The northern limestone karst landscape mostly belongs to Cao Bang and Ha Giang provinces, which was formed from late Paleozoic era to early Mesozoic era by a number of powerful geological uplifts that raised the extensive highly metamorphosed ancient marine deposits to considerable heights above sea level.An estimate in 2013 indicated that the limestone karsts account for 32% natural area of Cao Bang province, include the northern boundary of Vietnam and China to southeast districts comprising Ha Quang, Thong Nong, Trung Khanh, Ha Lang, Quang Hoa districts.The limestone landscape is characterized by solid rocky massifs, which were dissected into numerous isolated rocky mountain with acute peaks and vertical cliffs interspersed with narrow valleys.
The hot and humid tropical climate, with a lot of rain together with special geological features, have caused a high biodiversity value for the northern limestone mountains of Cao Bang. The flora is abundant in either number of species or taxon and has high density. The landscape is home to many rare and precious plant species, which have both economic and conservation value such as lady slipper orchids – Paphiopedilum spp., Quercus trungkhanhensis, Burretiodendron hsienmu etc. The fauna is characterized by many endemic species, which are only found in the limestone landscape, and many other species have only been studied preliminary for example Eastern black-crested gibbon – Nomascus nasutus, Stump-tailed macaque – Macaca arctoides, Bear – Ursus sp., Serow – Capricornis sp. etc.
Ha Giang remains a relatively large forest area, of which the natural forest is 345,860 ha, where is maintaining many rare and precious animals: large cat – Neofelis nebulosi, Tonkin snub-nosed monkey – Rhinopithecus avunculus, Bear – Ursus sp., macaques etc. and threatened plants: Cunninghamia konishii, Fokienia hodginsii, Burretiodendron hsienmu, Magnolia spp., Cupressus vietnamensis etc. Particularly Tay Con Linh Nature Reserve recorded the presence of 47 mammal and 140 bird species. The Phong Quang special used forest of Vi Xuyen district was classified as a typical protected area system of limestone karst in the Northeast of Vietnam. Ha Giang forest is not only preserving valuable biodiversity but also plays a significant role in protecting the watershed ecological environment of the Northern Delta region. Along with its resources and values, Ha Giang has high potential to become an ideal ecological destination in the North of Vietnam.
The northern limestone karst landscape is facing the risk of serious declining in quality and quantity due to human activities such as grazing, farming in limestone (corn crop), farming under the forest canopy (cultivating cardamom and Lysimachia). Besides, illegal logging and hunting have been taking place even inside protected areas. Its distinctive terrain leads to difficulty in forest restoration and species conservation. On the other hand, the livelihood of local communities highly depends on natural resources.
What is CCD doing?
CCD identified the northern limestone karst landscape as one of our strategic operational areas. CCD has been carrying out research activities and conservation projects for animals and plants such as Cao vit gibbon, slipper orchids in order to contribute to the preservation of its landscape and biodiversity values. In addition, we are also implementing community-based tourism activities to support local livelihood development and reduce their dependence on natural resources.