Unit 2 The Living World: Biodiversity

species richness

The number of different species in a community.

Relative abundance

The number of how many individuals are present for each species.

Ecosystem service

the many and varied benefits to humans gifted by the natural environment and from healthy ecosystems.

Ecological Hierarchy

species 🡪 population 🡪 community 🡪 ecosystem 🡪 biome 🡪 biosphere

Range of Tolerance

range of environmental conditions that are tolerable for survival in a species

Primary Succession

community change that occurs with new land formation: lichen 🡪 moss 🡪 small shrubs 🡪 small trees 🡪 large trees 🡪 climax community

Secondary Succession

community change that occurs with land already formed.

Bottleneck Effect

cut down of genetic diversity due to loss of individuals in a population.

Non-native species

a species that is not known historically in an area. Ex: cane toads in Australia

Species diversity

a count of how many species are in an area.

Ecotone

a transitional zone between two communities. Ex: intertidal zone.

Niche

an organism's job in a community.

Hybrid

the offspring of two different but closely related species.

Lichen

a symbiotic relationship of a fungus and an algae

Germination

sprouting of a seed

watershed

all land in a given area that drains into a particular stream, river, lake, wetland

resistance

a measure of how much a disturbance can affect flows of energy and matter in an ecosystem

resilience

The rate at which an ecosystem returns to its original state after a disturbance

intermediate disturbance hypothesis

ecosystems experiencing intermediate levels of disturbance are more diverse than those with high or low disturbance levels

ecosystem diversity

the variety of ecosystems within a given region

species diversity

the variety of species within a given ecosystem

genetic diversity

the variety of genes within a given species

species richness

the number of species in a given area

species evenness

the relative proportion of different species in a given area

biodiversity hotspot

the 25 biologically rich areas that have lost over 70% of their habitat

endemic species

a biologically unique species that is only found in 1 geographic location

pioneer species

the first species to inhabit an ecosystem after a disturbance or on newly formed rock

theory of island biogeography

a theory that explains the dual importance of habitat size and distance from the mainland on determining species richness