| rare species | A species of animal or plant that is considered rare, threatened, or endangered. (17 Dec 1997) |
|---|---|
| reactive oxygen species | Reactive intermediate oxygen species including both radicals and non-radicals. These substances are constantly formed in the human body and have been shown to kill bacteria and inactivate proteins, and have been implicated in a number of diseases. Scientific data exist that link the reactive oxygen species produced by inflammatory phagocytes to cancer development. (12 Dec 1998) |
| sensitive species | <ecology, zoology> Species that can only survive within a narrow range of environmental conditions and whose disappearance from an area is an index of pollution or other environmental change. Those species which rely on specific habitat conditions that are limited in abundance, restricted in distribution, or are particularly sensitive to development. Plant or animal species which are endangered species, or candidate species, protected bird species under endangered species laws and regulations, plant protection laws and regulations, Fish and Game codes, or species of special concern listings and policies, or species recognised by national, state, or local environmental organisations. (18 Nov 1997) |
| species | A taxonomic category subordinate to a genus (or subgenus) and superior to a subspecies or variety, composed of individuals possessing common characters distinguishing them from other categories of individuals of the same taxonomic level. In taxonomic nomenclature, species are designated by the genus name followed by a Latin or Latinised adjective or noun. (18 Nov 1997) |
| species area curve | The curve on a graph produced when plotting the cumulative number of plant species found in a series of quadrats against the cumulative number or area of those quadrats, it is used to determine the number of quadrats sufficient to adequately survey the herbaceous understory. (09 Oct 1997) |
| species group | <zoology> The taxonomic categories species and subspecies. (09 Jan 1998) |
| species indeterminata | <zoology> Undetermined species, one not identifiable with the description for a name already published. Usually given with a generic name only. (09 Jan 1998) |
| species inquirendum | <zoology> A species to be queried, a doubtfully identified species requiring further investigation. (09 Jan 1998) |
| species-specific | Applying only to a particular species, said of effects that vary depending on the species in question. (09 Oct 1997) |
| species-specific antigen | Antigenic components in the tissues and fluids of members of a species of animal, by means of which various species may be immunologically distinguished; e.g., serum albumin of horses is immunologically different from that of man, dogs, sheep, and so on. (05 Mar 2000) |
| species specificity | Restriction of a characteristic or response to the members of one species; it usually refers to that property of the immune response which differentiates one species from another on the basis of antigen recognition, but the concept is not limited to immunology and is used loosely at levels higher than the species. (12 Dec 1998) |
| species tolerance | The insensitivity to a particular drug exhibited by a particular species. (05 Mar 2000) |
| noncommercial species | Tree species that do not normally develop into suitable trees for conventional forest products because of small size, poor form, or inferior quality. (05 Dec 1998) |
| dominant species | <biology, ecology, zoology> For each stratum, dominant species are those that, when ranked in descending rank order and cumulatively totaled, immediately exceed 50 percent of the total dominance measure, plus any additional species comprising 20 percent or more of the total dominance measure for the stratum. (09 Oct 1997) |
| intermediate species | <chemistry> Species formed in a reaction consisting of more than one step. An intermediate is produced in one reaction and consumed in the following reaction. (09 Jan 1998) |