With implementation of Decision No.45/QĐ-TTg dated January 08th 2014 of the Prime Minister, the Phia Oac-Phia Den Nature Conservation Area in Nguyen Binh district will be expanded and upgraded into a National Park to better protect its outstanding natural landscape, diverse ecosystems and geoheritage values.
Phia Oac-Phia Den National Park has complex segmented terrains that are characterized by narrow valleys and high, steep mountains with the slope of over 38o. Many mountains are 1000m to nearly 2000m asl; for example, Phia Oac (1935m), which is the second highest mountain in Cao Bang, Niot Ti mountain (1574m), Tam Loang (1446m), Phia Den (1391m) and Ki Doan (1165m). Geologically, this area is a mixture of terrigenous, karst and granite intrusive rocks, resulting in a mixture of karst and non-karst landforms. The diversity of topography, geomorphology and geology, together with unusual local climatic conditions, creates special natural ecosystems.
According to local folk tales, a long time ago this mountain was named “Mậy Vác”. Mậy in Tay language means a tree, and “Vác” is the name of the tree. The tree is scientifically named Vù Hương “Cinnamomum parthenoxylon”, and it is a species of high economic value because of its high oil content in the roots, stem, bark, leaves and seeds. The timber is of high quality and is not subject to termite attack. It also has a pleasant smell, so it is very popular in the market. This is an endemic species that is recorded in Vietnam Red Book (2007) at the critically endangered level. In the early 20th century this mountain caught the eyes of the French. They chose Phia Oac-Phia Den for vacations, enjoying climate and unique biological resources.
Primitive forests in Phia Oac – Phia Den area
Today one can find vestiges of villas that are guest houses of officers dating from the French period. This forest still retains abundant primary features, especially the high-altitude sub-tropical evergreen rainforest ecosystem, the mid-altitude sub-tropical evergreen rainforest ecosystem, and mixed timber-bamboo forests with four-layered structure covering large areas. Some ecosystems are specific to high altitude environment, such as the dwarf forest and moss forest ecosystems.
Among the thousands of plant species are some which have high economic and conservation value, such as vù hương (Cinnamomum parthenoxylon), Indian mahogany (Chukiasia tabularis), sến mật (Madhuca pasquieri), iron wood, dẻ tùng (Amentotaxus argootaenia) and many precious medicinal plants. Also orchid populations as well as various fruit trees, including trám trắng (Canarium album) and trám đen (Canarium tramdeum), Brindle berry, dọc (Garcinia multiflora), dâu da (Baccaurea), lychee, longan, fig, and tamarind.
The healthy evergreen forests provide ideal wildlife habitat. Of the known animals and birds there are 80 species of mammals, hundreds of species of bird, reptile and amphibians, thousands of insect (beetle, butterfly, dragonfly) and aquatic species in rivers and streams. Rare species recorded in the 2007 Vietnam Red Book and the 2010 World Red Book include: musk deer (Moschus berezovski caobangensis), chamois (Naemorhedus sumatrensis), big sloth-monkey (Nycticebus coucang), small sloth-monkey (Nycticebus pygmaeus), vượn đen đông bắc (Nomascus concolor), khỉ cộc (Macaca arctoides), Asian black bear (Ursus thibethanus), Prionodon pardicolor, Viverricula malaccensis, Prionailurus bengalensis, cầy sao (Prionodon pardicolor), small Indian civet, wildcat, flying squirrel with white tail, sóc bay sao (Petaurista elegans), white pheasant (Lophura nycthemera), gà so ngực sụ (Arborophia charltoni), cobra (Naja naja), rắn sọc dưa (Colecognathus radiara), trăn đất (Python molurus), Elongated tortoise (Indotestudo elegata), rùa hộp ba vạch (Cuora trifasciata), kỳ đà nước (Varanus solvator), sa giông Việt Nam (Tylototriton vietnamensis), gecko (Gecko gecko), and ếch cây sần (Theloderma corticule). There are also rare species of butterfly: bướm phượng đuôi kiếm răng tù (Teinopalpus imperialis), bướm phượng đuôi kiếm răng nhọn (Teinoplpus aureus), five-horned rhinoceros beetle (Eupatorus graciticornis), and hundreds of aquatic species of high economic value.
These species are highly valuable biodiversity resources that are few in number in Vietnam. Moreover, Phia Oac-Phia Den is also the important watershed of Nguyen Binh and neighboring regions. It is the green curtain that contributes to reducing extreme climate phenomena, and is the green membrane that filters noise, emissions, waste water, and solid wastes from mining activities. It also contributes to reducing natural disasters such as landslide, erosion and flooding. Forest and biodiversity values of Phia Oac-Phia Den National Park have much potential to develop ecotourism and research. Together with the spiritual and aesthetic values, this is a lively space that can greatly contribute to the discovery and improvement of knowledge on the values of natural systems, as well as cultural identification of local people, increasing the love of nature, country, and homeland of the communities in the historical land of Cao Bang.