Ecology and Population Dynamics: Key Concepts and Models

Is the birth rate density dependent?

No, the birth rate is not necessarily density dependent.

Does this population lack a carrying capacity?

Yes, if the population lacks a carrying capacity, it can grow indefinitely.

Are predators more common than prey in this system?

No, typically prey populations are more numerous than predator populations.

Is the death rate density dependent?

Yes, the death rate can be density dependent, meaning it increases as population density increases.

What type of competition occurs between a daisy and a sunflower?

This interaction is interspecific competition, as they are different species competing for resources.

What type of competition occurs when multiple species of squirrels compete for acorns?

This is an example of scramble competition, where all individuals suffer reduced reproductive output due to resource limitation.

What population growth pattern shows rapid increases followed by severe drops?

The irruptive growth pattern demonstrates infrequent periods of rapid increase followed by density-dependent drops.

What happens when a population surpasses K and has a high r?

It is likely to experience chaos in population growth patterns.

Is an organism's fundamental niche usually smaller than its realized niche?

No, usually an organism's realized niche is smaller than its fundamental niche.

What is the effect of competition between species?

Competition between species usually reduces reproduction of all participants.

What describes the chemical interaction of Australian Pine Trees?

This is an example of allelopathy, where one species releases chemicals that inhibit the growth of others.

What favors the coexistence of two species?

Habitat heterogeneity favors the coexistence of two species.

What causes niche partitioning and character displacement?

These are caused by microevolutionary changes.

What type of competition is observed in male elks battling for females?

This interaction is best described as intrasexual competition.

What does the 'Paradox of Plankton' describe?

It describes the unexpected coexistence of many species of plankton despite limited resources.

What occurs when crickets are removed from an agricultural plot?

This is an example of competitive release, where the absence of one species allows others to thrive.

What type of competition occurs when species prevent others from settling?

This is called preemption competition.

Is it impossible for two competing species to stably coexist?

False, it is possible for two competing species to coexist under certain conditions.

What is the prey carrying capacity in the Lotka-Volterra model?

The prey carrying capacity is given by c x Npred.

What does the Lotka-Volterra model determine?

It determines the number of predators that mark the zero growth isocline of prey.

What type of functional response assumes constant prey mortality?

Type 1 functional response assumes a constant rate of prey mortality with changes in prey population size.

What type of predator functional response is expected with some refugia?

Type 3 functional response would be expected if the prey had some refugia available.

What does Optimal Foraging Theory predict?

It predicts that predators maximize energy gained from food relative to the energy expended to obtain it.

What type of interaction occurs when snook pass by batfish?

This interaction is best described as commensalism.

What describes the interaction of insects laying eggs in living animals?

This interaction is best described as parasitism.

Allelopathy

The chemical inhibition of one plant by another, due to the release of toxic substances.

Parasitoidism

A relationship where one organism (the parasitoid) lives on or in another organism (the host) and ultimately kills it.

Parasitism

A relationship where one organism (the parasite) benefits at the expense of another organism (the host).

Commensalism

A type of symbiotic relationship where one organism benefits while the other is neither helped nor harmed.

True or False: All symbiotic relationships benefit both participants.

False

True statement about parasitism

The close relationship between the participants leads to a high degree of host specificity by the parasite.

Definitive host vs Intermediate host

The definitive host is where the parasite reproduces sexually, while intermediate hosts are where the parasite may develop but does not reproduce sexually.

Coexistence of predators and prey

Can be maintained by prey switching, where predators switch to different prey based on availability.

Effect of selection by predators

This is referred to as cryptic coloration, where prey resemble their environment to avoid detection.

Warning coloration in prey species

When harmless prey adopt warning coloration, it is referred to as Batesian mimicry.

Prey population strategy

When prey species produce many offspring to overwhelm predators, this strategy is called predator satiation.

Secondary metabolites

Organic compounds produced by plants that serve as defenses against herbivores, such as tannins.

Biological Communities Concept

The Interaction Concept suggests that communities are combinations of species that persist together due to interspecific interactions.

Rank abundance curve

Curve B shows greater species richness.

Nodes in a food web

In a food web, the nodes represent taxa.

Community stability component

Resilience represents the tendency for a community to return to its original form after perturbation.

Rivet Hypothesis

The Rivet Hypothesis suggests that no species can be lost from a community because species hold the community together.

Technology for gut content analysis

Immunoassays can be used to identify proteins in gut content analyses.

Isotope concentration in food chains

The relative concentration of the heavier isotope decreases as consumed material makes its way up a food chain.

Stable isotopes and primary producers

True: Stable isotopes can be used to identify the primary producers in a community.

Brown Food Webs

Brown Food Webs are those that rely on detritus for energy.

Trophic Cascades

Trophic Cascades represent top-down control of communities.

Feral species

Feral species are those that were once domesticated but then returned to the wild.

Enemy Release Hypothesis

This hypothesis predicts that invasions are often successful because introduced species often lack a controlling predator.

Species invasions and community susceptibility

True: Species-poor communities are generally more susceptible to invasion than species-rich communities.

Characteristic of successful invaders

Successful invaders typically have an r-selected life history strategy.

Greatest number of extinctions

Besides invasive species introductions, habitat destruction is responsible for the greatest number of extinctions in the last 300 years.

What is noise pollution?

Unwanted or harmful sounds in the environment that can affect human and animal health.

What is parasitism?

A symbiotic relationship where one organism benefits at the expense of another, typically harming the host.

What is habitat destruction/loss?

The process by which natural habitat becomes incapable of supporting its native species, leading to biodiversity loss.

What is density dependent population growth?

Population growth that is limited by factors such as competition, predation, and disease, which become more intense as population size increases.

What is predation?

An interaction where one organism (the predator) kills and eats another organism (the prey).

What is competition in ecology?

The struggle between organisms for the same resources in an ecosystem, which can limit population growth.

What is density independent population growth?

Population growth that is affected by external factors such as weather, pollution, or natural disasters, regardless of population size.

What is irruptive population growth?

A sudden and dramatic increase in a species' population size, often followed by a crash.

What is chaos in population dynamics?

Complex fluctuations in population sizes that do not follow a predictable pattern.

What is allelopathy?

The chemical inhibition of one plant species by another, through the release of toxic compounds.

What are Australian pines known for in ecology?

They release chemicals that inhibit the growth of other plants, affecting local biodiversity.

What is preemption in competition?

A competitive strategy where an organism occupies a resource before others can access it.

What is refugia?

A safe space or habitat where a species can go to recover from adverse conditions.

What is a fundamental niche?

The full range of environmental conditions and resources an organism can potentially use.

What is a realized niche?

The actual conditions and resources a species uses, influenced by interactions with other species.

How does competition among species affect reproduction?

It generally lowers reproduction rates for all competing species involved.

What is habitat heterogeneity?

The variation in habitat types within a specific ecosystem, contributing to biodiversity.

What are microevolutionary changes?

Small-scale evolutionary changes that occur within populations over a short period.

What is competitive release?

When a species expands its niche due to the removal of a competitor.

What is Batesian mimicry?

A form of mimicry where a non-toxic species resembles a toxic one to avoid predation.

What is Müllerian mimicry?

A form of mimicry where two harmful species evolve to resemble each other, reinforcing avoidance by predators.

What is extirpation?

The local extinction of a species from a specific habitat or area.

What is the lagging phase in establishment?

The initial period after introduction of a species before it begins to reproduce and grow rapidly.

What are successful invasive species characterized by?

High reproductive rates, early sexual maturity, broad tolerance to environmental conditions, and lack of natural enemies.

What is the Optimal Foraging Theory?

The concept that organisms optimize their foraging behavior to maximize energy intake while minimizing effort.

What are the Lotka-Volterra equations?

Mathematical models that describe the dynamics of predator-prey interactions and population fluctuations.

What is niche partitioning?

The process by which competing species utilize resources differently to coexist.

What is prey satiation?

A strategy where prey species produce large numbers simultaneously to overwhelm predators.

What is the Tangled Bank Strategy?

The idea that genetic diversity among offspring increases survival chances in varying environments.

What is predator satiation?

A phenomenon where a sudden abundance of prey reduces the likelihood of individual prey being consumed.

What are secondary metabolites?

Organic compounds produced by plants that are not directly involved in growth or reproduction, often serving defensive roles.

What are phosphate derivatives?

Molecules containing phosphate groups that are crucial for energy transfer and cellular functions.

What are tertiary metabolites?

Complex organic compounds derived from secondary metabolites, often involved in specific ecological interactions.

What is stabilizing selection?

A type of natural selection that favors intermediate traits and reduces variation in a population.

What is the Individual Concept of species?

Defines species as distinct lineages with their own evolutionary histories.

What is the phylogenetic species concept?

Defines species based on shared ancestry and the smallest group with a common ancestor.

What is the interaction species concept?

Defines species based on their ecological roles and interactions with other species.

What is the organismal species concept?

Defines species based on similarities in form, function, and behavior.

What is a rank-abundance curve?

A graphical representation showing species richness and evenness by ranking species from most to least abundant.

What are immunoassays?

Laboratory techniques that utilize antibodies to detect and quantify specific substances.

What is the Novel Weapons Hypothesis?

The theory that invasive species succeed by producing unfamiliar chemicals that harm native species.

What is the Enemy Release Hypothesis?

The idea that invasive species thrive because they escape their natural predators and diseases.

What is EILA (Evolution of Increased Competitive Ability)?

The hypothesis that invasive species evolve to allocate more resources to growth and reproduction when freed from enemies.

What is the Resource Hypothesis?

Suggests that invasions are more likely when there are available or underutilized resources in an ecosystem.