Ecology Basics

Ecology

• Study of the relationship of organisms with each other and their environment.
• Environment consists of two major factors: biotic and abiotic.

Biotic and Abiotic Factors

• Biotic factors: living organisms that shape their environment (e.g. aquatic plants, fish, amphibians, algae, predation, zooplankton).
• Abiotic factors: non-living parts of an ecosystem that shape its environment (e.g. water availability, light, temperature, rainfall, wind).

Symbiosis

• Definition: any kind of relationship or interaction between two dissimilar organisms, where at least one organism is benefited.
• Three main types of symbiosis:
  • Parasitism: one organism benefits, the other is harmed (e.g. love bush on trees, tick on human skin, leeches on animals).
  • Mutualism: both organisms benefit from the association (e.g. digestive bacteria and humans, sea anemones and clownfish, spider crab and algae).
  • Commensalism: one organism benefits, the other is not harmed (e.g. sharks and remora fish, tree frogs using plants as protection, cattle egret and cattle).

Abiotic Factors

• Climatic factors (e.g. light, temperature, rainfall, wind, water availability).
• Edaphic factors (e.g. soil pH, texture, temperature, organic and mineral content).
• Aquatic factors (e.g. wave action, dissolved oxygen, salinity).
• Topographic factors (e.g. features of the earth's surface, angle of a slope).

Ecology Terms

• Community: interacting group of various species in a common location.
• Ecosystem: geographic area where biotic and abiotic factors work together to form a bubble of life.
• Habitat: place where an organism or community of organisms lives, including all living and nonliving factors.
• Niche: role an organism plays in a community.
• Population: group of organisms of one species that interbreed and live in the same place at the same time.
• Species: group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding.