Study on distribution and natural regeneration of Dalbergia cochinchinensis and Dalbergia oliveri in Dong Nai and Dak Lak provinces
Center for Nature Conservation and Development (CCD) is implementing a program to support protection and restoration efforts of wild endangered species. CCD priorities the strengthening of research, monitoring and law enforcement to effectively prevent illegal hunting, exploitation and trade of wild plants and animals of Vietnam and other countries being illegally transported and traded in Vietnam.
Following the research on distribution and natural regeneration assessment of Dalbergia cochinchinensis and Dalbergia oliveri in Kon Tum and Binh Phuoc provinces which were conducted during March and April, the similar research was implemented in Cat Tien National Park (Dong Nai province) and Yok Don National Park (Dak Lak province) in May and early Jun of 2020.
The survey results in the Southern of Cat Tien National Park reveal that there is only Vietnamese rosewood (Dalbergia oliveri) distributed naturally with an average density of trees whose diameter at breast height (DBH) from 6cm and above is approximately 6,8 trees/ha, average density of seedlings is 12,3 individuals/ha. Among 1,544 seedlings were recorded in all survey transects, the potential seedlings accounting for 39.31% while regeneration rate from seeds is 88.34%. The high regeneration rate from seeds indicates the potential for genetic diversity in the population and becomes an advantage for long-term conservation and restoration. D. oliveri was recorded in three types of forest in Cat Tien National Park consists of evergreen broad-leaf forest; semi-deciduous forest dominated by Lagerstroemia; bamboo-tree mixed forest. This species is one of the dominant species that plays an important role in the canopy structure of habitats in study areas.
In Yok Don National Park, Dalbergia cochinchinensis and D. oliveri were recorded in the same habitat. D. cochinchinensis currently distributes in some specific small areas in the park, trees’ density with DBH from 6cm and above is 0,7 tree/ha, density of seedlings is 4,3 individuals/ha. Of which shoot regeneration rate is 88.98%, regeneration rate from seeds is 11.02% and the potential seedlings accounting for 47.45%. Regarding to D. oliveri, the average density of trees (DBH>6cm) is 2,9 trees/ha, the average density of regenerated tree is 21,6 individuals/ha. Regenerated trees are mainly shoot regeneration growing after forest fire at the rate of 91.44% whereas regeneration rate from seed is only 8.56%. The non-potential seedlings were majority, accounting for 87.28%. However, Yok Don National Park is characterized by dry dipterocarp forest along with the intensive damages of forest fires in dry season that drives regenerated trees of Dalbergia difficult to grow into mature trees.