Tree canopy in Talbot Forest Scenic Reserve, Geraldine. PHOTO: INES STAGER The importance of all types of forests is celebrated internationally on March 21 each year. In 2012, the United Nations dedicated this date to recognise the immense value of forests. What is the definition of a forest? It is an ecosystem characterised by a dense community of trees. It consists of a canopy cover of more than 10%, with trees higher than 5m, covering an area of minimum 0.5ha.