Conservation Ecology

Lectures 24 & 25
Conservation Biology
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Conservation Biology –
The scientific study devoted to the preservation of earth’s biodiversity
Our Biodiversity Crisis
We are in the midst of the sixth mass extinction on earth.
The culprit?
- us
Biodiversity Loss
• Endangered species –
“in danger of extinction throughout all or a significant part of its range”
– Endangered Species Act 1973
Example: California Condor
• Threatened species – are declining; will likely become endangered
Example: Red-legged frog in CA
Why protect Biodiversity?
1. Ethics and Aesthetics
Intrinsic Value
(A bobcat in Yosemite)
2. We need other species!
Useful genes
- the rosy periwinkle (contains 2 substances currently used to treat cancer)
3. Ecosystem Services
– Examples:
Flood prevention
Clean air and water
Threats to Biodiversity:
1. Habitat loss/damage
- logging, development, farming, etc.
Lectures 24 & 25
Conservation Biology
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- Total loss or fragmentation
Edge effects
Fragmentation results in habitat edges
- favors edge-adapted species
- can reduce diversity
(The cowbird, a nest parasite)
2. Invasive species
often eat or outcompete local species
haven’t evolved with local species
Invasive Species
Bullfrogs in California
Ice plant in Santa Barbara
Kudzu in the Southeastern US
Feral pigs on the Channel Islands
- Introduced by farmers
- Currently threaten ten species, including Channel Islands Fox
3. Over-exploitation
- hunting
- harvesting
(Passenger pigeons: now extinct)
This web site provides useful information about the plight of the Passenger Pigeons:
Over-harvesting of seafood
(examples: Bluefin tuna; Red abalone)
Seafood watch, guidelines from the Monterey Bay Aquarium:
4. Pollution
Car exhaust
Chemical Pesticides
Lectures 24 & 25
Conservation Biology
Pollution: Biological magnification
Toxins accumulate as they are passed up the food chain
Top predators are most vulnerable
5. Global warming
Linked to:
Increase in burning of fossil fuel
Increase in greenhouse gases, especially CO2
Greenhouse Gases
Trap heat in earth’s atmosphere
• CO2
• Nitrous oxide
• Methane
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Lectures 24 & 25
Conservation Biology
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Effects of Global Climate Change (GCC)
1. Glaciers melting; Increase sea level
2. Species range shifts
- Spruce budworm invades Alaska
- Gelada baboons moving up the mountain in Ethiopia
3. Species resource base changes
(Polar bears losing hunting grounds)
Conservation Priorities
1. Preserve ecosystems or landscapes
- Reduce Fragmentation
- Nature Reserves
- Buffer zones
- Corridors
Wildlife corridor
2. Biodiversity hot spots
Areas of high endemism and species diversity
The California Floristic Province, where we live, is a Biodiversity Hotspot. There
are over 2,000 endemic species living in this province. For more information about
the California Floristic Province, see this web site:
Restoration Ecology
• Return degraded areas to their natural state
(Coal Oil Point Reserve)
Sustainable Development:
focus on the long-term health of human societies and the ecosystems that support life