Forests In Cambodia Research Articles

Physicochemical Soil Properties Following Selective Cutting of Large-Diameter Trees in a Lowland Dry Evergreen Forest in Cambodia

Physicochemical Soil Properties Following Selective Cutting of Large-Diameter Trees in a Lowland Dry Evergreen Forest in Cambodia

Motofish and Trashfish: Food values and rifts at the agrarian frontier

At the resource frontier of Prey Lang Forest in Cambodia, a new food regime marks multiple rifts in the social fabric. As the forest gives way to rural road development, migrant incursions, and cash cropping, long-term residents lament the paucity of available food. At the same time, new migrants suggest that there is now more food than ever. Based on how food is defined, we find one food, motofish, that emerged as a significant semiotic sign. It is a fish, regardless of species, that is farm-raised and carried from the market to the village by motorbike. It is opposed to a real fish that grows by itself in a river or stream. Long-term Kuy and Khmer residents of the forest see the fish as a sign of destruction and loss, because there are so few fish in the rivers and streams. New migrants see motofish as part of a new abundance coming to this remote corner of the world where there used to be no food. This abundance is facilitated by Cambodia's growing fish farming industry, fed by wild-harvested 'trashfish' and subsidized soy pellets. Motofish is more than a sign of gastropolitics, as it marks a rift in the semiotic landscape through which individual and collective worlds emerge. We use this worldmaking fish to launch a discussion of both the epistemic and metabolic rifts of agrarian transformation and how these rifts are interpreted by different actors in the same landscape: One that recognizes the metabolic rift and the other that carries with them its epistemic cleansing.

Quantifying the availability of seasonal surface water and identifying the drivers of change within tropical forests in Cambodia.

Surface freshwater is a vital resource that is declining globally, predominantly due to climate and land use changes. Cambodia is no exception and the loss threatens many species, such as the giant ibis a Critically Endangered waterbird. We aimed to quantify the spatial and temporal (2000-2020) change of surface water availability across northern and eastern Cambodia and to assess the impact of this on the giant ibis. We used a Random Forest Classifier to determine the changes and we tested the impact of land use and geographical covariates using spatially explicit regression models. We found an overall reduction of surface water availability of 4.16%. This was predominantly driven by the presence of Economic Land Concessions and roads which increased the probability of extreme drying and flooding events. The presence of protected areas reduced these probabilities. We found changes in precipitation patterns over the wider landscape did not correlate with changes in surface water availability, supporting the overriding influence of land use change. 98% of giant ibis nests recorded during the time period were found within 25m of surface water during the dry season, highlighting their dependency on surface water. The overall surface water decline resulted in a 25% reduction in dry season suitable habitat for the giant ibis. Although absolute changes in surface water over the whole area were relatively small, the impact on the highest quality habitat for ibis is disproportionate and therefore threatens its populations. Defining the threats to such an endangered species is crucial for effective management.

Mosquito diversity (Diptera: Culicidae) and medical importance in four Cambodian forests

BackgroundA total of 290 mosquito species are recorded in Cambodia among which 43 are known vectors of pathogens. As Cambodia is heavily affected by deforestation, a potential change in the dynamic of vector-borne diseases (VDBs) could occur through alteration of the diversity and density of sylvatic vector mosquitoes and induce an increase in their interactions with humans. Understanding mosquito diversity is therefore critical, providing valuable data for risk assessments concerning the (re)emergence of local VBDs. Consequently, this study mainly aimed to understand the spatial and temporal distribution of sylvatic mosquito populations of Cambodia by determining which factors impact on their relative abundance and presence.MethodsA study was conducted in 12 sites from four forests in Cambodia. All mosquitoes, collected during the dry and rainy seasons, were morphologically identified. The diversity and relative density of mosquito species in each site were calculated along with the influence of meteorological and geographical factors using a quasi-Poisson generalized linear model.ResultsA total of 9392 mosquitoes were collected belonging to 13 genera and 85 species. The most represented genera were Culex, accounting for 46% of collected mosquitoes, and Aedes (42%). Besides being the most abundant species, Culex pseudovishnui and Aedes albopictus, which are known vectors of numerous arboviruses, were present in all sites during both dry and rainy seasons. The presence of mosquito species reported to be zoo-anthropophilic feeders was also observed in both forested and urban areas. Finally, this study demonstrated that altitude, temperature and precipitation impacted the abundance of mosquitoes but also influenced species community composition.ConclusionThe results indicate an important diversity of mosquitoes in the four forests and an influence of meteorological and geographical factors on their community. Additionally, this work highlights in parallel the abundance of species considered to be of medical importance and therefore underlines the high risk of pathogen emergence/re-emergence in the region.Graphical

Evapotranspirational processes in a dry deciduous forest in Cambodia: clarifying the respective contributions of overstory and understory vegetation to the hydrologic cycle

Evapotranspirational processes in a dry deciduous forest in Cambodia: clarifying the respective contributions of overstory and understory vegetation to the hydrologic cycle

Re-thinking benefits of community protected areas in Mondulkiri, Cambodia

Balancing the needs of local people with biodiversity conservation is a universal challenge for protected area management. In Cambodia's forest landscapes, community-based forest management schemes are intended for rural communities to gain income in activities that support sustainable forest management in protected areas. Partnerships between communities, government, and non-government organizations to develop community-based forest management are still in their early stages, offering opportunities to learn from successes and challenges. In this paper, we report on the short-term results of a program led by WWF-Cambodia to support Community Protected Areas in Mondulkiri, Cambodia. Surveys were designed to capture changes in the knowledge, attitudes, and practices of members involved in community-based forest management. The surveys elicited local perceptions of benefits of involvement in forest enterprises and protection, and whether perceptions match the program's objective of conservation and income generation. The results of the short-term evaluation show that perceived benefits are linked to non-monetary attributes of the program, such as access to information and resources. There was no significant change in household income from forests over the two-year evaluation period. Overall, members perceived improvements in natural resource management, but expressed concerns over difficulties of managing forest enterprises. The short-term program evaluation suggests Community Protected Areas in Cambodia may have a positive impact on community governance but raises questions over realistic outcomes. Understanding local perceptions of the value of Community Protected Areas may help to better ground program objectives in local realities.

Impact of Climate Change on Forests in Cambodia

Cambodia is rich in forest resources, which play critical roles in local rural livelihoods, as well as providing valuable ecological and economic resources for the country’s economic development. Managing forests sustainably and equitably will be essential for maintaining the ecological integrity of the country, maintaining freshwater supplies and protecting biodiversity. Approximately 80% of the Cambodians live in rural areas depend upon the forests to support many people’s lives as a source of food, medicine and building products, and as a source of materials and goods for small business ventures. Forest degradation globally contributes around 17 % to Green House Gases (GHG) emissions, but in Cambodia represents the main factor in the country becoming a net emitter of GHGs. Climate change is one of the most environmental issues facing to the government. The study aimed at i) assessing the impact of climate change on NPP, Vegetation Carbon and Soil Organic Carbon using LPJ model; ii) projecting the spatial representation of Impact of climate change on NPP, Vegetation Carbon stocks, and Soil Organic Carbon. The Lund Potsdam Jena (LPJ) model combines process-based, large-scale representations of terrestrial vegetation dynamics and land-atmosphere carbon and water exchanges in a modular framework. The model climate data requirements are benign as it requires only Temperature, Rainfall and Cloudiness as climatology inputs. Model validation is used for Net Primary Productivity (NPP), Vegetation Carbon (VegC), and Soil Organic Carbon (SoC). Obtaining observation of NPP, VegC, and SoC data for the region from the published literature or from the international databases and compare these with the LPJ projections (Spatially or non- spatially). As results, LPJ Simulated distribution on NPP in Cambodia using different scenarios including Baseline, RCP 8.5, and RCP 8.5 with control CO2 generated based on NPP, VegC, and SoC. Also, LPJ simulated Soil carbon change (%) projections for Cambodia under the RCP 8.5 under the two scenarios of CO2 fertilization and no-CO2 fertilization.

Evapotranspiration from the understory of a tropical dry deciduous forest in Cambodia

The water balance of tropical dry deciduous forests is less well understood than some other forest ecosystems. To help close this knowledge gap, we separately measured the evapotranspiration from the whole ecosystem (ETW), transpiration (TR) and interception loss (IL) from overstory trees, and evapotranspiration from the understory vegetation (ETU) in a tropical dry deciduous forest in Cambodia. It was found that ETW was equivalent to 73.7% of rainfall (P) at the annual scale. In the dry season, ETW corresponded to 120.1% of P, which indicates the utilization of soil water replenished during the wet season. The sum of transpiration estimated by the thermal dissipation (TD) method with the original coefficient (TRG), IL, and ETU was smaller than ETW, except for the middle of the dry season, due to an underestimation of TRG. Although recently reported calibration coefficients can reasonably correct TRG, future calibrations of the TD method are highly recommended for the precise evaluation of single-tree-scale transpiration in tropical dry forests. The annual contribution of the understory vegetation to ETW (ETU/ETW) was 34.6%, leading to the conclusion that the understory vegetation cannot be ignored when trying to gain a comprehensive understanding of the hydrologic cycle in tropical dry forests. The seasonal variations in ETU/ETW were mainly controlled by the leaf area index (LAI) of overstory trees, resulting from the overall stability of ETW and decreasing trend of ETU with increasing LAI in the wet season, with the opposite holding true in the dry season, i.e., decreasing ETW with the decline of LAI and less variations of ETU. Thus, LAI influenced both the seasonality and the annual contribution in ETU/ETW, exerting a notable influence on hydrological cycling in this forest.

Can finance and market driven (FMD) interventions make “weak states” stronger? Lessons from the good governance norm complex in Cambodia

In the last 25 years, a range of scholars have endeavored to understand the creation of a myriad of transnational finance and market driven (FMD) governance interventions aimed at countries in the Global South who are asserted to suffer from "weak state" capacity or contain areas of “limited statehood”. This class of policy tools remains the dominant approach with which to foster improved governance in domestic settings in spite of a quarter century of frustrations over the pace and scale of change. We assess the ability of a good governance norm complex to help explain the persistent support of FMD tools in which countervailing or unanticipated impacts are viewed as the result of faulty design, rather than owing to the inherent contradictions of the complex itself. We illustrate the argument through a historical assessment of FMD tools in general, and the emergence in the last decade of “legality verification” in particular. We focus on Cambodia's forest sector to identify how policy designers might better anticipate the effects of the EU's “Forest Law Enforcement, Governance and Trade” (FLEGT) program on the variety of countervailing problems it is charged with improving.

Fighting Malaria in the Forests of Cambodia: A Community-Based Approach.

Fighting Malaria in the Forests of Cambodia: A Community-Based Approach.

Governing Cambodia’s Forests: The International Politics of Policy Reform

The destruction of Cambodia's forests gathered pace from the 1990s, receiving much international publicity at the time from environmental NGOs but far less scholarly treatment. That deficiency is now addressed by this detailed and sophisticated case study of the process by which aid donors and Cambodia's elites worked to designate much of the country's forests as suitable for industrial timber production, resulting in the marginalization and impoverishment of forest dwellers and ultimately the transformation of forests into enclosed plantations. The study highlights the way in which externally sponsored reform agendas are manipulated by domestic elites. As such it offers a powerful critique of the literature on 'ownership' as well as a clear and persuasive argument as to why forestry protection programmes so often fail within the modern international system. The book will appeal to a broad readership interested in political change in contemporary SE Asia, the politics of foreign aid, and those concerned with the conservation of the world's remaining tropical forests.

Development of an Operational Algorithm for Automated Deforestation Mapping via the Bayesian Integration of Long-Term Optical and Microwave Satellite Data

The frequent fine-scale monitoring of deforestation using satellite sensors is important for the sustainable management of forests. Traditional optical satellite sensors suffer from cloud interruption, particularly in tropical regions, and recent active microwave sensors (i.e., synthetic aperture radar) demonstrate the difficulty in data interpretation owing to their inherent sensor noise and complicated backscatter features of forests. Although the sensor integration of optical and microwave sensors is of compelling research interest, particularly in the conduct of deforestation monitoring, this topic has not been widely studied. In this paper, we introduce an operational algorithm for automated deforestation mapping using long-term optical and L-band SAR data, including a simple time-series analysis of Landsat stacks and a multilayered neural network with Advanced Spaceborne Thermal Emission and Reflection Radiometer and Phased Array-type L-band Synthetic Aperture Radar-2, followed by sensor integration based on the Bayesian Updating of Land-Cover. We applied the algorithm over a deciduous tropical forest in Cambodia in 2003–2018 for validation, and the algorithm demonstrated better accuracy than existing approaches, which only depend on optical data or SAR data. Owing to the cloud penetration ability of SAR, observation gaps of optical data under cloudy conditions were filled, resulting in a prompter detection of deforestation even in the tropical rainy season. We also investigated the effect of posterior probability constraints in the Bayesian approach. The land-cover maps (forest/deforestation) created by the well-tuned Bayesian approach achieved 94.0% ± 4.5%, 80.0% ± 10.1%, and 96.4% ± 1.9% for the user’s accuracy, producer’s accuracy, and overall accuracy, respectively. In the future, small-scale commission errors in the resultant maps should be improved by using more sophisticated machine-learning approaches and considering the reforestation effects in the algorithm. The application of the algorithm to other landscapes with other sensor combinations is also desirable.

Mapping mangrove forest cover using Landsat-8 imagery, Sentinel-2, Very High Resolution Images and Google Earth Engine algorithm for entire Cambodia

Currently there is limited information to estimate accurate and reliable mangrove forest area in Cambodia. Previous estimates did not explicitly illustrate the spatial distribution of mangrove for the entire country however, according to Global Forest Resource Assessment 2010, Cambodia’s mangrove area cover in 1990 and 2010 was calculated at 79,638 ha and 55,704 ha, respectively using extrapolation of 1992-1996 (original data from Remote Sensing of forest cover 1992/93 and 1996/97) for 1990 and extrapolation of 1996-2002 (original data from Remote Sensing of forest cover 1996/97 and 2002) for 2010. This study mapped the spatial distribution of Cambodia’s mangrove forest derived from 30 m × 30 m spatial resolution and polygon spatial extent from Landsat 8 (L8) image. Publicly available Landsat data was acquired from Google Earth Engine (GEE) Explorer including the Landsat Surface Reflectance-Landsat 8 (L8) OLI/TIRS; Top-Of-Atmosphere (TOA) L8 32-Day Reflectance Composite; Landsat Archive Pre-Collection from US Geological Survey (USGS, 2015); VHR Google-derived images (Collin et al. 2014) and field data collection from 63 plots representing the entire Cambodia of Surface Water Ambient Monitoring Program (SWAMP) to create a Google Fusion Table aiming at mapping the spatial resolution and extent. Random Forest (RF) Classifier, a supervised classification technique, was applied to three L8 images Archive Pre-Collection Level-1 (L8 OLI/TIRS) collected in December 2014, February 2015 and April 2015. Statistical analysis indicates the total area of mangrove forest cover reached 73,240ha with overall classification accuracy of 98.2%, 97.9% and 99.5% for three periods and the validation overall accuracy were 91.5%, 89.1% and 97.6%, respectively. Our findings suggest that L8 imagery and Google Earth Engine algorithm can be used to estimate area changes of mangrove forests in Cambodia with higher accuracy. The results of this study may be useful to assist decision making in planning for mangrove ecosystem restoration activities, evaluation of ecological services and in better estimation of carbon stock in mangrove forest. (Tier 1- default emission or Tier 3- plot data are more related to emission factor).

Evaluating the ability of community-protected forests in Cambodia to prevent deforestation and degradation using temporal remote sensing data.

Community forests are known to play an important role in preserving forests in Cambodia, a country that has seen rapid deforestation in recent decades. The detailed evaluation of the ability of community‐protected forests to retain forest cover and prevent degradation in Cambodia will help to guide future conservation management. In this study, a combination of remotely sensing data was used to compare the temporal variation in forest structure for six different community forests located in the Phnom Kulen National Park (PKNP) in Cambodia and to assess how these dynamics vary between community‐protected forests and a wider study area. Medium‐resolution Landsat, ALOS PALSAR data, and high‐resolution LiDAR data were used to study the spatial distribution of forest degradation patterns and their impacts on above‐ground biomass (AGB) changes. Analysis of the remotely sensing data acquired at different spatial resolutions revealed that between 2012 and 2015, the community forests had higher forest cover persistence and lower rates of forest cover loss compared to the entire study area. Furthermore, they faced lower encroachment from cashew plantations compared to the wider landscape. Four of the six community forests showed a recovery in canopy gap fractions and subsequently, an increase in the AGB stock. The levels of degradation decreased in forests that had an increase in AGB values. However, all community forests experienced an increase in understory damage as a result of selective tree removal, and the community forests with the sharpest increase in understory damage experienced AGB losses. This is the first time multitemporal high‐resolution LiDAR data have been used to analyze the impact of human‐induced forest degradation on forest structure and AGB. The findings of this work indicate that while community‐protected forests can improve conservation outcomes to some extent, more interventions are needed to curb the illegal selective logging of valuable timber trees.

Incorporating governance into forest transition frameworks to understand and influence Cambodia's forest landscapes

Academic inquiry into forest transitions has produced a rich body of literature examining the shift from net deforestation to net reforestation at multiple land use scales. However, researchers, practitioners, and policy analysts question the utility of current forest transition theory. Does it accurately describe and provide insight into strategies to influence patterns of forest change in countries where forest cover continues to decline? Forest transition theory has provided important insights into the ‘necessary but not sufficient’ conditions for countries shifting from net deforestation to net reforestation. To advance forest transition theory, scholars should recognize forests as complex and dynamic social-ecological systems and use analytical methods that accommodate that complexity. Transdisciplinary research that incorporates a broader range of qualitative and quantitative methods and tools is required. We analyzed the historical, social, and political factors influencing forest transition pathways in Cambodia. Cambodia exhibits similar economic pre-conditions to its neighbors, which have passed through a forest transition, yet deforestation rates remain high with no indication of slowing. We found that complex governance arrangements at multiple scales negatively influences Cambodia's forest cover and development trajectory. Attempts to nurture Cambodia's forest transition will require strengthening governance and institutions across all of the natural resource sectors. Further research that incorporates governance into forest transition frameworks is required to improve policy responses for post-transition forest outcomes.

Who Wants to Save the Forest? Characterizing Community-Led Monitoring in Prey Lang, Cambodia

Community monitoring is believed to be successful only where there is sustained funding, legislation for communities to enforce rules, clear tenure rights, and an enabling environment created by the state. Against this backdrop, we present the case of an autonomous grassroots-monitoring network that took the initiative to protect their forest, in a context, where no external incentives and rule enforcement power were provided. The aim was to analyze the socio-demographic and economic backgrounds, motivations and achievements of forest monitors, compared to non-monitors in the same communities. A total of 137 interviews were conducted in four villages bordering Prey Lang forest in Cambodia. We used binary logit models to identify the factors that influenced the likelihood of being a monitor. Results show that there were few (22%, n = 30) active monitors. Active monitors were intrinsically motivated forest-users, and not specifically associated with a particular gender, ethnicity, or residence-time in that area. The most common interventions were with illegal loggers, and the monitors had a general feeling of success in stopping the illegal activities. Most (73%, n = 22) of them had been threatened by higher authorities and loggers. Our results show that despite the lack of power to enforce rules, absence of external funding and land-ownership rights, and enduring threats of violence and conflicts, autonomous community monitoring may take place when community members are sufficiently motivated by the risk of losing their resources.

Effects of large aboveground biomass loss events on the deadwood and litter mass dynamics of seasonal tropical forests in Cambodia

Effects of large aboveground biomass loss events on the deadwood and litter mass dynamics of seasonal tropical forests in Cambodia

Book review: Andrew Cock, Governing Cambodia's Forests: The International Politics of Policy Reform (Nordic Institute of Asian Studies, Denmark 2016) 302 pp.

Book review: Andrew Cock, Governing Cambodia's Forests: The International Politics of Policy Reform (Nordic Institute of Asian Studies, Denmark 2016) 302 pp.

Governing Cambodia's Forests: The International Politics of Policy Reform

The destruction of Cambodia's forests gathered pace from the 1990s, receiving much international publicity at the time from environmental NGOs but far less scholarly treatment. That deficiency is now addressed by this detailed and sophisticated case study of the process by which aid donors and Cambodia's elites worked to designate much of the country's forests as suitable for industrial timber production, resulting in the marginalization and impoverishment of forest dwellers and ultimately the transformation of forests into enclosed plantations. The study highlights the way in which externally sponsored reform agendas are manipulated by domestic elites. As such it offers a powerful critique of the literature on 'ownership' as well as a clear and persuasive argument as to why forestry protection programmes so often fail within the modern international system. The book will appeal to a broad readership interested in political change in contemporary SE Asia, the politics of foreign aid, and those concerned with the conservation of the world's remaining tropical forests.

Using a tree-based approach to evaluate logging damage in a tropical mixed deciduous forest of Myanmar: comparison with cases in Cambodia

ABSTRACTLogging damage to residual trees is an important parameter when considering the sustainability of selective logging in tropical natural forests. Here, we applied a proposed tree-based approach to evaluate logging damage in a tropical mixed deciduous forest in Bago Yoma, Myanmar and compared the cases with semi-evergreen forests of Cambodia. The logging damage was assessed in twenty 0.1-ha plots, each of which contained the stump and crown of one felled tree, and multinomial logistic regression was used to quantify the probability of the felled tree causing severe, slight, or no damage to residual trees. In both cases of Myanmar and Cambodia, severe damage was dependent on the size of the residual and felled trees, while slight damage was independent of the size of felled trees. There was no slight damage of residual trees with ≥50 cm diameter at breast height (DBH) in Myanmar, whereas slight damage increased with residual tree size in Cambodia and in tropical rain forests of other countries. This difference could be attributed to the sparseness of standing trees (98 trees ha−1) in our study site in Myanmar, which made it easier to control the felling direction to avoid damage to larger residual trees. Additionally, the probability of increasingly severe damage with increasing DBH of the felled trees was higher in Myanmar than in Cambodia; one of the reasons may be the steeper terrain at the Myanmar site.