Ecology (from Greek: οἶκος, "house"; -λογία, "study of") is the scientific study of biological interactions among organisms and their environment, such as the interactions organisms have with each other and with their abiotic (non-living) environment. 

Topics of interest to ecologists include:

  •  the diversity, distribution, amount (biomass),
  •  number (population) of organisms, as well as 
  • competition between them within and among ecosystems. 

An example of a trophic food web is a way of studying the ecology of an environment. image: wikipedia

Ecosystems are composed of dynamically interacting parts including organisms, the communities they make up, and the non-living components of their environment. 

Ecosystem processes, such as:

  •  primary production, 
  • pedogenesis,
  •  nutrient cycling, and 
  • various niche construction activities, 

regulate the flux of energy and matter through an environment. 

These processes are sustained by organisms with specific life history traits, and the variety of organisms is called biodiversity. 

Biodiversity, which refers to:

  • the varieties of species, 
  • genes, and 
  • ecosystems, 

all which can enhance certain ecosystem services ( these are services that help humans, such as pollination of crops).


Salt pan creek mangrove swamp, NSW, Australia. Image: wikipedia/Adam.J.W.C.

History of ecology as a science

Ecology is an interdisciplinary field that includes biology and Earth science. The word "ecology" ("Ökologie") was coined in 1866 by the German scientist Ernst Haeckel (1834–1919). 

Ancient Greek philosophers such as Hippocrates and Aristotle laid the foundations of ecology in their studies on natural history. Modern ecology transformed into a more rigorous science in the late 19th century. 

Evolutionary concepts on adaptation and natural selection became cornerstones of modern ecological theory. 

Ecology is not synonymous with environment, environmentalism, natural history, or environmental science. It is closely related to evolutionary biology, genetics, and ethology. An understanding of how biodiversity affects ecological function is an important focus area in ecological studies. 

Ecologists seek to explain:

  •     Life processes, interactions and adaptations
  •     The movement of materials and energy through living communities
  •     The successional development of ecosystems, and
  •     The abundance and distribution of organisms and biodiversity in the context of the environment.

How ecology affects humans

Ecology is a human science as well. There are many practical applications of ecology in:

  •  conservation biology, 
  • wetland management, 
  • natural resource management (agroecology, agriculture, forestry, agroforestry, fisheries), 
  • city planning (urban ecology), 
  • community health, 
  • economics, 
  • basic and applied science, and 
  • human social interaction (human ecology). 

Organisms and resources compose ecosystems which, in turn, maintain biophysical feedback mechanisms that moderate processes acting on living (biotic) and nonliving (abiotic) components of the planet. 

The importance of ecosystems

Ecosystems sustain life-supporting functions and produce:

  •  natural capital like biomass production (food, fuel, fiber and medicine), 
  • the regulation of climate, 
  • global biogeochemical cycles, 
  • water filtration, 
  • soil formation, 
  • erosion control, 
  • flood protection and 
  • many other natural features of scientific, historical, economic, or intrinsic value.

Source: adapted from