Glossary
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[B] [C]
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[H] [I]
[J] [K]
[L] [M]
[N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z]
[N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z]
T
- Taiga
- The coniferous forest that extends across much of North America and Eurasia bounded by tundra to the North and by steppe to the south.
- Tannins
- Complex astringent substances containing phenolic compounds found in plants and usually making the plant material less readily digested. Especially common in bark, unripe fruits and galls on woody plants.
- Taxonomy
- The study of the rules, principles and practice of classifying living organisms.
- Tectonic plate
- An area of the earth's crust which moves during geological time resulting in continental drift and other major changes in the topography of the surface of the globe.
- Temperature coefficient
- see Q10.
- Temporal variation
- Variability in conditions, such as temperature, on an hourly, daily or seasonal basis.
- Terpenoids
- Aromatic hydrocarbons formed by many plants and responsible for many of the plant scents.
- Territoriality
- The establishment by an animal or animals of an area from which other individuals are partially or totally excluded.
- Tertiary
- A geological era lasting from approximately 65 to 2 million years ago.
- Thermoneutral zone
- The range of environmental temperatures for an endotherm over which it has to exert the minimum metabolic effort in order to maintain a constant body temperature.
- Thinning line
- The line on a plot of log mean individual weight against log density along which self-thinning populations of a sufficiently high biomass tend to progress, and beyond which they cannot pass.
- Third generation insecticides
- Synthesized, usually organic insecticides, which are nevertheless produced with the aim of minimizing the impact on non-pest, non-target species.
- Tiller
- A branch formed at or near ground level by grasses and sedges.
- Time-delay population model
- A model of population growth in which the net reproductive rate of individuals currently is determined by the population size some time previously.
- Tolerance (successional)
- Where modification of the environment by early occupants has little or no effect on subsequent performance of late-successional species.
- Topography
- Representation of the physical structure of an environment.
- Transfer efficiency
- Efficiency with which energy is passed through various steps in the trophic structure of a community.
- Transgenic
- An organism containing a gene which has been artificially transferred from a member of another species.
- Transient polymorphism
- The occurrence of two (or more) forms of a species or of genes (alleles) within a population while one form is being replaced by another.
- Transmission threshold
- The basic reproductive rate of a parasite that is a necessary condition for a disease to spread.
- Transpiration
- The evaporation of water from a plant surface.
- Triassic
- A geological era lasting from approximately 250 to 213 million years ago.
- Trichome
- Single- or many-celled outgrowth from the epidermis of a plant. A plant hair.
- Trophic level
- Position in the food chain assessed by the number of energy-transfer steps to reach that level.
- Trophic structure
- The organization of a community described in terms of energy flow through its various trophic levels.
- True predator
- A predator which kills other organisms (their prey) more or less immediately after attacking them, killing several or many over the course of its lifetime.
- Tundra
- The biome that occurs around the Arctic circle, characterized by lichens, mosses, sedges and dwarf trees.
- Turbulence
- Fluid flow in which the motion at any point varies rapidly in direction and magnitude.
- Turgor
- The distention of living tissue due to internal pressures.
