Biomes

Biodiversity - the variety of species living in balance within an ecosystem, biome or planet.

The Amazon rainforest is a biodiversity hotspot due to the number and variety of species

Biome - a major ecosystem characterised by commonalities of animals, plants and climate and soil.

For example, most hot and dry deserts have little rainfall with few plants and mammals.

BiomesBiodiversity

High biodiversity usually means a more stable system, with fewer cyclical explosions in prey or predator.

Biodiversity is a measure of the health of ecosystems, but not the total indicator. Polar ice sheets support less biodiversity but this healthy.

Biodiversity is read on three levels.

• Species Diversity - The amount of different species in the community and variation within populations of a given species.

• Species Diversity - The amount of different species in the community and variation within populations of a given species.

• Ecosystem Diversity - The variety of habitats, communities and ecological processes within and between ecosystems.

• Species Diversity - The amount of different species in the community and variation within populations of a given species.

• Ecosystem Diversity - The variety of habitats, communities and ecological processes within and between ecosystems.

• Genetic Diversity - The variety of genes held within all members of a population.

Biodiversity can affect the stability of ecosystems and the sustainability of populations, including humans...

... as each species are interdependent in both straightforward and subtle ways.

BiomesBiomes in more detail

There are 8 officially classified terrestrial biomes (plus marine and freshwater):

1. Temperate forest2. Tropical forest3. Conifer (taiga/boreal)4. Tropical savannah5. Temperate grassland6. Chaparral7. Tundra8. Desert

Temperate forests occur in eastern North America, north-eastern Asia, plus western and central Europe.

Climatic influences include well-defined seasons.

Flora is typified by deciduous trees is such species as oak and beech, plus temperate woodland flowers and fungi.

Fauna is represented by squirrels, rabbits, birds, deer, fox, and black bear.

Tropical forests occur closer to the equator than temperate forest.

Climatic influences include little seasonality or temperature variation, although they may have a rainy season.

Flora is highly diverse, with a vast variety of tree species and plants such as orchids, vines, ferns and mosses.

Fauna include numerous birds, bats, primates, small mammals, and insects.

Coniferous forests (taiga/boreal), are found in northern latitudes; Siberia, Scandinavia, Alaska, and Canada and Eurasia.

The main climatic influences are long winters and a short summer growing season.

Flora consists mostly of cold-tolerant evergreen conifers with needle-like leaves, such as pine, fir, and spruce.

Fauna include woodpeckers, hawks, moose, bear, weasel, lynx, fox, wolf, deer and hares

Tropical savannahs are found in a wide band on either side of the equator on the edges of tropical rainforests.

The main climatic influence is rainfall concentrated in half the year, followed by a long period of drought when fires can occur.

Flora consists mostly of grasslands with scattered shrubs or trees.

Fauna is highly diverse, including giraffes, zebras, snakes, worms, lions, leopards, hyenas, and elephants.

Chaparral is found on most continents, from the west coast of the US to the western tip of Australia and the coastal areas of the Mediterranean.

The main climatic influence is heat and lack of moisture. Winters are mild with summer so hot and dry that fires and droughts are common.

Flora is typified by small, hard leaves which hold moisture. Some of these plants are poison oak, scrub oak and cacti.

Fauna includes coyotes, jack rabbits, mule deer, alligator lizards, horned toads and praying mantis.

Arctic tundra is located in the far northern hemisphere, encircling the North Pole and extending south to the coniferous forests.

The main climatic influence is cold (-34°C) and lack of moisture with a summer growing season (3-12°C) of just 50 to 60 days.

Flora includes shrubs, sedges, reindeer mosses, liverworts, and grasses, small flowers and lichen.

Fauna includes caribou, arctic hares and squirrels, foxes and wolves.

Desert biomes occur wherever the rainfall is less than 50 cm/year. Hot-dry deserts occur in North Africa, south-western U.S., Mexico, and Australia.

Hot-dry desert biome is typified by heat with little seasonal variation, evaporation rates usually exceed rainfall rates.

Hot-dry desert vegetation is rare outside of oases. Plants are almost all ground-hugging shrubs such as Prickly Pears and Brittle Bush.

Hot-dry desert fauna includes nocturnal insects, arachnids, reptiles and birds.

Hot-dry desert fauna includes nocturnal insects, arachnids, reptiles and birds.

BiomesTaiga

Taiga is the largest terrestrial biome at 28% of the planet, located just below the tundra biome.

The main seasons are cold winters and snow, with humidity and high precipitation in summer.

There are few species of fauna in the taiga because of the harsh conditions, poor soil and permafrost.

Frost-resistant coniferous trees like pine, spruce and Douglas fir predominate as well as lichens and mosses.

Seed eaters like finches and sparrows, and omnivorous birds like crows stay all year round.

The taiga has an abundance of insects in summer, when many insect-eating birds like geese come to feed and breed.

Fauna of the taiga include snowshoe rabbits, red squirrels and voles. They are predated upon by wolverines, arctic fox, lynx and bobcat.

The current rate logging in boreal forests may cause their disappearance.

The permafrost contains a huge quantity of methane, a powerful greenhouse gas which may be released if the permafrost melts

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