Chapter 6

Human activity has transformed the biosphere by:

OVER HUNTING

AGRICULTURE

& uRBAN dEVELOPMENT

rENEWABLE RESOURCES - are capable of regenerating.

Ex: water and trees

nonrenewable resources - are not capable of regenterating.

ex: fossils fuels and natural gas

biodiversity - the total variety of all organisms in the biosphere.

biodiversity is important to human society because it provides:

foods

medicines

& other products

humans reduce biodiversity by:

1. Altering Habitats

Habitat Fragmentation - results in ecosystems being split into "pieces"

deforestation - cutting down forests

Leads to: severe soil erosion leading to changes in soil composition and plants in the area.

Leads to: Less carbon dioxide being absorbed by plants leading to possible changes in local climate.

2. hunting

Extinct Species - no member of the species is living.

Endangered species - there are only a few living members of the species.

threatened species - the species has several living members, but if the loss continues the species will become endangered.

3. INTRODUCING INVASIVE SPECIES

organisms that are introduced to an area that are not native to. these organisms tend to spread quickly and push the native species out.

ex: Fountain grass in Hawaii. Mongoose in Hawaii.

4. Pollution

Water pollution is primarily due to industrial and agricultural chemicals and sewage.

This leads to biological Magnification.

Biological Magnification - increasing the concentration of a harmful substance in organisms at higher trophic levels in the food chain or food web (ex: the insecticide DDT)

ADD PICTURE

AIR POLUTION LEADS TO

• SMOG
• aCID rAIN
• iNCREASE IN gREENHOUSE gASSES
• dECREASE IN aIR qUALITY

gOALS OF conservation OF bIOLOGY.

Protect individual species as well as entire habitats.

Manage resources including preservation of habitats and wildlife.