Teaching Ecology Post 6: Biomes of the World

Biomes: 

An Interesting Look at our World

A biome is a group of ecosystems that has the same general climate, and contains a particular group of plant and animal species.  A biome is characterized by certain soil and climate conditions.  An organism cannot live in just any old biome. Each species of organism has a set of particular adaptations that makes it well suited for a particular biome. Each plant and animal species has a different tolerance level.  Tolerance is the ability to survive and reproduce in conditions that are outside of the optimum conditions for that organism.  For example, an animal adapted to living in a desert has a high tolerance, since this animal can tolerate blistering hot temperatures during the day, and freezing temperatures at night.  An insect that lives in a rain forest, however, would die quickly if the temperature became too cold.

A biome has climax communities with little of no succession taking place.  The climax community is the result of succession.  In succession, the community proceeds through a series of stages until it reaches a stable end point. At each stage of succession, the organisms present alter the physical environment in ways that make it less favorable for their own survival, but more favorable to the survival of the species that follow them.  The climax community is the result of succession.  The plant and animal species of this climax community are stable populations that will remain constant over a long period of time.

Events called disturbances may change the face of a particular ecosystem.  Examples of disturbances include forest fires, floods, and volcanic eruptions.  These events have drastic effects on the organisms living in the community.  When these things happen, nature starts over (succession) in restoring living organisms to the area.

All of this is very interesting and my students are generally quite eager and receptive when I teach this information.  In almost every day of their life, these students are exposed to news events of hurricanes, floods, tsunamis, volcanic eruptions, forest fires, etc.  It is important that our biology students understand the impact of these disturbances and how these changes will affect a geographic area.

How many biomes are there, and how should we go about teaching them to our students??  In my experience, there is not a definitive answer to the "how many" question. It depends on which textbook or other informative source you read!  I begin with a simple explanation: There are terrestrial biomes and aquatic biomes.  I am sure that there will be some disagreement with this, but I have found that teaching 8 basic terrestrial biomes works the best for my students. Which 8?  I break them down into the following:

• tundra
• taiga
• chaparral
• temperate deciduous forests
• temperate grasslands
• deserts
• savannas
• tropical rain forests

The aquatic ecosystems can be subdivided in many ways as well.  You might first differentiate between ocean zones and freshwater zones.  Oceans zones would include photic zones, aphotic zones, intertidal zones, neritic zones, oceanic zones, benthic zones and estuaries.  Freshwater areas would include lakes, streams, rivers, marshes, bogs and swamps.

As you can see from above (I hope!), teaching the biomes should be very visual.  My students love pictures and visual examples of the concepts I am teaching.  In my PowerPoint presentation, I try to include as many photographs as possible.  There is only one drawback..... When you show a classroom full of students a LOT of pictures, they will ask a LOT of questions!!  But this is what makes teaching so much fun!  Here are a few of the slides from my Powerpoint presentation on biomes:

Biomes of the World PowerPoint with Notes for Teacher and Student

Have fun teaching!