The following terms are used by UNEP-WCMC and as such have been defined as UNEP-WCMC interprets them. Whilst we have attempted to include all current thinking on biodiversity terms, there will without a doubt be differences of opinion with respect to definitions.

A |B | C |D |E

F-L

M-R

S-Z

A	Accession	A sample of a crop variety collected at a specific location and time; may be of any size.
	Alien species	A species occurring in an area outside of its historically known natural range as a result of intentional or accidental dispersal by human activities (also known as an exotic or introduced species).
	Assemblage	An integrated group of species inhabiting a given area; the organisms within a community influence one another's distribution, abundance, and evolution. (A Human Community is a social group of any size whose members reside in a specific locality.)
B	Biodiversity	The variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.
	Biodiversity Information System (BIS)	The computerised storage and manipulation of biodiversity data. See EIS.
	Biogeography	A branch of geography that deals with the geographical distribution of animals and plants.
	Biological diversity	See Biodiversity.
	Biological resources	Includes genetic resources, organisms or parts thereof, populations, or any other biotic component of ecosystems with actual or potential use or value for humanity.
	Biologically unique species	A species that is the only representative of an entire genus or family.
	Biome	A major portion of the living environment of a particular region (such as a fir forest or grassland), characterised by its distinctive vegetation and maintained by local climatic conditions.
	Bioregion (bioregional planning)	A territory defined by a combination of biological, social, and geographic criteria, rather than geopolitical considerations; generally, a system of related, interconnected ecosystems.
	Biosphere reserves	Established under UNESCO's Man and the Biosphere (MAB) Program, biosphere reserves are a series of protected areas linked through a global network, intended to demonstrate the relationship between conservation and development.
	Biota	The living organisms of a region.
	Biotic	Pertaining to any aspect of life, especially to characteristics of entire populations or ecosystems.
	Breed	A group of animals or plants related by descent from common ancestors and visibly similar in most characteristics. Taxonomically, a species can have numerous breeds.
	Breeding line	Genetic lines of particular significance to plant or animal breeders that provide the basis for modern varieties.
	Buffer zone	The region near the border of a protected area; a transition zone between areas managed for different objectives.
	Buffer zones	Areas on the edge of protected areas that have land use controls and allow only activities compatible with protection of the core area, such as research, environmental education, recreation, and tourism.
C	Captive breeding	The propagation or preservation of animals outside their natural habitat, involving control by humans of the animals chosen to constitute a population and of mating choices within that population.
	Carrying Capacity	The maximum number of people, or individuals of a particular species, that a given part of the environment can maintain indefinitely.
	Centres of diversity	The regions where most of the major crop species were originally domesticated and developed. These regions may coincide with centres of origin.
	Climax community	The end of a successional sequence; a community that has reached stability under a particular set of environmental conditions.
	Co-management	The sharing of authority, responsibility, and benefits between government and local communities in the management of natural resources.
	Common property resource management	The management of a specific resource (such as a forest or pasture) by a well-defined group of resource users with the authority to regulate its use by members and outsiders.
	Community	An integrated group of species inhabiting a given area; the organisms within a community influence one another's distribution, abundance, and evolution. (A Human Community is a social group of any size whose members reside in a specific locality.)
	Community	A group of ecologically related populations of various species of organisms occurring in a particular place and time.
	Complementarity	The concept of achieving conservation efficiently by ensuring that a set of areas is assembled with due regard to the additional species that each brings into the network. This is the basis of a critical faunas analysis.
	Conservation	The management of human use of the biosphere so that it may yield the greatest sustainable benefit to current generations while maintaining its potential to meet the needs and aspirations of future generations: Thus conservation is positive, embracing preservation, maintenance, sustainable utilisation, restoration, and enhancement of the natural environment.
	Conservation of biodiversity	The management of human interactions with genes, species, and ecosystems so as to provide the maximum benefit to the present generation while maintaining their potential to meet the needs and aspirations of future generations; encompasses elements of saving, studying, and using biodiversity.
	Country of origin of genetic resources	The country which possesses those genetic resources in in-situ conditions
	Country providing genetic resources	The country supplying genetic resources collected from in-situ sources, including populations of both wild and domesticated species, or taken from ex-situ sources, which may or may not have originated in that country
	Critical faunas analysis	A methodology to identify the minimum set of areas which would contain at least one viable population of every species in a given animal or plant group.
	Critical habitat	A technical classification of areas in the United States that refers to habitats essential for the conservation of endangered or threatened species. The term may be used to designate portions of habitat areas, the entire area, or even areas outside the current range of the species.
	Cultivar	A cultivated variety (genetic strain) of a domesticated crop plant.
	Cultivar	International term denoting certain cultivated plants that are clearly distinguishable from others by one or more characteristics and that when reproduced retain their distinguishing characteristics. In the United States, 'variety' is considered to be synonymous with cultivar (derived from 'cultivated variety').
	Cultural diversity	Variety or multiformity of human social structures, belief systems, and strategies for adapting to situations in different parts of the world.
	Cutting	Plant piece (stem, leaf, or root) removed from a parent plant that is capable of developing into a new plant.
	Cycad	Any of an order of gymnosperms of the family cycadaceae. Cycads are tropical plants that resemble palms but reproduce by means of spermatozoids.
D	Domesticated or cultivated species	Species in which the evolutionary process has been influenced by humans to meet their needs.
	Domestication	The adaptation of an animal or plant to life in intimate association with and to the advantage of man.
E	Ecology	A branch of science concerned with the interrelationship of organisms and their environment.
	Ecosystem	A dynamic complex of plant, animal, fungal, and microorganism communities and their associated non- living environment interacting as an ecological unit.
	Ecosystem diversity	The variety of ecosystems that occurs within a larger landscape, ranging from biome (the largest ecological unit) to microhabitat.
	Ecotourism	Travel undertaken to witness sites or regions of unique natural or ecologic quality, or the provision of services to facilitate such travel.
	Endangered species	A technical definition used for classification in the United States referring to a species that is in danger of extinction throughout all or a significant portion of its range. IUCN The World Conservation Union (1994) definition, defines species as endangered if the factors causing their vulnerability or decline continue to operate.
	Endemic	Restricted to a specified region or locality.
	Endemic Bird Area (EBA)	A term used by BirdLife International to describe areas with two or more restricted- range bird species entirely confined to them
	Endemism	The occurrence of a species in a particular locality or region.
	Environmental Impact Assessment (EIA)	A method of analysis which attempts to predict the likely repercussions of a proposed major development (usually industrial) upon the social and physical environment of the surrounding area.
	Environmental Information System (EIS)	The computerised storage and manipulation of environmental data. This data may include a large proportion of geographical (spatial) information along with data specific to the description of plants, animals and their habitats. EIS are frequently derivatives of GIS.
	Equilibrium theory	A theory of island biogeography maintaining that greater numbers of species are found on larger islands because the populations on smaller islands are more vulnerable to extinction. This theory can also be applied to terrestrial analogues such as forest patches in agricultural or suburban areas or nature reserves where it has become known as 'insular ecology.'
	Exotic species	An organism that exists in the free state in an area but is not native to that area. Also refers to animals from outside the country in which they are held in captive or free-ranging populations.
	Ex-situ	Pertaining to study or maintenance of an organism or groups of organisms away from the place where they naturally occur. Commonly associated with collections of plants and animals in storage facilities, botanic gardens or zoos
	Ex-situ conservation	The conservation of components of biological diversity outside their natural habitats.
	Extant	Species are those whose members are living at the present time.
	Extinct	As defined by the IUCN, extinct taxa are species or other taxa that are no longer known to exist in the wild after repeated search of their type of locality and other locations where they were known or likely to have occurred.
	Extinction	Disappearance of a taxonomic group of organisms from existence in all regions.