Consumption and Trophic Interactions

Plasmodium parasite modifies human RBC

causes human rbc to have abnormal shape which is destroyed in the spleen

a trait that improves host defenses or parasite counter defenses may reduce

other aspects of growth, survival or reproduction

Encounter rate

the amount of times predator encounters a prey species. if low; predators should be generalists

handling time

the time a predator takes to capture and consume prey, which affects prey availability and predator efficiency. if long, predators should be specialists

most carnivores are ____

generalists

some carnivores concentrate on whatever prey is

most abundant

most herbivores are

specialists that feed on one or few species.

carnivores may have __ that help in prey capture

physical features

adaptations to escape being eaten

physical features (size, rapid movement, body armor)

warning coloration (aposematic)

crypsis (prey is camouflaged)

Mimicry (prey resembles another organism that is toxic or fierce)

behavior changes when predators are present

Masting

plants produce large numbers of seeds in some years and hide seeds from seed-eating herbivores in other years.

compensation (plants)

removal of plant tissue stimulates net growth

full compensation

no net loss of plant tissue

plant induced defenses

produced in response to herbivore attack

plant secondary compounds

toxic chemicals to reduce herbivores

plant structural defenses examples

tough leaves, spines thorns, pernicious hairs, etc

plant defenses can be ____ by some herbivores.

overcome

trophic levels

based on the number of feeding steps by which it is separated from autotrophs

1st autotrophic level

generates most of the dead organic matter in an ecosystem. consists of autotrophs or primary producers

2nd trophic level

herbivores that consume autotrophs, detritivores that consume dead organic matter

3rd or higher tropic level

carnivores that consume animals from the level below.

Food web

diagram showing connections between organisms and the food they consume. Shows qualitatively how energy flows from one component of this ecosystem to another.

Interaction webs

more accurately describe both trophic and non-trophic (competitive) interactions.

detritus

organic matter made of organisms that don’t get consumed as a means of death

omnivores feed at ___ level(s) of the food web

multiple

in terrestrial ecosystems, a ___ portion of biomass is consumed, ___ of the energy flow passes through the detritus.

small; most

detritivores

organisms that consume dead organisms and feces in a process called decomposition

Detritus is considered part of the ___ trophic level

1st

detritivores are considered part of the __ trophic level

2nd