Ecosystem Values and Disturbances

Values Resistance vs. Resilience

Intermediate Disturbance Hypothesis Succession (primary vs. secondary)

Value of an Ecosystem

Instrumental• Cultural services:

– The knowledge we gain• Provisions

– pharmaceuticals• Regulating Services

– Act as filters of Carbon dioxide

• Support Systems– Pollination– Filter water

Intrinsic• Value independent of any

benefit to humans.

What do you think happened here?

List some things that could cause disturbances in an ecosystem.

• Hurricanes• Ice storms• Volcanoes• Forest fires• Agriculture• Deforestation• Air pollution• surface mining

Resistance vs. Resilience

Resistance• The measure of how much a

disturbance can affect the flows of matter and energy in an ecosystem

Resilience • An ecosystem’s ability to

return to its original state.

Are all disturbances bad?

The intermediate Disturbance Hypothesis

States ecosystems experiencing intermediate levels of disturbance are more diverse than those with high or low disturbance levels.

http://www.google.com/url?sa=i&rct=j&q=forest&source=images&cd=&cad=rja&docid=zNaKBUIxNmQzhM&tbnid=DK_-rjJpmrZb3M:&ved=0CAUQjRw&url=http://miriadna.com/preview/1210&ei=3XoVUZiMCYr89QSbjoCQCw&bvm=bv.42080656,d.eWU&psig=AFQjCNEVAqErVjc4ZkyOMwyCF5CrsvB3eQ&ust=1360448599910099

Primary Succession vs. Secondary succession

Succession

http://www.google.com/url?sa=i&rct=j&q=primary+successsion&source=images&cd=&cad=rja&docid=Z4PR4kZLF53mtM&tbnid=rjr67IOSil1cGM:&ved=0CAUQjRw&url=http://kids.britannica.com/comptons/art-90130/Secondary-succession-takes-place-following-a-major-disturbance-such-as&ei=BHsVUabBK4Km9ASYw4DADg&bvm=bv.42080656,d.eWU&psig=AFQjCNE9i7Hb8UBH7QY59frVvU88NWTwSA&ust=1360448642483860

http://www.google.com/url?sa=i&rct=j&q=primary+successsion&source=images&cd=&cad=rja&docid=VCGSfN-miqqSUM&tbnid=3UabsTRVwyawhM:&ved=0CAUQjRw&url=http://science4jengling.wordpress.com/2012/11/13/unit-2-types-of-forests-and-their-formation-and-sustainability/&ei=R3sVUYHfEpGs8AT414D4Ag&bvm=bv.42080656,d.eWU&psig=AFQjCNE9i7Hb8UBH7QY59frVvU88NWTwSA&ust=1360448642483860

Aquatic succession

Now draw your own on the back of the paper…

• Include the labels– Primary succession or secondary succession– Pioneer species– Intermediate species– Climax community

4 stages