Definition: Degree of defoliation

Category: Forestry

the extent to which trees and plants have lost their leaves or needles, often as a result of exposure to pollutants, in a visually-assessed measure of defoliation of trees, as developed by the United Nations International Cooperative Programme of the Executive Committee for the Convention on Long-range Transboundary Air Pollution in Europe (ICP Forests). This programme monitors the condition of forests in Europe

Damage classes are from 0 to 4, as follows:

Class - Needle/Leaf loss - Degree of defoliation

0  -  up to and including 10%  -  none
1  -  > 10 to 25 %  -  slight (warning stage)
2  -  > 25 to 60 %  -  moderate
3  -  > 60 to < 100 %  -  severe
4  -  100%  -  dead http://epp.eurostat.ec.europa.eu/statistics_explained/index.php/Glossary:Degree_of_defoliation International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests)