Ecosystems

v  How ecosystems function: an overview

o   Ecosystem:

o   Nutrients:

v  Energy capture in ecosystems:

o   The rate of energy capture varies across the globe.

§  Net primary productivity (NPP):

 

 

§  Biomass

o   Human activities can increase or decrease NPP.

v  Energy flow through ecosystems:

o   An energy pyramid shows the amount of energy transferred up a food chain.

§  Trophic level

 

o   Secondary productivity is highest in areas of high NPP.

 

v  Nutrient cycles

o   Nutrient cycling:

 

o   Exchange pools:

 

o   Sulfur is one of several important nutrients with an atmospheric cycle.

 

§  Atmospheric cycle:

 

o   Phosphorus is the only major nutrient with a sedimentary cycle.

§  Sedimentary cycle:

 

o   Human activities can alter nutrient cycles.

 

§  Acid rain

 

v  Ecosystem design

 

 

 

v  The economic value of ecosystem services: