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Pioneer species are hardy species which are the first to colonize previously disrupted or damaged ecosystems, beginning a chain of ecological succession that ultimately leads to a more biodiverse steady-state ecosystem. Some lichens grow on rocks without soil, so may be among the first of life forms, and break down the rock into soil for other plants.〔LICHEN BIOLOGY AND THE ENVIRONMENT, LICHENS OF NORTH AMERICA, Sylvia and Stephen Sharnoff, ()〕 Since some uncolonized land may have thin, poor quality soils with few nutrients, pioneer species are often hardy plants with adaptations such as long roots, root nodes containing nitrogen-fixing bacteria, and leaves that employ transpiration. Pioneer species will die creating plant litter, and break down as "leaf mold" after some time, making new soil for secondary succession (see below), and nutrients for small fish and aquatic plants in adjacent bodies of water. ==Pioneer flora== Examples of the plants and organism that colonize such areas are pioneer species :Barren sand - lyme grass (''Leymus arenarius''), sea couch grass (''Agropyron pungens''), Marram grass (''Ammophila breviligulata'') :Salt water - green algae, marine eel grass (''Zostera spp.''), pickleweed (''Salicornia virginica''), and cordgrass (hybrid Spartina × townsendii'') ''and'' (''Spartina anglica''). :Clear water - algae, mosses, freshwater eel grass (''Vallisneria americana). :Solidified lava flows - swordfern (''Polystichum munitum''), ‘ōhi‘a lehua (''Metrosideros polymorpha''), ‘ohelo (''Vaccinium reticulatum'') and ‘āma‘u (''Sadleria cyatheoides''),〔(''Amazing Lava Products and Forms'' ), U.S. National Park Service. Retrieved 2015-06-16.〕 green algae :Disturbed areas such as construction sites, road cuttings and verges, cultivated lands - ''Buddleia davidii'', Nettles, ''Tagetes minuta'', ''Bidens pilosa'', ''Argemone mexicana'' :Bare clay - :Mountains - Lichens 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「pioneer species」の詳細全文を読む スポンサード リンク
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