Viet Nam’s natural forests are differentiated from planted forests based on the origin of the forest, with natural forests clearly defined as those “existing in nature or restored by natural regeneration”. The natural forest can be categorised into different types and forms based on the extent of stable forest structure (primary forests and secondary forests). Primary forests are the forests which have not yet been or are less influenced by humans or natural disasters and have a relatively stable structure, while secondary forests are forests that are influenced by humans or natural disasters, leading to changes in their structure. Secondary forest includes naturally restored forests, which are forests formed through natural regeneration on land areas that were previously deforested due to agricultural expansion, forest fires or exhaustive exploitation, and post-exploitation forests, which are forests that have undergone the exploitation of timber or other forest products.
 MARD Circular No. 34/2009/TT-BNNPTNT (2009), Article 5; the Law on Forestry (2017), Article 2(6).
Viet Nam defines biological diversity as the abundance of genes, organisms and ecosystems in nature.
 The Law on Biological Diversity (2008), Article 3(5).