The Bulgarian Biodiversity Portal is a part of the global information exchange network established by the Convention on Biodiversity (Clearing House Mechanism - CHM). Its purpose is to offer directly or provide links to the information on biodiversity you need.
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.
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.
These are externalities in which the external costs or benefits of the resource use are "one way".