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.

A (12) | B (4) | C (13) | D (3) | E (8) | F (7) | G (4) | H (2) | I (6) | L (5) | M (11) | N (3) | O (4) | P (5) | R (6) | S (9) | T (1) | U (1) | W (4) | Y (1) | Z (1)


In the context of food system sustainability, the concept of resilience refers to the ability of the food system to cope with and recover from socio-economic or environmental shocks and pressures. A resilient system has a certain degree of toughness and is able to bounce back against or adapt to disturbances. A resilient food system, for example, is able to keep providing food or other outputs such as livelihoods for farmers, drinking water, and biodiversity conservation under conditions of drought, a drop in food prices, war, climate change, the spread of virus in plants or animals, and so on. Resilience can be thought of at different scale levels. For example, what may be considered as resilient on a national level may not be understood to be resilient at a farm level. While some see resilience as synchronous with sustainability, others point out that a resilient system may also be one that resists needed transformation; an unsustainable status quo may in fact be resilient to change.


is a mammal with a four-compartmented stomach which enables it to acquire nutrients from plant-based food such as grasses, husks and stalks. Examples of ruminants include cattle, sheep, goats, deer, giraffes and camels. After swallowing, microbes in the ruminant’s rumen (its first stomach compartment) begin fermenting the food. This process generates fatty acids (nutrients which the ruminant absorbs through its rumen walls) and methane, which the ruminant eructs or burps. Through this process, ruminants are able to digest coarse cellulosic material which monogastrics and people cannot. Methane emissions from ruminants are a significant source of greenhouse gasses from ruminant-based livestock systems.


Ruminant animals are distinguished by their specialised digestive system and include species such as cattle, sheep, goats, deer, and camels. In particular, their large rumen stomach allows plant matter to be regurgitated, chewed again, and for microbes to ferment it. This breaks down plant matter into digestible molecules that can be absorbed by the animal and allows ruminants to be fed on coarse plant matter such as grass, whereas other species such as pigs and chickens cannot.

Selective breeding

Selective breeding refers to the deliberate human practice of choosing which plants or animals to breed together, based on specific characteristics, in order to selectively enhance these characteristics (and their genetic basis) in their offspring.

Sensitivity and uncertainty analysis

Sensitivity and uncertainty analysis are an integral part of any modelling process. Sensitivity analysis varies the possible values of input variables to a model in order to understand the difference that these assumptions make to results and conclusions that can be drawn. Uncertainty analysis investigates the potential effects of lack of knowledge or potential errors in the model design.


Silting refers to the transport and deposition of sediment on the riverbed, which changes the dynamics of the water flow and can affect aquatic ecosystems.

Specialist species

is a plant or animal species that is able to thrive in only a limited variety of environmental conditions, or that has a limited diet. Unlike endemic species, populations of the same specialist species may be present at different geographical locations around the world.


Stunting is a medical condition where childhood growth and development is impared as a result of inadequate nutrition, repeated infection, and inadequate psycosocial stimulation. Children are definied as stunted if their height for their age is abnormally low. Its effects can lead to an under developed brain, poor cognition and educational attainment, as well as higher risk of nutrition related chronic diseases in later life.

Subsistence farming

Subsistence farming refers to rearing animals and growing crops only for your own consumption, without having any surplus to take to market as a source of cash income.

Substitution effect

In economics, the substitution effect refers to the idea that as prices increase or as a product becomes scarce, people will replace such items with substitutes that are cheaper or easier to access. In the context of diets, substitution effects refer to the changes in the environmental footprint of a person's diet, according to the relative impact of foods that are substituted for one another.

Sustainable intensification

is a recently developed concept that is understood in different ways by its critics and supporters. A common understanding is that it denotes the principle of increasing or maintaining the productivity of agriculture on existing farmland while at the same time, reducing its environmental impacts. Understood in this way, SI designates a goal for the development of agricultural systems but does not, a priori, favour any particular agronomic route to achieve it. It may involve the intensification of different types of agricultural inputs (e.g. of knowledge, biotechnologies, labour, machinery) and apply these to different forms of agriculture (e.g. livestock or arable; agroecological or conventional). Forms of intensification that can be called sustainable intensification must lower environmental impacts and land use, relative to yields. However, for some, to merit the term ‘sustainable’ social, economic, and ethical criteria must also be considered.

System boundaries

The subjective boundaries that define what is included within the system under analysis (and so counted) and what is external to the system (and so not counted). System boundaries have multiple dimensions, including what stages are focused on (e.g. production, distribution), what inputs and outputs are measured (e.g. land, greenhouse gases), what geographic locations are included, and more.


Turbidity refers to the amount of light that can pass through water (i.e. its cloudiness), as a result of particles that are suspended within the fluid. It can vary naturally depending on location, but can have detrimental impacts on ecosystems if cause by human activity. For this reason, it is often used as an indicator of water quality.


Deficiencies of a particular component of food, usually due to insufficient intake and/or absorption of that component. This usually refers to energy (often measured in calories) or macronutrients (such as protein, carbohydrates, or fat), but can also refer to micronutrients (vitamins or minerals).

Water footprints

Water footprint is a metric that quantifies the amount of water used to produce each of the goods and services we use. It allows these goods and services to be compared in terms of their water impact, and so to the impact on limited water resources of consumption by individuals, organisations, and even nation states. Water footprints incorporate all the water used – i.e. unable to be used again due to evaporation or removal in products – across the full lifecycle of a produce from production through to consumption, including all inputs to production (e.g. feed crops used in pork production). It has three components: (1) green water - rainwater used in soils; (2) blue water - freshwater sources; (3) grey water - water amount needed to dilute pollution to safe levels.