Exam 4 Final Unit 4

What defines a population in ecology?

An interbreeding group of individuals comprising one gene pool.

What are the primary population parameters that indicate population increase?

Natality (births) and immigration (incoming organisms).

What factors contribute to a decreasing population in ecology?

Mortality (deaths) and emigration.

What is the difference between crude density and ecological density?

Crude density is total number of organisms per total area; ecological density considers only the suitable habitat area.

What is the capture and release study commonly used for?

To estimate the size of wildlife populations.

What are density independent factors?

Environmental factors that affect population size regardless of density, such as severe drought or severe cold.

What are density dependent factors?

Biological factors that affect population size based on the density of the population, such as competition.

What is amensalism in ecology?

A relationship where one organism is harmed while the other is unaffected.

What is the significance of the logistic growth model?

It describes how populations grow rapidly at first and then slow down as they approach the carrying capacity (K) of the environment.

What does the term 'carrying capacity' (K) refer to in population ecology?

The maximum number of individuals of a species that an environment can sustain indefinitely.

What does the Pearl-Verhulst Equation describe?

It models the growth of populations that experience resource limits, predicting that growth slows as population size approaches carrying capacity.

What are the three general stages of life in ecology?

Pre-reproduction, reproduction, and post-reproduction.

What does a survivorship curve show?

It illustrates the number of individuals alive at each age for a species.

What are the three types of survivorship curves?

Type I (high survival until old age), Type II (constant mortality rate), Type III (high mortality in young individuals).

What is the difference between natality and fecundity?

Natality refers to birth rates, while fecundity refers to the potential reproductive capacity of an individual or species.

What is Gause's Principle of Competitive Exclusion?

It states that complete competitors cannot coexist indefinitely if they are competing for the same resources.

What does it mean to say 'niche differentiation' occurs among guild species?

Species in the same guild develop differences in resource use to reduce competition.

What is the Lotka-Volterra model used for?

It predicts the dynamics of predator-prey populations over time.

What does the Intermediate Disturbance Hypothesis suggest?

More species are present in a community that experiences occasional disturbances than in a community that experiences frequent or rare disturbances.

What is primary succession?

The initial development of an ecosystem in a location devoid of plants.

What is secondary succession?

The recovery of an ecosystem after a major disturbance.

What does ecological efficiency refer to?

The efficiency at which energy or biomass is transferred from one trophic level to the next, typically around 10%.

What do trophic levels represent in an ecosystem?

The hierarchical positioning of organisms in a food chain, consisting of producers, consumers, and decomposers.

What is the significance of keystone species?

Species that have a disproportionately large impact on their environment relative to their abundance, helping to maintain the structure of ecological communities.