Cardamom Mountains Research Articles

Review of the Slender Geckos (Squamata: Gekkonidae: Hemiphyllodactylus) of the Cardamom Mountains of southwestern Cambodia, with descriptions of two new species and one country record

The gekkonid lizard genus Hemiphyllodactylus contains small, secretive species that are often overlooked in their habitats. Recent molecular and morphological analyses have resulted in the descriptions of numerous new species of Hemiphyllodactylus in mainland Southeast Asia and southern China, many of which were historically hidden within the geographically widespread taxon H. yunnanensis (Boulenger, 1903). Little is known on species diversity and distributions of Hemiphyllodactylus in Cambodia, and all previous reports from the country have been limited to provisional identifications owing to collections containing only a single female or juvenile specimen. We report on new collections of Hemiphyllodactylus specimens from opposite ends of the Cardamom Mountain range in southwestern Cambodia. Morphological and molecular data support the hypothesis that these collections contain three distinct species, two of which are described as new species and one of which is assigned to the geographically widespread H. typus Bleeker, 1860 as a new country record for Cambodia. Hemiphyllodactylus bokor sp. nov. from Preah Monivong Bokor National Park in Kampot Province and Hemiphyllodactylus samkos sp. nov. from Phnom Samkos Wildlife Sanctuary in Pursat Province are related to species from adjacent areas in southern Vietnam, southern Laos, and southeastern Thailand, as well as a clade from India, but are readily differentiated in mitochondrial DNA and in having unique combinations of mensural and meristic morphological characters. Additional species diversity of Hemiphyllodactylus likely exists in Cambodia.

Recent Progress in Taxonomic Studies, Biogeographic Analysis, and Revised Checklist of Reptiles in Indochina

The Indochinese Peninsula represents one of the key global biodiversity hotspots in Southeast Asia. The herpetofauna of Indochina (herein including Vietnam, Laos, Cambodia, and Thailand) currently (as by 10 August 2023) comprises 882 native and six invasive species of reptiles and is one of the richest in the world. About 40% of the Indochinese reptile species were discovered or recorded within the first two decades of the 21st century. We review the literature and our field data to assess all recent discoveries and taxonomic changes; we compile an annotated checklist of reptilian fauna of Indochina, including updated faunal lists for Vietnam and Thailand. Reptile species checklists for Laos and Cambodia are published for the first time. For each species we provide the following information: scientific name; recommended common name in English; information on type specimens; information on recognized subspecies; type locality; data on its distribution within Indochina and beyond; IUCN conservation status; taxonomic comments and the most important references. We review the distribution of each reptilian species across the 23 biogeographic subregions of Indochina, estimate the similarity among the regional faunas and evaluate their species richness and endemism. In total, we record 882 native reptile species belonging to three orders, 34 families and 163 genera; of them 408 species (46.3%) are endemic to Indochina. Comprising 512 known species, the reptilian fauna of Thailand is the richest (114 country endemics, 22.3%), followed by Vietnam with 496 species (157 endemics, 31.7%), Laos with 250 species (39 endemics, 15.6%), and Cambodia with 191 species (15 endemics, 7.9%). A cluster analysis of faunal similarity between the subregions revealed three major groupings, corresponding to the Sundaland fauna south of the Isthmus of Kra, the subtropical fauna of northeastern Indochina, and the tropical fauna of mainland Indochina. Within the latter grouping four clusters can be distinguished: (1) northern, central and southern Annamites, (2) western Indochinese subregions, (3) central-south Vietnam lowlands including the Bolaven Plateau and Cardamom Mountains, (4) and the depleted faunas of river deltas, coastal areas and offshore islands. We identify the Northern, Central and Southern Annamites, the Northwest Uplands of Vietnam, Laos and Thailand, Southern Tenasserim in Thailand as the major centers of reptilian diversity in Indochina. The highest number of Indochinese endemic reptilian species was recorded in Central-Southern Vietnam Lowlands, Northern Annamites, and Central Annamites. The analysis of reptilian distribution patterns suggests the presence of 20 clusters of species sharing similar distribution patterns across Indochina. Our results further underline the key role of Indochina as an important area for diversity and conservation of reptiles. Among 882 native species of Indochinese reptiles, 356 species (40.4%) are considered as Data Deficient (DD) or were Not Evaluated (NE) according to the IUCN Red List criteria, while 106 species (12.0%) were considered Vulnerable (VU), Endangered (EN) or Critically Endangered (CR), 17 species (1.9%) were considered to be Near Threatened (NT), and 403 species (45.7%) to be of the Least Concern (LC) status. Our work has implications for elaboration of further conservation efforts for Indochinese reptiles on regional and global levels, as well as for a better understanding of the biogeographic patterns of reptilian richness and endemism in Asia.

Combining Camera Trap Data and Environmental Data to Estimate the Effects of Environmental Gradients on Abundance of the Asian Elephant Elephas maximus in Cambodia

Asian elephant (Elephas maximus) populations in Cambodia are currently declining, and the effect of environmental degradation on the abundance and health of elephants is poorly understood. We used camera trap data from 42 locations between 2016 to 2020 in the southern Cardamom Mountains to investigate the impact of environmental degradation on the abundance and condition of Asian elephants. Camera trap data were organized using CameraSweet software to retrieve both number of individuals and their condition. For a number of individuals, we defined independent captures spatially and temporally. To assess condition, we created a visual scoring system based on past research (Wemmer et al. 2006, Fernando et al. 2009, Morfeld et al. 2014, Wijeyamohan et al. 2014, Morfeld et al. 2016, Schiffmann et al. 2020). This scoring system relies on visual assessment of the muscle and fat in relation to the pelvis, ribs, and back bone. To validate this subjective scoring system, two scorers reviewed elephant captures by using 10 reference photos and then reviewing each other’s assessment in the first five images showing the elephant's body condition. This method minimizes subjective assessment from two scorers. Environmental variables (Suppl. material 1) such as distance to forest edge, forest integrity index, elevation, global human settlements, distance to road, distance to river, night light and forest cover were obtained, then reclassified in ArcGIS to a common 1 km grid. We implemented hierarchical N-mixture models to investigate the impacts of environmental variables on abundance and used cumulative link models to investigate the impact of the same environmental variables on condition. We found that Asian elephant abundance exhibited a significant positive relationship with distance to forest edges, where abundance was greater further away from a forest edge. We found that body condition score exhibited the relationship with forest cover and Forest Landscape Integrity Index, which suggested that grassland and less dense forest support better condition. Moreover, males exhibited significantly higher scores for body condition than females, while babies, juveniles, and subadults all exhibited lower body condition scores compared to adults. The significantly lower body condition of young elephants is concerning and suggests that conservation managers in the region should prioritize environmental conditions that support young elephant health. Our results identify key environmental variables that appear to promote Asian elephant abundance and health in the Cardamom Mountains, thus informing relevant conservation actions to support this endangered species in Cambodia and beyond.

Recent Progress in Taxonomic Studies, Biogeographic Analysis, and Revised Checklist of Amphibians in Indochina

The Indochinese Peninsula is recognized as one of the key global biodiversity hotspots. The amphibian fauna of Indochina (including Vietnam, Laos, Cambodia and Thailand) is one of the richest in the world. About 60% of the known species were described within the last 20 years. We review the literature and our data to assess all recent discoveries and taxonomic changes and compile the first annotated checklist of the amphibian fauna of Indochina since the middle of the 20th century, including updated faunal lists for Vietnam and Thailand. Amphibian checklists for Laos and Cambodia are published for the first time. For each species we provide the following information: scientific name; recommended common name in English; information on type specimens; type locality; data on its distribution within Indochina and beyond; IUCN conservation status; taxonomic comment and the most important references. We review the distribution of each species across the 23 biogeographic subregions of Indochina, estimate the similarity among the regional faunas and evaluate their species richness and endemism. In total we record 423 amphibian species belonging to three orders, 11 families and 71 genera; 199 species (47%) are endemic to Indochina. Comprising 270 known species, the amphibian fauna of Vietnam is the richest (98 endemics, 36.3%), followed by Thailand with 194 species (29 endemics, 14.9%), Laos with 121 species (13 endemics, 10.7%), and Cambodia with 72 species (6 endemics, 8.3%). A cluster analysis of faunal similarity between the subregions shows two major assemblages, divided by the Isthmus of Kra. Within the northern mainland portion of Indochina three clusters can be distinguished: (1) northeastern and northwestern uplands of Vietnam and northern Laos; (2) Northern, Central, and Southern Annamites, the Bolaven Plateau, and central-south Vietnam lowlands; (3) western Indochinese subregions. We identify the Northeast and Northwest Uplands of Vietnam, the Northern, Central and Southern Annamites, the Cardamom Mountains, the mountains of Northeast Thailand, Northern Tenasserim and southern Peninsular Thailand as nine major centers of diversity and endemism of Indochinese amphibians. The analysis of amphibian distribution patterns across Indochina suggests the presence of 14 chorotypes grouped in five major range types. Our results underline the role of Indochina as a key area for amphibian diversity and conservation. Among 423 species of Indochinese amphibians, 152 species (35.9%) were considered as data deficient (DD) or were not evaluated (NE) according to the IUCN Red List criteria; while 76 species (18.0%) were considered vulnerable (VU), endangered (EN) or critically endangered (CR), 20 species (4.7%) were considered to be near threatened (NT), and 175 species (41.4%) to be of the least concern (LC). Our study thus has implications for further conservation efforts on regional and global levels, as well as for understanding the biogeographic patterns of amphibian richness and endemism in Asia.

Transformation of Southwestern Area of Cambodia’s Cardamom Mountains in the Beginning of the Twenty-first Century: Remote Sensing Analysis on Processes of Farmland Expansion by Pioneer Migrants

Transformation of Southwestern Area of Cambodia’s Cardamom Mountains in the Beginning of the Twenty-first Century: Remote Sensing Analysis on Processes of Farmland Expansion by Pioneer Migrants

Isotopic insights into the jar-and-coffin mortuary ritual of the Cardamom Mountains, Cambodia

AbstractThe use of coffins and jars as funerary receptacles was common across Southeast Asia. During the fifteenth to seventeenth centuries AD, cremation was the dominant mortuary tradition on the Angkorian plains, but in the Cardamom Mountains to the south, contemporaneous groups practised a unique burial tradition involving the deposition of un-cremated bone in exposed ceramic vessels and log coffins. The authors present the first geochemical analysis of individuals from this highland culture, specifically the site of Phnom Pel. The childhood diets of those interred in jars and coffins may have been sourced from different areas within the Cardamom Mountains, suggesting that the individuals came from discrete groups.

A new Leptobrachella (Anura: Megophryidae) from the Cardamom Mountains of Cambodia.

The species-rich, megophryid frog genus Leptobrachella Smith, 1925 is distributed throughout the uplands of mainland Southeast Asia but is conspicuously absent from the Cardamom Mountains of southwestern Cambodia, where it has been known only by a single, undetermined metamorphic specimen collected nearly two decades ago. We report two adult female specimens of Leptobrachella collected a decade later at a second locality in the Cardamom Mountains and use mitochondrial DNA, nuclear DNA, and morphology to show that it represents a distinct species. Leptobrachella neangi sp. nov., named after its collector, is most closely related in mitochondrial and nuclear DNA to L. fuliginosa (Matsui, 2006) and L. melanoleuca (Matsui, 2006) from western Thailand, but has uncorrected pairwise distances of 8.69-10.99% in a mitochondrial 16S gene fragment from its two sister species. The new species is also readily distinguished from these and other congeners by having the combination of (1) SVL 35.4-36.3 mm in two adult females, (2) distinct dorsolateral glandular line absent, (2) belly transparent, immaculate purplish gray in life, creamy white in preservative, (3) dark inguinal blotch absent, (4) tympanum with black coloration extending from line under supratympanic fold, (5) dorsal skin with small, irregular bumps and ridges, and (6) iris coppery orange around pupil, fading to gold at periphery, not distinctly bicolored. The new species is the first named Leptobrachella from the Cardamom Mountains and the third from Cambodia.

<i>Impatiens cardamomensis</i> (Balsaminaceae), a new species from Cambodia

Impatiens cardamomensis S. H. Cho, C. K. Lim & H. Won, a new species of the family Balsaminaceae from the Cardamom Mountain Range in southwestern Cambodia, is described and illustrated. The species is similar to I. noei from Thailand in that it possesses solitary flowers, fusiform capsules, and compressed seeds, but is readily distinguished by its ovate to widely ovate leaves, shorter petioles, widely elliptic dorsal petals and smaller seeds.

Wildlife and Livelihoods in the Cardamom Mountains, Cambodia

This study provides a preliminary assessment of the use of wild meat and fish by rural communities in the Northern Cardamoms, Cambodia. We used a case-study approach in three villages, to identify key characteristics and drivers of wildlife use, with a view to informing the design of future larger-scale investigations of wild meat and fish use in the Cardamoms. Interviews with 41 households, conducted from August to October 2013, were used to investigate the main livelihood activities of each household, including hunting and fishing activity, key hunting techniques and hunted and consumed species. Group discussions with households and hunters were used to determine the relative importance of hunting and fishing as a livelihood activity and food source. We found that over 80% of interviewed households hunted, and similarly over 90% fished. Hunters employed a range of techniques, and caught at least 38 different mammal, bird and reptile species. However, our results suggest that arable farming is the backbone of livelihoods in these villages, providing the bulk of household incomes, and that most households are hunting to prevent crop-raiding, or opportunistically, rather than to supply the commercial trade. While households expressed a preference for wild meat, bought domestic meats and fish were eaten more frequently. A potentially lucrative commercial trade with high profits per animal exists but catches are unpredictable, and hunting is dangerous. However, as many species populations are already heavily depleted, even low hunting offtakes could have significant impacts on vulnerable species. Previous research suggests that commercial hunting which targets larger-bodied and high-value species for the international wildlife trade is mainly conducted by professional hunting groups, external to local communities. The importance of agricultural trade to local communities suggests that “wildlife-friendly farming” initiatives may help to both secure a fair and reliable price for village agricultural products, while promoting conservation of biodiversity in the Cardamoms mountains. However, due to the likely larger impacts of commercial hunting groups, declines in biodiversity are likely to continue without stricter enforcement of wildlife trade laws in Cambodia's towns and cities, and the reduction of demand for wildlife products in consumer countries.

Release of critically endangered crocodiles: Development and application of a food web approach to determine suitability of release habitat

Abstract The Siamese Crocodile (Crocodylus siamensis) is a critically endangered medium‐size crocodilian endemic to Southeast Asia. Extirpated from much of its natural range, conservation efforts in the Cardamom Mountains of Cambodia include the release of captive‐reared juveniles and sub‐adults into river reaches known to support adult C. siamensis populations. Despite conservation concerns, the biology of wild C. siamensis is not well studied and the ecology of ecosystems at release locations is poorly understood. Fish are thought to comprise a major component of the diet of C. siamensis. Here, the aim was to characterize fish communities within three potential C. siamensis release locations, focusing on community composition, density, size class structure and food web dynamics. The survey sites varied in both C. siamensis density and human fishing pressure, and the results are interpreted in light of these drivers. Genomic interrogation of fishes of the Cardamom Mountains distinguished 13 distinct fish species, contributing to genetic databases and adding to the documented taxon list for the region. The presence of two previously unconfirmed fish genera in the region is confirmed. The first estimates of fish density, biomass and size class distribution for three rivers in the Cardamom Mountains are provided. The three potential C. siamensis release reaches that were sampled showed clear differences in fish community composition, structural and trophic dynamics. Fish density and biomass were highest in the high‐density C. siamensis survey reach and lowest in the high human fishing pressure reach. Survey reaches with food webs that were more reliant on autochonously driven food webs supported higher densities and biomass of fish. These results have important implications for future C. siamensis conservation efforts in Cambodia and contribute valuable ecological information on a relatively unexplored region.

The Southeast Asian water frontier: coastal trade and mid-fifteenth c. CE “hill tribe” burials, southeastern Cambodia

In mainland Southeast Asia, the so-called water frontier unified an otherwise geographically broad and culturally disparate economic network of long-, medium-, and short-distance trade of the 14th–17th century CE “Age of Commerce.” Focus on the rise of the larger port towns supporting this burgeoning maritime trade (e.g., Ayutthaya, Melaka, Hoi An) has overshadowed smaller maritime operations that must have serviced less regulated coastlines. In this paper, we evaluate the evidence of likely supply lines for relatively remote sites in the Southern Cardamom Ranges of southwestern Cambodia. We present the results of a geochemical analysis of ceramics from two contemporary and short-lived assemblages: comprehensively dated mid-15th c. to mid-17th c. CE burial complexes in the Cardamom Mountains, and a dated shipwreck (KohS’dech) recovered from waters off the adjacent coastline. We compare the shipwreck assemblage with other wreck assemblages to contextualize it within larger maritime exchange patterns. The KohS’dech wreck assemblage appears typical of a Southeast Asian short-haul coastal trader of this period, with a cargo consisting of a range of utilitarian household ceramics: large, medium, and small glazed stoneware storage jars, earthenware cooking pots, stoves and mortars, and “tableware” bowls. Comparison of burial, shipwreck, and reference ceramic compositional data confirms the jars and fine wares predominantly came from multiple production centers in Central and Northern Thailand. The few Angkorian jars identified in the burials were evidently heirlooms from what was, by the mid-15th c. CE, a likely defunct Khmer production complex east of Angkor. The results of this provenience analysis highlight (a) the Cardamom burials as an example of previously undocumented unregulated coastal interaction and (b) the relatively sophisticated and coordinated market-oriented strategies of inland ceramic producers at this time. For mainland Southeast Asia, the water frontier integrated not only ethnically diverse maritime port communities, but also those in more remote inland regions.

Six new species of the Cyrtodactylus intermedius complex (Squamata: Gekkonidae) from the Cardamom Mountains and associated highlands of Southeast Asia

An integrative taxonomic analysis using color pattern, morphology, and 1449 base pairs of the ND2 mitochondrial gene and its five flanking tRNAs demonstrated that eight species-level lineages occur within the Cyrtodactylus intermedius complex (Cyrtodactylus intermedius sensu stricto, C. phuquocensis and related populations) of the Cardamom mountains and associated highlands that have a sequence divergence ranging 3.4-8.9%. Additionally, each lineage is discretely diagnosable from one another based on morphology and color pattern and most occur in specific geographic regions (upland areas, karst formations or islands) that prevent or greatly restrict interpopulation gene flow. Six of these lineages were masquerading under the nomen C. intermedius and are described as the following: Cyrtodactylus auralensis sp. nov. endemic to Phnom Aural, the highest mountain in Cambodia; C. bokorensis sp. nov. endemic to the Bokor Plateau, Cambodia; C. cardamomensis sp. nov. from the main block of the Cardamom mountains; C. thylacodactylus sp. nov. endemic to Phnom Dalai the northernmost peak of the Cardamom mountains; C. laangensis sp. nov. endemic to the Phnom Laang karst formation, Cambodia; and C. septimontium sp. nov. from the Bảy Núi Hills of southwest Vietnam.

Population density and habitat loss of Chestnut-headed Partridge Arborophila cambodiana in south-west Cambodia

SummaryThirty-two percent of bird species in South-East Asia are likely to become extinct by the end of this century. However, due to a lack of data this number may be an underestimate. The Chestnut-headed Partridge Arborophila cambodiana found in south-west Cambodia’s Cardamom Mountain range is a largely unknown potentially at-risk species. We used line transects and camera traps to survey A. cambodiana in four protected areas in the Cardamom Mountains to estimate population densities. We also assessed their current distribution range and broad scale habitat changes from 1996 to 2016. We found A. cambodiana in evergreen and semi-evergreen forest at a density of 1.23 calling males/km2, and at altitudes above 400 m and where the slope was between 11 and 43o. From 1996 to 2016 A. cambodiana’s potential habitat decreased by 11%, whilst the total evergreen forest cover in the Cardamom Mountains decreased by 20%. A. cambodiana has a very restricted range within which the habitat has been fragmented. Compounded by human disturbance and development activities that negatively affect the species, we suggest a revision of its IUCN Red List status from ‘Least Concern’ to ‘Near Threatened’ as it partially meets a range of threatened Red List species criteria.

Diurnal pattern of rainfall in Cambodia: its regional characteristics and local circulation

We analyze the hourly rainfall data of 30 rain gauges in Cambodia from 2010 to 2015 to focus on the diurnal pattern of rainfall and its regional characteristics, with the underlying mechanisms inferred from the observed data. The observed annual rainfall in inland Cambodia ranges from 1087 to 1528 mm on station-average. Approximately 5–20% of the annual rainfall occurs during the pre-monsoon season, 50–78% during the summer monsoon season, and 12–36% during the post-monsoon season. During the pre-monsoon season, rainfall is dominant on the coast and over the Cardamom Mountains, with a maximum in the afternoon. The rainfall amount is smaller around the Tonle Sap Lake. During the summer monsoon season, rainfall is larger in the northern region and smaller in the western region in inland Cambodia, in both amount and proportion to annual rainfall. The rainfall amount on the coast is distinctively large. The diurnal rainfall maximum occurs in the early afternoon in the Cardamom Mountains, in the afternoon on the plain at the southwestern side of the Tonle Sap Lake, in the evening on the wide area of the northeastern side of the lake, and in the early morning on the coast. The clear regional characteristics in the diurnal rainfall pattern suggest significant effects of local features, even during the Asian summer monsoon season. During the post-monsoon season, rainfall is larger on the southwestern side of the Tonle Sap Lake with dominant nocturnal rainfall. These diurnal patterns are, however, not clear on some days, and analysis of the synoptic-scale atmospheric condition suggests the effect of the large-scale low-pressure system and disturbances on the appearance of the clear diurnal rainfall pattern. The effect of land–lake and mountain–valley circulations on forming the diurnal rainfall pattern is also implied from ground-observed meteorological data, although further numerical studies are required to examine the detailed mechanisms. The study of local effects on rainfall with consideration of the land-surface dynamics may aid flood and drought management in Cambodia by facilitating a greater understanding of its rainfall pattern.

Overlapping zones of exclusion: carbon markets, corporate hydropower enclaves and timber extraction in Cambodia

ABSTRACTThis contribution looks at the interplay of different logics of governing the environment, resources and people in Cambodia that materialise in overlapping zones of exclusion, thereby co-producing new relations of resource control in a complex frontier constellation: a frontier for water, forest and carbon commodities and also for state control. Focusing on three Clean Development Mechanism (CDM) hydropower dams, the paper analyses a partly unintentional, but significantly consequential coalescence of distinct spaces of governing located in the Cardamom Mountains: a forest conservation zone, the CDM technological zone, an enclaved corporate hydropower zone and a semi-official timber logging zone. While the CDM element has exposed the projects internationally, it has obscured several problematic aspects and dynamics of resource politics connected to the dams that are revealed in this paper. These include the vulnerabilisation of local fisher communities, incarceral labour practices on the dams’ construction sites and accelerated logging in the conservation zone. The paper also shows how the interaction of the studied zones takes place through their distinct mechanisms of exclusion with the effects of more centralised resource control and the bracketing of the associated dispossessions.

Camera trapping in the Cardamom Mountain Landscape, Cambodia, reveals Asian elephant calves with severe injuries from wire snares

Camera trapping in the Cardamom Mountain Landscape, Cambodia, reveals Asian elephant calves with severe injuries from wire snares

An initial survey of aquatic and semi-aquatic Heteroptera (Insecta) from the Cardamom Mountains and adjacent uplands of southwestern Cambodia, with descriptions of four new species

Previous collections of aquatic Heteroptera from Cambodia have been limited, and the biota of the country has remained essentially undocumented until the past several years. Recent surveys of aquatic Heteroptera in the Cardamom Mountains and adjacent Kirirom and Bokor plateaus of southwestern Cambodia, coupled with previous literature records, demonstrate that 11 families, 35 genera, and 68 species of water bugs occur in this area. These collections include 13 genus records and 37 species records newly listed for the country of Cambodia. The following four new species are described based on these recent surveys: Amemboa cambodiana n. sp. (Gerridae); Microvelia penglyi n. sp., Microvelia setifera n. sp. and Microvelia bokor n. sp. (all Veliidae). Based on an updated checklist provided herein, the aquatic Heteroptera biota of Cambodia as currently known consists of 78 species, and has an endemism rate of 7.7%, although these numbers should be considered provisional pending further sampling.

Vertical structure of orographic precipitating clouds observed over south Asia during summer monsoon season

Orography profoundly influences seasonal rainfall amount in several places in south Asia by affecting rain intensity and duration. One of the fundamental questions concerning orographic rainfall is nature of the associated precipitating clouds in the absence of synoptic forcing. It is believed that these clouds are not very deep, however, there is not much information in the literature on their vertical structure. The present study explores the vertical structure of precipitating clouds associated with orographic features in south Asia using data collected with the precipitation radar on board the Tropical Rainfall Measuring Mission satellite. Two types of precipitating clouds have been defined based on cloud echo top height, namely, shallow echo-top cloud and medium echo-top cloud. In both, radar reflectivity factor is at least 30 dBZ at 1.5 km altitude, and tops of shallow and medium echo-top clouds lie below 4.5 km and between 4.5 and 8 km, respectively. The Western Ghats contains the highest fraction of the shallow echo-top clouds followed by the adjacent eastern Arabian Sea, while the Khasi Hills in Meghalaya and Cardamom Mountains in Cambodia contain the least fraction of them. Average vertical profiles of shallow echo-top clouds are similar in different mountainous areas while regional differences are observed in the medium echo-top clouds. Below 3 km, precipitation liquid water content in medium echo-top clouds is the highest over the Western Ghats and the eastern Arabian Sea. The average precipitation liquid water content increases by \(0.16\,\hbox { gm m}^{-3}\) for shallow echo-top clouds between 3 and 1.5 km altitude, while the corresponding increase for medium echo-top clouds is in 0.05–0.08 \(\hbox { gm m}^{-3}\) range.

Heterogeneous Impact of a Collective Payment for Environmental Services Scheme on Reducing Deforestation in Cambodia

Payments for Environmental Services (PES) are increasingly used in tropical countries as incentives to improve forest conservation outcomes, notably in forests managed or owned by rural communities. However, little is known about the performance and the suitable conditions under which collective PES can be effective. We assess the impact of a collective PES on reducing deforestation in the Cardamom Mountains, Cambodia. We use a quasi-experimental approach combining covariate matching with difference-in-difference estimation as a procedure to assess program effectiveness on reducing deforestation. We find that the PES program contributed additionally saving on average about 0.17 percentage point of the enrolled PES area per year during 2005–12. We also highlight that characteristics such as slope, proximity to roads, and number of households are associated with heterogeneous PES impact. We finally call for improving both data availability and impact assessment methods in order to test better theories of change that take into account not only the ability of payments to reduce opportunity costs of conservation but also to consider how PES are turned into improved community collective action likely to improve the local enforcement of conservation.

Early Permian radiolarians from the extension of the Sa Kaeo Suture in Cambodia – tectonic implications

AbstractA reconnaissance survey of part of western Cambodia has found quarries in and near the town of Pailin containing chert, basalt, volcaniclastic rocks, gabbro and serpentinite. Abandoned quarries contain chert and basalt clasts in a volcaniclastic matrix and may constitute a mélange. A new, recently active, quarry contains these rock units in close and coherent contact but they lack the serpentinitic matrix of the Thung Kabin Mélange of eastern Thailand. The rock units are in close contact and may best be described collectively as a dismembered ophiolite. The mélange–ophiolite association constitutes a 3 km wide, 20 km long E–W belt separating a northern 200 km2 block of the mainly amphibolitic Pailin Crystalline Complex from a southern area of Triassic submarine fan siliciclastic rocks. The cherts yield the first documented radiolarian fauna from Cambodia and include a moderately well-preserved Asselian–Sakmarian age fauna consisting of Pseudoalbaillella sakmarensis, Pseudoalbaillella scalprata morphotype scalprata, Pseudoalbaillella sp. cf. P. simplex, Pseudoalbaillella u-forma morphotype II, Pseudoalbaillella sp. cf. P. elegans, Pseudoalbaillella sp. cf. P. lomentaria, Albaillella sp., Pseudoalbaillella spp., Trilonche? sp., Latentifistularia gen. et sp. indet. and Entactinaria gen. et sp. indet. The Pailin ophiolitic rocks, mélange and volcanic rocks occur within a generally E–W-trending belt, which suggests that the Sa Kaeo Suture does not extend southeastwards paralleling the Thai–Cambodian border, nor extend under the Cardamom Mountains but, rather, extends eastwards into Cambodia and possibly then turns southwards along the strike of the Pursat–Kampot Fold Belt.