Unit 2: All Words

biodiversity

the variety of life in the world or in a particular habitat or ecosystem.

species diversity

The number and relative abundance of species in a biological community.

genetic diversity

a measure of the genetic variation among individuals in a population

ecosystem diversity

variety of habitats, communities, and ecological processes in the biosphere

Speciation

Formation of new species

species richness

the number of different species in a community

species evenness

the relative proportion of different species in a given area

bottleneck effect

a reduction in the genetic diversity of a population caused by a reduction in its size, ususally by a natural disaster

generalist species

species with a broad ecological niche

specialist species

species with a narrow ecological niche

inbreeding depression

genetically similar parents mate and produce inferior offspring

ecosystem resilience

ability to recover from change or disturbance

ecosystem services

Important environmental benefits, such as clean air to breathe, clean water to drink, and fertile soil in which to grow crops, that ecosystems provide

provisioning services

Benefits of biodiversity that humans use, including lumber, fur, meat, crops, water, and fiber

regulating services

benefits of biodiversity that include climate regulation, flood control, and water pollution

supporting services

the basic ecosystem processes, such as nutrient cycles and soil formation, that are needed to maintain other services

cultural services

benefits of biodiversity that provide aesthetic, spiritual, or recreational value

Overharvesting

catching or removing from a population more organisms than the population can replace

sequester

to isolate

island biogeography

the study of the species composition and species richness on islands

Evolution

The gradual change in a species over time

range of tolerance

the limits to the abiotic conditions that a species can tolerate

optimal range

the amount of an abiotic factor that produces the highest possible population

zone of physiological stress

zone of abiotic conditions where small numbers of individuals can survive

zone of intolerance

A region that is so far removed from an organism's optimal range for an environmental variable that the organism cannot survive.

disturbance

A discrete event that disrupts an ecosystem or community. .

Migration

movement of genes from one population to another

Fitness

Ability of an organism to survive and reproduce in its environment

Adaptation

A trait that helps an organism survive and reproduce

Mutation

a random error in gene replication that leads to a change

selective pressure

Something that makes it harder for an organism to survive in an environment.

primary succession

succession that occurs on surfaces where no soil exists

secondary succession

type of succession that occurs in an area that was only partially destroyed by disturbances

pioneer species

First species to populate an area during primary succession

climax community

A stable, mature community that undergoes little or no change in species over time

lichen

symbiotic association between a fungus and a photosynthetic organism