The uppermost dark-colored layer of a soil consisting largely of partly disintegrated organic debris.
(1) Area or zone of a glacier where snow and ice ablation exceed accumulation. (2) The area of a glacier where more glacier mass is lost than gained.
The change that takes place so rapidly and unexpectedly that human or natural systems have difficulty adapting to it.
(1) In general: the process of absorbing; taking up of water and nutrients by assimilation or imbibition. The taking up by capillary, osmotic, chemical or solvent action, such as the taking up of a gas by a solid or liquid, or taking up of a liquid by a solid. (2) In biology: the movement of a fluid or a dissolved substance across a cell membrane. (3) In plants: water and mineral salts are absorbed from the soil by roots. (4) In animals: solubulized food material is absorbed into the circulatory system through cells lining the alimentary canal.
The number of individuals or related measure of quantity (such as biomass) in a population, community or spatial unit.
Adaptation of living organisms to all aspects of the environment, not just the climatic. Examples of acclimation would be adjustment of plants to growth at elevated atmospheric carbon dioxide concentrations or to soil water deficits.
Change in natural chemical balance caused by an increase in the concentration of acidic elements. Acid precipitation has a lower pH than normal as a result of acid-forming precursor molecules introduced into the atmosphere by human activities
A measure of how acidic a solution may be. A solution with a pH of less than 7.0 is considered acidic.
Adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities.; Genetically determined characteristic that enhances the ability of an organism to cope with its environment.; The process of change in structure and/or function that makes an organism or a population better suited to survive in a slow or rapidly changing environment. Adaptation may be achieved by phenotypic tuning to prevailing environmental conditions, or through evolutionary changes of genetic structure at the population level.; Adjustment in natural or human systems to a new or changing environment, including anticipatory and reactive adaptation, private and public adaptation, and autonomous and planned adaptation.; The morphological, physiological, and behavioural characteristics and processes organisms have acquired and utilize to survive.
(1) The ability of an ecosystem to adjust to climate change (including climate variability and extremes) to moderate potential damages, to take advantage of opportunities, or to cope with the consequences. (2) The ability to identify and implement effective actions in response to changing circumstances. (3) The ability of systems, institutions, humans and other organisms to adjust to potential damage, to take advantage of opportunities, or to respond to consequence.
A governance approach that incorporates methods of adaptive management, adaptive policy making and transition management for addressing complex, uncertain and dynamic issues. Adaptive governance relies on polycentric institutional arrangements for decision making at multiple scales. Spanning the local and global levels, this form of governance provides for collaborative, flexible, learning-based approaches to ecosystem management.
The process by which a substance is held or bound to a surface by chemical and/or physical attraction.
The advanced gap corresponds to the difference between the advanced mandate, and the biodiesel and cellulosic mandates. It corresponds to fuels being able to achieve a 50% greenhouse gas reduction.
Pertaining to wind activity, especially in relation to wind erosion.
An aerated soil is a soil with a good movement of air through the soil structure. The opposite being a wet waterlogged soil.
A plant-cultivation technique in which the roots hang suspended in the air while nutrient solution is delivered to them in the form of a fine mist climate geoengineering.
A collection of airborne solid or liquid particles, with a typical size between 0.01 and 10 micrometres (μm), that resides in the atmosphere for at least several hours. Aerosols may be of either natural or anthropogenic origin.
An indicator that detects the presence of UV-absorbing aerosols such as dust and soot.
A measure of radiation extinction due to the interaction of radiation with aerosol particles in the atmosphere, primarily due to the processes of scattering and absorption. Also referred to as aerosol optical thickness.
One of two airborne means of infectious disease spreading. In aerosol form, viral particles are suspended in the air by physical and chemical forces for hours or more. In droplet form, in contrast, viral particles remain airborne for a few seconds after someone sneezes or coughs and are able to travel only a short distance before gravitational forces pull them down.
US-coined term for any plan or programme designed to combat the effects of discrimination against minorities, women, the elderly and other groups.
Establishment of forest plantations on land that is not classified as forest.
Aflatoxins are poisonous substances produced by certain kinds of fungi (moulds) that are found naturally all over the world; they can contaminate food crops and pose a serious health threat to humans and livestock. Aflatoxins also pose a significant economic burden, causing an estimated 25% or more of the world’s food crops to be destroyed annually.
(also spelled ‘trypanosomiasis’): A disease of livestock (‘African animal trypanosomosis’) and humans (‘sleeping sickness’). These diseases are caused by single-celled trypanosome parasites (Trypanosoma brucei gambiense, Trypanosoma rhodesiense and Trypanosoma brucei brucei) that are transmitted to their animal and human hosts by the bite of trypanosome- infected tsetse flies (genus Glossina), which are found only in Africa.
An internally agreed plan of action for the next century, which was adopted in 1992 at the United Nations Conference on Environment and Development.
The benefits that come when firms and people locate near one another together in cities and industrial clusters. These benefits all ultimately come from transport costs savings: the only real difference between a nearby fi rm and one across the continent is that it is easier to connect with a neighbor.
(1) Agricultural intensification can be technically defined as an increase in agricultural production per unit of inputs (which may be labour, land, time, fertilizer, seed, feed or cash). For practical purposes, intensification occurs when there is an increase in the total volume of agricultural production that results from a higher productivity of inputs, or agricultural production is maintained while certain inputs are decreased (such as by more effective delivery of smaller amounts of fertilizer, better targeting of plant or animal protection, and mixed or relay cropping on smaller fields). Intensification that takes the form of increased production is most critical when there is a need to expand the food supply, for example during periods of rapid population growth. Intensification that makes more efficient use of inputs may be more critical when environmental problems or social issues are involved. In either case, changes caused by intensification are to be understood conceptually in contrast to extensive adjustments, which involve increases or decreases in the amount of inputs used. Historically, the most common and effective extensive adjustment in agricultural production has been to increase or decrease the area of land planted. (2) An increase in agricultural production per unit of inputs (e.g. labour, land, time, fertilizer, seed, feed, cash). This intensification has been a prerequisite to human civilization. Increased production is critical for expanding food supply; intensification that makes efficient use of inputs is critical for maintaining the health of agricultural environments.
Agricultural landscapes can be described in terms of the three elements: structure, which concerns the interaction between environmental features, land-use patterns and human-made objects; functions, which are the provision of environmental services for farmers and society; and the values society puts on agricultural landscapes and the costs of maintaining and enhancing landscape provisions by agriculture. Because the underlying human and natural processes are subject to change and evolution, landscapes are "dynamic systems".
(1) Agroecology is the integrative study of the ecology of the entire food system, encompassing ecological, economic and social dimensions. (2) An interdisciplinary field of knowledge involving a set of concepts and principles oriented towards the design and management of sustainable ecosystems. (3) An integrated approach that simultaneously applies ecological and social concepts and principles to optimize interactions between plants, animals, humans and the environment while addressing social aspects to achieve sustainable and fair agri-food systems.
Organisms and environment of an agricultural area considered as an ecosystem.
The intentional integration of trees and shrubs into crop and animal farming systems to create environmental, economic, and social benefits.
The application of technology in agriculture.
(1) The fraction of solar energy that is diffusely reflected from the Earth back into space. It shows how reflective earth's surface is. (2) The proportion of the incident light or radiation that is reflected by a surface.
These are mineral horizons in which the main feature is loss of silicate clay, iron, aluminium, or some combination of these, leaving a concentration of sand and silt particles, and in which all or much of the original rock structure has been obliterated.
Alfisols are soils developing under forest covers of the humid midlatitudes. Eluviation is moderate and base status is fairly high in these soils. Common to the humid continental and humid subtropical climates, these soils are well developed and contain a subsurface layer of clay called an argillic horizon.
A reproductive explosion of algae in a lake, river, or ocean.
Species accidentally or deliberately introduced outside its normal distribution.
Unlawfully transferring records or losing custody of them to an unauthorized organization or person.
A process that lowers the amount of acid in a solution. In medicine, an alkali, such as sodium bicarbonate, may be given to patients to lower high levels of acid in the blood or urine that can be caused by certain medicines or conditions.
The accumulation of sodium ions on exchange surfaces of soils, resulting in high pH values and often collapse of soil structure due to dispersion of clays.
All of the deaths that occur in a population, regardless of the cause. It is measured in clinical trials and used as an indicator of the safety or hazard of an intervention.
Hay fever, a type of inflammation in the nose which occurs when the immune system overreacts to allergens in the air.
Includes three main groups: (1) Renewable Energy (Solar, Wind, Hydro, Geothermal, Biomass) (2) Fuel Cells and Hydrogen (3) Energy Conservation and Enabling Technologies.
(1) Living, active, or occurring in the absence of free oxygen. (2) Descriptive of a condition in which molecular oxygen is not available.
Equipment where anaerobic digestion is operated; i.e. the process of degradation of organic materials by microorganisms in the absence of oxygen, producing CH4, CO2 and other gases as by-products.
Life processes taking place in the absence of molecular oxygen, particularly growth under anaerobic conditions.
The anthraquic horizon comprises the puddled layer and the plough pan of a soil under long continued paddy cultivation.
An ancient zoonotic disease that continues to cause serious illness in livestock, where it is a particular threat to cattle and small ruminants like sheep and goats. It can affect all warm-blooded animals, including humans. Treatment is possible with early diagnosis but often there are no symptoms and infected animals die swiftly. Humans generally acquire the disease directly or indirectly from infected animals or occupational exposure to infected or contaminated animal products. Although many countries have confirmed cases, this is not, in the main, a disease of wealthy countries. Incidences of both animal and human anthrax are frequently associated with conflict.
Anthric properties (from Greek anthropos, human) apply to some cultivated soils with mollic or umbric horizons.
Anthropedogenic horizons (from Gr. anthropos, human, and pedogenesis) comprise a variety of surface and subsurface horizons which result from long-continued cultivation.
A term used by scientists to name a new geologic epoch (following the most recent Holocene) characterized by significant changes in the Earth’s atmosphere, biosphere and hydrosphere due primarily to human activities.
Of, relating to, or resulting from the influence of human beings on nature.
Greenhouse-gas emissions resulting from human activities.
Human-generated (anthropogenic) noise in the oceans and inshore regions.
The promotion of equality of opportunity for everyone by protecting them from unfair discrimination in certain areas of activity and from sexual harassment and certain associated objectionable conduct.
A weather system with high atmospheric pressure at its centre, around which air slowly circulates in a clockwise (northern hemisphere) or counter-clockwise (southern hemisphere) direction. Anticyclones are associated with calm, fine weather.
The ability of a microorganism (like bacteria, viruses, and some parasites) to stop an antimicrobial (such as antibiotics, antivirals and antimalarials) from working against it. As a result, standard treatments become ineffective, infections persist and may spread to others.
Basic ecological unit composed of living and non-living elements interacting in water.
An aquifer is an underground layer of water-bearing rock. Water-bearing rocks are permeable, meaning they have openings that liquids and gases can pass through. Sedimentary rock such as sandstone, as well as sand and gravel, are examples of water-bearing rock. The top of the water level in an aquifer is called the water table.
Land under temporary crops (double-cropped areas are counted only once), temporary meadows for mowing or pasture, land under market and kitchen gardens, and land temporarily fallow (less than five years). The abandoned land resulting from shifting cultivation is not included in this category.
The area of forest and other wooded land where insect attack or disease or fire is the primary cause of forest disturbance or damage.
The argic horizon (from L. argilla, white clay) is a subsurface horizon which has a distinctly higher clay content than the overlying horizon.
It is a type of marital union where the bride and groom are selected by a third party rather than by each other.
They are solid or liquid substances that are: (i) created or modified substantially by humans as part of an industrial or artisanal manufacturing process; or (ii) brought to the surface by human activity from a depth where they were not influenced by surface processes.
An invertebrate animal having an exoskeleton, a segmented body and paired jointed appendages. Arthropods include insects, arachnids (such as ticks and spiders), myriapods and crustaceans.
(1) Ash content is an important factor of biofuel, always measured on the dry basis, which refers to the solid residue remaining after complete combustion. While the ash content of fuelwood is generally around 1%, some species of agrofuels can register a very high ash content. (2) The amount of residue when a sample of paper is burned under controlled conditions so that all ignitable matter is removed. The ash derives from the mineral loading in the paper.
A condition in which certain fungi infect the tissues, especially the lungs.
Also known as ‘passive’ or ‘healthy’ disease carriers: Individuals that, while infected with a pathogen, neither report nor appear to have any symptoms or signs of illness.
A line that continually approaches a given curve but does not meet it at any finite distance.
(1) Difference at any given time between the actual soil moisture content in the root zone, soil and the wilting point. (2) Available moisture (or water) is the percentage content of water in the soil at the range between field capacity and wilting point.
(1) Soil water content usable by plants, based on the effective root penetration depth. (2) It is the water available for plant growth held between field capacity and permanent wilting point.
Double average over space and time of water falling on a given area in a year.
A severe, often fatal, type of influenza that affects birds, especially poultry, and that can also be transmitted to humans. Known informally as avian flu or bird flu, the type with the greatest risk is highly pathogenic avian influenza (HPAI). Of three types of influenza viruses (A, B and C), influenza A virus is a zoonotic infection with a natural reservoir almost entirely in birds. Avian influenza, for most purposes, refers to the influenza A virus. Though influenza A is adapted to birds, it can also stably adapt and sustain person-to- person transmission.
Freshwater or marine sediments that are devoid of living eukaryotic organisms.