GLOSSARY AND ACRONYMS
of terms related to the biodiversity

ultraviolet radiation

Radiation beyond the violet (high energy) end of the visible light spectrum. UV-B is the middle range wave-length of the three UV bands, and is largely absorbed in the Earth's atmospheric ozone layer; prolonged exposure to UV-B can be biologically damaging.

umbrella species

Species whose occupancy area (plants) or home range (animals) are large enough and whose habitat requirements are wide enough that, if they are given a sufficiently large area for their protection, will bring other species under that protection.

unidirectional externality

These are externalities in which the external costs or benefits of the resource use are "one way".

unintended release

Any release of GMOs which is not a deliberate release.

upwelling

A process by which water rises from lower depths into the shallows, usually the result of divergence or offshore currents.

use value

Values obtained through the use of a resource. This includes direct and indirect use values and instrumental values. Preservation in this sense is as much a use as development.

utility function

A description of the way in which the well-being of individuals depends on different combinations of goods and services consumed.