Ecology Grade 9 Vocab Words

Biogeochemical cycles

The movement of matter through the biotic and abiotic environment.

Water cycle

The series of processes that cycle water through the environment.

Carbon cycle

The biogeochemical cycle in which carbon is cycled through the lithosphere, atmosphere, hydrosphere, and biosphere.

Nitrogen cycle

The series of processes in which nitrogen compounds are moved through the biotic and abiotic environment.

Limiting factor

Any factor that restricts the size of a population. Limiting factors may be biotic, such as the availability of food, or abiotic, such as access to water. Human influences often act as limiting factors.

Tolerance range

The abiotic conditions within which a species can survive. Near the upper and lower limits of the tolerance range, individuals experience stress. This will reduce their health and their rate of growth and reproduction.

Optimal range

An area within a species tolerance range in which the species is best adapted. Each species has a tolerance range for every abiotic factor.

Competition

When two individuals vie for the same resource, like humans and insects compete for the same crop plants.

Predation

When an individual (the predator) kills and eats another individual (the prey), such as when wolves kill and eat a caribou.

Mutualism

When two organisms interact, with both benefiting. Lichen, for example, is a mutualistic relationship between algae and fungi.

Paratism

When one organism (the parasite) lives on or in a host and feeds on it.

Commensalism

When one organism benefits and the other neither benefits nor is harmed.

Carrying capacity

The maximum population size of a particular species that a given ecosystem can sustain.

Biodiversity

The variety of life in a particular ecosystem; also known as biological diversity.

Species richness

The number of species in an area.

Extinct

Refers to a species that has died out and no longer occurs on Earth.

Extirpated

A species that no longer exists in a specific area.

Endangered

A species facing imminent extirpation or extinction.

Threatened

A species that is likely to become endangered if factors reducing its survival are not changed.

Special concern

A species that may become threatened or endangered because of a combination of factors.

Invasive species

Introduced species with growing populations that spread and have a negative effect on their environment - a non-native species whose intentional or accidental introduction negatively impacts the natural environment.

Impacts of invasive species

Ecological, economic, tourism, health.

Ecological impacts

Invasive species compete with or feed on native species, leading to population decline or extinction.

Invasive species change ecosystem dynamics by altering nutrient cycles or energy flow.

Economic impacts

Damage to forests and agricultural crops causes financial losses.

Competition with invasive plants lowers crop yields.

Diseases and pests may destroy livestock and crops, kill trees, and harm important species such as honeybees.

Tourism impacts

Species loss and reduced water quality have negative impacts on wildlife viewing, fishing, and water-based recreation.

Waterways can become choked with invasive aquatic plants, rendering them impassable to boats.

Health impacts

Disease-causing organisms, such as the West Nile virus, are introduced.

Pesticides used to control invasive species cause pollution and are health risks.

Methods of controlling introduced species

Chemical control, mechanical control, biological control.

Chemical control

Ex. pesticides, which are used mostly on forest and agricultural pests because trees and crops have significant economic value. They dramatically reduce crop damage, but there are environmental risks.

Mechanical Control

Some invasive species can be controlled with physical barriers or removal. Invasive plants can be cut down, burned, or even removed by hand. Invasive animals can be hunted or trapped.

Biological Control

Uses intentionally introduced organisms to control the invasive species. Although biological control rarely eradicates an invasive species, it may reduce population sizes to ecologically tolerable levels.