Study on distribution and natural regeneration of Dalbergia cochinchinensis and Dalbergia oliveri in Kon Tum and Binh Phuoc provinces
Rosewood species (Dalbergia spp.) are high economic value and have been the most illegal logging and trading in Vietnam and Indochina region. As a result, many wild populations of rosewood species have been depleted in majorities of localities in Vietnam; few populations remained in specific protected areas are being threatened. Dalbergia cochinchinensis and Dalbergia oliveri are being protected by national and international laws and regulations such as Decree 06/2019/ND-CP dated on 22 January 2019 (Group IIA) and Convention on International Trade in Endangered Species (CITES) (Annex II).
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.
During March and April 2020, CCD conducted a distribution survey and regeneration assessment of D. cochinchinensis and D. oliveri in Dak Uy protected area (special use forest/SUF) of Kon Tum province and Bu Gia Map national park of Binh Phuoc province. Although the survey was affected by the COVID-19 pandemic and governmental social distancing policies, the survey team completed the field trips as expected schedule.
Findings of D. cochinchinensis in Dak Uy SUF revealed that density of trees with diameter at breast height (DBH) from 6 cm and above is approximately 15 trees/ha; density of seedlings are about 35 individuals/ha, of which potential seedlings are 27 individuals/ha, accounting for 76% – relatively high. Shoot regeneration rate is about 56.7% and regeneration rate from seeds is 43.3%. In terms of tree species composition, D. cochinchinensis dominates amongst the average of 17 other tree species in each established sample plot. There is no record of the existence of D. oliveri in Dak Uy forests.
The survey of D. oliveri in Bu Gia Map national park resulted that tree density with DBH from 6 cm and above is 7.6 individuals/ha; density of seedlings is more than 5.6 individuals/ha, of which potential seedlings are about 2.8 individuals/ha, equivalent to 49%. Shoot regeneration rate is 55.7% and seed originated regeneration is 44.3%. Amongst the average of 24 tree species per plot, D. oliveri accounts for a small percentage of 5.8%. Not any D. cochinchinensis was recorded in Bu Gia Map national park.
The following are photographs of the two surveys.
