Biodiversity
A Measure of how many species are in an area
Why is Biodivers ity Important ?
Why Maintain Diversity? Ecosystem Services!
To purify our air and water (phytoplankton)
To reduce floods (vegetation)
To generate fertile soil…
To pollinate…
To cycle nutrients…
To protect from erosion…
To control agricultural pests!
Why We Need Species? Economic Goods!
Why We Need Species? Sources of Food
Aspirin Codeine Why We Need Species? Sources of Medicines
Provide us with recreation Ecotourism: giving $$ to a country to view their environment. Why We Need Species?
Contain genetic info that tells the story of Earth! Why We Need Species?
# of Species? 1.3 million catalogued ≈ 8.7 ± 1.3 mill –Undiscovered: insects, fungi, bacteria
Threatened Species Species has few individuals and is near becoming endangered.
Gelada Baboon
Grizzly Bear
Northern Spotted Owl Threatened-US ESA Habitat loss in Canada and No. US! Need old growth forest, top predators, and are specialists.
Species has fewer individuals; at risk of becoming extinct. Endangered Species
White Abalone
Barred Bandicoot
Case Study: California Condor Scavenger bird; eats dead carcasses = 273 individs. Endangered: low birth rates, late sexual maturity, poaching, lead poisoning, DDT, and power lines. X Ray shows bottle caps and metal shards
of E. S. Intrinsic Characteristics of E. S. Extremely localized/require LARGE territory Low birth rates Island species/extreme specialists Low adaptability Late sexual maturity
Species no longer exists on Earth. 1,138 documented today since 1600 Extinct Species
Tecopa Pupfish, CA
Yangtze River Dolphin AKA Bajii Last sighting 2004 Causes: heavy transportation on river, overfishing, dams, collision w/ boats, H 2 O pollution.
Case Study: Passenger Pigeon 200 yrs ago 3-5 billion –world’s most abundant bird –1 flock =10 mi wide, 100 mi long) Killed for its meat Martha died in 1914.
Types of Extinctions Background extinction: species die/yr Caused by natural selection. Mass Extinction: 1000’s spcs die/yr Caused by dramatic env. change. 5-6 so far Humans causing 6 th ??
Too many people! Weak/no laws High consumption rates Root Causes of Extinction
Humans Cause Extinction Habitat Loss/ Habitat Fragmentation
Humans Cause Extinction Hunting/Poaching
Humans Cause Extinction Overfishing
Humans Cause Extinction Capture and Sale of Exotics 2.5 million birds caught illegally / yr 1 bird in store = 10 deaths in transit
Humans Cause Extinction Global Warming
Introduction of Non-Native Species – species that does not belong in area. Humans Cause Extinction Cane Toad Zebra Mussels in Great Lakes Iceplant at Beach
Non-Natives/Exotics Cause problems w/ native species because: 1.Can usually outcompete natives 2.Eat same food resources as natives 3.No natural predators in new area. 4.Reproduce w/ no limits on growth. Amer. Bullfrog in CA Crayfish in CA