Policy implications for community-managed forestry in Cambodia from experts’ assessments and case studies of community forestry practice     

Sareth Nhem  Young Jin Lee  Sopheap Phin 《山地科学学报》2018,15(11):2531-2551

Over the last 40 years, it has been shown at the global level that sustainable forestry can be achieved through comprehensive forest management,with the decentralized institutional arrangements of community-managed forestry coordinated by effective policy implementation. However, there is still a shortage of evidence regarding whether communitybased forestry is well characterized by forest policies,assessing what action is most needed and how best to address the challenges faced by community-based forestry in halting deforestation and promoting rural livelihoods. The study analyzed experts' assessments of the characteristics and success of communitymanaged forestry in Cambodia and explored three case studies of community-managed forestry practice to identify priorities for addressing forest policy implementation inadequacies in halting deforestation and promoting rural livelihoods. There were two methods of data collection. Firstly, this study used a survey of 27 experts to analyze perceptions about how far forest policy supported community-managed forestry effectively, the major challenges faced by the national community-managed forestry program, and the community-managed forestry contribution to halting deforestation and reducing rural poverty.Secondly, data was collected by content analysis of three case studies to explore the knowledge and practical experience of local experts about community-managed forestry practice at local level.The study employed Kendall's Coefficient of Concordance to analyze the level of concordance of experts on related forest policies(n=15) considering community-managed forestry, the challenges faced by the national community-managed forestry program,and the actions required to enable communitymanaged forestry to support communities. Analysis revealed that experts were in moderate agreement,denoted by Kendall's W=0.152, on how well forest policies articulate and implement the characteristics of community-managed forestry. Ranking of the major challenges faced by the national communitymanaged forestry program yielded Kendall's W of0.104, indicating the confidence in the ranking among experts was fair. There was only low confidence in the ranking of the action needed, with Kendall's W of0.055. Content analysis of the three case studies examining local experts' opinions on the attributes of community-managed forestry concerning the access,local participation and protection of the sustainable forestry revealed that Attribute one ‘Local people have access to the forest land and forest resources', and Attribute three ‘Local people begin by protecting and restoring the forests', received high attention from local experts. Of lesser importance or agreement was attributing two: local participation in decision-making concerning the forest.  相似文献   

Circular time-domain reflectometry system for monitoring bridge scour depth     

Jung-Doung Yu  Jong-Sub Lee 《Marine Georesources & Geotechnology》2020,38(3):312-321

Abstract

Sediment has a severe effect on bridge stability, and time-domain reflectometry (TDR) is a suitable method for assessing scour depth. This paper presents a fundamental study to demonstrate the suitability of a circular TDR system to enhance the resolution when monitoring scour depth with consideration of detailed local changes over a wide area around piers. A total of 32 electrodes are vertically installed on a cylinder pier around the circumference at ～7.36?mm intervals. Scour depth is investigated through small-scale laboratory experiments, where a measured waveform reflects the artificially constructed scour depth with high resolution (≈5?mm). Different scour types including circular, mushroom, elliptical, and irregular shapes are developed to verify the application of circular TDR, and shapes are predicted through the detailed local distribution. The influences of the reflected waveform according to water level change, temperature variation, and salinity effect are investigated as additional considerations, and the relative deviation of scour depth is analyzed. This study demonstrates that the proposed circular TDR system achieves better resolution than existing single TDR systems and may provide a better alternative technique for monitoring scour depth.  相似文献   

Influence of environmental disturbances and reproductive strategy on genetic diversity and differentiation of Zostera marina populations on the southern coast of Korea     

Young Kyun Kim  Seung Hyeon Kim  Joo Mi Yi  Sang Rul Park  Kun‐Seop Lee 《Marine Ecology》2019,40(1)

The genetic diversity and differentiation of four Zostera marina populations along the southern coast of Korea were estimated using random amplified polymorphic DNA (RAPD) markers to determine the effects of natural and anthropogenic stresses and reproductive strategy on within‐population genetic diversity. The mean number of alleles and gene diversities, indicating population genetic diversity, was highest in the Z. marina population that was exposed to repeated environmental disturbances, and lowest in the most undisturbed population. The higher genetic diversity in the disturbed population was associated with a higher contribution of sexual reproduction to population persistence. This suggests that both the level of disturbances and the reproductive strategy for population persistence contributed significantly to population genetic diversity at the study sites. According to the analysis of molecular variance (AMOVA), 76% genetic variation was attributable to differences among individuals within populations. The observed genetic differentiation (F_ST = 0.241) among Z. marina populations at the study sites appeared to result from reduced meadow size, increased genetic drift, and a high incidence of asexual reproduction. Increased population genetic diversity can enhance resistance and resilience to environmental disturbances; thus, this investigation of seagrass population genetics provides valuable new insights for the conservation, management, and restoration of seagrass habitats.  相似文献   

M2 Tidal Current Estimation from One-day Observation Data off the Western and Southern Coasts of Korea     

Lee  Seok  Oh  Kyung-Hee  Jang  Sung-Tae  You  Hak Yoel  Park  Joonsung  Song  Kyu-Min 《Ocean Science Journal》2019,54(1):39-50

Ocean Science Journal - A practical method to estimate the M2 tidal current is proposed based on one-day current observations. In this method, the semi-diurnal constituent, composed of several...  相似文献   

R/V Isabu-Based First Ultraclean Seawater Sampling for Ocean Trace Elements in Korea     

Kim  Suk Hyun  Ra  Kongtae  Kim  Kyung-Tae  Jeong  Hyeryeong  Lee  Jihyun  Kang  Dong-Jin  Rho  Taekeun  Kim  Intae 《Ocean Science Journal》2019,54(4):673-684

Ocean Science Journal - Trace elements (Mn, Fe, Co, Ni, Cu, Zn, etc.) are essential micronutrients for marine organisms and are thus related to major issues in the ocean, such as climate change,...  相似文献   

Investigating the Effects of Different LED Wavelengths on Aggregation and Swimming Behavior of Chub Mackerel (Scomber japonicus)     

Lee  Donggil  Oh  Wooseok  Gim  Byeong-Mo  Lee  Jung Suk  Yoon  Euna  Lee  Kyounghoon 《Ocean Science Journal》2019,54(4):573-579

Ocean Science Journal - Efficient fish aggregation systems are essential for catching chub mackerel (Scomber japonicus), which is a major target of purse seine fisheries in South Korea. To aid the...  相似文献   

Origin of the metamorphosed clasts in the CV3 carbonaceous chondrite breccias of Graves Nunataks 06101, Vigarano,Roberts Massif 04143, and Yamato‐86009     

Kaori Jogo  Motoo Ito  Shigeru Wakita  Sachio Kobayashi  Jong Ik Lee 《Meteoritics & planetary science》2019,54(5):1133-1152

We observed metamorphosed clasts in the CV3 chondrite breccias Graves Nunataks 06101, Vigarano, Roberts Massif 04143, and Yamato‐86009. These clasts are coarse‐grained polymineralic rocks composed of Ca‐bearing ferroan olivine (Fa_24–40, up to 0.6 wt% CaO), diopside (Fs_7–12Wo_44–50), plagioclase (An_52–75), Cr‐spinel (Cr/[Cr + Al] = 0.4, Fe/[Fe + Mg] = 0.7), sulfide and rare grains of Fe‐Ni metal, phosphate, and Ca‐poor pyroxene (Fs₂₄Wo₄). Most clasts have triple junctions between silicate grains. The rare earth element (REE) abundances are high in diopside (REE ~3.80–13.83 × CI) and plagioclase (Eu ~12.31–14.67 × CI) but are low in olivine (REE ~0.01–1.44 × CI) and spinel (REE ~0.25–0.49 × CI). These REE abundances are different from those of metamorphosed chondrites, primitive achondrites, and achondrites, suggesting that the clasts are not fragments of these meteorites. Similar mineralogical characteristics of the clasts with those in the Mokoia and Yamato‐86009 breccias (Jogo et al. 2012 ) suggest that the clasts observed in this study would also form inside the CV3 chondrite parent body. Thermal modeling suggests that in order to reach the metamorphosed temperatures of the clasts of >800 °C, the clast parent body should have accreted by ~2.5–2.6 Ma after CAIs formation. The consistency of the accretion age of the clast parent body and the CV3 chondrule formation age suggests that the clasts and CV3 chondrites could be originated from the same parent body with a peak temperature of 800–1100 °C. If the body has a peak temperature of >1100 °C, the accretion age of the body becomes older than the CV3 chondrule formation age and multiple CV3 parent bodies are likely.  相似文献   

Experimental investigation of three-dimensional earth pressure according to aspect ratio of retaining wall     

Byung-Suk Park  Sang Duk Lee 《Marine Georesources & Geotechnology》2018,36(2):181-189

The purpose of this study is to investigate the scale and load distribution of three-dimensional active earth pressure and the load transferred to the adjacent soil by changing the aspect ratio of a retaining wall through a series of model tests. In this research, 42 earth pressure plates of different heights and widths were installed to evaluate the earth pressures by considering the wall aspect ratio and the change of earth pressure. The test results showed that the active earth pressures were uniformly converged when the percentage of limit displacement against wall height was 0.12%. The distribution of active earth pressure on the wall showed a parabola shape for most aspect ratios while the wedge shape identified by the model test was similar to the shell-shaped model. In this paper, two diagrams were proposed regarding the active earth pressure according to the aspect ratio of a retaining wall; (1) a diagram of earth pressure conversion against the aspect ratio based on evaluated three-dimensional active earth pressures with traditional two-dimensional earth pressures, (2) a load transfer diagram based on the horizontal distance by analyzing the horizontal and vertical load transfer ranges with the relevant increasing rates.  相似文献   

Re-evaluation of Morphological Diagnostic Characteristics of <Emphasis Type="Italic">Hexapleomera</Emphasis> Dudich, 1931 (Crustacea: Tanaidacea), with Description of a New Species     

Jin?Hee?Wi  Chang-Keun?Kang  In?Tae?Lee  Hyeon?Gyeong?JeongEmail author 《Ocean Science Journal》2018,53(4):641-653

An undescribed species of Tanaidacea was collected from Yokji Harbor in the southern coast of Korea. Hexapleomera yokjidona n. sp. can be distinguished from other species of the genus by the distinguishing features of a uropod with five articles, a pleopod basal article lacking inner seta, a mandible setal row with two setae, maxilliped coxa with two proximal setae, pereonites 1–3 together longer than wide, and pereopods 2–3 propodus with three ventral setae. To prove that H. yokjidona is a new species, detailed morphological characteristics of both genders are described and a comprehensive comparison among the species of the genus is tabulated. Additionally, diagnostic characteristics previously used to identify the species of Hexapleomera are reassessed and upgraded.  相似文献   

Physiological Characteristics and Related Biochemical Parameters of Snow Algae from King George Island,Antarctica     

Bo?Kyung?Kim  HyoungMin?Joo  Boyeon?Lee  Dong-Hun?Lee  In-Young?Ahn  Sun-Yong?HaEmail author 《Ocean Science Journal》2018,53(4):621-630

Red and green snow caused by snow algal blooms is common on glaciers and snowfields worldwide. Reddish and greenish snow samples containing algae were collected at the vicinity of penguin rockeries on King George Island (62°13′S, 58°47′W, near the King Sejong Station), Antarctica in February 2017 to investigate their physiology. Eight pigments and six fatty acids were detected from the samples. No difference in pigment and fatty acid (FA) composition was found between reddish and greenish snow samples. In contrast, spectral profiling and mycosporine-like amino acids (MAAs) were different between reddish and greenish snow. Particularly in greenish snow, a high absorbance between 450–600 nm was observed. The average MAA concentration was 316.0 μg g^-1 in greenish snow, which was higher than that of reddish snow (278.2 μg g^-1). The MAA to Particulate organic carbon (POC) ratio (mg (g C)^-1) for reddish snow (6.2 mg (g C)^-1) was higher than that of greenish snow (2.6 mg (g C)^-1). These results suggest that reddish and greenish snow are considered to be the same species based on pigment and FA composition. Compared with photoprotective pigments, MAAs offer snow algae a more effective photoprotection strategy to promote tolerance of natural levels of ultraviolet radiation (UVR).  相似文献