Conservation Biology Flashcards
What is conservation biology?
-Scientific study of the nature and status of earth’s biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions
What is extinction?
- Fact of life
- all species become extinct eventually
- species becoming extinct 100-1000 faster than before humans
Describe how extinctions have come about through history?
- Humans have caused extinctions
- changing climate has caused extinctions
- Australia had large variety of animals that became extinct when humans arrived (Africa didn’t have equivalent mass extinctions)
Why are islands prone to extinction?
- They evolved in the absence of predators
- Humans brought competitors and disease
- Island populations are usually small which increases risk for extinction
What are endemic species?
- Species found naturally in only one geographic area and no place else
- usually occupy restricted ranges
What are hotspots?
-Areas where species have high endemism
How is habitat lost and how does it effect species?
- Land can be cleared for agriculture, housing, and economic development
- losing land is a threat to species
Describe values of biodiversity?
- Resources for our survival are found: food, medicine, clothing, energy, shelter
- 40% of prescription/nonprescription drugs have active ingredients extracted from plants
What economic value is found in biodiversity?
- Pollination
- Water quality
- Buffers against storms/droughts
- Prevent loss of minerals/nutrients
ex. tropical rainforest provide more economic benefits than if they were destroyed
What are the problems of valuing ecosystems?
- No good estimate of monetary value of services provided by the ecosystem
- People who gain benefits of environmental degradation are often not same people who pay the costs
What are some causes of extinction?
- Habitat loss
- Introduced species
- Pollution
- Loss of genetic variation
What is habitat fragmentation?
- Dividing the habitat into small, unconnected areas
- Bad because of relationship between range size and extinction rate
What is edge effects?
- Changes in microclimate along the edge of a habitat
- The climate on the edge of the habitat is different than the center (in respect to habitat fragmentation)
Describe pollution?
- Aquatic environments are particularly vulnerable
- Many lakes are sterilized by acid rain
Describe disruption?
ex. people who visit bat caves even as little as four times a month caused a large decline in population size
What is exploitation?
- Overkilling of a species
ex. whales overkilled, they take 2-3 years to have children so repopulating themselves takes a long time
Describe introduced species?
- Brought by others/not originally there
- Threaten native species and habitats
Describe colonization?
- process by which a species expands its geographic range
- humans can transport plants and animals, expanding their range
ex. zebra mussels
Describe how extinction cascade happens?
- Disruption to ecosystem causes extinction cascade
- Human activities that effect one species can effect many other species
Describe the difference between weather and climate?
- Weather: short term changes
ex. temp, air pressure, wind, precipitation - Climate: average conditions in a particular area over a long period of time
ex. temp, precipitation (fluctuations normal)
Describe the natural greenhouse effect?
- Greenhouse gases absorb heat radiated by the earth
- The gases then emit infrared radiation that warms the atmosphere
Why are oceans warming?
- They absorb 1/3 of CO2 from the atmosphere
- The CO2 combines with he water to make carbonic acid
- Acidity threatens corals, snails, shelled animals, phytoplankton
What are the effects of a warmer atmosphere?
- Positive feedback loop: accelerated melting of polar ice
- Climate tipping point: melting of summer arctic sea ice , changes in arctic seawater temperatures can influence the jet stream
