Topic 3: Biodiversity + Conservation (3.1 Biodiversity and evolution; 3.2 Human impact biodiversity; 3.3 Conservation))

(3.1) Explain (the significance) of biodiversity.

Biodiversity

• Biodiversity as species richness (# species) + evenness (proportions of)

  • 3 types—habitat (# range habitats in biome), species, genetic diversity

• recall: ecosystem resilience as withstanding change + maintaining system sustainability

Genetic Diversity

• Greater genetic diversity = more ADAPTABLE; evolution

  • ex. Cheetah w/ LOW genetic diversity, hard to adapt

  • ex. European red fox; high genetic diversity, three distinct genetic make-ups!!

What does biodiversity DEPEND on?

1. Complexity of ecosystem

   1. if one species/food dies, other can fill

2. Stage succession

   1. earlier stage succession = less biodiversity because harsher abiotic conditions (temperature, water supply nutrients)

3. Other limiting factors

   1. other water, light, heat, raw materials, etc. always limited

Natural selection

• natural selection indicates when diseased/weaker individuals die BEFORE reproducing, and stronger individuals breed, resilience SPREADS (over time)!!

What are Pros/CONS Biodiversity??

• PROS:

  • greater resilience, disease resistance, *nutrient cycling

• CONS

  • possible result of fragmentation (or rapid invasive pioneer species)

(3.1) How harness natural resources AFFECTS biodiversity?

(3.2) Causes/impacts of biodiversity LOSS.

Determine Human IMPACTS on biodiversity??

1. Habitat LOSS

   1. Natural + man-made disasters

      1. natural:

         1. Eruption of Mount st. Helens, reducing vast areas to wasteland, killing thousands animals

         2. Haiti 2010 Earthquake; kills 160k people

      2. man-made

         1. Exxon Valdez (1989) oil spill; 1500 mile radius death

         2. Chernobyl nuclear explosion

• ==> HABITAT DESTRUCTION (deforestation, etc.), FRAGMENTATION (patchwork towns, roads, etc.) , DEGRADATION (Bangladesh, Sri Lanka, etc.)

2. Pollution.

   1. air pollution (fossil fuels, exhaust, industry, etc.)

   2. water pollution (sewage, oil spills)

   3. light pollution (disrupting natural growth cycles, plants)

   4. noise pollution

   5. soil pollution (contaminated w/ heavy metals, etc.)

3. Non-native species + Exotic pet trade

   1. Dutch Elm disease enters Europe via imported American logs

   2. poaching.

      1. critically endangered; rhinos, elephants, pangolins, sea turtles

**HOW does CLIMATE CHANGE affect OCEANS??

• global warming—forcing animals away

• warming reducing water vapor in atmosphere (decreasing vegetation growth)

• polar ice caps melting

• ocean acidification —> affecting absoprtion of calcium/carbonate ions; coral bleaching, shells weakening

  • (add nitrates, add algal blooms)

The IUCN Red List

• Critically endangered species → Carnaby’s black-cockatoo, Rafflesia flower, Tiger

• Extinct → Tasmanian tiger, Dodo (esp. vulnerable bc endemic to island)

island animals

→ island animals (small pop., endemic, lower genetic diversity, no predators etc.)  + combined pressure animals (large, need larger territory, hunted “sport”) most vulnerabl. 

**TRAGEDY OF THE COMMONS

• **TRAGEDY OF THE COMMONS = ‘common’ resources (water, etc.); if you don’t take it, someone else will

(3.3) How HELP, CONSERVE biodiversity?

Why is biodiversity valuable?

• a. food sources; rice, wheat, maize are over half the world’s food

• b. natural products

  • palm oils, rubber, honey

• environmental stuff

  • disease resistance, nutrient cycling (worms), resilience

Conservation strategies

• international agreements/legal; Montreal, Kyoto, etc.

• captive breeding (zoos)—later, reintroduction, bioreserves, sanctuaries seed banks, etc.

• protect keystone species —> ex. sea otters w/ urchins, beaver w/ dams

• education

• research!