Biomes - Abiotic Factors
An ecosystem :
- is an interacting, biological community (plants and animals).
- interacting with abiotic sources to derive energy and nutrients.
- linked together through energy flow.
- name can be applied on many scales - from planets to flowerpots.
A biome
- is a large recognizable assemblage of plants and animals in functional interaction with its environment.
- a useful scale for biogeographers (and us).
- usually identified by the dominant vegetation type.
- typically are organized into 10 to 15 categories. We will use 6 simplified categories.
- abiotic factors are physical and geographic influences.
Abiotic Factors (characteristics) of Major Land Biomes
Biome Average Annual Precipitation Average Temp. Range Soil Other Tundra Less than 25 cm -25° C to 4° C Permafrost, poorly developed, wet Low evapotranspiration Coniferous Forest 35 cm to 75 cm -10° C to 14° C Poorly developed, acidic, wet Low evapotranspiration. Cold winters Deciduous forest 75 cm to 125 cm -6° C to 28° C Well developed, good minerals Distinct seasons Grassland 25 cm to 75 cm 0° C to 25° C Deep, dark and productive Irregular precipitation. High evapotranspiration. Can have cold winters Tropical rain forest 200 cm to 450 cm 25° C to 28° C Highly weathered clay soils, low in nutrients Constant warm and humid Desert Less than 25 cm 24° C to 40° C High mineral content with little organic material Irregular precipitation. Warm and cold deserts exist.
Biome Chart
Biomes
Physical Characteristics
Plants
Animals
Tundra 2 seasons, dry, frozen deserts, winter: extreme cold and snow, summer: flooding caused
by snow melt, permafrost layer (permanently
frozen, about 3 m below ground), location: far
north and far south - towards the polar ice caps,
average temperature: 10 degrees celsius
rainfall: 25 cm/yr
snow: 10 - 20 cm/yr
no trees, dominated by mosses and lichens and grasses, some small
shrubs
insect blooms, large hooved mammals (Caribou, Musk Ox), Bears,
wolves, small rodents (lemmings),
migrants during the breeding
season
Taiga/Boreal Forest long winter, short fall and spring, 2-3 months of summer, wetter seasons,
heavy rain and snow
location: coniferous forest, far nothern and far
southern latitudes
trees 5 - 10 m high, boreal forest, conifers - pine,
spruce, bog plants (ferns and mosses)
diverse array of migrants from the tropics with few resident species
(Moose, Bear, Lynx, fox, voles),
large insect blooms
Temperate Deciduous Forest 4 seasons, rainfall: 80-140 cm/yr complex levels of vegetation deciduous trees, loose leaves
in fall
diverse array of migrants from the tropics and resident species
Savanna dry, rainfall: 90 - 150 cm/yr location: tropical to subtropical,
3 seasons
grasses, forbs, trees short and (2m tall) clumped together (10 m tall)
large ungulates, large predators Temperate Grassland temperate and some subartic grassland (extreme northern prairies - steppes and
some extreme southern grasslands -
pampas of Argentina)
rainfall: 25-70 cm/yr
grasses large ungulates Chaparral mild wet winter followed by hot, dry, summer many plants dependent on regular fires
associated with Chaparral
location: near coastlines (California, Chile,
Mediterranean
short trees and shrubs diversity of mammals, birds, insects, etc. that like dry
habitats
Desert very dry, rainfall: less than 25 cm/yr location: primarily equatorial but some reach
into temperate regions
cactus, sagebrush, creosote and shrubs
small rodents, reptiles Tropical rainforest very wet - heavy rainfall, soil - poor in nutrients, temperature constant throughouth the year
wet and dry seasons
location: equatorial, 23.5 degree N latitude -
23.5 degree S latitude
large trees- broad-leaved evergreens, epiphytes, not much forest
floor vegetation (little sunlight).
canopy 30 - 40 m above ground
highest diversity of animals Aquatic Biome freshwater and marine Marine - Pelagic Zone deep ocean, dependent on upwellings algae various birds, large mammals fish
Marine - Benthic ocean floor, no light none detritus feeders, predatory fish Marine - Estuaries where rivers flow into the ocean, mix of saltwater and freshwater, marshes rich in plants and
animals
aquatic vegetation, marsh plants rich variety Marine - Intertidal zone shoreline to shallow waters algae marine worms, clams, oysters, Biome Chartcrustaceans
Coral reefs tropical oceans algae coral, fish