Biodiversity Under Attack

Question 1

3 levels of biodiversity

Answer 1

Genetic diversity: amount of genetic variation within and between populations of a single species
Species diversity: diverse of number of species, greater variety means an ecosystem that can withstand more pressure
Community and ecosystem diversity: ??

Factors that limit biodiversity and distribution: natural of human

Local extinction: species lost from 1 ecosystem
Global extinction: species lost from all ecosystems

Question 2

How humans decrease biodiversity

Answer 2

Habitat loss: biggest cause, brough by clearing land for agriculture, urban development, forestry, mining, pollution, climate change

Over harvesting: exceeding rates of hunting (or consuming plants), problem especially for slowly reproduction animals and those restricted to living in a small area

Introduces/invasive species: those that humans move from native locations, problem if introduced species is invasive, outcompete native species, prey upon it, transmits decease, hard to expel from new locale

Global change: reduces the capacity of earth to support life, nutrient enrichment (add too much nitrogen and phosphorus for plants), toxins, greenhouse effect vs climate change

All lead to the disruption of food chains and webs

Can cause extinction vortex (gets small, less genes, gets smaller, etc)

Question 3

Bioaccumulations vs biomagnifications

Answer 3

Bioaccumulation: when an organism cannot break down toxins accumulating in their body, gets stored in fatty tissues

Biomagnification: accumulation of the toxins at a trophic level to the next

Question 4

Greenhouse effect

Answer 4

Process by which thermal radiant from planetary surface is absorbed by atmosphere greenhouse gases and re-radiated in all directions

Caused by atmospheric water, co2, methane

Necessary to keep surface of earth at habitable temperature, but excessive can lead to global warming

Question 5

Climate change

Answer 5

Climate is not only weather
Can be regional or global
Caused by abiotic or biotic

Causes:

Natural:change in earths orbit, volcanos

Humans

Effects:
Snow and ice cover can decrease and sea levels may rise
Rainfall patterns and growing seasons can change
Heat waves
Floods
Droughts