Ecology Preliminary Exam III

What is a biological species?

A group of organisms that can interbreed and produce fertile offspring.

What are the three types of population distribution?

Clumped, Random, and Uniform.

What does the Coefficient of Dispersion indicate?

It helps infer the type of distribution of a population.

What are Ramets and Genets?

Ramets are individual clones, while Genets are the genetic individuals from which ramets arise.

What is the difference between estimates and counts in population studies?

Estimates are approximations of population size, while counts are actual tallies of individuals.

What is a Quadrat?

A sampling method used to estimate population density in a defined area.

What is the Lincoln-Peterson method used for?

To estimate the abundance of a population using mark/recapture techniques.

What information can age pyramids provide?

They can estimate changes in population abundance over time.

What does 'qx' represent in life tables?

Mortality rate at a specific age.

What is 'lx' in the context of life tables?

Survivorship, or the proportion of individuals surviving to a certain age.

What does 'sx' indicate in life tables?

Survival rate, or the probability of surviving from one age to the next.

What are the three types of survivorship curves?

Type I, Type II, and Type III.

What do Leslie matrices incorporate?

Survivorship and fecundity to predict population growth.

How do you calculate the geometric growth rate (λ)?

By comparing population sizes at two different times.

What is carrying capacity?

The maximum population size that an environment can sustain.

What is the Allee effect?

A phenomenon where population growth is hindered at low population densities.

What is a metapopulation?

A group of spatially separated populations of the same species that interact through immigration and emigration.

What does Levins' metapopulation model calculate?

The probability of local extinction and persistence.

What is competitive exclusion?

The principle that two species competing for the same resources cannot coexist.

What is resource partitioning?

The division of resources among species to reduce competition.

What are invasive species?

Non-native species that spread widely and cause harm to ecosystems.

What is the difference between fundamental and realized niche?

Fundamental niche is the potential mode of existence, while realized niche is the actual mode of existence due to biotic interactions.

Mortality

The rate of death in a population.

Survivorship

The proportion of individuals surviving at each age.

Survival rate

The percentage of individuals that survive from one age to the next.

Age-specific life expectancy

The average number of years a person of a specific age can expect to live.

Cohorts

Groups of individuals born during the same time period.

Mortality Curve

A graphical representation of the mortality rate at different ages.

Survivorship Curve

A graph that shows the number of individuals surviving at each age.

Type I, II, and III survivorship curves

Different patterns of survivorship that illustrate how mortality varies with age.

Transect

A method used in ecological studies to sample and measure the distribution of organisms.

Abundance

The total number of individuals of a species in a given area.

Density

The number of individuals of a species per unit area.

Full Detection Strip

The area within which all individuals of a species are detected during a survey.

Coefficient of Detection

A measure that quantifies the likelihood of detecting an individual within the detection strip.

Competition

The interaction between organisms or species in which both are harmed by the presence of each other.

Competitive Exclusion

A principle stating that two species competing for the same resources cannot coexist if other ecological factors are constant.

Resource (or Niche) partitioning

The process by which competing species use the environment differently to coexist.

Inter- and Intraspecific competition

Inter-specific competition occurs between different species, while intra-specific competition occurs within the same species.

Exploitative & Interference competition

Exploitative competition occurs when species compete indirectly through the consumption of shared resources, while interference competition occurs when species directly compete for resources.

Allelopathy

The chemical inhibition of one species by another, often through the release of toxic substances.

Logistic growth equations for 2 competitive populations/species

Mathematical models that describe how populations grow in relation to resource limitations and competition.

Competition coefficients

Parameters that quantify the effect of one species on the growth rate of another species in competition models.

Zero growth rate isocline

A graphical representation in competition models indicating the population sizes at which a species' growth rate is zero.

Invasive species

Non-native species that spread widely in a new habitat and cause harm to the environment, economy, or human health.

Endemic, Native, Indigenous, & Alien (Introduced) Species

Endemic species are native to a specific location; native species are found naturally in a region; indigenous species are native and have evolved in that region; alien species are introduced from other regions.

Character displacement

The phenomenon where species evolve distinct traits to minimize competition when they coexist in the same environment.

Niche, N-variable hypervolume

The multidimensional space that defines the conditions and resources required for a species to survive and reproduce.

Fundamental & realized niche

The fundamental niche is the full range of conditions under which a species can survive, while the realized niche is the actual conditions under which a species exists, influenced by competition and other factors.

What is a metapopulation?

A group of local populations (demes) that are connected by dispersal and exchange of individuals.

What are demes in the context of metapopulations?

Local populations within a metapopulation that can experience local extinction and recolonization.

What factors are involved in calculating the probability of local extinction in a metapopulation?

Extinction and colonization rates, as well as the dynamics of local populations.

What does Levins' metapopulation model represent?

The relationship between the probability of persistence (P) and the rates of extinction (e) and colonization (m).

What are sources and sinks in metapopulation ecology?

Sources are areas where local populations have a positive growth rate, while sinks are areas where populations decline.

How can the probability of extinction or persistence of all local populations within a metapopulation be calculated?

By using regional metapopulation models that incorporate local population dynamics.

What do Leslie matrices incorporate?

Leslie matrices incorporate age-specific survival and fecundity rates to model population dynamics.

What is the geometric growth rate, λ, and how is it calculated?

The geometric growth rate, λ, is the ratio of the population size at one time to the population size at a previous time, calculated as λ = N(t+1) / N(t).

How can you estimate N at time t if you know N0 and λ?

You can estimate N at time t using the formula N(t) = N0 * λ^t.

What is the intrinsic growth rate, r?

The intrinsic growth rate, r, is the rate at which a population increases in size if there are no density-dependent forces regulating the population.

What factors are included in population growth models?

Population growth models include birth rate, death rate, immigration, and emigration.

What does carrying capacity refer to in population dynamics?

Carrying capacity refers to the maximum population size that an environment can sustain indefinitely without degrading the habitat.

What is the logistic growth equation and its components?

The logistic growth equation is dN/dt = rN(1 - N/K), where N is the population size, r is the intrinsic growth rate, and K is the carrying capacity.

When does a population in logistic growth experience its highest growth rate?

A population in logistic growth experiences its highest growth rate when the population size is at half of the carrying capacity (N = K/2).

What is the Allee effect?

The Allee effect is a phenomenon where a population's growth rate decreases at low population densities, often due to difficulties in finding mates or cooperative behaviors.

Mortality, qx

The probability of dying between age x and x+1.

Survivorship, lx

The proportion of individuals surviving to age x.

Survival rate, sx

The proportion of individuals surviving from age x to age x+1.

Age-specific life expectancy, ex

The average number of additional years an individual of age x is expected to live.

Mortality Curve

A graphical representation of the mortality rates of a population over time.

Survivorship Curve

A graph that represents the number of individuals surviving at each age for a given species or cohort.

Type I, II, and III survivorship curves

Different patterns of survivorship that illustrate how mortality rates vary with age.

What are the three types of population distribution?

Clumped, Random, and Uniform

What is the Coefficient of Dispersion used for?

To infer the type of distribution in a population.

What are Ramets and Genets in population ecology?

Ramets are individual organisms in a clonal population, while Genets are the genetic individuals or clones.

What is the difference between estimates and counts in population studies?

Estimates provide an approximation of population size, while counts provide exact numbers of individuals.

What is a Quadrat in ecological sampling?

A square or rectangular plot used to sample and study the distribution of organisms.

What is the Lincoln-Petersen method used for?

To estimate the abundance of a population using mark/recapture techniques.

What is the utility of age pyramids in population ecology?

To estimate changes in population abundance over time.