Glossary of terms

Here you will find definitions of terms used in resources on the Foodsource website. You will also find these definitions on the right-hand side within chapters. If you have any suggestions for new glossary items, let us know here.

2 (1) | A (13) | B (6) | C (15) | D (6) | E (8) | F (12) | G (4) | H (3) | I (7) | L (5) | M (12) | N (7) | O (4) | P (9) | R (7) | S (10) | T (1) | U (2) | W (4) | Y (1) | Z (2)


Biodiversity refers in the broadest sense to the variety and variability of living organisms in a particular area, or on earth in general. More specifically, the concept is used to denote different aspects of the variety and variability of life, e.g. the number of species in an area (species richness) or the size of species’ populations (species abundance). Biodiversity is measured in different ways and at various scales from the genetic through to the landscape level.

Biodiversity conservation

Biodiversity conservation refers to all human activity aimed at the preservation of both the variety and variability of living organisms in a particular area of concern, or on earth in general. People value different aspects of biodiversity in different ways, and can have different priorities in biodiversity conservation e.g. to protect an endemic species or a species that supports an ecological process important to human wellbeing such as pollination.

Biological nitrogen fixation

Biological nitrogen fixation is the process through which atmospheric nitrogen (N2) is converted into ammonia (NH3) or related nitrogenous compounds by bacteria. BNF includes both the fixation of these compounds by bacteria that are present in the soil and by bacteria that live in the root nodules of legumes and certain other plant and tree species. The latter form of BNF is a symbiotic process: the bacteria provide the plant or tree with nitrogen compounds while the plant or tree provides the bacteria with carbohydrates. Nitrogen-fixating plant and tree species are often able to live on relatively poor soils with little need for additional manure or synthetic nitrogen fertiliser. Increased reliance on BNF as opposed to fertilisers is often considered to be an important aspect of a more sustainable food system.


Biomass refers to dry weight of plant-based material that has been harvested or is available on an area of land. Typically, it refers to the use of plants not for food or fibre, but rather for (bio)energy.


Biotechnology is defined by the United Nations as “any technological application that uses biological systems, living organisms, or derivatives thereof, to make or modify products or processes for specific use”. Applied to agriculture, biotechnology involves controversial as well as uncontroversial practices. Examples of biotechnology are the genetic engineering of crops (GMOs), conventional cross-breeding, breeding based on individual plants’ and animals’ genetic traits (molecular marking), cloning animals, and the production of new vaccines using microbiological methods.

C3 plants

C3 plants are those whose method of photosynthesis is adapted to cooler and wetter climates. They represent the majority of plants globally and include rice, soybean, and wheat. C3 plants are less efficient at creating energy for growth than C4 type plants in hot and dry climates.

C4 plants

C4 plants are those whose method of photosynthesis is adapted to hotter and dryer climates. They represent only a small fraction of plants globally. Examples include some grasses, maize, sugar cane, millet, and sorghum. In hot and dry climates, it is more efficient at creating energy for growth than C3 plants.

Carbon dioxide equivalent

Carbon dioxide equivalent (CO2.eq) is a measure used to compare and combine the warming effect of emissions from different greenhouse gases, using single measure of impact. This is done on the basis of a conversion factor known as the Global Warming Potential (GWP), which is the ratio of the total energy trapped by a unit of greenhouse gas (e.g. a tonne of methane) over a specific period of time (normally 100 years), to that trapped by carbon dioxide over the same time period.

Carbon intensity

Carbon intensity refers to the amount of carbon emissions that are produced to achieve a specific outcome. For example, the carbon intensity of electricity is the emission produced per unit of electricity supply.

Carbon price

A carbon price is a cost that must be paid for the right to produce a unit of carbon pollution. This may take the form of a carbon tax on pollution or an obligation to buy permits from a carbon market. In either case, the goal is to promote investment by polluters to reduce emissions of carbon dioxide and other greenhouse gases.

Carbon sequestration

Carbon sequestration is any process by which carbon dioxide is removed from the atmosphere and stored elsewhere, whether by biological or technological means. There are two main types of carbon sequestration, terrestrial (carbon plants and soils), and geologic (carbon stored in rock formations) . One classic example of carbon sequestration is reforestation.

Carbon sinks

A carbon sink is a reservoir (natural or artificial) which accumulates and stores carbon over time. The process of removing carbon dioxide from the atmosphere by increasing the sink capacity of the reservoir (which could be a soil) is called carbon sequestration

Carbon stock

Carbon stock refers to the amount of carbon stored in plants, soils, and ecosystems.

Choice architecture

Choice architecture refers to the design of which choices are made available or not to people in a given context, and how these different choices are presented to them. In any context, there is always a choice architecture affecting decision making, whether deliberately designed or not. For example people's purchasing decisions in a shop are dictated by the products available to buy in a grocery shop, their price, their presentation and visibility, the extent to which they are advertised and promoted and so forth: these collectively constitute the choice architecture.

Climate smart agriculture

Climate smart agriculture (CSA) was first introduced by the FAO in 2010 as an integrated approach geared at reorienting and redesigning agricultural systems to address and build resilience to climate change, and is often discussed in the context of low-income countries. CSA involves three interconnected elements: increasing agricultural productivity and incomes; adapting and building resilience to climate change; and the mitigation of greenhouse gas emissions. It aims to identify context specific agricultural strategies supporting these elements and guide coordinated actions among stakeholders (e.g. farmers, researchers, private sector, civil society and policy makers) from the farm to the global level. CSA is criticised for justifying nearly any form of agriculture (thereby ‘greenwashing’ unsustainable practices) and for failing to address enduring inequalities in food production and distribution. CSA is closely related to the concepts of sustainable intensification and ecological intensification but differs from them in its strong focus on planning and implementation for climate change adaptation and mitigation, and less on reducing environmental impacts beyond emissions.