Main threats and examples

Published by the Norwegian Environment Agency Lag rapport Les på norsk



Physical disturbance Mainly various types of construction, for example building houses and roads, watercourse regulation, draining of watercourses, extraction of minerals and deposits and construction of power lines.  
Land use Mainly a result of agricultural and forestry activities. Changes in agricultural methods include the introduction of modern techniques, e.g. drainage, cultivation and fertilization of new land, ploughing of previously unploughed land, new crop strains, use of pesticides and the abandonment of traditional methods (e.g. disuse of pastures and hey meadows, which become overgrown). In forestry threats can be due to clear-cutting, pesticide use, introductions of alien tree species, drainage, afforestation, removal of dead wood, forest fires, disturbance and destruction of vulnerable areas through  increased traffic and wear and tear etc.  
Excessiv harvesting Refers mainly to overfishing of marine waters, and the resulting lack of food for other marine species. May also include unintentional catches of fish in fishing nets, faunal crime and collection of excessive numbers of animals or plants.  
Pollution  All kinds of pollution that exceed the tolerance limits of nature. In particular oil pollution, emissions of hazardous substances like heavy metals and pesticides, and eutrophication.  
Spread of alien species Introduction and spread of alien species to Norway or parts of the country, which results in  competition between alien and native species or predation of native species. Also includes the spread of alien diseases.  
Other  Includes factors that influence species outside Norway’s borders, either on migration or in their overwintering areas. Also includes any other factor not included in the preceding categories.