BIOL595 Exam 2: Habitat Degradation and Loss

what is habitat loss?

• extreme changes in habitats that make them unable to support more than a fraction of their original species and ecological functions

what is habitat degradation?

• all other less extreme changes to a habitat

what is biodiversity an indicator of?

• the health of an ecosystem

what are some anthropogenic causes of habitat degradation/loss?

• mining, deforestation, pollution, agriculture

what are the four agricultural methods that cause habitat degradation?

1. growing crops

2. grazing

3. silviculture

4. aquaculture

which two habitats have been most affected by agricultural crops?

1. prairies (97% tallgrass, >60% mixed/shortgrass lost)

2. wetlands (85% lost)

what is silviculture?

• agriculture of trees

what is clear cutting?

• cutting every tree down in a given area

• efficient, but destroys an ecosystem

what is selective logging?

• cutting down certain trees within a given area

what is seed tree cutting?

• leaving certain trees for seed production

what is a shelterbelt?

• leaving a row of trees as a windbreak to protect the soil from erosion

• also provides seed trees

what are the four types of extraction without replacement?

1. mining

2. fisheries

3. old growth forests

4. groundwater

what are gob piles?

• waste piles from mining that contain heavy metals

• these turn into runoff and enter waterways

what is trawling?

• dragging a weighted net along the bottom of the ocean floor

what are old growth forests?

• forests that contain trees that take a very long time to grow

• EX: sequoias, redwoods

what are the six types of infrastructure development that lead to habitat degradation?

1. human settlement/urbanization

2. industry

3. transportation (land, air, water)

4. dams/canals

5. recreation/tourism

6. electrical/communication transmission lines

what are the three types of pollution that can cause habitat degradation?

1. atmospheric

2. land

3. water

what are the four types of atmospheric pollution?

1. smog

2. acid rain

3. ozone depletion

4. global warming

what does the ozone layer do?

protects us against UV rays

what are the biggest degraders of the ozone layer?

• propellant chemicals

what are the five types of land pollution?

1. agricultural chemicals (fertilizers, herb/pesticides)

2. industrial chemicals

3. household chemicals (cleaning products, pharmaceuticals)

4. roadside wastes (oil, rubber, salt)

5. light/noise pollution

what are the five types of water pollution?

1. chemicals from the land in the waterways (agricultural, industrial, household)

2. sediment (soil)

3. sewage/livestock waste

4. oil spills

5. thermal pollution

what is thermal pollution?

• using water for cooling

• sends warm water back out into the waterways

what biotic change can lead to habitat degredation?

• the introduction of a non-native invasive species

what is the differense between an exotic and an invasive species?

exotic: not native, don’t damage

invasive: not native, cause damage

what is lentic water?

• rather still/slow moving water

what is lotic water?

• rather fast water

what are the three trophic states of lentic water systems?

1. oligotrophic

2. mesotrophic

3. eutrophic

describe the oligotrophic level

• low level of primary production

• low concentration of plant nutrients

• high concentration of dissolved O2

• clear water

• overall HEALTHY

describe the mesotrophic level

• intermediate level of primary productivity

• medium level of nutrients

• clear water

describe the eutrophic level

• very high level of surface productivity

• excessive nutrients (nitrogen phosphorus)

• contains anoxic “dead zone”

describe the process of eutrophication

1. limiting nutrient added to system

2. dense surface vegetation

3. shades out all water underneath

4. no photosynthesis in water column

5. oxygen being used up, but not replaced

6. anoxic conditions

7. dead zone