Ecology/Evolution 4

Ecosystem approach

emphasizing the storage and transfer of energy and matter including many chemicals needed for life

The global phosphorus (P) cycle

-DNA, cell membranes, ATP

-no atmospheric pool

-main pool: rock/sediments

-Long residence time in rock and biotic pools

-flux from water phosphate to plants doesn't require organisms

The global nitrogen (N) cycle

- major component of proteins and DNA

-important atmospheric pool

-flux from atmosphere pool to plants requires specialized bacteria(nitrogen fixers)

-soil to atmosphere

-long atmospheric RT: 14 million years

-Ocean RT: 20,000

-Plant RT: 3 years

-Soil RT: 9 years

The global carbon cycle

-building block of life

-photosynthesis and respiration(specialized organisms)

-large atmospheric pool

-huge rock pool

-flux out of FF is 60,000x greater than into

-Plant RT: 5 years

-Atmosphere RT: 3 years

-Rock RT: 150 million years

Greenhouse gases

carbon dioxide, nitrous oxide, methane

Greenhouse effect

A natural process that helps maintain steady and life sustaining surface temperatures on earth. Sunlight heats the surface of the earth and that heat radiates back to the atmosphere. While some of that heat escapes to space, certain gases in the earths atmosphere trap heat within the atmosphere which warms the atmosphere and earths surface.

Effects of climate change

-Glacier loss

-Earlier spring for many organisms indicated by first breeding attempts

-change in global ocean currents which affect temperature

-change in sea level