Studied by 4 people
population
a group of organisms of the same species living in the same place at the same time
community
all of the populations living in the same area at the same time
interdependence
if one species is removed from a community it can affect the whole community
habitat
place where an organism lives
ecosystem
all the biotic factors and all the abiotic factors that interact within an area at one time
biotic factors
living components
abiotic factors
non-living components
do ecosystems vary in size and scale
yes
what does ecology study
distribution of species
abundance of species
interactions between species
interactions between species and their abiotic environment
ecologists
biologists that study interactions by investigating ecosystems
quadrat
square frames made of wood or wire used to investigate population size
how do we use quadrats
they are placed on the ground and the organisms within them are recorded
what do quadrats help estimate
commonly the abundance of plant species
what do we record to measure abundance in a quadrat
number of individual specoes
species richness
percentage cover
species richness
total number of different species is recorded
percentage cover
approximate percentage of the quadrat area in which an individual species is found is recorded
when do we use percentage cover in investigating population size
when it is difficult to count individuals
investigating population size in 2 different areas using quadrats - apparatus
2 tape measures
quadrat
random number generator
species key
investigating population size in 2 different areas using quadrats - method
use tape measures to lay out a survey area
use random number generator to create a set of coordinates to place first quadrat
count number of chosen species within quadrat
repeat for second quadrat
estimate population using equation
investigating population size in 2 different areas using quadrats - equation for estimated population size
(total area / area sampled) x total number of species population counted
investigating population size in 2 different areas using quadrats - results
compare abundance of study species in each survey area
biotic factors influencing species abundance
competition
predator-prey relationships
interactions with other organisms within food chain
abiotic factors influencing species abundance
light intensity
mineral availability
water availability
pH
temperature
salinity
investigating population size in 2 different areas using quadrats - limitations
missing individual organisms when counting in a quadrat
difficult to identify species
investigating population size in 2 different areas using quadrats - CORMS
C - study area
O - same species of quadrats
R - repeat for reliability
M1 - number of designated study species
S - size of quadrat, random way of quadrats, day of investigation
biodiversity
range and variety of different species of organisms on earth or within an ecosystem
what does biodiversity consider
species richness
variation within species
distribution and population size of species
high biodiversity
lots of different species
lot of variation
even distribution
how is biodiversity reduced
by human activities
what do different species depend on each other for
food
shelter
maintenance of physical environment
advantages of a high biodiversity
stability of ecosystems
reduced dependence
resilient to environmental impacts
what is a food web used for
to demonstrate the importance of biodiversity in an ecosystem
measuring biodiversity - apparatus
2 tape measures
quadrat
random number generator
species key
measuring biodiversity - method
use tape measures to lay out survey area
use random number generator to create a set of coordinates for first quadrat
count number of different species within quadrat
repeat for 10 quadrats
repeat for second survey area
measuring biodiversity - results
compare number of different species
measuring biodiversity - high biodiversity
larger number of different species
how is the measurement of biodiversity simplistic?
doesn’t tell us about distribution or population size
measuring biodiversity - limitations
easy to miss individual organisms
identifying and distinguishing between species
measuring biodiversity - CORMS
C - study area
O - same species of quadrats
R - repeat for reliability
M1 - number of designated study species
S - size of quadrat, random way of quadrats, day of investigation
abiotic factors that affect a community
light intensity
temperature
moisture levels
soil pH and mineral content
wind intensity and direction
carbon dioxide levels
oxygen levels
light intensity
needed for photosynthesis
temperature
affects rate of photosynthesis
moisture levels
water for survival
wind intensity and direction
affects transpiration
carbon dioxide levels
required for photosynthesis
oxygen levels
aquatic animals need high oxygen concentrations
biotic factors that affect a community
availability of food
new predators
new pathogens
competitions
availability of food
more food = higher chance of surviving and reproducing
new predators
unbalances the ecosystem
new pathogens
population may decline as a result of lack of immunity and resistance
competition
if two species compete for resources and one is better adapted, then that species will outcompete the other
