Mark-recapture & biodiversity

ecosystem

a group of interacting organisms living in a particular area & their abiotic environment

biotic factors

living components of the ecosystem

abiotic factors

non-living components of the ecosystem

what both affects an ecosystem’s biodiversity & abundance of species

biotic & abiotic factors

trophic level

feeding level that an organism belongs to

trophic levels

primary, secondary, tertiary, quaternary (rarely)

fun fact abt trophic levels

~ 10% of energy at any level is transferred to the next level → rest is lost as heat

net primary productivity (NPP)

• plant biomass in a given area

• gives an indication of carrying capacity

food webs

• Represent relationships between biotic factors of an ecosystem

• Interacting groups of species in a specific area make up communities

• Arrow always points toward the predator

Mark & recapture

• Estimate the size of a population where it is impractical to count every individual

• Capture a small number of individuals, put a harmless marker on them, and release them back into the population

• This can be used to calculate the population density

Mark and Recapture: Calculate population

lincoln-petersen method: N=MC/R

• N = estimate of total population size

• M = # of animals captured & marked initially

• C = # of animals captured 2nd time (including recaptures)

• R = # of animals that were found to be marked the 2nd time

species richness

total count of diff species w in a specific area

• focusing solely on variety, counts “how many” types

species evenness

the equality of individuals across those species

• assesses how equally “balanced” their populations are

Shannon-Weiner Index (H)

• a widely used ecological metric that measures species diversity by combining richness and evenness

• Higher values indicate greater diversity and complexity within a community

• It is commonly used to quantify ecosystem health, with typical values ranging between 1.5 and 3.5.