EEB 3407: Exam Questions with Correct Answers
Community
A group of individuals of different species occupying a particular place at a particular time.
Resource
Something organisms use that can be depleted, such as food, nutrients, or safe space.
Condition
An environmental factor that affects organisms but is not used up, such as temperature or pH.
Niche
The range of biotic and abiotic tolerances and requirements that allow a species to survive
and reproduce.
Fundamental niche
The environmental conditions and resources under which a species can survive and reproduce
without interspecific interactions.
Realized niche
The actual conditions and resources under which a species survives and reproduces in the
presence of interspecific interactions.
Fundamental vs. realized niche
Fundamental niche excludes interspecific interactions; realized niche includes them.
Resource competition
Competition that occurs when species use the same limiting resource.
, R*
The minimum amount of a resource needed to sustain a species.
Lower R*
Indicates a better competitor for that limiting resource.
Resource competition outcome
When species compete for one limiting resource in a homogeneous environment, the species
with the lowest R* usually wins.
Zero net growth isocline/ZNGI
A line showing combinations of species densities or resources where population growth is
zero.
Isocline
A set of points where a population does not increase or decrease.
Stable coexistence
Occurs when both species can invade from low abundance and persist together.
Unstable coexistence
Occurs when neither species can invade from low abundance; outcome depends on starting
conditions.
Competition
A -,- interaction where both species have negative net effects on each other.
Exploitation
Community
A group of individuals of different species occupying a particular place at a particular time.
Resource
Something organisms use that can be depleted, such as food, nutrients, or safe space.
Condition
An environmental factor that affects organisms but is not used up, such as temperature or pH.
Niche
The range of biotic and abiotic tolerances and requirements that allow a species to survive
and reproduce.
Fundamental niche
The environmental conditions and resources under which a species can survive and reproduce
without interspecific interactions.
Realized niche
The actual conditions and resources under which a species survives and reproduces in the
presence of interspecific interactions.
Fundamental vs. realized niche
Fundamental niche excludes interspecific interactions; realized niche includes them.
Resource competition
Competition that occurs when species use the same limiting resource.
, R*
The minimum amount of a resource needed to sustain a species.
Lower R*
Indicates a better competitor for that limiting resource.
Resource competition outcome
When species compete for one limiting resource in a homogeneous environment, the species
with the lowest R* usually wins.
Zero net growth isocline/ZNGI
A line showing combinations of species densities or resources where population growth is
zero.
Isocline
A set of points where a population does not increase or decrease.
Stable coexistence
Occurs when both species can invade from low abundance and persist together.
Unstable coexistence
Occurs when neither species can invade from low abundance; outcome depends on starting
conditions.
Competition
A -,- interaction where both species have negative net effects on each other.
Exploitation
