Species Abundance and Biodiversity Flashcards

This set of vocabulary flashcards covers key concepts from the 'Species Abundance & Biodiversity' lecture, including definitions of ecological indices, niche theory, and measurement methodologies.

Biodiversity

The diversity of plant and animal life, as represented by the number of extant species, including levels of variation such as genetic, species, and ecosystem.

Abundance

The total number of organisms in an area, which does not take biodiversity into account.

Species Richness

The total number of different species in an area, without accounting for the abundance of each species.

Diversity

A measure that incorporates both the total number of species in an area and the evenness of their abundances.

Community

A group of populations occupying the same geographical area at the same time.

Simpson's Index of Diversity (D) Formula

$D = \frac{N(N-1)}{\sum n(n-1)}$ where $N$ is the total number of organisms and $n$ is the number of individuals of each species.

Saildrones

A relatively new, autonomous technology that can stay out at sea for months to collect continuous data on protected species like whales.

Biological Species Concept

Groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.

Tolerance Limits

The range of environmental factors beyond which individuals of a species cannot survive, grow, or reproduce.

Specialist Species

Species with a narrow niche that often have limited resource use or specific environmental requirements.

Generalist Species

Species with a broad niche that can tolerate a wide range of environmental conditions and utilize various resources.

Ecological Niche

The range of ecological resources in 3-D space for a species, including habitat, substratum, food, and environmental variation.

Fundamental Niche

The full range of theoretical environmental conditions and resources an organism can occupy in the absence of limiting factors like competition.

Realized Niche

The actual niche an organism occupies, which is typically narrower than the fundamental niche due to biotic interactions.

Interference Competition

Direct competition for the same resource, such as corals on a reef competing for space, which can slow growth and stop reproduction.

Shannon-Wiener Index (H')

A quantitative measure of biodiversity that accounts for both the total number of species and their abundance; calculated as $H' = -\sum p_i \ln(p_i)$.

Habitat Heterogeneity

The variety of environmental structures; increasing heterogeneity leads to increased niche availability and higher species richness.

Habitat Assessment Score (HAS)

A visual assessment tool used to score habitat categories like rugosity, variety of growth forms, height of architecture, refuge size, and live cover.

Disturbance

Any relatively discrete event that eliminates organisms and creates opportunities for new organisms to become established.

Ecosystem Resilience

Also called ecological robustness, it is the ability of an ecosystem to maintain its normal patterns of nutrient cycling and biomass production after a disturbance.

Evenness

The extent to which species in a community are equally abundant; high evenness means most species have similar population sizes.

Dominance

The extent to which one or a few species dominate a community, often defining the community's organization.

Relative Density

A measure of dominance calculated by dividing the total individuals of species A by the total individuals of all species.