From 1962 to 1971 huge areas of primary tropical forest in Vietnam were exposed to spraying of herbicides. Investigating the current condition of ground associations in southern Vietnam and considering the problem of military influence in the form of destruction of tropical forest ecosystems, it is possible to ascertain that significant areas of forests have been destroyed. The most severe damage was observed in former mangrove and light dipterocarp forests. Close, complexly organized forests have survived due to a number of reasons. Our research in primary and human-transformed Vietnam tropical forest ecosystems has shown that forest reactions to human intervention are specific. Reactions are determined by a complex of factors, in particular the species composition of plants, spatial structure of the forest community, presence of the main forest species of trees, phenology and physiology of forest plants, features of forest microclimate, relief, structure of the soil and its hydrology. It is important to emphasize that a huge variety of growth conditions and accordingly a variety of types of tropical forests after full destruction of their structure, have still not regenerated naturally. Paradoxically, the "favorable" tropical climate is the basic factor in the lack of forest recovery, after the other main factor of human interference. Destruction of forest vegetation has resulted in the formation of savanna-like climax herb community which normally would not occur in lowland terrains in Vietnam. These landscapes, formerly covered with trees, have lost forever their primary forest cover.
A.N. Kuznetsov, S.P. Kuznetsova, Phan Luong, Nguyen Dang Hoi
Viet Nam - Russia Tropical Centre
(Proceedings of 3rd National Scientific Conference on Ecology and Biological Resources, Hanoi 22th October 2009 - IEBR)