Species Interactions Lecture

Interactions between 2 species can…

benefit, harm, or have no effect on each of them

Competition

negative/negative. Both do worse when together

What is competition?

resource use by one individual that reduces its availability for others.

Who competes in intraspective competition?

Individuals of the same species compete for mates or for space.

Who competes in interspective competition?

Individuals of different species compete for space, water, or food.

Examples of resources species require

Food, water, shelter, etc.

Examples of the range of tolerable conditions each species has

temperature, precipitation, soil composition, branch thickness, etc.

What is Niche

the total range of all abiotic/biotic conditions tolerated and all resources used.

Fundamental Niche

Niche that a species could potentially occupy

Realized Niche

Subset of the fundamental Niche that a species actually occupies

Competitive Exclusion Principle

Resource exists -> competition exists for a resource -> weaker competitor excluded

Mutualism

positive/positive. Both species benefit (do better together)

Facultative mutualism

organisms can survive independently. relationship is beneficial but not necessary for survival.

Obligate mutualism

Organisms rely on each other for survival. relationship is necessary for survival

Functions of mutualism

nutrition, defense, communication, dispersion

bioluminescence

light-producing bacteria hosted by another organism

pollination

act of transferring pollen grains from the male to female parts of flowers (needed before fertilization)

Antagonism

negative/positive. One does worse, one does better when together.

Forms of antagonism

Predation, parasitism, herbivory

Commensalism

positive/unaffected. One does better when together, one is unaffected.

Amensalism

negative/unaffected. One does worse when together, one is unaffected