Community Ecology, Biodiversity, and Disruptions

Flashcards focusing on key terms and definitions related to community ecology, biodiversity, and various interactions and disturbances within ecosystems.

Community

A group of populations of different species living closely and capable of interacting.

Niche

The role and position a species has in its environment.

Fundamental niche

The niche potentially occupied by the species if there were no limiting factors.

Realized niche

The portion of the fundamental niche the species actually occupies.

Interspecific interactions

Interactions of individuals from one species with individuals of another species.

Competition

A -/- relationship where individuals of different species compete for limited resources.

Competitive exclusion principle

Two species competing for the same resource cannot coexist permanently.

Niche partitioning

Natural selection drives competing species into different patterns of resource use.

Predation

A +/- relationship where one species kills and eats the other species.

Cryptic coloration

Camouflage that helps prey avoid detection by predators.

Batesian mimicry

A harmless species mimics a harmful one to avoid predation.

Mullerian mimicry

Two or more bad-tasting species resemble each other.

Herbivory

A +/- relationship where one organism eats part of a plant or alga.

Symbiosis

When 2 or more species live in direct contact with one another.

Parasitism

A (+/-) relationship where one organism derives nourishment from another.

Mutualism

A (+/+) relationship where both organisms benefit from the interaction.

Commensalism

A (+/0) relationship where one organism benefits and the other is neither harmed nor benefited.

Facilitation

A (+/+ or 0/+) relationship where one species positively affects another's survival without direct contact.

Species diversity

The variety of different organisms within a community.

Species richness

The number of different species in a community.

Relative abundance

The proportion each species represents of all individuals in the community.

Simpson's diversity index

A measure of diversity based on species richness and relative abundance.

Keystone species

Species that play a more pivotal role in their ecosystem, often not abundant.

Disturbance

An event that changes a community by removing organisms or altering resource availability.

Ecological succession

The gradual process by which species composition of a community changes over time after a disturbance.

Primary succession

Changes occurring on an entirely new habitat that has not been colonized.

Secondary succession

Changes that clear an existing community but leave the soil intact.

Human disturbances

Human activities that significantly disrupt ecosystems, leading to biodiversity loss.

Habitat loss

The single greatest threat to biodiversity, often due to agricultural development and urbanization.

Invasive species

Nonnative species that can competitively exclude native species from habitats.

Overharvesting

Harvesting organisms faster than their populations can rebound.

Global change

Alterations to climate, atmospheric chemistry, and ecological systems reducing Earth's capacity to sustain life.

Biogeographical factors

Large scale factors contributing to species diversity variations across different regions.

Pathogens

Disease-causing organisms and viruses that significantly affect biodiversity.