Biomes - Abiotic Factors

An ecosystem :

  1. is an interacting, biological community (plants and animals).
  2. interacting with abiotic sources to derive energy and nutrients.
  3. linked together through energy flow.
  4. name can be applied on many scales - from planets to flowerpots.

A biome

  1. is a large recognizable assemblage of plants and animals in functional interaction with its environment.
  2. a useful scale for biogeographers (and us).
  3. usually identified by the dominant vegetation type.
  4. typically are organized into 10 to 15 categories. We will use 6 simplified categories.
  5. 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.