Biodiversity Ch. 5 Notes

Definition: Biodiversity Bio = life Diversity = variety  Variety of species in an area

Benefits of Biodiversity 1. Ecosystem stability  Replacements / alternatives 2. Economic value  Harvest / use  Use “best” individual or trait 3. Aesthetic value  It’s “nice” 4. Scientific value

Genetic Diversity  Variety of genes and traits  A few will survive new / changing conditions  Evolution: some traits will be “best” and passed on  Helps with survival

Species Diversity  Number of different species, and their abundance  Fills and replaces niches  Greatest at the equator, decreasing toward the poles

Ecosystem Diversity  Variety of ecosystems / biomes / habitats  Different conditions support different species  Allow for different tolerances

Threats to Biodiversity: 5.2 Extinction  2 Types:  1.) Background extinction  Slow, gradual  More common in small habitats and islands  2.) Mass extinction  Lots of species in a short time  Due to major disasters, continental drift, climate change

Extinction  Occur occasionally  444 mya, 360 mya, 251 mya, 200 mya, 65 mya  One may be occurring now  Extinction rate is 1,000 times greater than normal

Factors that Threaten Biodiversity  1.) Overexploitation  Too much use  Usually Value  Ex.) “The Lorax”

Continued…  2.) Habitat Loss :  Destruction  Cleared for farms or houses  Disruption  Organism removed  Food web interrupted / lost

Continued…  3.) Habitat Fragmentation  Broken into “islands”  Creates many edges that can be hard to live in

Continued…  4.) Pollution :  Toxins  Can affect all organisms  Often magnified as you move up the food chain

Pollution Continued…  Acid rain  Dissolves nutrients out of soil  Eutrophication  Fertilizers drain into water and help algae take over

Continued…  5.) Introduced Species :  Prey on, or out-compete, many existing species  Ex.) Zebra mussels, kudzu (U.S.)  Almost ~40% of all extinctions since 1750 have come from introduced species

Conserving Biodiversity: 5.3  Resources are helped by biodiversity  2 types:  Non-renewable resources  Very slow replacement / not replaced  Ex.) Oil / coal, Metals / minerals  Renewables  Replaced very quickly  Ex.) Solar, Wind, Water, Food  Sustainable use  Rate of use = rate of replacement

Protecting Biodiversity  Protected areas  Parks, preserves, etc.  Habitat corridors  Connect small “islands” so animals can safely migrate

Protecting Biodiversity  Hot spots (Pg. 132)  Special protections due to lots of biodiversity  Many endemic species found only there  Laws and treaties  CITES (No longer trading endangered organisms)

Restoring Biodiversity  Bioremediation  Use living things to clean up pollution  Bacteria, fungi  Ex.) Oil spills, mine contamination  Bioaugmentation  Adding predators to limit one population  Opens up the habitat for other species  Ex.) Ladybugs/ Aphids