Eco-imperialism has been defined in various ways but is often used to refer to a situation where actors (e.g. people, communities, organisations or governments) that are perceived as powerful impose their ecological rationalities and actions, objectives or policies on other actors. A historical example of eco-imperialism can be seen in the development of national parks in the Americas by Western colonisers who (in many cases violently) expelled indigenous communities from the land.

With roots in the social sciences and heterodox economics, ecological economists appreciate the economic value of nature but argue that it also has many highly subjective social and philosophical values. They see the market valuation of nature as an inherently political act that limits our ability to protect nature – only a democratic process of comprehensive social change can achieve this goal.

Ecological intensification is the principle of using the natural functionalities of an ecosystem to produce greater amounts of food, fibre, and fuel in sustainable ways. Underpinning EI is the idea that ecological functions (e.g. pollination and predator/prey relationships) can be integrated into agricultural practices, ideally leading to ‘agroecosystems’ that are sustained by natural processes and avoid many negative environmental impacts. Ecological intensification is closely related to the concepts of sustainable intensification and climate smart agriculture, but differs in its strong focus on the potential of enhancing ecological processes in food production.

An ecological niche describes the role an organism plays within a community (which here refers to all the different groups of species commonly found within a particular area). A particular species’ ecological niche encompasses all resources and conditions (both biotic and abiotic) required for a species to maintain a viable population and its interactions with other species (including competitors and predators). 

As an example, we might talk about the ecological niche occupied by large, grazing herbivores: they are able to digest widespread but energy-poor and cellulose-rich food; they move relatively large distances and substantially alter the distribution of plant species across these ranges, creating grasslands and retarding or preventing afforestation; they are predated only by the largest carnivores in their habitats. Such a niche exists in many ecosystems but can be occupied by different specific species (larger deer, cattle, buffalo, etc.).

All abiotic processes (processes related to non-living things such as warming from sunlight) and biotic processes (processes related to living things such as plant, animal and microbial activities) or combinations thereof that influence the state of an ecosystem.

Ecological restoration refers to the principle of restoring something, for example a landscape or an ecosystem, based on ecological principles, processes or methods. An example of this can be the restoration of an deforested area by allowing forest to re-emerge through various forest succession stages rather than planting a mixture of the plant species that used to be present before the area was deforested. Ecological restoration can take place as part of a rewilding strategy. Rewilding strategies, however, tend to come with more specific ideas about which species should be present or (re)introduced and a clear overall vision about particular processes in the ecosystem that should be encouraged.

Ecology is a field of science that studies the interactions and connections between plants and animals and their natural environment.

Ecomodernism is an environmental philosophy rooted in the belief that technological progress can allow humans to flourish while minimising our impacts on the environment, in particular by freeing up land for conservation by intensifying the production of food and other resources using technology. Ecomodernism as a movement encompasses a diversity of views, but perhaps the most coherent exposition of the ecomodernist philosophy is the Ecomodernist Manifesto of 2015. Read the full TABLE explainer What is ecomodernism? for a more detailed discussion of the movement and its ideas.

An ecosystem is a structural and functional unit in ecology that describes living organisms, their physical environment, and all their interrelationships in a particular unit space. Ecosystems consist of two main components. The biotic component consists of all animals, plants, and other living organisms. The abiotic component consists of all non-living aspects of the physical environment (climate, non-living components of soil, nutrient and light availability, etc.). The interactions between biotic and abiotic components of an ecosystem naturally maintain an equilibrium in the environment.

Ecosystem restoration refers to the process of restoring aspects of an ecosystem that have been lost through for example the reintroduction of species or management practices to regain lost landscape features. The restoration of an ecosystem can be an outcome of rewilding. Not all rewilding strategies, however, aim to restore (aspects of) ecosystems that have been lost. Some rewilding strategies are more future oriented.

Ecosystem services are the tangible and intangible benefits that are provided by ecosystems to humans, which both enable human life and that contribute to its quality. Ecosystem services include provisioning services such as food and water; regulating services such as flood and disease control; cultural services such as spiritual, recreational, and cultural benefits; and supporting services such as nutrient cycling that maintain the conditions for life on Earth.

Ecotoxicity refers to the toxicology of pollutants in the environment. The study of ecotoxicology includes consideration of the interaction of pollutants both with abiotic aspects of the environment - soil, air and water; and how they interact with living systems, at the level of cell, organ, and organism to communities and ecosystems.

Eddy covariance is a meteorological monitoring technique that can be used to measure the movement of different gases in situ. Applications include, for example, to measure the concentration of methane in the air near agricultural sources.

Endemic species is a plant or animal species that is unique to a specific geographic location, such as a country or an island. Usually the area where an endemic species live is isolated, making it difficult for the species to move to other areas. Endemic species are often uniquely adapted to the specific environment in which they live. Almost all endemic species are specialist species.

Enteric fermentation is a natural part of the digestive process of ruminant animals (e.g. cattle and sheep) where microbes decompose and ferment the food present in large rumen portion of the stomach. As a byproduct of this fermentation process, some bacteria species in the stomach produce methane.

With roots in neo-classical economics, environmental economists state that nature’s value lies in the ecosystem services it offers; and objective assessment can assign monetary value to these services. They argue that fully incorporating nature’s economic value into markets then leads to solutions that protect it. See also ecological economists.

Epidemiology is a scientific discipline that uses data mathematical tools to understand the patterns of disease found in human populations and changes therein. It seeks to explain exactly how these patterns are caused in order to identify ways to control and treat health problems.

Eutrophication refers to the buildup of nutrients in a body of water (e.g. nitrogen and phosphorus) to a level in excess of what would occur naturally and to which aquatic ecosystems are adapted. This can result in detrimental impacts on many aquatic plants and animals, as well as the rapid overgrowth of some plants and algae.

Extensive agriculture has no clearly bounded definition, but generally refers to production systems that use minimal inputs, are often lower yielding, and cover a large land-area in relation to animal numbers. An example of this is continuous grazing of entirely pasture fed livestock including sheep and cattle. The practice may be contrasted with intensive agriculture in debates around livestock production.

Externalities are side-effects of activities or economic transactions that affect people who did not take part in the activity or transaction. Externalities can be negative (for example second-hand smoke from cigarettes can make other people ill) or positive (for example vaccines can protect those who do not receive them, by reducing the spread of disease). Externalities are not usually reflected in the price of an economic transaction, because the costs are usually borne by third parties.