Ecology T3 Flashcards

Questions and Answers

Name three general features of mutualism.

Mutualisms are typically generalist and diffuse (facultative), populations of mutualists tend to have great stability, and mutualisms are often more common in stressful habitats.

If mutualisms provide benefit for both parties, why is there a conflict of interest between them?

The interests of mutualistic interactors are not necessarily equal, leading to conflicts, as seen in pollination where flowers want pollinators for genetic diversity, and bees want nectar for energy.

Describe two important mutualisms between animals and plants.

Seed dispersal by frugivores and ant-plant interactions where ants collect extra floral nectar.

Cleaner fish benefit from mutualism by getting ______.

food Signup and view all the answers

The honeyguide and honey badgers both benefit from finding ______.

honey Signup and view all the answers

What is competition?

When two or more organisms use the same resources that are in short supply Signup and view all the answers

What is the difference between intraspecific and interspecific competition?

Intraspecific competition is between members of the same species, while interspecific competition is between different species. Signup and view all the answers

What is exploitative and interference competition?

Exploitative competition occurs when individuals use the same resources without direct contact, while interference competition involves direct contact between competing individuals. Signup and view all the answers

Describe the type of competition for Bluegills and Crappies competing for minnows.

Interspecific competition and exploitative competition. Signup and view all the answers

How does density-dependent regulation work in population dynamics?

It regulates population growth rates based on population density. Signup and view all the answers

What is a competition coefficient?

It represents the effects of one species on another in terms of competition. Signup and view all the answers

What is the difference between fundamental and realized niches?

The fundamental niche is the full range of conditions possible for a species, while the realized niche is the actual conditions occupied after interactions. Signup and view all the answers

What is niche overlap and how does it relate to competition?

Niche overlap occurs when two species share resources, increasing the potential for competition. Signup and view all the answers

The competitive exclusion principle states that complete competitors can coexist.

False Signup and view all the answers

What is predation?

Predation is when one organism obtains nutrients by killing another organism. Signup and view all the answers

What are the costs of cannibalism?

Both B and C Signup and view all the answers

What is the difference between a functional and a numerical response in predators?

A functional response is an individual level response to prey, while a numerical response is a population level response involving predator reproduction. Signup and view all the answers

What is switching in terms of predation?

Switching is when predators change their food preference based on the availability of different prey types. Signup and view all the answers

What is mutualism?

Mutualism is an interaction where both organisms benefit from the relationship. Signup and view all the answers

What is the difference between obligate and facultative mutualism?

Obligate mutualism means species cannot survive without each other, while facultative mutualism allows for survival without the interaction. Signup and view all the answers

Study Notes

Competition

Competition occurs when organisms use the same limited resources, negatively affecting each other.
Intraspecific competition: occurs within a species (e.g., emperor penguins for nesting).
Interspecific competition: occurs between different species (e.g., vultures and wild dogs over carcasses).
Exploitive competition: individuals compete without direct contact, common among species like deer and squirrels.
Interference competition: involves direct contact while competing for resources, typical in species like red-winged blackbirds.

Types of Competition Scenarios

Bluegills vs. crappie in a weed bed: interspecific competition and exploitive since they don't contact each other.
Humans competing for Kraft Mac and Cheese: intraspecific competition and interference since they directly engage.
Web-building spiders: interspecific competition and exploitive, not directly contacting each other.

Density-Dependent Regulation

Density-dependent regulation occurs when population growth is controlled by population density.
Negative density-dependence leads to reduced growth due to crowding, predation, and competition.
Density affects births and survival:
- Below carrying capacity (K): more births and reduced competition.
- Above K: higher mortality, increased competition for resources.
- At K: slow progression of births and offspring survival.

Mechanisms of Density Influence

Increased density leads to higher intraspecific competition over resources, reducing survival and reproduction rates.
Population growth decreases with density due to limited resources.

Lotka-Volterra Equations

Lotka-Volterra competition equations predict outcomes of interspecific competition, incorporating competition coefficients for each species.

Niche Concepts

A niche represents the ecological role of an organism.
Fundamental niche: full range of conditions for survival and reproduction.
Realized niche: the actual niche occupied after interactions are accounted for.
Niche breadth is the range of conditions a species can tolerate, depicted as a bell curve for optimum performance.

Niche Overlap and Competition

Greater niche overlap indicates increased potential for competition among species.

Competitive Exclusion Principle

Competitive exclusion principle states that complete competitors cannot coexist; two species competing for the same resources will not survive together in the same area.

Consequences of Competition

Different species may exploit resources differently (e.g., ants vs. rodents with seeds).
Competition can lead to extinction of a species or changes in niche (e.g., chipmunks on different mountains).
Character displacement may occur, resulting in morphological changes due to competition.

Limiting Similarity Theory

Limiting similarity explains how similar species can coexist by having different resource uses or adaptations.

Ghost of Competition Past

Reflects past interspecific competition's lasting impacts on species behavior, distribution, or morphology.

Predation and Cannibalism

Predation: one organism feeds on another, causing its death.
Cow eating grass is not predation; apple consumption is predation, unlike grass or beer.
Benefits of cannibalism include food and reduced competition; costs involve potential disease and social issues.

Functional and Numerical Responses

Functional response: individual level adjustment to prey density.
Numerical response: population level adjustment to prey; includes Type I, II, and III responses based on prey saturation effects.

Switching Behavior in Predators

Switching occurs when predators change prey based on availability, enhancing hunting efficiency.

Optimization in Foraging

Optimization suggests organisms maximize benefits and minimize costs in foraging and reproduction.

Overarching Mechanisms Against Predation

Organisms use visual, structural, behavioral, and chemical tactics to avoid predation.
Examples include crypsis, mimicry, warning coloration, and structural adaptations.

Lotka-Volterra Laboratory Studies

Gause and Luckinbill's studies on Didinium and Paramecium supported model predictions; coexistence is enhanced by environmental complexity.

Parasitism and Its Role

Parasitism: nutrients obtained from hosts causing harm, distinct from predation and competition.
Essential for controlling host populations and influencing ecological dynamics.

Types of Parasites

Endoparasites live within hosts (e.g., tapeworms); ectoparasites live on host surfaces (e.g., skin mites).

Transmission of Parasites

Direct transmission: occurs without an intermediate host; most common.
Indirect transmission involves an intermediate host; often specialized and less common in plants.

Prevalence and Intensity of Parasites

Prevalence: proportion of hosts infected; intensity: count of parasites on a host.
Variability in distributions shapes the relationship between these two parameters.

Regulation of Host Populations

Parasites can reduce host survival and reproduction, affecting population sizes similarly to competition.

Mutualism

Mutualism: both organisms benefit (+,+), distinct from other interactions.
Obligate mutualism: species reliant on each other; facultative mutualism: can exist independently.

Features and Conflicts in Mutualisms

Mutualisms often have inherent conflicts of interest; for example, pollination dynamics between plants and insects.

Classic Mutualism Examples

Cleaner fish enhance reef diversity while obtaining food; honeyguides assist in locating honey for humans and honey badgers.

Important Animal-Plant Mutualisms

Seed dispersal is crucial for evolutionary relationships, affecting survival and reproduction strategies in both groups.

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Description

Test your knowledge on competition in ecology with these flashcards. Explore the differences between intraspecific and interspecific competition, and learn about exploitative and interference competition. Perfect for anyone studying ecology and environmental science.