Biology 120                             Major Ecological Communities: Biomes                     R. Irwin

Ecological communities:
Biomes: major community types

Global pattern:

Global Location tropics (around equator) around 30° latitude and dry sides of mountains temperate region (around 35 to 45° latitude); warmer, drier regions or regions with high fire frequency temperate region (around 35 to 45° latitude); cooler, wetter regions or regions with low fire frequency around 45-65° latitude around 65° and farther north (northerm hemisphere) or 65° and south (southern hemisphere)
Climate hot and wet hot and dry warm summers, cold winters; moderately wet  warm summers, cold winters; moderately wet  moderate summers, very cold winters; moderately dry  short moderate summers, long very cold winters; dry 
Biome Tropical Rainforest Desert Grassland Temperate Deciduous Forest Taiga Tundra
Main Plant Life
 
 

 

         
Soil
 
 
 
 
         
Human Use/Impact 
 
 

 

         

Questions:
1.  What two factors are the main determinants of the major forms of plant species that can potentially occur in a community?  Are these factors biotic or abiotic?
2.  You are traveling from Ecuador (which is on the equator) to Barrow, Alaska (which is very far north.)  Describe how the kinds of plant in the communities you pass through will change.
3.  You are in an area with very low annual rainfall.  Suppose that the average temperature is very hot.  The biome you are most likely to be in is the __________________.  Now suppose the average temperature is very cold.  The biome you are most likely to be in is the _____________________
4.  Compare the soil found in the three forest biomes you have studied in this class: the tropical rainforest, the temperate deciduous forest, and the taiga.  What causes the differences in soil? If each forest is cut down and crops are grown, which soil is most likely to support agriculture for the longest time?  Why?
5. Compare the soil found in the three non-forest biomes you have studied in this class: the desert, the grassland, and the tundra.  What causes the differences in soil? If each forest is cut down and crops are grown, which soil is most likely to support agriculture for the longest time?  Why?
6. What main plant growth forms occur in each of the biomes you have studied in this class?  For each biome, describe features of the main plant growth forms that occur that particularly suite that plant growth form to the climate of the biome.
7.  The biome with the highest biodiversity is: _______________________________
8. How do the three forest biomes (tropical rainforest, temperate deciduous forest, taiga) that we have studied compare with regard to annual temperature and precipitation?