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2. Topographical patterns of species composition in a deciduous dipterocarp forest in Kratie Province, Cambodia

Author

Ito, Eriko, Furuya, Naoyuki, Ohnuki, Yasuhiro, Miyamoto, Kazuki, Araki, Makoto, Tamai, Koji, Shimizu, Takanori, Iida, Shin'ichi, kanzaki, Mamoru, Monda, Yukako, Kabeya, Naoki, Yagi, Takanobu, Shimizu, Akira, Toriyama, Jumpei, Tith, Bora, Keth, Samkol, Ly, Chandararity, Op, Phallaphearaoth, Chann, Sophal, and Kiyono, Yoshiyuki

Subjects
forest type, forest floor vegetation, topography, spatial heterogeneity, tree recruitment, Conservation, dry dipterocarp forest, forest fire
Published
2022

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

Author

IIDA, Shin’ichi, primary, SHIMIZU, Takanori, additional, TAMAI, Koji, additional, KABEYA, Naoki, additional, SHIMIZU, Akira, additional, ARAKI, Makoto, additional, OHNUKI, Yasuhiro, additional, ITO, Eriko, additional, KENZO, Tanaka, additional, TORIYAMA, Jumpei, additional, KUBOTA, Tayoko, additional, YAMANAKA, Tsutomu, additional, CHANN, Sophal, additional, and LEVIA, Delphis F., additional

Published
2022
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15. Practicalities of Non-Destructive Methodologies in Monitoring Anthropogenic Greenhouse Gas Emissions from Tropical Forests under the Influence of Human Intervention

Author

Mitsuo Matsumoto, Preap Sam, Satoshi Saito, Chann Sophal, Chairil Anwar Siregar, Tomoaki Takahashi, Bora Tith, Jumpei Toriyama, Tamotsu Sato, Yoshio Awaya, Y. Ochiai, Yoshiyuki Kiyono, Yoshio Inoue, Hidetoshi Asai, Naoyuki Furuya, and Eriko Ito

Subjects
Ecology, Land use, Logging, Plant community, Forestry, Subtropics, Land cover, Greenhouse gas, Forest ecology, Environmental science, Animal Science and Zoology, Agronomy and Crop Science, Stock (geology), Biotechnology
Abstract

We examined non-destructive methodologies for practicalities in monitoring anthropogenic greenhouse gas (GHG) emissions from tropical dry-land forest under the influence of various forms of human intervention. Spaceborne SAR withstood comparison with Landsat ETM+ in land cover classification of degraded tropical forest. For measurement of carbon stock and GHG flux per unit land area, the gain-loss method requires both growth rate and removal rate of forest carbon stock. However, the latter has rarely been obtained in tropical forest. For the stock-difference method, permanent sampling plot data can be used to estimate mean carbon stock per unit land area of each forest type. For cyclic land use that includes a clear-cutting stage such as slash-and-burn agriculture, chronosequential changes in carbon stock can be predicted by determining the time and spatial-distribution of cleared land. Changes in forest biomass by logging, storm-damage, etc., may be identified by monitoring the presence and diameter of the crowns of overstory trees. We developed five equations containing the parameter for crown diameter for estimating tree biomass. Overstory height can be a parameter for estimating ecosystem carbon stock of various plant communities, and forest height can be measured by airborne and spaceborne sensors, etc. Generic equations containing the parameter for overstory height are available for estimating community biomass of tropical and subtropical forests. PALSAR has an advantage over other remote systems by enabling frequent sensing and semi-direct biomass estimation using backscattering coefficients. However, no reasonable remote sensing methods exist for monitoring the amount of carbon loss by forest conversion and logging in forests with high biomass. To compensate for the faults of the present PALSAR methodologies and to enable practical and frequent monitoring of all types of forests by humans, it is vital to devise a new methodology to detect changes in high-biomass forests.

Published
2011
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16. Two phenological variants of Terminalia alata coexist in a dry dipterocarp forest

Author

Ito, Eriko, primary, Chann, Sophal, additional, Tith, Bora, additional, Keth, Samkol, additional, Ly, Chandararity, additional, Op, Phallaphearaoth, additional, Furuya, Naoyuki, additional, Ohnuki, Yasuhiro, additional, Iida, Shin’ichi, additional, Shimizu, Takanori, additional, Tamai, Koji, additional, Kabeya, Naoki, additional, Yagi, Takanobu, additional, and Shimizu, Akira, additional

Published
2017
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17. A feasibility study for determining the mean annual aboveground biomass gain of tropical seasonal forests in Cambodia

Author

Kiyono, Yoshiyuki, primary, Ito, Eriko, additional, Monda, Yukako, additional, Toriyama, Jumpei, additional, Saito, Hideki, additional, Furuya, Naoyuki, additional, Sum, Thy, additional, Tith, Bora, additional, Keth, Nang, additional, Keth, Samkol, additional, Chandararity, Ly, additional, Phallaphearaoth, Op, additional, Chann, Sophal, additional, and Sokh, Heng, additional

Published
2017
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19. <S1-10> Wood density and water content in diverse species from lowland dipterocarp rainforest and dry dipterocarp forest

Author

Tanaka, Kenzo, Ichie, Tomoaki, Inoue, Yuta, Kendawang, Joseph Jawa, Chann, Sophal, Tanaka, Kenzo, Ichie, Tomoaki, Inoue, Yuta, Kendawang, Joseph Jawa, and Chann, Sophal

Abstract

We compared the wood density and water content of various tree species in lowland dipterocarp rainforest in Sarawak and dry dipterocarp forest in Cambodia. We collected wood core samples of 134 species from Lambir National Park, Sarawak and those of 44 species from Kratie Province, Cambodia. Sarawak (0.64 g cm-3) and Cambodia (0.64 g cm-3) did not differ in average wood density. In contrast, wood water content in Cambodia (0.42 g cm-3) showed significantly larger values than that in Sarawak (0.35 g cm-3). There was a negative correlation between wood density and water content in Cambodian trees, while the relation was not significant for Sarawak trees. The higher water content in Cambodian trees may indicate the greater importance of stem water storage under the drier environment in dry dipterocarp forest than in lowland dipterocarp rainforest.

Published
2016

21. Allometric Equations for Tropical Seasonal Deciduous Forests in Cambodia: A Method of Estimating Belowground Tree Biomass with Reduced Sampling Loss of Roots

Author

MONDA, Yukako, primary, ITO, Eriko, additional, KIYONO, Yoshiyuki, additional, SATO, Tamotsu, additional, TORIYAMA, Jumpei, additional, SOKH, Heng, additional, CHANN, Sophal, additional, TITH, Bora, additional, KETH, Samkol, additional, PHALLAPHEARAOTH, Op, additional, and BOUNTHABANDID, Soukanh, additional

Published
2016
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22. Considering the practical rationality of experimental operation in developing countries: Reality and challenges under a rigid community forestry system in Cambodia

Author

Kurashima, Takayuki, Matsuura, Toshiya, Miyamoto, Asako, Sano, Makoto, Chann, Sophal, Kurashima, Takayuki, Matsuura, Toshiya, Miyamoto, Asako, Sano, Makoto, and Chann, Sophal

Abstract

Influential stakeholders have highlighted many constraints inherent in conventional scientific forest management plans for community forestry (CF) and presented simpler alternatives. Nevertheless, some developing countries continue to use rigid, complex and high-cost plans and regulations. This article considers two issues: (1) why heavily-regulated or rigid CF systems were originally introduced and why they continue to be used in developing countries despite critiques and counterproposals; and (2) under what circumstances will such CF systems face an impasse, and what can be done to resolve the situation. Using Cambodia as a case study, we examine the development of a rigid CF system, review negative factors influencing the upland forested area, clarify the unfavorable situations arising from these factors and discuss likely problems associated with the CF management system. International organizations played a key role in the introduction and maintenance of rigid, complex and high-cost CF systems in Cambodia. Conflicts and crises arise when the administration prosecutes local farmers for illegal cultivation or deprives communities of CF management rights because of the expansion of commercial crop cultivation and the lack of adequate community management in response to unprecedented changes. A likely practical solution to the probable impasse is the development and funding of a functional network of CF management committees, rather than the adoption of an entirely new, alternative system.

Published
2015

23. Two phenological variants of Terminalia alata coexist in a dry dipterocarp forest.

Author

Ito, Eriko, Chann, Sophal, Tith, Bora, Keth, Samkol, Ly, Chandararity, Op, Phallaphearaoth, Furuya, Naoyuki, Ohnuki, Yasuhiro, Iida, Shin’ichi, Shimizu, Takanori, Tamai, Koji, Kabeya, Naoki, Yagi, Takanobu, and Shimizu, Akira

Subjects
*TERMINALIA, *PETASITES kablikianus, *SOILS, *WATER balance (Hydrology), *COMBRETACEAE
Abstract

Two morphological variants of Terminalia alata ( Combretaceae) differed in leaf flushing phenology and spatial distribution in a Cambodian deciduous forest. The hairy-type trees displayed leaf exchange behavior in the middle of the dry season. The glabrous type flushed new leaves 3 months after the wet season started. The leafless period of the hairy type was estimated to be <1 month, whereas that of the glabrous type lasted more than 5 months. The landscape-scale leaf exchange behavior was similar to that of the hairy type. The two types showed clear spatial separation. The hairy type was limited to flat areas with deep soils. The dominance of the glabrous type in hilly areas with shallow soils suggests that it is adapted to water-limited environments. The abundance of the glabrous type in hilly areas and its unique leaf phenology probably influence the carbon, energy and water balance at the landscape level. [ABSTRACT FROM AUTHOR]

Published
2018
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24. Aboveground Biomass Estimation Using Structure from Motion Approach with Aerial Photographs in a Seasonal Tropical Forest

Author

Ota, Tetsuji, primary, Ogawa, Miyuki, additional, Shimizu, Katsuto, additional, Kajisa, Tsuyoshi, additional, Mizoue, Nobuya, additional, Yoshida, Shigejiro, additional, Takao, Gen, additional, Hirata, Yasumasa, additional, Furuya, Naoyuki, additional, Sano, Takio, additional, Sokh, Heng, additional, Ma, Vuthy, additional, Ito, Eriko, additional, Toriyama, Jumpei, additional, Monda, Yukako, additional, Saito, Hideki, additional, Kiyono, Yoshiyuki, additional, Chann, Sophal, additional, and Ket, Nang, additional

Published
2015
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34. Calibration of tipping‐bucket flow meters and rain gauges to measure gross rainfall, throughfall, and stemflow applied to data from a Japanese temperate coniferous forest and a Cambodian tropical deciduous forest

Author

Iida, Shin'ichi, primary, Shimizu, Takanori, additional, Kabeya, Naoki, additional, Nobuhiro, Tatsuhiko, additional, Tamai, Koji, additional, Shimizu, Akira, additional, Ito, Eriko, additional, Ohnuki, Yasuhiro, additional, Abe, Toshio, additional, Tsuboyama, Yoshio, additional, Chann, Sophal, additional, and Keth, Nang, additional

Published
2012
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37. Soil Carbon Stock in Cambodian Monsoon Forests

Author

TORIYAMA, Jumpei, primary, OHTA, Seiichi, additional, OHNUKI, Yasuhiro, additional, ITO, Eriko, additional, KANZAKI, Mamoru, additional, ARAKI, Makoto, additional, CHANN, Sophal, additional, TITH, Bora, additional, KETH, Samkol, additional, HIRAI, Keizo, additional, and KIYONO, Yoshiyuki, additional

Published
2011
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40. Estimating Diameter at Breast Height from Measurements of Illegally Logged Stumps in Cambodian Lowland Dry Evergreen Forest

Author

ITO, Eriko, primary, FURUYA, Naoyuki, additional, TITH, Bora, additional, KETH, Samkol, additional, CHANDARARITY, Ly, additional, CHANN, Sophal, additional, KANZAKI, Mamoru, additional, AWAYA, Yoshio, additional, NIIYAMA, Kaoru, additional, OHNUKI, Yasuhiro, additional, ARAKI, Makoto, additional, SATO, Tamotsu, additional, MATSUMOTO, Mitsuo, additional, and KIYONO, Yoshiyuki, additional

Published
2010
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45. Considering the Practical Rationality of Experimental Operation in Developing Countries: Reality and Challenges under a Rigid Community Forestry System in Cambodia.

Author

Takayuki Kurashima, Toshiya Matsuura, Asako Miyamoto, Makoto Sano, and Chann, Sophal

Subjects
COMMUNITY forestry, FORESTS & forestry, FOREST management, LOGGING, FOREST monitoring
Abstract

Influential stakeholders have highlighted many constraints inherent in conventional scientific forest management plans for community forestry (CF) and presented simpler alternatives. Nevertheless, some developing countries continue to use rigid, complex and high-cost plans and regulations. This article considers two issues: (1) why heavily-regulated or rigid CF systems were originally introduced and why they continue to be used in developing countries despite critiques and counterproposals; and (2) under what circumstances will such CF systems face an impasse, and what can be done to resolve the situation. Using Cambodia as a case study, we examine the development of a rigid CF system, review negative factors influencing the upland forested area, clarify the unfavorable situations arising from these factors and discuss likely problems associated with the CF management system. International organizations played a key role in the introduction and maintenance of rigid, complex and high-cost CF systems in Cambodia. Conflicts and crises arise when the administration prosecutes local farmers for illegal cultivation or deprives communities of CF management rights because of the expansion of commercial crop cultivation and the lack of adequate community management in response to unprecedented changes. A likely practical solution to the probable impasse is the development and funding of a functional network of CF management committees, rather than the adoption of an entirely new, alternative system. [ABSTRACT FROM AUTHOR]

Published
2015
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46. Stable Isotope Studies of Rainfall and Stream Water in Forest Watersheds in Kampong Thom, Cambodia.

Author

Sawada, Haruo, Araki, Makoto, Chappell, Nick A., LaFrankie, James V., Kabeya, Naoki, Shimizu, Akira, Chann, Sophal, Tsuboyama, Yoshio, Nobuhiro, Tatsuhiko, Keth, Nang, and Tamai, Koji

Abstract

Stable isotopes, such as deuterium (D) and oxygen-18 (18O), are widely used in hydrology as environmental tracers because they move with the water itself. Information obtained from stable isotope data can improve our understanding of the processes associated with the source of water and system dynamics and also provide quantitative estimates related to flow dynamics and transport parameters. In this chapter, stable isotope ratios (δD, δ18O) of rainfall and stream water were studied from 2003 in four forest watersheds in the Kampong Thom Province of Cambodia. The stable isotope ratios of rainfall during the dry season from November to April lined up below the local meteoric water line (LMWL), implying that rainfall during the dry season may be affected by secondary evaporation during its descent. When these data were discarded, the slope and the intercept of the LMWL were 7.95 and 9.11, respectively, and close to those of the global meteoric water line (GMWL). The volumetric weighted means of δD and δ18O values in rainfall were −6.7‰ and −43.9‰, respectively. During the period from January to March, when little rainfall occurred, the δD values of stream water were near the volumetric weighted mean of δD in the rainfall. During the period from April to December, when a considerable amount of rain fell, the temporal variation in δD in rainfall was less evident in stream water. The range of variation in the δD value of stream water differed among the watersheds, which may indicate that the residence time of stream water differs from watershed to watershed. [ABSTRACT FROM AUTHOR]

Published
2007
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47. Runoff Characteristics and Observations on Evapotranspiration in Forest Watersheds, Central Cambodia.

Author

Sawada, Haruo, Araki, Makoto, Chappell, Nick A., LaFrankie, James V., Shimizu, Akira, Kabeya, Naoki, Nobuhiro, Tatsuhiko, Kubota, Tayoko, Tsuboyama, Yoshio, Ito, Eriko, Sano, Makoto, Chann, Sophal, and Keth, Nang

Abstract

We measured precipitation, runoff, and several meteorological factors associated with evapotranspiration in evergreen broadleaf forest watersheds in Kampong Thom Province, central Cambodia. All the studied watersheds have flat topography, with Vatica odorata and Mynistica iners as the primary plant species. The mean tree height in the upper crown layer was 27 m and the maximum tree height was 45 m. Meteorological factors were observed from a 60-m-high meteorological observation tower. The heat budget method, which incorporates the Bowen ratio, was used to calculate the energy balance above the forest canopy. To estimate evapotranspiration, meteorological data were collected during two sampling periods: October 2003, near the end of the rainy season, and March 2004, in the middle of the dry season. Average daily evapotranspiration levels calculated for the late rainy season and middle of the dry season were 4.4 mm/day and 4.9 mm/day, respectively. A continuous simulation model (modified HYCY model) was then applied with the obtained streamflow data for the watersheds. Evapotranspiration calculated using the tower observations was included as a model parameter. The estimated runoff matched observed runoff comparatively well for small watersheds. The model parameters varied in correspondence with the watershed size. [ABSTRACT FROM AUTHOR]

Published
2007
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48. Measurements of Wind Speed, Direction, and Vertical Profiles in an Evergreen Forest in Central Cambodia.

Author

Sawada, Haruo, Araki, Makoto, Chappell, Nick A., LaFrankie, James V., Tamai, Koji, Shimizu, Akira, Nobuhiro, Tatsuhiko, Kabeya, Naoki, Chann, Sophal, and Keth, Nang

Abstract

The wind characteristics of speed, direction, and vertical profile were studied to determine the effects of undulations in the local topography and canopy surface on flux observations made from a tower in an evergreen forest in Kompong Thom Province, Cambodia. Three seasonal patterns of wind speeds and directions were identified. The first occurred in December and January and was characterized by northerly monsoons that persisted all day, as well as a diurnal variation in wind speed, with a maximum and minimum around noon and near sunset, respectively. A second pattern, in February, was characterized by southerly to westerly prevailing monsoon winds, along with an easterly mountain wind observed in the early morning. Wind speed was low throughout the day. The third pattern was similar to the second but included brief, strong winds associated with squalls. Thus, regional effects on circulation were limited, and monsoon winds were found to dominate the meteorological system above the evergreen forest of central Cambodia. In the forest, the estimated roughness length and zero plane displacement height averaged 18.3 m and 7.5 m, respectively, and the average canopy height was 27.2 m. The dependence of roughness length and zero plane displacement height on the wind direction was within the standard deviation. Thus, the undulating canopy surface had little effect on the tower flux observations. [ABSTRACT FROM AUTHOR]

Published
2007
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49. Year-Round Observation of Evapotranspiration in an Evergreen Broadleaf Forest in Cambodia.

Author

Sawada, Haruo, Chappell, Nick A., LaFrankie, James V., Nobuhiro, Tatsuhiko, Shimizu, Akira, Kabeya, Naoki, Tsuboyama, Yoshio, Kubota, Tayoko, Abe, Toshio, Araki, Makoto, Tamai, Koji, Chann, Sophal, and Keth, Nang

Abstract

We conducted a year-round observation of meteorological elements using a meteorological observation tower 60 m in height to evaluate evapotranspiration in an evergreen broadleaf forest watershed in central Cambodia. The period of observation was from November 2003 to October 2004. Solar radiation was consistent throughout the year. The integrated values of net radiation and downward and upward shortwave radiation were 5.09, 6.79, and 0.76 GJ m−2 year−1, respectively. The temperature observed above the forest canopy was lowest and highest in the first and latter half of the dry season, respectively. The mean air temperature was 26.4°C. The saturation deficit was high in the late dry season (>30 hPa) and low during the rainy season (<25 hPa). The evapotranspiration rate was estimated from these observed meteorological parameters using the heat-balance method incorporating the Bowen ratio. The evapotranspiration rate was higher in the dry season than in the rainy season. Seasonal variation in evapotranspiration corresponded to the variation in the saturation deficit above the forest canopy. The amount of year-round evapotranspiration was 1139.7 mm. The water budget calculations from observation data suggested a water loss of 1202.8 mm for the experimental watershed. Thus, the observed evapotranspiration and water loss amounts were similar. [ABSTRACT FROM AUTHOR]

Published
2007
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50. Soil pore characteristics of evergreen and deciduous forests of the tropical monsoon region in Cambodia.

Author

Toriyama, Jumpei, Ohta, Seiichi, Araki, Makoto, Kosugi, Ken'ichirou, Nobuhiro, Tatsuhiko, Kabeya, Naoki, Shimizu, Akira, Tamai, Koji, Kanzaki, Mamoru, and Chann, Sophal

Subjects
SOIL science, SOIL testing, SOIL moisture
Abstract

Both evergreen and deciduous forests (Efs and Dfs) are widely distributed under similar climatic conditions in tropical monsoon regions. To clarify the hydraulic properties of the soil matrix in different forest types and their effects on soil water storage capacity, the soil pore characteristics (SPC) were investigated in Ef and Df stands in three provinces in Cambodia. Soils in the Ef group were characterized in common by large amounts of coarse pores with moderate pore size distribution and the absence of an extremely low K at shallow depths, compared to Df group soils. The mean available water capacity of the soil matrix (AWC) for all horizons of the Ef and Df group soils was 0·107 and 0·146 m m, respectively. The mean coarse pore volume of the soil matrix (CPV) in the Ef and Df groups was 0·231 and 0·115 m m, respectively. A water flow simulation using a lognormal distribution model for rain events in the early dry season indicated that variation in SPC resulted in a larger increase in available soil water in Ef soils than in Df soils. Further study on deeper soil layers in Ef and each soil type in Df is necessary for the deeper understanding of the environmental conditions and the hydrological modelling of each forest ecosystem. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Published
2011
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