also be found in secondary succession
Secondary succession
Secondary succession is one of the two types of ecological succession of plant life. As opposed to the first, primary succession, secondary succession is a process started by an event that reduces an already established ecosystem Secondary succession is one of the two types of ecological...

, such as an established ecosystem being reduced by an event such as: a forest fire, deforestation
Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use....

, or clearing; quickly colonizing open spaces which previously supported vegetation.

Common examples of the plants in such areas include:
  • Birch
    Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...

     - Betula spp.
  • Fireweed
    Epilobium angustifolium, commonly known as Fireweed , Great Willow-herb , or Rosebay Willowherb , is a perennial herbaceous plant in the willowherb family Onagraceae...

     - Epilobium angustifolium
  • Raspberry
    The raspberry or hindberry is the edible fruit of a multitude of plant species in the genus Rubus, most of which are in the subgenus Idaeobatus; the name also applies to these plants themselves...

     - Rubus spp.
    Rubus is a large genus of flowering plants in the rose family, Rosaceae, subfamily Rosoideae. Raspberries, blackberries, and dewberries are common, widely distributed members of the genus. Most of these plants have woody stems with prickles like roses; spines, bristles, and gland-tipped hairs are...

  • Heath
    -Habitats:* Heath or heathland, low-growing woody vegetation, mostly consisting of heathers and related species* Heaths in the British National Vegetation Classification system...

    s - Ericaceae spp.
    The Ericaceae, commonly known as the heath or heather family, is a group of mostly calcifuge flowering plants. The family is large, with roughly 4000 species spread across 126 genera, making it the 14th most speciose family of flowering plants...

  • Graminoids, forb
    A forb is a herbaceous flowering plant that is not a graminoid . The term is used in biology and in vegetation ecology, especially in relation to grasslands and understory.-Etymology:...

    s, and wildflowers - native
    Native plant
    Native plant is a term to describe plants endemic or naturalized to a given area in geologic time.This includes plants that have developed, occur naturally, or existed for many years in an area...

    , introduced
    Introduced species
    An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...

    , and invasive species
    Invasive species
    "Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....

    : such as fire dependent seed, cone
    Conifer cone
    A cone is an organ on plants in the division Pinophyta that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity...

    , and resprouter
    Resprouters are plant species that are able to survive fire by the activation of dormant vegetative buds to produce regrowth.Plants may resprout by means of lignotubers at the base or epicormic buds on the trunk or major branches....

    Chaparral 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...

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