AS Level - Practical Skills Flashcards
DAFOR scale
A qualitative scale that judges the abundance of organisms. Initials stand for: Dominant, Abundant, Frequent, Occasional, Rare
Dependent variable
The factor which may be controlled by the independent variable ie the ‘results’ that are measured
Heterogenous
Uneven, with local concentrations
Homogenous
Evenly mixed
Hypothesis
The theory or explanation that is being investigated
Independent variable
The factor that is deliberately altered or measured to see if it controls the dependent factor
Lincoln index
A catch, mark, release, recapture method of estimating animal populations
Null hypothesis
The no-link theory against which the hypothesis is tested
Pitfall trap
A method of sampling populations of mobile animals that live on the soil surface, by collecting individuals that fall into traps set into the ground
Pooter
A mouth-suction device to pick up invertebrates in soil or leaf litter
Quadrat
An area, usually square or circular, in which samples are taken. The size of the quadrats depends upon the organisms being studied
Secchi disc
A circular disc divided into four black and white segments that is used to estimate water turbidity
Surber sampler
An aquatic invertebrate sampling frame and net that provides more quantitative data than kick sampling
Transect
A line or belt of sampling sites across an area
Tllgren funnel
A piece of equipment used to extract invertebrates from soil or leaf litter
