6.1 - The organism in the environment
● ***Population: group of individuals of same species, living in same place at a certain
time
● ***Community: linking together populations of different species living together in
same place
○ There are links/interactions between different species within community
■ Group of species existing together have certain requirements which
they all find in that particular place; interdependent (predator-prey
relationships......)
● ***Habitat: place where organisms live
○ Often, a habitat is general area where many species found
● ***Ecosystem: whole integrated mixture of biotic (生物) (living) & abiotic (非生物)
(physical/non-living) components existing in particular habitat
○ Biotic - interdependent; surviving/growing on essential abiotic components
■ ***Abiotic components - e.g.: water, mineral ions, atmospheric gases;
warmth, light, shelter
● Interdependence of species → providing means for energy transfer
Biodiversity
● ***Definition: range/variety of living organisms within an ecosystem
○ I.e.: richness/number of different species in an area
○ ALSO takes into account distribution of each species within area - how evenly
they are spread (i.e.: distribution)/population sizes of different species
Distribution of organisms in their habitats
● Quadrats (樣方) used to estimate population size
○ Whole population hard to count - time-consuming
○ Need to place quadrats randomly so no bias on data collection
■ Method of data collection - place 2 measuring tapes on ground at 90˚,
giving grid; choose random numbers (with random number
generator), using them as grid references for quadrats
■ MUST do repeats (in different areas)
● ***After sampling, need to calculate mean of all results, then
multiply up to ratio of whole area
○ Given that animal does NOT move away quickly
○ Need to decide between number or “percentage cover”
1
● ***Population: group of individuals of same species, living in same place at a certain
time
● ***Community: linking together populations of different species living together in
same place
○ There are links/interactions between different species within community
■ Group of species existing together have certain requirements which
they all find in that particular place; interdependent (predator-prey
relationships......)
● ***Habitat: place where organisms live
○ Often, a habitat is general area where many species found
● ***Ecosystem: whole integrated mixture of biotic (生物) (living) & abiotic (非生物)
(physical/non-living) components existing in particular habitat
○ Biotic - interdependent; surviving/growing on essential abiotic components
■ ***Abiotic components - e.g.: water, mineral ions, atmospheric gases;
warmth, light, shelter
● Interdependence of species → providing means for energy transfer
Biodiversity
● ***Definition: range/variety of living organisms within an ecosystem
○ I.e.: richness/number of different species in an area
○ ALSO takes into account distribution of each species within area - how evenly
they are spread (i.e.: distribution)/population sizes of different species
Distribution of organisms in their habitats
● Quadrats (樣方) used to estimate population size
○ Whole population hard to count - time-consuming
○ Need to place quadrats randomly so no bias on data collection
■ Method of data collection - place 2 measuring tapes on ground at 90˚,
giving grid; choose random numbers (with random number
generator), using them as grid references for quadrats
■ MUST do repeats (in different areas)
● ***After sampling, need to calculate mean of all results, then
multiply up to ratio of whole area
○ Given that animal does NOT move away quickly
○ Need to decide between number or “percentage cover”
1
