Ecology Exam 4 Studyguide

Interference

Direct and aggressive interaction between individuals

Intraspecific competition

Competition within the same species

Self-thinning

Mortality among competing plants due to intense competition

Gause's principle

Competitive exclusion: two species with identical niches cannot coexist indefinitely

Beak size variation

Ground finches' beak size correlates with diet and seed hardness

Niche overlap

Competition occurs where niches overlap regarding limited resources

Competitive exclusion

Strong competition leading to one species outcompeting and excluding another

Realized niche

Actual niche space a species occupies due to competition

Fundamental niche

Theoretical niche a species could occupy without competition

Exploitative interactions

Relationships like predation and parasitism affecting population dynamics

Territoriality

Behavioral defense of a specific area against others

Predation

Killing and consuming of prey by predators

Herbivory

Consumption of plants by herbivores

Parasitism

Consuming host without aiming to kill it

Parasitoids

Organisms that consume and kill their host

Predator-prey paradox

Joint evolution of predator and prey involving reciprocal selection pressures

Exploitation competition

Competition arising from resource exploitation

Allelopathy

Chemical inhibition of one species by another

Host-pathogen dynamics

Dynamic relationships between hosts and pathogens

Adelina tribolli

Intracellular parasite affecting competition in flour beetles

Arm race

Adaptation and counter-adaptation between interacting species

Niche restriction

Competition restricting species to realized niches

Insectivorous rodents

Rodents mainly feeding on insects

Granivores

Animals that primarily feed on grains or seeds

Mange mites

Caused hair loss, deterioration, and death in foxes

Fox population decline

Decreased by 70% due to mange mites

Mountain hares

Increased 2-4 times after predator population decline

Abundance cycles

Temporal dynamics in predator-prey relationships

Snowshoe hares

In boreal forests, fed on shrubs and saplings

Winter browse

Consisted of buds and stems of shrubs

Elton's proposal

Abundance cycle linked to solar radiation variation

Keith's theory

Suggested overpopulation as a factor

Decimation causes

Includes disease, parasitism, and stress at high density

Predation impact

Accounts for 60-98% of snowshoe hare mortality

Utida's study

Explored reciprocal interactions in adzuki bean weevils

Refuges importance

Needed for hosts and prey to persist against exploitation

Gasue's experiment

Attempted to create population cycles with p.caudatum and didinium nasutum

Six-spotted mite

Eotetranychus sexmaculatus, part of population oscillations study

Predatory mite

Typhlodromus occidentalis, studied for population oscillations

Living in groups

Can act as a refuge for protection from predators

Mutualisms definition

Interactions beneficial to both species involved

Facultative mutualism

Species survive without the interaction

Obligate mutualism

Both species require the interaction for survival

Symbiosis

Specialized form of mutualism where species integrate physiologically

Mycorrhizae

Fungus/plant root association for nutrient exchange

Allen's study

Explored water relations of Agropyron smithii and associated plants

Species diversity factors

Include richness, evenness, and environmental complexity

Community structure

Incorporates species number, abundance, and diversity

Guild

Group of organisms with similar ecological roles