A term used to describe surviving remnants of natural phenomena. It often refers to ancient species which have survived while others become extinct.
|Radiation dating techniques||Scientific methods of dating materials, e.g. rocks, by examining the comparative decay times of radioactive isotopes of elements. Early techniques were based on rubidium and strontium; more recent techniques utilise lead and uranium|
|Raptors||A collectively term for birds of prey, including owls|
|Red Data book||The official lists of UK species (plants, mammals, birds etc.) of highest conservation value/concern|
|Regeneration||The continuation/replacement of a woodland by self–seeding – through seed from existing, or felled/burnt trees in the same area. Does not involve planting|
|Reintroduction||The re–establishment of a species to a country after it has become extinct: a controversial practice that not everyone believes is ecologically justifiable or achievable|
|Responsible access||A term currently used within the access debate, referring to access, by individuals or groups, undertaken voluntarily in a responsible manner, and thereby acceptable to landowners/managers|
|River capture||The process by which the headwaters of a drainage system become redirected into another drainage system as a consequence of the breaching of a watershed|
|River terraces||Flat, terrace–like landforms along rivers remnants of past floodplains, at times of higher sea levels|
Runoff is a term used to describe the water, from rain, snowmelt or irrigation, that flows over the land surface and is not absorbed into the ground, instead flowing into streams or other surface waters or land depressions.