field expeditions

October–November 2008: GWC conducted an expedition to assess biodiversity and identify priority sites for biological conservation in southwest Cambodia.

The Cardamom Mountains region of southwest Cambodia is one of the largest wilderness areas remaining in mainland Southeast Asia. This region preserves a remarkable number of globally threatened species, many of which have been extirpated from other parts of their ranges. However, without proper conservation and protection, this area and its biodiversity are susceptible to human threats, including logging and poaching.

The Cardamom Mountains contain approximately 1,870,000 hectares of dense forest cover, rivers and streams, coastal wetlands, and mangrove forests. The region consists of three main massifs, Mount Samkos, the Central Cardamom Mountains, and Mount Aural. Elevation ranges up to 1,771 meters (Mount Aural), with a variety of natural forest types according to altitude, aspect, geology and hydrology, including dry deciduous forest, semi-deciduous forest, lowland evergreen forest, hill evergreen forest, bamboo thickets and pine forest. The region also contains sizeable areas of natural marshes and grassland. Human density is very low, with the vast majority of settlements confined to lowland areas nearby rivers. This area is also the key watershed for the western section of Cambodia, providing water supply, climate regulation, and abundant fisheries for hundreds of thousands of people.

There is partial protection of the range, including the Mount Samkos Wildlife Sanctuary (3,338 km2) and the Mount Aural Wildlife Sanctuary (2,536 km2). In between these two protected areas, much of the Central Cardamom Mountains has been designated as the Central Cardamoms Protection Forest. The Cardamom Mountains region also contains significant natural areas down to the coast of the Gulf of Thailand.

Most protection efforts have concentrated on the aforementioned areas, which primarily cover forests at middle to high elevations. There has been surprisingly little attention to the lowlands, which form a relatively narrow band between the Cardamom highlands and the Gulf of Thailand. A patchwork of protected areas also covers these lowlands including the Peam Krasop NP, Ream NP, Botum Sakor WS, Southern Cardamom Protection Forest, and Dong Peng Multiple Use Area.

Until recently, the majority of Cambodia was under security risk, which, combined with poor infrastructure, prevented access to forests except for limited areas of the country, such as the northeast (Desai and Vuthy, 1996; Timmins and Soriyun, 1998; FFI, 2000). The Cardamom Mountains was one of the last refuges for Khmer Rouge, making most of the area inaccessible until recently.

The majority of the Cardamom Mountains region remains unexplored, and the status and distribution of most species remains entirely unknown. There has been very little survey work conducted in the region, and most has focused on the highlands, other localized sites, or a few focal species. These surveys have, however, found very significant populations of global significance for a suite of large highly threatened vertebrates including Siamese crocodiles (Crocodylus siamensis), Asian Elephants (Elephas maximus) and Asian arowana (Scleropages spp). The lowlands have received little attention, with some brief surveys for birds, otters, turtles (Mundkur et al. 1995; Goes et al. 1998; Tordoff et al. 2005; Holloway 2003), all of which have provided evidence that in particular the wetlands in the lowlands could be very important for global biodiversity conservation. It is also very clear that the lowlands, much more so than the highlands, are under considerable threat from a range of factors including population in migration, infrastructural development, tourism development, agriculture and silviculture, and hunting to supply highly lucrative wildlife markets both nationally and internationally. Although not all of this lowland area can be conserved, there is a very urgent need to assess conservation priorities. This assessment will enable informed conservation decisions based on prioritization of species and locations.

This project’s main pursuit will be detailed biodiversity surveys primarily of the lowlands, between Peam Krasop NP and Ream NP and including the Botum Sakor WS, Southern Cardamom Protection Forest, and Dong Peng Multiple Use Area areas, with the aim of identifying conservation needs and priority species and sites. Botum-Sakor National Park (176,900 hectares) was established in 1993, but little is known about its fauna or flora apart from general information gleaned from satellite images. Satellite images in 1988-1989 indicated that approximately 87% of the area was in a natural or semi-natural state, with a large expanse of dense evergreen forest and significant areas of mangroves, dunes, and aquatic plant formations. Images from 2002 showed the area remaining in relatively good natural condition. However, Botum Sakor is at serious risk for tourism development in the next few years. Peam Krasop Wildlife Sanctuary consists of 26,000 hectares of coastal wetland, including mangrove and melaleuca forests. Peam Krasop, and the coastal seasonally inundated forests found between it, and Botum Sakor are likely to be of global biological importance for a suite of wetland and grassland species. These areas add significant conservation value to the protected area network in southwest Cambodia, with several species suspected to not be found elsewhere in the Cardamom Mountains region.

These areas could include significant populations of large waterbirds, including Milky Stork (Mycteria cinerea), Greater Adjutant (Leptoptilos dubius), White-shouldered Ibis (Pseudibis davisoni), White-winged Duck (Cairina scutulata), and Masked Finfoot (Heliopais personatus). In addition, there thought to be significant populations of Smooth-coated Otters (Lutrogale perspicillata) and possibly also Hairy-nosed Otter (Lutra sumatrana) and at least five turtle species including globally important populations of Mangrove Terrapins (Batagur baska) and Yellow-headed Temple Turtle (Heosemys annandalii). The area provides a crucial site for freshwater fish breeding and feeding grounds, as well as populations of dolphins within the rivers. Currently, there are teams surveying and monitoring otters and turtles. There is no other planned work underway on other aspects of the region’s biodiversity, and an urgent need for more extensive surveys. There are virtually no actual detailed biological data, and no in-depth surveys of note. In fact, all previous work has been brief and superficial (e.g., Goes et al. 1998).

The current conservation plans for the area from Botum Sakor to Peam Krasop are focusing on including the area in a ridge-to-reef conservation approach, with some species-specific conservation efforts in localized areas for the Siamese Crocodile, Asian Elephant and Asian Arowana. A need to examine the upstream hydro-dam impacts, especially on the wetlands and coastal habitats, has been identified. There is some work with the Asia Development Bank to demarcate the area as a key site for conservation management within the region’s development corridor. There is a large knowledge gap in this key area that is under high and increasing development pressure, with real opportunities for conservation if science exists to argue for its unique status. Biological survey information will be used in detailed prioritization assessments, and will feed into strategies for conservation of these unique ecosystems containing key species.

A useful perspective about the cultural history and current status of the coastal Cambodia human population was recently written in a New York Times article.