bio chapter 5

quadrats measure?

abundance and distribution

what organism quadrants used for

stationary organisms

equation for population density quadrants

population size/ area x total no. of quadrants

population size quadrats equation

no. individuals in selected quadrant/ no. of selected quadrants x total no. of quadrants

advantages of quadrats

cost effective, easy data collection

disadvantages of quadrants

not good for mobile organisms, prone to study errors

2 types of transects

belt and line

transects measure

distribution

useful for what type of organisms

immobile/stationary organisms

positives of transects

visualise changes in community, quick data collection

negatives of transects

can miss information, may not be representative of whole area

pitfall traps measure?

abundance and diversity

types of pitfall traps

wet and dry

pitfall traps types organisms

very small organisms (invertebrates

positives pitfall traps

easy to use, collects a large sample

negatives pitfall traps

may not accurately reflect population density, can be effected by weather

CMR measures?

abundance and population size

type of organism measured CMR

mobile animals and organisms

formula for CMR

N=Mn/m where population size=N, M= no. initially marked, n=no. members in 2nd capture, m= no. marked individuals in 2nd capture

positives of CMR

cost effective, adaptable

negatives of CMR

assumptions and potential biases

GPS measures

Population distribution, habitat and feeding habits

what type of organisms tracked by GPS

highly mobile organisms

positives of GPS

enhanced safety, real time monitoring

negatives of GPS

expensive, potential misses of data

population

group of individuals in same species living in same area at same time

carrying capacity

max population size of a species that can be supported in a given environment

population dynamics

the way populations of a species change in size and structure overtime

abundance

number of organisms in a particular species in a population

r selected species

fast growing, short lifespan and fast reproducing species, often first to to take up unused resources

k selected species

slow growing, long lived, typical in established biological community

r selection

opportunistic species quickly colonise an unstable ecosystem leading to rapid population increase and decrease and eventual replacement of competitors

k selection

slow growth sustained overtime

population density

no. of same species individuals in same habitat at a particular time per unit area

formula for population density

popu size/ total land area

population composition

measurable characteristics of population (age, sex ratios, fertility rate)

formula for population growth rate

(birthrate + immigration) - (death rate + emigration)

distribution

where in the physical space members of different species are found

density

no. indevidas in given area

factors that limit population growth

availability of resources, predation, disease

density dependent factors

effects on population that vary depending on population density

density independent factors

effect all individuals in population

lag phase

slow growth phase

exponential growth phase

rapid increase in population and birth rate and low mortality

transition phase

population growth rate decreases

plateau phase

birth = death population reached carry capacity and limiting factors keep it stable

distribution types

random, clumped, uniform

types of data collection for habitats

drone surveys, field surveys, camera trap, acoustic monitoring