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Biodiversity Ch. 5 Notes Definition: Biodiversity Bio = life Diversity = variety Variety of species in an area Benefits of Biodiversity 1. Ecosystem stability 2. Economic value 3. Harvest / use Use “best” individual or trait Aesthetic value 4. Replacements / alternatives It’s “nice” 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 Parks, preserves, etc. Habitat areas 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
