• Korean Journal of Plant Resources
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• v.27 no.2
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• pp.183-187
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• 2014

Hovenia dulcis var. koreana Nakai, the oriental raisin tree, has been considered not only fruit but an herbal medicine in East Asia including Korea, Japan and east China. As honey plant, value of this species had been rising steadily. The aim of this study was conducted to develop the propagation technique by scion collection time, scion age and vinyl house on survival rate of H. dulcis. The survival rate by veneer grafting showed no significant differences among 3 new cultivars. The scion collection at the northern temperature zone was observed to be the most appropriate time before the spring equinox when the plants are fully dormant. Especially, the installation of vinyl house showed 86% survival rate by veneer grafting. The scion age was effective 1 year shoot than 2 years shoot for increase the grafting survival rate. In this case, the installation of vinyl house can contribute above 80%.

• Journal of Forest and Environmental Science
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• v.10 no.1
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• pp.32-37
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• 1994

This study was carried out to clarify the primary hosts of Tetrastichus sp. and its host relationship, development and reproductive capacity. Protopulvinaria mangiferae was parasitized by Aneristus ceroplastae, Microterys flavus, Coccophagus hawaiiensis. All of these primary parasitoid were attecked by the hyperparasite Tetrastichus sp.. Tetrastichus sp. was bound to be a solitary ectoparasite. Eggs were laid on the pupa of the primary host or attached to the inner surface of the integument of the scale insect. Threshold of the development and thermal constants for completion of immature stages were $9.8^{\circ}C$ and 272 day-degrees, respectively. At $25^{\circ}C$ the life span of both sexes without any food or with water were very short as compared with that with honey. After a pre-oviposition periods of about one day they laid on overage 220 eggs each, almost all during the first half of their life. The value of the net reproduction(Ro), the mean length of a generation(T) and the intrinsic rate of natural increase(r) were calculated as 99.6, 32days and 0.142 per female per day respectively.

• Journal of Korean Society of Forest Science
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• v.112 no.2
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• pp.136-144
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• 2023

This study aimed to determine the optimal fertilization level for the production of Hovenia dulcis Thunb. seedlings. The height, root collar diameter, biomass, seedling quality index, and chlorophyll content of Hovenia dulcis container seedlings (1-0) according to six fertilization treatments (control, 0.5, 1.0, 1.5, 2.0, 2.5 g·L^-1) were investigated. The height, root collar diameter, and biomass of Hovenia dulcis container seedlings increased with increasing fertilization, but there were no significant differences among the ≥1.5 g·L^-1 treatments, and the 2.5 g·L^-1 fertilization treatment was associated with significantly lower height growth. The seedling-quality index showed a high but non-significant difference in the ≥1.5 g·L^-1 treatment range, and the chlorophyll content was highest in the 1.5 g·L^-1 treatment group. Considering the environmental and cost aspects of fertilization, the appropriate level of fertilization required for superior container seedling production of Hovenia dulcis was 1.5 g·L^-1, and a minimum fertilization treatment of ≥0.5 g·L^-1 should be applied to meet the minimum seedling specifications. These results are expected to be used as basic data for establishing an efficient seedling-production system and stable supply of Hovenia dulcis, which is used as a medicinal and honey plant.

• Journal of Korean Society of Forest Science
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• v.90 no.3
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• pp.277-294
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• 2001

This study is aimed to analyze and to evaluate the technology development for sanddune fixation and sandy land conservation in China, resulting from the project of "Studies on the desertification combating and sand industry development". There are various types of sanddunes, including shrub-bunch type, dendritic, honey combed lattice, crescentic, parabolic, pyramid, complex and irregular types, domed, and so on. The height distribution ratios of these sanddunes are 13% of less than 5m, 17% of 6~10m, 18% of 11~25m, 14% of 26~50m, 28% of 51~100m, 10% of more than 100m, and so on. In dry land of China, shifting direction of the sanddune is mainly varying with main direction of wind, but types of shifting sanddunes have many differences in accordance with region, topography, size and shape of sanddunes. The main sanddune fixation technologies could be divided into the bio-ecological measures, physical measures and chemical measures. The bio-ecological measures include such vegetation measures as shrub-grasses measures, sandbreaks between sand dunes, sand fixation shelterblets and establishment of farmland shelterbelts, etc. The physical measures include establishment of high-sanddune stabilization walls and low-sanddune stabilization walls, sanddune fixation levees and coverage method with sediment clay, etc. The chemical measures include fixation-materials spraying and synthetical liquid spraying methods, etc. Besides, irrigation and sand settlement measures, shifting sand trapping channel, ditchsand fixation measures, etc. have been effectively applied.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.2
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• pp.28-39
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• 2008

This study was conducted to evaluate the rehabilitation measures and select appropriate tree species and rehabilitation methods for rehabilitating the rock desert areas in Guizhou, China. The study was carried out during the periods from 2003 to 2006 and results are as follows. Afforestation site is classified as a dolomite sandstone hilly country, a halfstony hilly country, a karst physiognomy, a rock desertification farmland and an latent rock desertification farmland by soil type and rock desertification status. Total afforestation area of Xuiwen is 1,300ha and afforestation area of a dolomite sandstone hilly country, a halfstony hilly country, a karst physiognomy, a rock desertification farmland and an latent rock desertification farmland are respectively 104.0ha (8.0%), 146.6ha (11.3%), 200.5ha (15.4%), 705.7ha (54.3%) and 143.2ha (11.0%). Planted tree species were selected by five site types. Robinia pseudoacacia, Chamaecyparis obtusa, Thuja orientalis, Cupressus duclouxiana and Juniperus chinensis L. var. chinensis were planted in a dolomite sandstone hilly country and Choerospondias axillaris and Robinia pseudoacacia were planted in a halfstony hilly country. Cupressus duclouxiana, Zanthoxylum bungeanum, Lonicera fulvotomentosa, Ilex kudincila, Quercus aliena, Quercus variabilis, Choerospondias axillaris, Koelreuteria bipinnata, Cryptomeria japonica, Cinnamomum camphora and Cinnamomum bodinieri were planted in a karst physiognomy. Cupressus duclouxiana, Toona sinensis, Robinia pseudoacacia, Lonicera fulvotomentosa, Eucommia ulmoides, Ilex kudincha. Zanthoxylum bungeanum and Magnolia officinalis were planted in a rock desertification farmland. Lonicera fulvotomentosa, Juglans sinensis, Pyrus pyrifolia, Choerospondias axillaris, Prunus salicina and Diospyros Kaki was planted in an latent rock desertification farm land. Robinia pseudoacacia showed high survival rate in 2004 and 2005, but Zanthoxylum bungeanum and Cinnamomum camphora showed slightly low survival rate in 2004. Survival rate of planting species in 2005 was over 80% because some species which showed low survival in 2004 were changed with other species and a proper afforestation method was applied. Growth rate of tree species was evaluated by height and diameter growth rate. Cupressus duclouxiana showed a highest height growth rate in 2004. Toona sil1ensis, Choerospondias axillaris, Koelreuteria bipinnata, and Cinnamomum camphora showed almost 100% height growth rate in 2005, although they showed a negative height growth rate in 2004. Robinia pseudoacacia showed a good growth rate in the rock desertification farmland and the halfstony hilly country so it could give a commercial benefit like honey as well as an afforestation effect.

• Journal of Korean Society of Forest Science
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• v.82 no.4
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• pp.311-318
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• 1993

This study was conducted to obtain necessary information to improve beekeeping farmhouses management and to establish related problem. Using data obtained from 50 beekeeping farmhouses in Korea, current status of management and optimum sales scale were analysed. The results of the study are summarized as follows ; 1. Managers of beekeeping farmhouses are relatively old(64% of them is over 50 years old) and highly educated and experienced(76% of them is in the business more than 10 years). 2. Only a portion of managers(38%) considers beekeeping as a major job, while the rest(62%) involves as a side job working with other agricultural business. 3. Major supply of labor force comes from family group. Total input of family labor is 6.4 months a year. Fourty-four percent of management units is migrating and 56% of them is settled in specific locations. 4. In 1991, the average number of conventional beehive casks per farmhouse is decreased by 2.94 casks but improved-type beehive casks is increased by 13.79 casks. Total number of beehive casks per farmhouse is increased by 12.66 casks during the year. 5. Major cost items of beekeeping farmhouses include bee colony aquisition cost, feeding cost, depreciation cost, wages in an order. The average yearly profit rate of farmhouses is about 29.4%. 6. The break-even point of honey sales is about 3 million won. The optimum sales scale was 52.2l, then average production cost was estimated 53,800Won.