niche
includes all of the resources required for survival, growth, and reproduction
Competition
harms both participants. occurs when two or more species try to obtain the same limited resource.
Mutualism
both species benefit, relationship improves the fitness of both partners. +/+
Commensalism
benefits one and does not affect the other, one species benefits, but the other is not significantly affected. +/o
Symbiotic
relationships occur when two species share a close (and often lifelong) relationship in which one typically lives in or on the other.
competitive exclusion principle
the species that acquires more of the resources will eventually "win," while the less successful species will die out.
Resource partitioning
the division of resources to avoid interspecific competition for limited resources in an ecosystem
parasitism
harms onr and benifits another, one species benefits at the expense of another +/-
Herbivores
consume plants.
Predators
animals that kill and eat other animals
prey
An organism that is killed and eaten by another organism
Coevolution
two species evolve together
species richness
is the total number of species occupying a habitat
Species evenness
describes the proportion of a community that each species occupies.
Succession
gradual change in a community's species composition
Primary succession
occurs in an area where no community previously existed (such as following a volcanic eruption).
Pioneer species
the first to colonize the new area.
Secondary succession
occurs when a community is disturbed but not destroyed.
climax conditions
diversity and composition are stable
trophic level
describes its position in the food chain. Dictates organisms for energy aqured from food.
Primary producers
use energy from an inorganic source (such as sunlight) to produce organic molecules.
Consumers/ heterotrophs
obtain energy from eating producers or other consumers
detritus
dead tissue and organic wastes such as feces.
Decomposers
return the inorganic nutrients in detritus to the environment
food web
realistic depiction of the feeding relationships in a community
Keystone species
central to maintaining diversity in a community.
Primary production
energy trapped by producers and stored as food molecules that consumers can eat.
biomagnification
a chemical becomes most concentrated in organisms at the highest trophic levels
Nitrogen fixation
microbes convert N_2 to a source that cycles through producers and consumers
denitrification
bacteria convert NH4 and NO3 back to N2 and release it to the atmosphere
eutrophication
excessive nutrients ultimately lead to oxygen-poor water that cannot sustain much life
Studied by 32 People