Ecosystem Profile: Indochina

Conservation Outcomes
Biological diversity cannot be saved by ad hoc actions (Pressey 1994). In order to support the delivery of coordinated conservation action, CEPF is investing effort in defining conservation outcomes: the quantifiable set of species, sites, and corridors that must be conserved to maximize the long-term persistence of global biodiversity. By presenting quantitative and justifiable targets against which the success of investments can be measured, conservation outcomes allow the limited resources available for conservation to be targeted more effectively, and their impacts to be monitored at the global scale. Therefore, conservation outcomes form the basis for identifying biological priorities for CEPF investment in Indochina.

Biodiversity is not measured in any single unit but, rather, is distributed across a hierarchical continuum of ecological scales (Wilson 1992). This continuum can be condensed into three levels: species, sites and corridors (inter-connected landscapes of sites). These three levels interlock geographically, through the occurrence of species at sites and of species and sites in corridors, but are nonetheless identifiable. Given threats to biodiversity at each of the three levels, quantifiable targets for conservation can be set in terms of Extinctions Avoided (species outcomes), Areas Protected (site outcomes), and Corridors Created (corridor outcomes).

Conservation outcomes are defined sequentially, with species outcomes defined first, then site outcomes and, finally, corridor outcomes. Since species outcomes are extinctions avoided at the global level, they relate to globally threatened species (in the IUCN categories Critically Endangered, Endangered, and Vulnerable). This definition excludes data deficient species, which are considered to be priorities for further research but not necessarily for conservation action per se, as well as species threatened locally but not globally threatened, which are considered to be national or regional conservation priorities but not high global priorities. Species outcomes are met when a species' global threat status improves or, ideally, when it is removed from the Red List.

Because of the CEPF focus on global biodiversity hotspots, it is crucial that the process used to derive conservation targets for CEPF is based on a global standard. The principal basis for defining species outcomes for this document is the global threat assessments contained within The 2002 IUCN Red List of Threatened Species (IUCN 2002a), which represented the best available data source on the global conservation status of species at the time the expert roundtables were held in 2003. For amphibians, the results of the Global Amphibian Assessment (IUCN-SSC and CI-CABS 2003), which has completed threat assessments and prepared distribution maps for most Old World amphibian species, are used. Furthermore, for certain bird species, recent re-assessments of their global threat status contained within Globally Threatened Bird Updates (BirdLife International 2003b) are used. Local experts review draft lists of globally threatened species based on these sources to confirm which species occur in the region of analysis.

Given that many species are best conserved through the protection of a network of sites at which they occur, the next stage is to define a set of "key biodiversity areas," important for the conservation of species, which form the basis for species outcomes. The most important criterion for defining key biodiversity areas is the regular occurrence of significant numbers of one or more globally threatened species. The major challenge here is to determine whether a given threatened species recorded at a given site regularly occurs in significant numbers. In most cases, in the absence of detailed data on population size and minimum area requirements, it is necessary to make a provisional assessment, based on a consideration of the ecological requirements, density and home-range size of the species in question, and the availability of suitable habitat at the site.

In addition to the occurrence of globally threatened species, key biodiversity areas are also defined on the basis of the occurrence of restricted-range species and congregatory species. Sites regularly supporting significant populations of restricted-range species are global conservation priorities, because there are few or no other sites in the world for which conservation action for these species can be taken. This criterion is only used to define key biodiversity areas for birds, as this is the only group for which the concept of restricted-range species has been quantitatively defined: species with a global breeding range of less than 50,000 km2 (Stattersfield et al. 1998). Sites supporting a high proportion of the total population of one or more congregatory species at a particular time of year (for example, breeding, wintering, and staging sites for migratory waterbirds) are conservation priorities because these species are particularly susceptible to threats at these sites. Again, this criterion is only used to define key biodiversity areas for birds, as this is the only group for which comprehensive population estimates for congregatory species are available (Wetlands International 2002); a threshold of 1 percent of the Asian biogeographic population is used.

Site outcomes are met when a key biodiversity area is protected, through improved management or expansion of an existing conservation area, or creation of a new conservation area. Improved management of an existing conservation area will involve changing management practices for a key biodiversity area, in order to improve the long-term conservation of species' populations and the ecosystem as a whole. Expansion of an existing conservation area will involve increasing the proportion of a key biodiversity area under conservation management to meet species' area requirements or include other previously excluded species or habitats. Creation of a new conservation area will involve designating all or part of a key biodiversity area as a conservation area, and initiating effective long-term management. Conservation areas are not limited to actual or potential protected areas but also include sites that could potentially be managed for conservation by local communities, private landowners, military units, or other stakeholders.

The starting point for defining key biodiversity areas in Indochina was the Important Bird Area (IBA) networks in each country, identified by BirdLife International and collaborating organizations (Tordoff 2002, Ounekham and Inthapatha 2003, Seng Kim Hout et al. 2003, R. Pimathai in litt. 2003, S. Chan in litt. 2003). As the IBA networks included most key sites for the conservation of globally threatened, restricted-range and congregatory bird species, it was only necessary to supplement them through the definition of additional key biodiversity areas for other taxonomic groups. This was done through consultation with local experts in each country, complemented by literature review.

While the protection of a network of sites would probably be sufficient to conserve most elements of biodiversity in the medium term, the long-term conservation of all elements of biodiversity requires the protection of inter-connected landscapes of sites or conservation corridors. This is particularly important for the conservation of broad-scale ecological and evolutionary processes (Schwartz 1999), and also for the conservation of species with wide home ranges, low natural densities, migratory behavior or other characteristics that make them unlikely to be conserved by site-based interventions alone. Such species are termed landscape species (Sanderson et al. 2001). In addition, conservation corridors can support the integration of habitat management consistent with conservation objectives (ranging from strict protection to sustainable use) into local, regional, and national land-use planning processes. Consequently, corridor outcomes are defined, based on conservation corridors, in addition to site and species outcomes.

Corridor outcomes are met when a conservation corridor maintains intact biotic assemblages and natural processes. Maintaining intact biotic assemblages requires the maintenance of intact ecological communities, a prerequisite for which is the conservation of landscape species. Maintaining natural processes involves achieving the long-term sustainability of intact ecological and evolutionary processes that are species-driven and essential for the long-term viability of natural ecosystems.

In order to allow the persistence of biodiversity, inter-connected landscapes of sites must be anchored on core areas, embedded in a matrix of natural and/or anthropogenic habitats (Soulé and Terborgh 1999). Therefore, conservation corridors are anchored on key biodiversity areas (core areas), with the rest of the conservation corridor comprising either areas that have the potential to become key biodiversity areas in their own right (through management or restoration) or areas that contribute to the ability of the conservation corridor to support all elements of biodiversity in the long term.

Therefore, key biodiversity areas are the starting point for defining conservation corridors. First, conservation corridors are defined wherever it is considered necessary that connectivity be maintained between two or more key biodiversity areas in order to meet the long-term conservation needs of landscape species. Then, additional conservation corridors are defined wherever it is considered necessary to increase the area of actual or potential natural habitat in order to maintain evolutionary and ecological processes. In the latter case, the definition of conservation corridors is largely subjective, due to limitations of time, lack of relevant data, and absence of detailed criteria. Given these limitations, emphasis is placed on maintaining continuums of natural habitat across environmental gradients, particularly altitudinal gradients, in order to maintain such ecological processes as altitudinal migration of bird species, and to provide a safeguard against the potential impacts of climate change.

Conservation corridors are defined through consultation with local experts, complemented by analysis of spatial data on land cover, elevation and human population distribution, and consideration of the results of previous landscape-scale conservation planning exercises. In Indochina, the results of an ecoregion-based conservation assessment conducted in Cambodia, Lao P.D.R. and Vietnam by WWF (Baltzer et al. 2001) and an analysis of forest complexes in Thailand conducted by the Royal Forest Department (1999) were the key sources of information for defining conservation corridors. Because natural habitats are more fragmented in Indochina than in many other regions, the average conservation corridor size was relatively small. One consequence of this was that a relatively large number of conservation corridors were defined, with the benefit that CEPF funding could be more precisely targeted geographically.

In theory, within any given region, or, ultimately, for the whole world, conservation outcomes can be defined for all taxonomic groups. However, this is dependent upon the availability of data on the global threat status of all taxa, and on the distribution of globally threatened species among sites and across corridors. In Indochina, because these data were only available for mammals, birds, amphibians, and, to a lesser degree, reptiles, fish, and plants, conservation outcomes were only defined for these groups.

The approach of using global threat assessments as the basis for defining species outcomes, and, consequently, site and corridor outcomes, has a number of limitations, the most serious being that these assessments are incomplete for many taxonomic groups. However, taxonomic groups for which comprehensive global threat assessments have been completed, particularly birds, have been shown to be effective indicators of biodiversity in general, especially when used to define networks of priority sites for conservation (Howard et al. 1998, Burgess et al. 2002). Furthermore, the definition of conservation outcomes is an adaptive process: As more species are assessed as globally threatened, additional conservation outcomes can be defined.

Species Outcomes
A total of 492 globally threatened species occur in Indochina, comprising 60 mammal species, 73 bird species, 33 reptile species, 46 amphibian species, 32 fish species and 248 plant species (Table 1 and Appendix 1). To date, global threat assessments have not been conducted for any invertebrate species that occurs in the region, although this should not be taken as an indication that the group is a low conservation priority. Certain invertebrate groups, for instance several cave-dwelling taxa, are characterized by high levels of endemism but also high levels of threat; although huge gaps remain, there have been great increases in knowledge on such species during recent years (Deharveng 2002). Also for many vertebrate and plant groups, global threat assessments are far from comprehensive. For example, global threat assessments have not been conducted for any member of the Orchidaceae family, a group of plants widely recognized to be facing high levels of threat from habitat loss and overexploitation. In Indochina, therefore, comprehensive global threat assessments are a priority for invertebrates, fish, plants, and reptiles other than turtles.

Of the 492 globally threatened species in Indochina, 265 (equivalent to 54 percent of the total) occur in Vietnam, including 70 that are not found elsewhere in the region, 235 (48 percent) occur in southern China, including 122 that are not found elsewhere in the region, 204 (41 percent) occur in Thailand, including 77 that are not found elsewhere in the region, 104 (21 percent) occur in Cambodia, including two that are not found elsewhere in the region, and 102 (21 percent) occur in Lao P.D.R., including one that is not found elsewhere in the region. Although Cambodia and Lao P.D.R. support very few globally threatened species not found elsewhere in the region, they should still be considered high priorities for CEPF investment because they support some of the largest extant habitat tracts in the region, and, consequently, for many species, support the most viable populations and/or represent the greatest opportunity for conservation success.

Eighty-two of the globally threatened species in Indochina are Critically Endangered, 131 are Endangered and 279 are Vulnerable. The 10 Critically Endangered mammal species in the region include three primate species: Tonkin snub-nosed monkey, Delacour's leaf monkey and white-headed leaf monkey. The former two species are endemic to Vietnam and the latter is endemic to Vietnam and southern China. All three are among the most threatened primate species in the world, with global populations under 500 individuals (Nadler et al. 2003). The Critically Endangered mammal species also include three large mammals: lesser one-horned rhinoceros, hairy rhinoceros and kouprey. Within the region, lesser one-horned rhinoceros is only known to persist at a single site in Vietnam (Polet et al. 1999) and hairy rhinoceros is only known to persist at a single site in Thailand, while the continued occurrence of kouprey is unconfirmed. In addition, two bat species in the region are Critically Endangered: Vietnam leaf-nosed bat (Paracoelops megalotis) and Wroughton's free-tailed bat (Otomops wroughtoni). Within the region, the latter species is known only from a single site in Cambodia (Walston and Bates 2001), while there are no recent records of the former species, which is endemic to the region (Corbet and Hill 1992). Critically Endangered mammal species also include small-toothed mole (Euroscaptor parvidens) and Chapa pygmy doormouse (Typhlomys chapensis), both of which are believed to be endemic to Vietnam, although there have been no confirmed records of either species since the first half of the 20th century (Corbet and Hill 1992, Lunde and Nguyen Truong Son 2001).

The eight Critically Endangered bird species in Indochina comprise: Gurney's pitta, a species endemic to peninsular Thailand and Myanmar which is highly threatened by clearance of its lowland forest habitat; giant ibis and white-shouldered ibis, the former being endemic to the region and the latter being only otherwise known from a small population on Borneo; and white-rumped vulture and slender-billed vulture, whose Indochinese populations are of increasing significance as they do not appear to have been affected by the factor responsible for the precipitous declines undergone by the Indian Subcontinent populations over the last decade (Pain et al. 2003); Christmas Island frigatebird (Fregata andrewsi), which occurs in significant numbers as a non-breeding visitor to coastal areas in the region, chiefly the west coast of peninsular Thailand; Chinese crested tern (Sterna bernsteini), for which there is only one confirmed record from the region; and white-eyed river martin, one of the most enigmatic bird species in the world, of which there have been no confirmed records in the last 25 years (BirdLife International 2001).

The nine Critically Endangered reptile species comprise Siamese crocodile and eight species of turtle: mangrove terrapin (Batagur baska), painted terrapin (Callagur borneoensis), striped narrow-headed softshell turtle (Chitra chitra), Indochinese box turtle (Cuora galbinifrons), Chinese three-striped box turtle (C. trifasciata), Zhou's box turtle, Vietnamese pond turtle (Mauremys annamensis) and East Asian giant softshell turtle (Rafetus swinhoei). The fact that so many species of turtle in the region are assessed as globally Critically Endangered is a strong indication of the extreme levels of threat faced by turtles as a group, particularly from overexploitation.

Only one amphibian species in Indochina is currently listed as Critically Endangered: speckle-bellied metacarpal-tubercled toad, which is endemic to Yunnan province in southern China. In addition, only three fish species in Indochina are currently listed as Critically Endangered: dwarf botia (Botia sidthimunki), leaping barb (Chela caeruleostigmata) and freshwater sawfish. Considerably more information on fish species status and distribution is necessary before a more comprehensive global threat assessment can be made for the group. It is probable that the region supports many more fish species of the highest global conservation concern.

Finally, 51 Critically Endangered plant species are known to occur in Indochina. Thirty-four of these are members of the Dipterocarpaceae family, including 13 species of Hopea, eight species of Dipterocarpus, eight species of Shorea and three species of Vatica. All of these species are high-value timber trees, severely threatened by overexploitation, as are most of the other Critically Endangered plant species in the region. Also included among the Critically Endangered plant species are three conifers in the Pinaceae family, Abies yuanbaoshanensis, A. ziyuanensis and Pinus squamata, all of which are endemic to southern China, and threatened by habitat loss and overexploitation.

Site Outcomes
A total of 362 key biodiversity areas were defined in Indochina (Appendix 2 and Figures 2a-2e). Of these, 215 sites (equivalent to 59 percent of the total) were defined for globally threatened mammal species, 229 (63 percent) were defined for globally threatened, restricted-range or congregatory bird species, 100 (28 percent) were defined for globally threatened reptile species, 42 (12 percent) were defined for globally threatened amphibian species, 16 (4 percent) were defined for globally threatened fish species, and 169 (47 percent) were defined for globally threatened plant species (Table 2).

The number of key biodiversity areas defined for globally threatened plant species would likely be considerably higher if more detailed information was available on the distribution of plant species among sites. Similarly, the number of key biodiversity areas defined for globally threatened fish species would undoubtedly be significantly higher if detailed data were available on the distribution of fish species among sites, and a comprehensive global threat assessment reflecting true global conservation priorities within this group had been conducted.

Table 2. Summary of Key Biodiversity Areas in Indochina

Taxonomic Group Cambodia Lao P.D.R. S. China Thailand Vietnam Total
Mammals 18 31 31 60 75 215
Birds 39 24 39 62 65 229
Reptiles 21 19 16 32 12 100
Amphibians 0 1 17 11 13 42
Fish 2 4 0 10 0 16
Plants 8 8 42 75 36 169
All key biodiversity areas 40 38 69 113 102 362

Of the 362 key biodiversity areas in Indochina, only 229 (equivalent to 63 percent of the total) are wholly or partly included within gazetted protected areas. This indicates that, while protected area-based approaches could form an important component of any conservation strategy for the region, there also exists great potential for conservation action at sites outside of formal protected areas. The proportion of key biodiversity areas outside of gazetted protected areas varies significantly among countries, from 65 percent in Vietnam to only 16 percent in Thailand; this indicates that the opportunity for conservation action outside of formal protected areas may be greater in some countries than others.

Several key biodiversity areas are known to support large numbers of globally threatened species. These include Chhep in Cambodia; Nakai-Nam Theun and Xe Pian in Lao P.D.R.; Huanglianshan and Xishuangbanna in southern China; Hala-Bala, Huai Kha Khaeng and Khao Banthad in Thailand; and Ke Bang, Ngoc Linh, Phong Nha and Pu Mat in Vietnam, all of which are known to support at least 30 globally threatened species. These sites should not necessarily be considered to be the highest priorities for conservation action in the region, however, as they may not necessarily be the most important for the conservation of any particular species and other sites that have received less survey effort to date may support similar numbers of globally threatened species.

As the comprehensiveness of available data on the distribution of globally threatened species among key biodiversity areas vary significantly among taxonomic groups, key biodiversity areas identified as being important for the conservation of one taxonomic group may also be important for other groups for which data are not yet available. In addition, there are likely to be other important sites for the conservation of globally threatened species in the region that have not been identified during this process, especially for plants and fish.

Corridor Outcomes
A total of 53 conservation corridors were defined in Indochina (Table 3). The conservation corridors cover a total area of 539,047 km2, equivalent to 36 percent of the total area of Indochina. They range in size from 1,014 km2 (Ke Go and Khe Net Lowlands) to 26,430 km2 (Mu Ko Similan-Phi Phi-Andaman Corridor). The full list of key biodiversity areas within each conservation corridor is presented in Appendix 3.

Many of the conservation corridors were defined for the conservation of landscape species. In Indochina, these species were taken to comprise Asian elephant, Irrawaddy dolphin (Orcaella brevirostris), rufous-necked hornbill (Aceros nipalensis), plain-pouched hornbill (A. subruficollis), great hornbill (Buceros bicornis), rhinoceros hornbill (B. rhinoceros), sandbar-nesting birds, vultures, large waterbirds, black-faced spoonbill, and migratory freshwater fish. For all of these species, conservation of individual sites in isolation is unlikely to meet their long-term conservation needs. Other conservation corridors were defined on the basis of their importance for maintaining ecological and evolutionary processes, including shorebird migration, annual flooding cycles, and altitudinal migration.

The 53 conservation corridors include 295 key biodiversity areas (equivalent to 81 percent of the total). Moreover, the coverage of globally threatened species within the conservation corridors is very good: Of the 375 globally threatened species for which reliable data on their distribution among sites were available, 369 (equivalent to 98 percent of the total) are confirmed to regularly occur in significant numbers in one or more conservation corridor.

Table 3. Summary of Conservation Corridors in Indochina

Conservation Corridor Countries Area (km2) # of Key Biodiversity Areas
Bolaven Plateau Lao P.D.R. 4,428 2
Cambodia-Lao P.D.R.-Vietnam Tri-border Forests Cambodia, Lao P.D.R. and Vietnam 11,278 4
Cardamom and Elephant Mountains Cambodia 14,380 5
Central Annamites Lao P.D.R. and Vietnam 32,951 18
Central Indochina Limestone Lao P.D.R. and Vietnam 8,017 4
Chumphon Thailand 1,777 2
Damingshan Range S. China 4,710 3
Di Linh Vietnam 5,188 2
Doi Phuka-Mae Yom Lao P.D.R. and Thailand 17,105 10
Eastern Plains Dry Forests Cambodia and Vietnam 19,905 8
Hainan Mountains S. China 16,780 19
Hala-Bala Thailand 7,387 7
Hong Kong-Shenzhen Mountains S. China 1,332 3
Huanglianshan/Hoang Lien Mountains S. China and Vietnam 20,215 6
Inner Gulf of Thailand Thailand 1,413 2
Kaeng Krachan Thailand 5,488 2
Ke Go and Khe Net Lowlands Vietnam 1,014 2
Khao Banthad Thailand 4,088 4
Khao Luang Thailand 2,449 3
Khlong Saeng-Khao Sok Thailand 8,165 8
Lower Eastern Forest Complex Thailand 4,155 5
Lowland Dong Nai Watershed Vietnam 8,328 5
Lum Nam Pai-Salawin Thailand 24,402 7
Mae Ping-Om Koi Thailand 8,716 3
Mekong Delta Coastal Zone Vietnam 3,950 8
Mekong River and Major Tributaries Cambodia, Lao P.D.R., S. China and Thailand 17,070 11
Mu Ko Similan-Phi Phi-Andaman Thailand 26,430 11
Nam Et-Phou Louey Lao P.D.R. 4,411 2
North-western Mekong Delta Wetlands Cambodia and Vietnam 7,865 7
Northern Annamites Lao P.D.R. and Vietnam 21,220 7
Northern Highlands Limestone S. China and Vietnam 24,477 17
Northern Indochina Limestone Vietnam 6,757 10
Northern Plains Dry Forests Cambodia and Lao P.D.R. 19,460 4
Phanom Dongrak-Pha Tam Thailand 3,537 2
Phu Khieo-Nam Nao Thailand 13,430 5
Phu Miang-Phu Thong Thailand 9,968 2
Quang Binh-Quang Tri-Xe Bangfai Lowlands Lao P.D.R. and Vietnam 3,823 2
Red River Delta Coastal Zone Vietnam 2,262 7
Sekong Plains Cambodia 3,873 1
Shiwandashan Range S. China 2,464 2
South China Shorebird Flyway S. China 23,720 8
Southern Annamites Main Montane Block Vietnam 10,220 5
Southern Annamites Western Slopes Cambodia and Vietnam 3,932 2
Sri Lanna-Khun Tan Thailand/span> 20,227 1
Tongbiguan-Dehong Zizhizhou S. China 1,244 2
Tonle Sap Lake and Inundation Zone Cambodia 17,614 10
Upper Chu River Watershed Vietnam 4,497 2
Upper Eastern Forest Complex Thailand 9,730 4
Western Forest Complex Thailand 24,256 12
Xe Khampho-Xe Pian Lao P.D.R. 4,786 3
Xishuangbanna-Simao S. China 8,562 5
Yunwushan Range S. China 3,851 4
Zuojiang Valley S. China 1,740 6

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