Bio 1108 Mount Saint Helen

ballistic

method of seed dispersal; explosion

facilitation

commensalism followed by competition (+ 0 then - -)

Liebig’s Law of Minimum

growth is dictated by the scarcest resource (limiting factor) not by the total resources available

redundancy

multiple species playing the same role

dynamic equilibrium

realistic end of succession; overlapping stages

anthropogenic

disturbance caused by humans

resistance

ability to withstand a disturbance (compares pre-disturbance vs immediately after disturbance)

resilience

how closely the post recovery resembles the pre-disturbance ecosystem (pre-disturbance vs post recovery)

recovery

how quickly an ecosystem recovers

nitrogen fixation

atmospheric nitrogen gas is converted into ammonia (NH3) by N fixing bacteria, and then is turned into ammonium (NH4+) (step 1 in the picture)

nitrification

nitrifying bacteria converts ammonium into nitrites (NO2-), and then into nitrates (NO3-) (step 2)

assimilation

plants take up nitrates through their roots (step 3)

endosymbiosis

one species lives inside the tissue of another

ectosymbiosis

one species lives on the outside surface of another (ex: barnacles living on whales)

interspecific competition

competition between individuals of different species

intraspecific competition

competition between individuals of the same species

species richness

the number of species in an ecosystem

biodiversity

a measure of species richness and abundance in an ecosystem

types of complexity

structural (forest layers and patchiness) and biological (species richness and biodiversity)