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.

Ecology

Study of living organisms in their non-living world.

Biotic Factor

Living item (ex: bacteria).

Abiotic Factor

Not living item (ex: rock).

Ecosystem Services

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

Ecological Hierarchy

Species 🡪 population 🡪 community 🡪 ecosystem 🡪 biome 🡪 biosphere.

Population

A group of individuals of the same species.

Community

A group of populations interacting together.

Ecosystem

A group of communities interacting together.

Biosphere

Another name for earth.

Natural Selection

Survival of the fittest.

Salinity

Level of salt in the water.

Brackish

Medium levels of salinity. Often occurs in wetlands where salt and freshwater mix.

Gaia Hypothesis

Organisms interact with their inorganic surroundings on Earth to form a synergistic self-regulating, complex system that helps to maintain and perpetuate the conditions for life on the planet.

Range of Tolerance

Range of environmental conditions that are tolerable for survival in a species.

Ecological Footprint

A measure of human impact on Earth's ecosystems. It's typically measured in area of wilderness or amount of natural capital consumed each year.

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 there 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 species.

Lichen

A symbiotic relationship of a fungus and an algae.

Germination

Sprouting of a seed.

Competitive Exclusion Principle

Species with the same niche in the same area cannot coexist.

Keystone Species

Often a dominant predator whose removal allows a prey population to explode and often decreases overall diversity. Ex: sea otter.

Predation

The preying of one animal on others.

Mimicry

The close external resemblance of an animal or plant (or part of one) to another animal, plant, or inanimate object.

Aerobic

Using oxygen.

Anaerobic

Using no oxygen.