Primary Forest
Definition
See Mature (climax) forest.
Source
"Glossary", FOREST RESTORATION RESEARCH UNIT, 2008. "Research for Restoring Tropical Forest Ecosystems: A Practical Guide". Biology Department, Science Faculty, Chiang Mai University, Thailand. http://www.forru.org/PDF_Files/rfrtfpdf/rfrtfappendix.pdf
Alternative definition
Naturally regenerated forest of native species, where there are no clearly visible indications of human activities and the ecological processes are not significantly disturbed.
Alternative source
Terms and Definitions - FRA 2015, Forest Resources Assessment Working Paper 180, FAO, 2015 (http://www.fao.org/docrep/017/ap862e/ap862e00.pdf).