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BIOLOGICAL DIVERSITY (BIODIVERSITY)
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Bios: life
Diversitas: variety
Is the variability among living organisms which includes:
 Within Species
 Between Species
 Of Ecosystems
Ecosystem Diversity
- Measure of the number of different kinds of ecosystems in an area
- Ex
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Genetic Diversity
- Sum total of genetic info in genes of an organism

POPULATION DYNAMICS

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Population density
- Determines the umber of species in a certain area
Number of species / unit area
Spatial distribution pattern
Dispersion - specific pattern of spacing among members of a population within a specified area

1) Clump dispersion - very obvious classification into groups
2) Random dispersion - no specific area of spacing
3) Uniform dispersion - equal spacing
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Population carrying capacity
- Number of organisms that can be supported by a given environment

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Population crash/ dieback
- Death of members of a population due to exceeding carrying capacity
- can be avoided if some members migrate or obtain new resources to reduce competition

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Population growth rate
- population size change as response to certain limiting conditions in the environment
o Birth rate
- one way to increase population size
- number of individual births in a given population in a certain time
o Death rate
- number of individual deaths in a certain population at a given time
 Immigration
- movement of individual births in a population move into another group of population
 Emigration
- happens when some member leave the group

Population change = (births + immigration) - (deaths + emigration)

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Ecosystem Stability
- ability of an ecosystem to maintain its structure over a long period of time despite disturbances
Structure
- physical and geological landscape, diversity and population sizes of species and their
interactions
Function
- water and nutrient cycling or biomass productivity

How to archive stability?
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Resistance
- when structure and function of an ecosystem stay normal despite changes
Resilience
- when it can regain its normal structure and function after a disturbance

What’s the important of biodiversity?
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Economic value
Ecological value

EXTINCTION
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total disappearance of all members of a certain species

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Local extinction
- certain population of organisms endemic to a place die out
 Background extinction
- gradual process of becoming extinct
 Mass extinction
- rate of extinction dramatically increases as large population of organisms die outing a short
period of time
- caused by certain events
 Speciation
- formation of new species to withstand the catast
 Premature extinction
- caused by human activities
 Threatened species
- species that could be extinct
o critically endangered
o endangered
o vulnerable

Threats
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natural factors

(Global cooling/warming, ateroid, earthquakes, volcanoes, disease, epidemics )
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human factors

(Habitat destruction, invasive species, pollution, too much consumption



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