Alternative site for the Global ecosystem typology with additional information for ecosystem profiles and indicative maps.
This site is maintained by jrfep
The five realms represent all parts of the biosphere. A conceptual model of ecosystem assembly was used to describe and compare the ecological drivers and traits that characterise the five realms. This comparative analysis helped to identify major gradients of variation and informed the definition of functional biomes (level 2) and ecosystem functional groups (level 3) within each realm.
The Atmospheric realm includes the gaseous medium and its suspended particulate liquids and solids above the terrestrial realm, extending to the altitudinal limits of life.
The Freshwater Realm includes all permanent and temporary freshwater bodies as well as saline water bodies that are not directly connected to the oceans and characterised by water regimes defined by frequency, duration, flow velocity, depth and extent of inundation.
The Marine Realm includes all connected saline ocean waters characterised by waves, tides and currents.
The Subterranean realm includes the earth’s crust and subsurface voids characterised by an absence or very low intensity of sunlight.
The Terrestrial realm includes all dry land, its vegetation cover, proximate atmosphere and substrate (soils, rocks) to the rooting depth of plants, and associated animals and microbes.
Transitional realms accommodate continuous variation among the core units. The interface between terrestrial and freshwater realms is occupied by palustrine wetlands, some of which accumulate peat under impeded substrate drainage. The freshwater-marine transitional realm is occupied by brackish aquatic ecosystems on marine coasts. The marine-terrestrial transitional realm is characterised by steep environmental gradients in desiccation, salinity and wave and tide disturbance, occupied by contrasting shoreline ecosystems. The interface of marine and terrestrial seepage is sometimes influenced by seepage or outflow of freshwater, supporting intertidal wetlands and deltaic systems. Unique ecosystems also occur where the subterranean realm meets the interface of freshwater and marine realms, respectively.
The functional biomes belonging to these transitional realms are linked to all their parent realms.