By methodology used for investigation

• Field ecology – Collection of information outside a laboratory, library or workplace setting –
• Quantitative ecology – application of advanced mathematical and statistical tools to perform ecological researchPages displaying wikidata descriptions as a fallback –
• Theoretical ecology – scientific discipline devoted to the study of ecological systems using theoretical methodsPages displaying wikidata descriptions as a fallback – the development of ecological theory, usually with mathematical, statistical and/or computer modeling tools.

By spatial scale of ecological system under study

• Global ecology – Global sum of all ecosystems on Earth –
• Macroecology – Study of relationships between organisms and their environment at large spatial scales –
• Microecology – Microbial ecology or ecology of a microhabitat.

By level of organisation or scope

Arranged from lowest to highest level of organisation:^[1]

• Autecology – ecological study of a single individual, population, or speciesPages displaying wikidata descriptions as a fallback – the study of individual organisms of a single species in relation to their environment;
• Synecology – Associated populations of species in a given areaPages displaying short descriptions of redirect targets – the study of homogenous or heterogenous groups of organisms in relation to their environment;
  • Population ecology – Study of the dynamics of species populations and how these populations interact with the environment – the study of homogenous groups of organisms related as a single species;
  • Community ecology – Associated populations of species in a given area – the study of heterogenous groups of organisms of multiple associated species;
  • Ecosystem ecology – Study of living and non-living components of ecosystems and their interactions.

By biological classification or taxon under study

• Human ecology – Study of the relationship between humans and their natural, social, and built environments –
• Animal ecology – Scientific study of the relationships between living animals and their environment –
• Insect ecology – The study of how insects interact with the surrounding environment –
• Microbial ecology – Study of the relationship of microorganisms with their environment –
• Plant ecology – The study of effect of the environment on the abundance and distribution of plants.

By biome under study

• Benthic ecology – The study of the interaction of sea-floor organisms with each other and with the environment –
• Desert ecology – The study of interactions between both biotic and abiotic components of desert environments –
• Forest ecology – Study of interactions between the biota and environment in forests. –
• Grassland ecology – Area with vegetation dominated by grasses –
• Marine ecology – The study of the interactions between organisms and environment in the sea –
• Aquatic ecology – The study of interactions between organisms and the environment in water –
• Urban ecology – Scientific study of living organisms.

By biogeographic realm or climatic area under study

• Arctic ecology – Study of the relationships between biotic and abiotic factors in the arctic –
• Polar ecology – Relationship between plants and animals and a polar environment –
• Tropical ecology – Study of the relationships between the biotic and abiotic components of the tropics.

By ecological aspects or phenomena under investigation

• Behavioral ecology – Study of the evolutionary basis for animal behavior due to ecological pressures –
• Chemical ecology – Study of chemically-mediated interactions between living organisms – which deals with the ecological role of biological chemicals used in a wide range of areas including defense against predators and attraction of mates;
• Disease ecology – Sub-discipline of ecology – which studies host-pathogen interactions, particularly those of infectious diseases, within the context of environmental factors;
• Ecophysiology – Study of adaptation of an organism's physiology to environmental conditions – which studies the interaction of physiological traits with the abiotic environment;
• Ecotoxicology – study of effects of released pollutants on the environment and biotaPages displaying wikidata descriptions as a fallback – which looks at the ecological role of toxic chemicals (often pollutants, but also naturally occurring compounds);
• Evolutionary ecology – Interaction of biology and evolution – or ecoevolution which looks at evolutionary changes in the context of the populations and communities in which the organisms exist;
• Fire ecology – Study of fire in ecosystems – which looks at the role of fire in the environment of plants and animals and its effect on ecological communities;
• Functional ecology – branch of ecologyPages displaying wikidata descriptions as a fallback – the study of the roles, or functions, that certain species (or groups thereof) play in an ecosystem;
• Genetic ecology – Study of genetic material in the environment –
• Landscape ecology – Science of relationships between ecological processes in the environment and particular ecosystems –
  • Landscape limnology – Spatially explicit study of lakes, streams, and wetlands as they interact with landscapes –
• Molecular ecology – Field of evolutionary biology –
• Paleoecology – Study of interactions between organisms and their environments across geologic timescales –
• Social ecology – Study of relationships between people and their environment –
• Soil ecology – Study of the interaction of soil and life – the ecology of the pedosphere –
• Sensory ecology – study of how organisms acquire, process, and respond to information from their environmentPages displaying wikidata descriptions as a fallback –
• Spatial ecology – Study of the distribution or space occupied by species –
• Thermal ecology – study of the interactions between temperature and organismsPages displaying wikidata descriptions as a fallback – the study of the relationship between temperature and organisms.

Ecology-involved interdisciplinary fields

• Agroecology – Study of ecological processes in agriculture –
• Applied ecology – sub-field within ecology that considers the application of the science of ecology to real-world (usually management) questionsPages displaying wikidata descriptions as a fallback – the practice of employing ecological principles and understanding to solve real world problems (includes agroecology and conservation biology);
  • Conservation ecology – Study of threats to biological diversity – which studies how to reduce the risk of species extinction;
  • Restoration ecology – Scientific study of renewing and restoring ecosystemsPages displaying short descriptions of redirect targets – which attempts to understand the ecological basis needed to restore impaired or damaged ecosystems;
• Biogeochemistry – Study of chemical cycles of the earth that are either driven by or influence biological activity –
• Biogeography – Study of the distribution of species and ecosystems in geographic space and through geological time –
• Ecological design – Design approach sensitive to environmental impacts –
• Ecological economics – Interdependence of human economies and natural ecosystems –
• Ecological engineering – Environmental engineering –
• Ecological anthropology – Study of cultural adaptations to environments –
  • Festive ecology – Study of ecology and cultural events –
• Ecological health – term in medicine about management of environmental factors that may reduce the risk of unhealthy behaviorPages displaying wikidata descriptions as a fallback –
• Ecosophy – Philosophy of ecological harmony or equilibrium as developed by Arne Næss or Félix Guattari –
• Environmental psychology – Academic study of the mind's relationship to one's immediate surroundings –
• Natural history – Study of organisms including plants or animals in their environment –
• Systems ecology – Holistic approach to the study of ecological systems –

Other disciplines

Ecology has also inspired (and lent its name to) other non-biological disciplines such as:

• Media ecology
• Industrial ecology
• Information ecology

Terrestrial realms

Biogeographic realm – Broadest biogeographic division of Earth's land surface. The World Wildlife Fund (WWF) developed a system of eight biogeographic realms (ecozones):

• Nearctic – Biogeographic realm encompassing temperate North AmericaPages displaying short descriptions of redirect targets 22.9 mil. km² (including most of North America)
• Palearctic – Biogeographic realm covering most of EurasiaPages displaying short descriptions of redirect targets 54.1 mil. km² (including the bulk of Eurasia and North Africa)
• Afrotropical – One of Earth's eight biogeographic realmsPages displaying short descriptions of redirect targets 22.1 mil. km² (including Sub-Saharan Africa)
• Indomalayan – One of the Earth's eight ecozonesPages displaying short descriptions of redirect targets 7.5 mil. km² (including the South Asian subcontinent and Southeast Asia)
• Australasian – One of the Earth's eight biogeographic realms 7.7 mil. km² (including Australia, New Guinea, and neighbouring islands). The northern boundary of this zone is known as the Wallace line.
• Neotropical – One of Earth's eight biogeographic realmsPages displaying short descriptions of redirect targets 19.0 mil. km² (including South America and the Caribbean)
• Oceanian – Terrestrial biogeographic realm 1.0 mil. km² (including Polynesia, Fiji and Micronesia)
• Antarctic – One of Earth's eight biogeographic realms 0.3 mil. km² (including Antarctica).

Ecoregions

Ecoregion – Ecologically and geographically defined area that is smaller than a bioregion

The World has over 800 terrestrial ecoregions. See Lists of ecoregions by country.