IB ESS Formulas -

Net primary productivity

calculated by subtracting respiratory losses (R) from gross primary productivity (GPP).

NPP = GPP - R

Gross secondary productivity (GSP)

the total energy or biomass assimilated by consumers and is calculated by subtracting the mass of fecal loss from the mass of food consumed

GSP = food eaten - fecal loss

Net secondary productivity (NSP)

calculated by subtracting respiratory losses (R) from GSP.

NSP = GSP - R

CBR (crude birth rate)

= # of births / population size x1000

CDR (crude death rate)

=# of deaths / population size x 1000

NIR (natural increase rate)

= CBR - CDR/10 (migration is ignored)

TFR (total fertility rate)

= average no of children/woman

DT (doubling time)

= time in years to double the population size

formula = 70/NIR

Respiration

glucose + oxygen -> carbon dioxide + water (releases ATP energy and heat)

Photosynthesis

carbon dioxide + water (& solar energy) -> glucose + oxygen

Lincoln index

- measures the abundance of motile organisms using capture-mark-recapture

n1*n2/ m2

- n1 is the number caught in the first sample

- n2 is the number caught in the second sample

- m2 is the number caught in the second sample that were marked.

Simpson diversity index

- measures species diversity in two similar habitats. Remember, higher the value of D, greater the diversity. A lower value in one habitat may indicate human impact.

D= N(N-1)/ Σ(n-1)

- D is the Simpson diversity index.

- N is the total number of organisms of all species found.

- n is the number of individuals of a particular species.

- Σ is the sum

% change

= change (final - original)/ original number × 100

% (percentage)

= (value/total value)×100

Earth Overshoot Day

the approximate date on which humanity's annual demand on the planet's resources exceeds what our planet can renew in a year

(global biocapacity/world EF) x365

efficiency (energy efficiency)

energy output/energy input x100

Quadrants

pop size= mean x total area/ area of each quadrant