Palaeos Palaeos Ecology
Life Biomes


Ecology: Biomes


The biome is a major terrestrial assemblage of plants, animals, and microorganisms that has a characteristic appearance and occurs over large geographical areas on the earth's surface.

Biomes are largely determined by combination of temperature (in term determined by latitude) and rainfall, as indicated by the following diagram:

Biome diagram from external linkEnvironmental Biology - Grasslands page

for a geographical representation see the external linkHoldridge Life-Zone map at the external linkNPP Database

Biomes can be divided up in several ways, but it is most usual to list six or seven: (from tropical to polar): tropical rainforest, savanna, desert, grassland. temperate deciduous forest, taiga (boreal forest), tundra.  These ecosystems differ dramatically from one another, largely because of climatic factors.

very dry
Very cold
taiga (boreal forest)
temperate deciduous forest


tropical rainforest

The ocean can be considered an eighth biome, or even a succession of biomes, determined by depth and proximity to the continental shelf.  Sometimes freshwater ecosystems are also considered biomes.

The biomes mentioned above are those currently in existence on earth.  However, some of them have not always been around.  The first forests appeared during the late Devonian,  modern deciduous trees in the Cretaceous, and grasslands only in the Miocene epoch.  Biomes during the Jurassic, the Permian or the Carboniferous were very different.   Fern savannas for example seem have served as vast prairies which provided food for herds of grazing sauropod dinosaurs.

During the Holocene biomes have changed radically.  Two artificial biomes could be added, the agricultural and the urban landscapes, as environments modified by man.



Web SiteWorld Wide Biome project

drawingslinksBiome Basics

Web SitelinksBiome Resources

web pagelinksBiomes - annotated list of links

links pageBiomes - huge list of links

web pagelinksBiomes - list of links

web pagelinksModern Ecosystems - has material on Biomes

web pagemapsGlobal land environments since the last interglacial by Jonathan Adams

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MAK 12 May 1999, last revised 21 November 1999