Conifers play an important ecological and economic role in the forests of the mountains that stretch from the far north of Vietnam and Lao PDR to southern Vietnam and Cambodia. Information about their distribution and ecology is scant with the majority of current information relating to Vietnam where 90% of species are threatened. The mountains of Lao and Cambodia retain large areas of primary forest but are still poorly known despite their importance as refuges of biodiversity.
Since 2000, ICCP staff have been working to document and conserve the conifers of this area. Project partners have included government environmental and forestry organisations, universities, protected area authorities, national IUCN offices and NGOs.
Between 2001 and 2004, ICCP staff coordinated the Darwin Initiative project Preservation, rehabilitation and utilisation of Vietnamese montane forests. Major outputs included a Conservation Status Review of all Vietnamese conifers, bi-lingual field guides for the identification of conifers, edible mushrooms and propagation manuals.
In Lao PDR, ICCP staff also coordinated the recent Darwin Initiative Taxonomic training for a neglected biodiversity hotspot within Lao PDR and produced the first Checklist of the Vascular Plants of Lao PDR. During field work seven conifer species not previously known from Lao PDR were recorded and documented. In Cambodia, ICCP staff carried out the first conifer surveys in Virachay National Park in Ratanakiri Province and the Cardamon mountains. The work in Vietnam and Lao PDR was sponsored by the Darwin Initiative while survey work in Virachay was undertaken on behalf of the World Bank's Biodiversity and Protected Area Management Programme (BPAMP).
An Overview of the Conifers of Cambodia, Lao PDR and Vietnam
Currently, up to 37 taxa from 19 genera have been recorded. Globally this represents ca 5 % of the world's known species and nearly one third of known genera. Four species have been described within the last 15 years. Several species, subspecies and varieties are endemic, while three others are represented by small, isolated populations that are separated by hundreds or thousands of kilometers from other populations of that species. Most other species are either at the southern or most northern part of their range. 40% are listed as globally threatened and northern Vietnam, along with the adjoining parts of Lao PDR is recognised by the IUCN's Conifer Specialist Group as one of the world's ten hotspots for threatened conifers.
In Cambodia, Lao PDR and Vietnam, the conifers are concentrated in five main areas:
Region 1: North-eastern Vietnam (north and east of the Red River): Much of this area consists of heavily eroded limestone mountains with elevations up to 1600m asl. Conifers frequently dominate the upper ridges. The climate is monsoon tropical with cold winter temperatures and summer rains. Endemic taxa: Cupressus tonkinensis. Other taxa: Cephalotaxus mannii, Calocedrus rupestris, Fokienia hodginsii, Keteleeria davidiana, Pinus kesiya, P. wangii subsp kwangtungensis, Pseudotsuga sinensis, Tsuga chinensis, Dacrycarpus imbricatus, Dacrydium elatum, Nageia fleuryi, Podocarpus neriifolius, P. pilgeri, Amentotaxus argotaenia, A. yunnanensis (incl. A hatuyenensis), Taxus calcicola, T. chinensis, Xanthocyparis vietnamensis.
Region 2: Hoang Lien Son massif (Vietnam): The forests of this area tend to be dominated by members of the angiosperm families Fagaceae and Lauraceae. The highest peaks are above 3000m and the climate is generally very wet and cool, with year round rainfall. Endemic taxa: Abies delavayi subsp. fansipanensis. Other taxa: Cephalotaxus mannii, Fokienia hodginsii, Taiwania cryptomerioides, Keteleeria evelyniana, Tsuga dumosa, Dacrycarpus imbricatus, Dacrydium elatum, Nageia wallichiana, Podocarpus neriifolius, Amentotaxus yunnanensis, Taxus chinensis.
Region 3: Northwest Vietnam and northern Lao (Vietnam: Son La to Nghe An; Lao: Phongsali to Khammouan): In this region, elevations tend to be lower than in the Hoang Lien Son massif, and the climate is generally drier. The limestone areas of this region are less diverse in conifer species than those in Region 1. Endemic taxa: Pinus cernua, P. eremitana, P. wangii subsp wangii. Other taxa: Cephalotaxus mannii, Calocedrus rupestris, Cunninghamia konishii, Fokienia hodginsii, Glyptostrobus pensilis, Keteleeria evelyniana, Pinus dalatensis (inc. P. anemophila), P. kesiya, P. wangii subsp kwangtungensis, P. latteri (P. merkusii s.l.), Dacrycarpus imbricatus, Dacrydium elatum, Nageia fleuryi, N.wallichiana, Podocarpus neriifolius, P. pilgeri, Amentotaxus argotaenia, A. yunnanensis, Taxus calcicola, T. chinensis.
Region 4: Central Annamite Ranges, southern Vietnamese Highlands, northeast Cambodia (Vietnam: south from Quang Binh, Lao: south from Savannaket, Cambodia: Ratanakiri and Mondulkiri) : Throughout this area, conifer species are strongly associated with changes in local climate. At lower elevations (600-1600m asl) and with lower rainfall, Pinus kesiya and P. latteri are relatively common; at higher elevations and with higher rainfall members of the Cupressaceae and Podocarpaceae are more common. Endemic taxa:Pinus krempfii. Other taxa: Cephalotaxus mannii, Calocedrus macrolepis, C. rupestris, Fokienia hodginsii, Glyptostrobus pensilis, Keteleeria evelyniana, Pinus dalatensis, P. kesiya, P. latteri, Dacrycarpus imbricatus, Dacrydium elatum, Nageia wallichiana, Podocarpus neriifolius, Amentotaxus poilanei, Taxus wallichiana.
Region 5: Southwest Cambodia (Elephant and Cardamom Mountains): This area is separated from the main Annamite ranges (Regions 2-4) by the Mekong and its associated delta and plains. Maximum altitudes reach 1771m and the climate has a strong monsoonal influence with some areas receiving more than 4000mm rainfall. Endemic taxa: none. Other taxa: Pinus kesiya, P. latteri, Dacrydium elatum, Dacrycarpus imbricatus, Podocarpus neriifolius, P.pilgeri and Nageia wallichiana). The Podocarps tend to be associated with wet, poorly drained areas at a range of elevations but most commonly above 500m asl. Pinus latteri is relatively widespread while Pinus kesiya is only known from a single location.