Accession A sample of a crop variety collected at a specific location and time; may be of any size. Adaptation A genetically determined characteristic that enhances an organism's ability to cope with its environment. 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 introduced species. (See, "Guidelines for Translocations of Living Organisms") Allele One of several forms of the same gene. Arthropods The animal phylum comprised of crustaceans, spiders, mites, centipedes, insects, and related forms. The largest of the phyla, containing more than three times the number of all other animal phyla combined. Assemblage See "Community." Avifauna All of the birds found in a given area. Biodiversity The totality of genes, species, and ecosystems in a region or the world. Biogeochemical Cycles The movement of massive amounts of carbon, nitrogen, oxygen, hydrogen, calcium, sodium, sulfur, phosphorus, and other elements among various living and non-living components of the environment--including the atmosphere, soils, aquatic systems, and biotic systems--through the processes of production and decomposition. Biogeography The scientific study of the geographic distribution of organisms. Biological Resources Those components of biodiversity of direct, indirect, or potential use to humanity. (Used interchangeably with "Biotic Resources") Biome A major portion of the living environment of a particular region (such as a fir forest or grassland), characterized 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. (See, "Elements and Dynamics of Bioregional Management") Biota All of the organisms, including animals, plants, fungi, and microorganisms, found in a given area. Biotechnology Any technology that is applied to living organisms to make them more valuable to people. (See, "Guidelines for Minimizing the Potential Social and Ecological Dangers of Biotechnology") Biotic Pertaining to any aspect of life, especially to characteristics of entire populations or ecosystems. Buffer zone The region near the border of a protected area; a transition zone between areas managed for different objectives. Carrying Capacity The maximum number of people, or individuals of a particular species, that a given part of the environment can maintain indefinitely. Center of Diversity Geographic region with high levels of genetic or species diversity. Center of Endemism Geographic region with numerous locally endemic species. Characteristic Diversity The pattern of distribution and abundance of populations, species, and habitats under conditions where humanity's influence on the ecosystem is no greater than that of any other biotic factor. Class In taxonomy, a category just beneath the phylum and above the order; a group of related, similar orders. Climax Community The end of a successional sequence; a community that has reached stability under a particular set of environmental conditions. Cline Change in population characteristics over a geographical area, usually related to a corresponding environmental change. Clone A population of individuals all derived asexually from the same single parent. 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.) Comparative Advantage Relative superiority with which a region or state may produce a good or service. 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 utilization, 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. Cosmopolitan Widely distributed over the globe. Cryogenics The branch of physics relating to the effects and production of very low temperatures; as applied to living organisms, preservation in a dormant state by freezing, drying, or both. Cultivar A cultivated variety (genetic strain) of a domesticated crop plant. Cultural diversity Variety or multiformity of human social structures, belief systems, and strategies for adapting to situations in different parts of the world. (See, "Conserving Cultural Diversity") Decomposition The breakdown of organic materials by organisms in the environment, releasing energy and simple organic and inorganic compounds. About 10 percent of the energy that enters living systems through photosynthesis in plants passes to herbivores, and a fraction of this energy then passes to carnivores. Whether feeding on living or non-living material, however, the detritivores (the organisms consuming non-living material, such as many fungi, bacteria, and earthworms) and consumers break down organic material (such as sugars and proteins) to obtain energy for their own growth, thereby returning the inorganic components (the nutrients) to the environment, where they are again available to plants. Demography The rate of growth and the age structure of populations, and the processes that determine these properties. Donor Control A predator-prey interaction in which the predator does not control the prey population size. Ecosystem The organisms of a particular habitat, such as a pond or forest, together with the physical environment in which they live; a dynamic complex of plant, animal, fungal, and microorganism communities and their associated non-living environment interacting as an ecological unit. Ecosystems have no fixed boundaries; instead, their parameters are set according to the scientific, management, or policy question being examined. Depending upon the purpose of analysis, a single lake, a watershed, or an entire region could be an ecosystem. (See "Biodiversity in Ecosystems") Ecotourism Travel undertaken to witness sites or regions of unique natural or ecologic quality, or the provision of services to facilitate such travel. Ecotype A genetically differentiated subpopulation that is restricted to a specific habitat. Endemic Restricted to a specified region or locality. Environmental Heterogeneity The physical or temporal patchiness of the environment. Heterogeneity exists at all scales within natural communities, ranging from habitat differences between the top and underside of a leaf, to habitat patches created by treefalls within a forest, to the pattern of forests and grasslands within a region. The mosaic of habitat patches within an ecosystem is created by such disturbances as fire and storms; differences in microclimate, soils, and history; and both deterministic and random population variation. Patches in early stages of succession provide unique structural habitats and contain different species than those in late-successional stages do. Evolution Any gradual change. Organic evolution is any genetic change in organisms from generation to generation. Ex situ Conservation A conservation method that entails the removal of germplasm resources (seed, pollen, sperm, individual organisms, from their original habitat or natural environment. Keeping components of biodiversity alive outside of their original habitat or natural environment. Extinction The evolutionary termination of a species caused by the failure to reproduce and the death of all remaining members of the species; the natural failure to adapt to environmental change. (See, "A History of Extinction", "Mechanisms for the Loss of Biodiversity" ?Species Extinctions: Causes and Consequences", and "Extinction-Prone Groups of Species.") Fauna All of the animals found in a given area. Flora All of the plants found in a given area. Frugivore An animal that eats fruit. Gene The functional unit of heredity; the part of the DNA molecule that encodes a single enzyme or structural protein unit. Gene Bank A facility established for the ex situ conservation of individuals (seeds), tissues, or reproductive cells of plants or animals. (See, "Species Extinctions: Causes and Consequences") Genetic diversity Variation in the genetic composition of individuals within or among species; the heritable genetic variation within and among populations. (See "Genetic Diversity" and "Agriculture and Genetic Diversity".) Genotype The set of genes possessed by an individual organism. Germplasm The genetic material, especially its specific molecular and chemical constitution, that comprises the physical basis of the inherited qualities of an organism. Grassroots [organizations or movements]. People or society at a local level, rather than at the center of major political activity. Guild A group of organisms that share a common food resource. Habitat The environment in which an organism lives. Habitat can also refer to the organisms and physical environment in a particular place. Hybridization Crossing of individuals from genetically different strains, populations, or species. Inbreeding A mating system involving the mating or breeding of closely related individuals, the most extreme form of which is self-fertilization. It is used to "fix" economically useful genetic traits in genetically improved populations; however, it also can result in fixation of deleterious recessive alleles. (See on "Ex Situ Conservation") Inbreeding Depression A reduction in fitness or vigor as a result of fixation of deleterious, recessive alleles from consistent inbreeding in a normally outbreeding population. Indicator Species A species whose status provides information on the overall condition of the ecosystem and of other species in that ecosystem. Indigenous Peoples People whose ancestors inhabited a place or country when persons from another culture or ethnic background arrived on the scene and dominated them through conquest, settlement, or other means and who today live more in conformity with their own social, economic, and cultural customs and traditions than with those of the country of which they now form a part (also: "native peoples" or "tribal peoples"). (See: "Conserving Amazonia's Biodiversity: The Perspective of the Coordinating Body for the Indigenous Peoples' Organizations of the Amazon Basin (COICA)") In situ Conservation A conservation method that attempts to preserve the genetic integrity of gene resources by conserving them within the evolutionary dynamic ecosystems of the original habitat or natural environment. Intellectual Property Right A right enabling an inventor to exclude imitators from the market for a limited time. Introduced 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 alien species.(See "Mechanisms for the Loss of Biodiversity," "A History of Extinction", "Biodiversity Conservation and Forest Management," " and "Ecological Restoration and Rehabilitation" and "Guidelines for Translocations of Living Organisms") In vitro Storage of plant or animal germplasm in tissue-culture form in glass containers. Keystone Species A species whose loss from an ecosystem would cause a greater than average change in other species populations or ecosystem processes. (See: "Biodiversity Loss: Cascade Effects and "Biodiversity Conservation and Forest Management.") Landraces A crop cultivar or animal breed that evolved with and has been genetically improved by traditional agriculturalists, but has not been influenced by modern breeding practices. (See: "On-Farm Landrace Conservation and Enhancement in Ethiopia.") Life Form Characteristic structure of a plant or animal. Minimum Viable Population The smallest isolated population having a good chance of surviving for a given number of years despite the foreseeable effects of demographic, environmental, and genetic events and natural catastrophes. (The probability of persistence and the time of persistence are often taken to be 99 percent and 1000 years, respectively.) Mutualism Relationship between two or more species that benefits all parties. Mycorrhizal Fungi A fungus living in a mutualistic association with plants and facilitating nutrient and water uptake. National Income Accounts System of record by which the vigor of a nation's economy is measured. (Results are often listed as Gross National Product, or Gross Domestic Product.) Native Species Plants, animals, fungi, and microorganisms that occur naturally in a given area or region. Nitrogen Fixation A process whereby nitrogen fixing bacteria living in mutualistic associations with plants convert atmospheric nitrogen to nitrogen compounds that plants can utilize directly. Nectarivore An animal that eats nectar. Non-governmental Organization (NGO) A non-profit group or association organized outside of institutionalized political structures to realize particular social objectives (such as environmental protection) or serve particular constituencies (such as indigenous peoples). NGO activities range from research, information distribution, training, local organization, and community service to legal advocacy, lobbying for legislative change, and civil disobedience. NGOs range in size from small groups within a particular community to huge membership groups with a national or international scope. Orthodox Seed Seed that can be dried to moisture levels between 4 and 6 percent and kept at low temperatures. Parataxonomists Field-trained biodiversity collection and inventory specialists recruited from local areas. Patent A government grant of temporary monopoly rights on innovative processes or products. Pathogen A disease-causing microorganism; a bacterium or virus. Phenotype The morphological, physiological, biochemical, behavioral, and other properties of an organism that develop through the interaction of genes and environment. (See genotype.) Phylogenetic Pertaining to the evolutionary history of a particular group of organisms. Phylum In taxonomy, a high-level category just beneath the kingdom and above the class; a group of related, similar classes. Population A group of individuals with common ancestry that are much more likely to mate with one another than with individuals from another such group. Predator Control A predator-prey interaction in which the predator controls the prey population size; that is, in which the predator population is the limiting factor for the prey population size. Primary [or natural] forest A forest largely undisturbed by human activities. Primary Productivity The transformation of chemical or solar energy to biomass. Most primary production occurs through photosynthesis, whereby green plants convert solar energy, carbon dioxide, and water to glucose and eventually to plant tissue. In addition, some bacteria in the deep sea can convert chemical energy to biomass through chemosynthesis. Primary production refers to the amount of material produced. Net primary production is the measure of the actual accumulation of biomass after some of the products of photosynthesis (or chemosynthesis) are expended for the plant's own maintenance. Productivity, or the rate of production, is affected by various environmental factors, including the amount of solar radiation, the availability of water and mineral nutrients, and temperature. (See "Biodiversity in Ecosystems") Protected Area A legally established land or water area under either public or private ownership that is regulated and managed to achieve specific conservation objectives. Recalcitrant Seed Seed that does not survive drying and freezing. Rehabilitation The recovery of specific ecosystem services in a degraded ecosystem or habitat. Restoration The return of an ecosystem or habitat to its original community structure, natural complement of species, and natural functions. Seedbank A facility designed for the ex situ conservation of individual plan varieties through seed preservation and storage. Selection Natural selection is the differential contribution of offspring to the next generation by various genetic types belonging to the same populations. Artificial selection is the intentional manipulation by man of the fitness of individuals in a population to produce a desired evolutionary response. Species A group of organisms capable of interbreeding freely with each other but not with members of other species. Species Diversity A function of the distribution and abundance of species. Approximately synonymous with Species Richness. In more technical literature, includes considerations of the evenness of species abundances. An ecosystem is said to be more diverse, according to the more technical definition, if species present have equal population sizes and less diverse if many species are rare and some are very common. (See "Relative Number of Described Species in Major Taxa.") Species Richness The number of species within a region. A term commonly used as a measure of Species Diversity, but technically only one aspect of diversity. (See "Tropical Forest Species Richness" and "Coral Reef Species Richness.) Stability A function of several characteristics of community or ecosystem dynamics, including the degree of population fluctuations, the community's resistance to disturbances, the speed of recovery from disturbances, and the persistence of the community's composition through time. Subspecies A subdivision of a species; a population or series of populations occupying a discrete range of differing genetically from other subspecies of the same species. Succession The more or less predictable changes in the composition of communities following a natural or human disturbance. For example, after a gap is made in a forest by logging, clearing, fire, or treefall, the initial (or "pioneer") species are often fast-growing and shade-intolerant. These species are eventually replaced by shade-tolerant species that can grown beneath the pioneers. If a community is not further disturbed, the outcome of the successional sequence may be a so-called climax community whose composition is unchanging. In practice, many communities are frequently disturbed and may never reach a climax composition. Sustainable development Development that meets the needs and aspirations of the current generation without compromising the ability to meet those of future generations. Systematics The study of the historical evolutionary and genetic relationships among organisms and of their phenotypic similarities and differences. Taxon (pl. taxa) The named classification unit (e.g. Homo sapiens, Hominidae, or Mammalia) to which individuals, or sets of species, are assigned. Higher taxa are those above the species level. Taxonomy The naming and assignment of organisms to taxa. Trophic Level Position in the food chain, determined by the number of energy-transfer steps to that level. Variety See Cultivar. Vascular Plants Plants with a well-developed vascular system that transports water, minerals, sugars, and other nutrients throughout the plant body. Excludes the bryophytes: mosses, hornworts, and liverworts. Related Sites: Botanical Glossaries (Australian National Botanic Gardens) Talking About Biodiversity: Terms (World Resources Institute) "Kids Action: Glossary" (Rainforest Action Network) Multi-volume, multimedia virtual glossary of biological terms (The Museum of Paleontology, University of California at Berkeley) Mapping Our Genes Glossary (U.S. Office of Technology Assessment) The Origin of Species Glossary (Charles Darwin/W.S. Dallas)