Honors BiologyECOLOGY

ADDITIONAL INFORMATION

Phosphorus Cycling Phosphorus is essential because

is a key component in molecules like DNA / RNA

Phosphorous is not very common in the biosphere, it remains mostly in rock, soil minerals, and ocean sediments.

As rock and sediments weather phosphate is released… washed into rivers and streams… carried to the ocean where it is used by marine organisms.

EutrophicationWhat is it? Over-enrichment of water by

nutrients such as nitrogen and phosphorusHow is it caused? Primarily from

agricultural and urban runoff into rivers, lakes, oceans

Results? Hypoxia (click link above)◦Nutrients cause algal blooms (rapid increase

in algae population) which results in more food for bacteria

◦Bacteria then increase in number and use up the dissolved oxygen

◦The result is oxygen depletion and many fish and aquatic insects cannot survived

Impacting SpeciesInvasive Species:

◦ Species which is not native to area and adapt to the new area easily / reproduce quickly.

◦ To be classified as an invasive species it must harm property, the economy, or native plants and animals of the region (click title for more)

Keystone Species: ◦ A species (population) that has a large effect on a

specific ecosystem, the ecosystem would be dramatically different or cease to exist altogether if the keystone species were removed… like a domino effect.

◦ Many times a keystone species is a predator which controls the distribution and population of large number of prey species. (click title for more)

◦ http://www.classzone.com/cz/books/bio_07/resources/htmls/animated_biology/unit5/bio_ch16_0507_ab_foodwbfx.html

Demographic Transitionhttp://www.globalchange.umich.edu/globalchange2/current/lectures/human_pop/human_pop.html

Age Distribution

Japan

Biological MagnificationSee Fig6-16 pg 152Concentration of a

pollutant (DDT-pesticide) is multiplied as it passes up the food chain.

By the time it reaches the top it can be multiplied 10million X

Endangered Species ACT 1973 Provides for the conservation of 

species that are endangered or threatened throughout all or a significant portion of their range, and the conservation of the ecosystems on which they depend.

A "species" is considered:◦ ENDANGERED if it is in danger of extinction throughout all or

a significant portion of its range.◦ THREATENED if it is likely to become an endangered species

within the foreseeable future. NOAA's National Marine Fisheries Service (NMFS) and

the U.S. Fish and Wildlife Service (USFWS)share responsibility for implementing the ESA. Generally, USFWS manages land and freshwater species, while NMFS manages marine and "anadromous" species. NMFS has jurisdiction over 94 listed species.