BILDSTUDY6

BILDSTUDY6 - Lecture 12 Human Impacts 1. Nutrient...

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Lecture 12 Human Impacts 1. Nutrient Enrichment i.e fertilizer serves as N (nutrient) provider for land a. Critical load – amount of nutrient that can be absorbed by plants i. Excess fertilizer leach into aquatic ecosystems b. Eutrophication – increase productivity as a result of increase nutrient i. Phytoplankton grow and die : decomposition by bacteria causes reduction in oxygen (anoxic/hypoxic conditions) killing fish c. Dead zones : areas of low oxygen in the world’s ocean 2. Toxins in the environment: such as DDT concentration a. Biological magnification - toxic chemicals are a greater risk to top-level predators in trophic level then primary consumers because of concen. 3. Climate change: Greenhouse effect a. Solar radiation is absorbed by earth which re-emits (trapped)heat radiation b. Greenhouse gases: Water, Carbon dioxide, Methane c. Svante Arrhenius: published that carbon dioxide would warm climate d. Charles David Keeling(SIO): measured CO 2 concentration & made keeling curve which was very accurate
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This note was uploaded on 02/21/2010 for the course BILD BILD 3 taught by Professor Woodruff during the Fall '08 term at UCSD.

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