Communities and Biomes

Life in a Community

A community is interconnected and each biotic factor contributes something.

This makes each organism important and often necessary.

Due to different factors being present in different places, ecosystems look different in different places across the globe.

Limiting Factors

A limiting factor is something that restricts the numbers, reproduction, existence, or distribution of organisms in a community or ecosystem. It can be biotic or abiotic.Examples can be number of

predators, rainfall, temperature, or disease.

Tolerance

The ability of an organism to withstand changes in its’ environment is called tolerance. Each organism has its’ own range of tolerance.

Succession

Succession is a change over time. It is orderly and often includes a change in species and/or natural changes.

Succession often takes decades or centuries to see.

There are two primary types:Primary SuccessionSecondary Succession

A climax community is one which is stable and undergoes little or no change.

Primary Succession

Primary Succession is when communities of organisms colonize barren land.

Think of a volcanic island that emerges from the sea or when lava covers land and solidifies.

Pioneer species are species which are the first to arrive and take hold in primary succession.They include lichens and microorganisms.They will eventually die and become the basis for

soil.

After a while the primary succession slows down and the community becomes stable.We call this a climax community.

It undergoes little to no change in species and remains similar.Changes can still occur as some species’

populations or makeup will change.

Secondary Succession

Secondary Succession is when an existing climax community is severely disrupted in some way:A fireA farm field that lies fallow for yearsA building or city that is abandoned.

Secondary succession takes less time than primary succession and involves very different species.

An Example of Secondary SuccessionMount St. Helens erupted in Washington in 1980.

Mount St. Helens Video

http://www.pbs.org/wgbh/nova/earth/mt-st-helens.html

Biomes

How Biomes are Determined

Biomes are determined by sharing similar Keystone Species and characteristics.

It can also be said that a biome shares a similar type of climax community.

Factors Affecting Biomes

Vegetation DifferencesTemperatureLatitudePrecipitationClimateHumiditySpecies within the Biome

Keystone Species

A keystone species is an organism (usually a plant or animal) that is connected or associated with a particular biome.

Types of Biomes

Alpine TundraArctic TundraChaparralCoral ReefDeep Ocean/Open OceanDesert

EstuarySavanna/PrairieTaiga/Boreal ForestTemperate/Deciduous ForestTropical Rainforest

Biome Presentations

Working in groups of 2, YOU are going to present the biomes to the rest of the class. This will serve as our major grade for the chapter.

Necessary Categories to Include

Keystone Animal Species Keystone Plant Species Precipitation Sunlight Temperature Climate/Seasons Altitude/Latitude/Location on Earth Dangers to this Biome Coolest thing about this biome Something that most people don’t know about the

biome

Grading

I will grade using the rubric I will now hand out.We will use our next lab period as a time for

you to do some research on your own.You will need to create a presentation AND a

handout and hand both in.The presentation can be made with PowerPoint OR

Prezi.It must last from 10-20 minutes.The handout must be handed in the day before you

are scheduled to present.

Prezi

If you don’t like or have PowerPoint you can use Prezi.

Here are a couple of examples:

http://prezi.com/pgh5a3xbuicm/save-the-ocean/

http://prezi.com/6rv9n-sxedgk/tribute-to-existence-our-space-in-space/